/* LiteWebChat — Cool Blue Studio
   Aesthetic: modern cool-dark AI chat workspace
   Keep all existing class/id hooks intact for app.js compatibility. */

:root {
    /* Surfaces */
    --bg-deep: #0b0f14;
    --bg-color: #0d1117;
    --bg-elevated: #141b24;
    --bg-soft: #1a2330;
    --bg-hover: #1f2a38;
    --bg-active: #243041;

    /* Text */
    --text-color: #e6edf3;
    --text-secondary: #9fb0c0;
    --text-muted: #7d8b99;
    --text-faint: #5d6a78;

    /* Brand — cool azure blue */
    --accent-color: #58a6ff;
    --accent-soft: rgba(88, 166, 255, 0.14);
    --accent-mid: rgba(88, 166, 255, 0.28);
    --accent-strong: rgba(88, 166, 255, 0.48);
    --accent-glow: rgba(88, 166, 255, 0.18);

    /* Semantic */
    --prompt-color: #3fb950;
    --prompt-soft: rgba(63, 185, 80, 0.14);
    --error-color: #f85149;
    --error-soft: rgba(248, 81, 73, 0.12);
    --warning-color: #d29922;
    --warning-soft: rgba(210, 153, 34, 0.14);
    --success-color: #238636;
    --success-soft: rgba(35, 134, 54, 0.14);
    --info-color: #79c0ff;
    --info-soft: rgba(121, 192, 255, 0.12);

    /* Borders & lines */
    --border-color: #30363d;
    --border-soft: rgba(230, 237, 243, 0.06);
    --border-strong: rgba(230, 237, 243, 0.12);
    --divider: rgba(230, 237, 243, 0.07);

    /* Layout */
    --radius-xs: 6px;
    --radius-sm: 10px;
    --radius-md: 14px;
    --radius-lg: 18px;
    --radius-xl: 24px;
    --radius-pill: 999px;

    --sidebar-width: 300px;
    --content-max: 820px;
    --composer-max: 820px;

    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.28);
    --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.32);
    --shadow-lg: 0 20px 48px rgba(0, 0, 0, 0.42);
    --shadow-glow: 0 0 0 1px var(--accent-mid), 0 8px 28px var(--accent-glow);

    --font-family: "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, sans-serif;
    --font-mono: "SF Mono", "Cascadia Code", "Consolas", "Courier New", monospace;

    --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
    --ease-in: cubic-bezier(0.4, 0, 1, 1);
    --dur-fast: 150ms;
    --dur: 220ms;

    --safe-top: env(safe-area-inset-top, 0px);
    --safe-right: env(safe-area-inset-right, 0px);
    --safe-bottom: env(safe-area-inset-bottom, 0px);
    --safe-left: env(safe-area-inset-left, 0px);
}

/* ---------- Reset & base ---------- */

* {
    box-sizing: border-box;
    scrollbar-width: thin;
    scrollbar-color: var(--border-color) transparent;
    -webkit-tap-highlight-color: rgba(88, 166, 255, 0.14);
}

*::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

*::-webkit-scrollbar-track {
    background: transparent;
}

*::-webkit-scrollbar-thumb {
    background-color: var(--border-color);
    border-radius: 4px;
    border: 2px solid transparent;
    background-clip: padding-box;
}

*::-webkit-scrollbar-thumb:hover {
    background-color: var(--text-faint);
}

html, body {
    height: 100%;
    margin: 0;
    padding: 0;
    font-family: var(--font-family);
    background-color: var(--bg-deep);
    color: var(--text-color);
    color-scheme: dark;
    font-size: clamp(13.5px, 2.1vw, 14.5px);
    line-height: 1.5;
    overflow: hidden;
    -webkit-text-size-adjust: 100%;
    -webkit-font-smoothing: antialiased;
    text-rendering: optimizeLegibility;
}

button, input, select, textarea {
    font: inherit;
    touch-action: manipulation;
    color: inherit;
}

button {
    cursor: pointer;
}

button:disabled,
select:disabled,
input:disabled,
textarea:disabled {
    cursor: not-allowed;
}

/* ---------- Shell ---------- */

#terminal {
    display: flex;
    flex-direction: column;
    height: 100vh;
    height: 100dvh;
    width: 100%;
    background:
        radial-gradient(ellipse 80% 50% at 10% -10%, rgba(88, 166, 255, 0.07), transparent 55%),
        radial-gradient(ellipse 60% 40% at 95% 100%, rgba(63, 185, 80, 0.04), transparent 50%),
        var(--bg-deep);
}

.storage-warning {
    background-color: var(--warning-color);
    color: #1a140c;
    padding: 8px 14px;
    text-align: center;
    font-size: 0.88em;
    font-weight: 600;
    display: none;
    transition: background-color var(--dur) ease, color var(--dur) ease;
}

.storage-warning.online {
    background-color: var(--success-color);
    color: #fff;
}

.storage-warning.offline {
    background-color: var(--error-color);
    color: #fff;
}

.app-shell {
    position: relative;
    display: flex;
    flex: 1;
    min-height: 0;
    overflow: hidden;
}

/* ---------- Notifications ---------- */

.notification-region {
    position: fixed;
    z-index: 2200;
    top: calc(16px + var(--safe-top));
    right: calc(16px + var(--safe-right));
    display: grid;
    width: min(380px, calc(100vw - 32px - var(--safe-left) - var(--safe-right)));
    gap: 10px;
    pointer-events: none;
}

.app-toast {
    display: grid;
    grid-template-columns: 34px minmax(0, 1fr) 32px;
    align-items: start;
    gap: 10px;
    padding: 13px 12px;
    border: 1px solid var(--border-strong);
    border-radius: var(--radius-md);
    background: rgba(20, 27, 36, 0.96);
    box-shadow: var(--shadow-md);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    pointer-events: auto;
    animation: toast-enter var(--dur) var(--ease-out) both;
}

.app-toast.leaving {
    animation: toast-leave 0.16s var(--ease-in) both;
}

.app-toast-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 32px;
    height: 32px;
    border-radius: 50%;
    background: var(--info-soft);
    color: var(--info-color);
    font-size: 0.9rem;
    font-weight: 800;
}

.app-toast[data-type="success"] {
    border-color: rgba(63, 185, 80, 0.35);
}

.app-toast[data-type="success"] .app-toast-icon {
    background: var(--prompt-soft);
    color: var(--prompt-color);
}

.app-toast[data-type="warning"] {
    border-color: rgba(88, 166, 255, 0.4);
}

.app-toast[data-type="warning"] .app-toast-icon {
    background: var(--warning-soft);
    color: var(--warning-color);
}

.app-toast[data-type="error"] {
    border-color: rgba(248, 81, 73, 0.4);
}

.app-toast[data-type="error"] .app-toast-icon {
    background: var(--error-soft);
    color: var(--error-color);
}

.app-toast-copy {
    min-width: 0;
    padding-top: 1px;
}

.app-toast-title {
    color: var(--text-color);
    font-size: 0.9rem;
    font-weight: 700;
    line-height: 1.35;
}

.app-toast-message {
    margin-top: 3px;
    color: var(--text-secondary);
    font-size: 0.82rem;
    line-height: 1.45;
    overflow-wrap: anywhere;
}

.app-toast-close {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 32px;
    height: 32px;
    padding: 0;
    border: 0;
    border-radius: var(--radius-xs);
    background: transparent;
    color: var(--text-muted);
    font-size: 1.15rem;
    line-height: 1;
}

.app-toast-close:hover {
    background: rgba(255, 255, 255, 0.06);
    color: var(--text-color);
}

@keyframes toast-enter {
    from {
        opacity: 0;
        transform: translateY(-8px) scale(0.98);
    }
    to {
        opacity: 1;
        transform: translateY(0) scale(1);
    }
}

@keyframes toast-leave {
    to {
        opacity: 0;
        transform: translateY(-6px) scale(0.98);
    }
}

/* ---------- Sidebar ---------- */

.sidebar {
    position: relative;
    z-index: 4;
    display: flex;
    flex-direction: column;
    gap: 12px;
    width: var(--sidebar-width);
    min-width: 260px;
    padding: calc(14px + var(--safe-top)) 12px calc(12px + var(--safe-bottom)) calc(12px + var(--safe-left));
    border-right: 1px solid var(--border-soft);
    background: color-mix(in srgb, var(--bg-elevated) 92%, transparent);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    overscroll-behavior: contain;
}

.sidebar-header {
    display: flex;
    flex-direction: column;
    gap: 10px;
    padding: 2px 4px 0;
}

.sidebar-brand-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 10px;
}

.sidebar-brand-mark {
    display: flex;
    align-items: center;
    gap: 10px;
    min-width: 0;
}

.brand-logo {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 34px;
    height: 34px;
    flex-shrink: 0;
    border-radius: 10px;
    background: linear-gradient(145deg, rgba(88, 166, 255, 0.28), rgba(88, 166, 255, 0.08));
    border: 1px solid var(--accent-mid);
    color: var(--accent-color);
    font-weight: 800;
    font-size: 0.95rem;
    letter-spacing: -0.03em;
    box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.08);
}

.sidebar-kicker {
    color: var(--accent-color);
    font-size: 0.7em;
    font-weight: 700;
    letter-spacing: 0.14em;
    text-transform: uppercase;
    line-height: 1.2;
}

.sidebar-brand {
    margin-top: 2px;
    font-size: 1.05em;
    font-weight: 700;
    letter-spacing: -0.02em;
    color: var(--text-color);
    line-height: 1.2;
}

.sidebar-caption {
    color: var(--text-muted);
    font-size: 0.82em;
    line-height: 1.45;
    padding: 0 2px;
}

.sidebar-icon-button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    flex-shrink: 0;
    padding: 0;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    background: transparent;
    color: var(--text-secondary);
    transition: background var(--dur-fast) ease, border-color var(--dur-fast) ease, color var(--dur-fast) ease, transform var(--dur-fast) ease;
}

.sidebar-icon-button svg {
    width: 18px;
    height: 18px;
    stroke: currentColor;
    fill: none;
    stroke-width: 1.75;
    stroke-linecap: round;
    stroke-linejoin: round;
}

#sidebar-close-button {
    display: none;
}

.primary-sidebar-button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    width: 100%;
    min-height: 42px;
    padding: 10px 14px;
    border: 1px solid var(--accent-mid);
    border-radius: var(--radius-md);
    background: linear-gradient(180deg, rgba(88, 166, 255, 0.22), rgba(88, 166, 255, 0.1));
    color: #f0f6fc;
    font-weight: 600;
    font-size: 0.92em;
    box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.08);
    transition: background var(--dur-fast) ease, border-color var(--dur-fast) ease, transform var(--dur-fast) ease, opacity var(--dur-fast) ease;
}

.primary-sidebar-button svg {
    width: 16px;
    height: 16px;
    stroke: currentColor;
    fill: none;
    stroke-width: 2;
    stroke-linecap: round;
    stroke-linejoin: round;
}

.primary-sidebar-button:disabled,
.sidebar-actions button:disabled,
.sidebar-icon-button:disabled,
#upload-button:disabled,
#send-button:disabled,
#search-button:disabled {
    opacity: 0.45;
    cursor: not-allowed;
    transform: none;
}

.sidebar-section-title,
.sidebar-footer-title {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 8px;
    padding: 4px 6px 0;
    color: var(--text-muted);
    font-size: 0.72em;
    font-weight: 650;
    letter-spacing: 0.08em;
    text-transform: uppercase;
}

.session-count-badge {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 22px;
    height: 20px;
    padding: 0 7px;
    border-radius: var(--radius-pill);
    background: var(--accent-soft);
    color: var(--accent-color);
    font-size: 0.95em;
    font-weight: 700;
    letter-spacing: 0;
    text-transform: none;
}

.session-section-actions {
    display: flex;
    align-items: center;
    gap: 5px;
}

.session-manage-button,
.session-batch-cancel-button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 26px;
    height: 26px;
    padding: 0;
    border: 1px solid transparent;
    border-radius: var(--radius-xs);
    background: transparent;
    color: var(--text-muted);
}

.session-manage-button svg,
.session-batch-cancel-button svg,
.session-batch-delete-button svg {
    width: 14px;
    height: 14px;
    fill: none;
    stroke: currentColor;
    stroke-width: 1.8;
    stroke-linecap: round;
    stroke-linejoin: round;
}

.session-manage-button:hover:not(:disabled),
.session-manage-button:focus-visible,
.session-manage-button[aria-pressed="true"] {
    outline: none;
    border-color: var(--accent-mid);
    background: var(--accent-soft);
    color: var(--accent-color);
}

.session-manage-button:disabled {
    opacity: 0.4;
    cursor: not-allowed;
}

.session-batch-toolbar {
    display: grid;
    grid-template-columns: auto minmax(0, 1fr) 28px auto;
    align-items: center;
    gap: 7px;
    min-height: 38px;
    margin: 0 2px 4px;
    padding: 5px 6px 5px 9px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    background: rgba(255, 255, 255, 0.025);
}

.session-batch-toolbar[hidden] {
    display: none !important;
}

.session-select-all {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    color: var(--text-secondary);
    font-size: 0.75rem;
    cursor: pointer;
    white-space: nowrap;
}

.session-select-all input,
.session-item-checkbox {
    width: 15px;
    height: 15px;
    margin: 0;
    accent-color: var(--accent-color);
    cursor: pointer;
}

.session-selected-count {
    min-width: 0;
    color: var(--text-faint);
    font-size: 0.72rem;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.session-batch-cancel-button:hover:not(:disabled),
.session-batch-cancel-button:focus-visible {
    outline: none;
    background: var(--bg-hover);
    color: var(--text-color);
}

.session-batch-delete-button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 5px;
    min-height: 28px;
    padding: 4px 8px;
    border: 1px solid rgba(248, 81, 73, 0.28);
    border-radius: var(--radius-xs);
    background: var(--error-soft);
    color: var(--error-color);
    font-size: 0.74rem;
    font-weight: 650;
}

.session-batch-delete-button:hover:not(:disabled),
.session-batch-delete-button:focus-visible {
    outline: none;
    border-color: rgba(248, 81, 73, 0.46);
    background: rgba(248, 81, 73, 0.18);
}

.session-batch-delete-button:disabled {
    opacity: 0.38;
    cursor: not-allowed;
}

.session-list {
    flex: 1;
    min-height: 0;
    display: flex;
    flex-direction: column;
    gap: 2px;
    overflow-x: hidden;
    overflow-y: auto;
    padding: 2px 2px 8px;
    scrollbar-gutter: stable;
    overscroll-behavior: contain;
}

.session-item {
    position: relative;
    z-index: 0;
    isolation: isolate;
    width: 100%;
}

.session-item-checkbox {
    display: none;
    position: absolute;
    top: 50%;
    left: 12px;
    z-index: 3;
    transform: translateY(-50%);
}

.session-list.is-batch-managing .session-item-checkbox {
    display: block;
}

.session-list.is-batch-managing .session-item-main {
    padding-right: 12px;
    padding-left: 40px;
}

.session-list.is-batch-managing .session-item-delete {
    display: none;
}

.session-list.is-batch-managing .session-item.is-selected .session-item-main {
    border-color: rgba(88, 166, 255, 0.3);
    background: var(--accent-soft);
}

.session-item-main {
    width: 100%;
    padding: 10px 40px 10px 12px;
    border: 1px solid transparent;
    border-radius: var(--radius-sm);
    background: transparent;
    color: var(--text-color);
    text-align: left;
    cursor: pointer;
    font-family: inherit;
    font-size: inherit;
    transition: background var(--dur-fast) ease, border-color var(--dur-fast) ease, color var(--dur-fast) ease;
}

.session-item-main.is-active {
    border-color: rgba(88, 166, 255, 0.22);
    background: linear-gradient(90deg, rgba(88, 166, 255, 0.12), var(--bg-active) 40%);
    box-shadow: inset 2px 0 0 var(--accent-color);
}

.session-item-main.is-active .session-item-title {
    color: #f0f6fc;
}

.session-item-delete {
    position: absolute;
    top: 50%;
    right: 6px;
    z-index: 2;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 28px;
    height: 28px;
    padding: 0;
    border: 0;
    border-radius: var(--radius-xs);
    background: transparent;
    color: var(--text-faint);
    transform: translateY(-50%);
    opacity: 0;
    transition: opacity var(--dur-fast) ease, background var(--dur-fast) ease, color var(--dur-fast) ease;
}

.session-item-delete svg {
    width: 14px;
    height: 14px;
    stroke: currentColor;
    fill: none;
    stroke-width: 1.75;
    stroke-linecap: round;
    stroke-linejoin: round;
}

.session-item:hover .session-item-delete,
.session-item-main:focus-visible ~ .session-item-delete,
.session-item-delete:focus-visible {
    opacity: 1;
}

.session-item-delete:disabled {
    opacity: 0.4;
    cursor: not-allowed;
}

.message-action-button:disabled,
.branch-switch-button:disabled,
.branch-selector:disabled {
    opacity: 0.4;
    cursor: not-allowed;
    transform: none;
}

.session-item-title {
    display: block;
    font-weight: 600;
    font-size: 0.92em;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.session-item-preview {
    display: -webkit-box;
    margin-top: 3px;
    color: var(--text-muted);
    font-size: 0.78em;
    line-height: 1.4;
    overflow: hidden;
    overflow-wrap: anywhere;
    -webkit-line-clamp: 1;
    -webkit-box-orient: vertical;
}

.session-item-meta {
    display: none;
}

.session-empty {
    padding: 28px 16px;
    border: 1px dashed var(--border-color);
    border-radius: var(--radius-md);
    background: rgba(255, 255, 255, 0.015);
    color: var(--text-muted);
    line-height: 1.6;
    text-align: center;
    font-size: 0.88em;
}

.sidebar-footer {
    display: flex;
    flex-direction: column;
    gap: 8px;
    padding-top: 10px;
    border-top: 1px solid var(--divider);
}

.sidebar-footer select {
    width: 100%;
    padding: 9px 11px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    background: var(--bg-deep);
    color: var(--text-color);
    font-family: inherit;
    font-size: 0.88em;
    outline: none;
    transition: border-color var(--dur-fast) ease, box-shadow var(--dur-fast) ease;
}

.sidebar-footer select:focus {
    border-color: var(--accent-mid);
    box-shadow: 0 0 0 3px var(--accent-soft);
}

.loading-indicator {
    display: none;
    padding: 7px 11px;
    border-radius: var(--radius-sm);
    background: var(--accent-soft);
    color: var(--accent-color);
    font-size: 0.82em;
}

.loading-indicator.show {
    display: inline-flex;
    align-items: center;
}

.sidebar-toggle-card {
    border-radius: var(--radius-sm);
    background: rgba(255, 255, 255, 0.02);
}

.sidebar-actions {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 6px;
}

.sidebar-actions button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    min-height: 38px;
    padding: 8px 10px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    background: transparent;
    color: var(--text-secondary);
    font-size: 0.86em;
    transition: background var(--dur-fast) ease, border-color var(--dur-fast) ease, color var(--dur-fast) ease;
}

.sidebar-actions button svg {
    width: 15px;
    height: 15px;
    stroke: currentColor;
    fill: none;
    stroke-width: 1.75;
    stroke-linecap: round;
    stroke-linejoin: round;
}

.account-row {
    display: grid;
    grid-template-columns: minmax(0, 1fr) 38px;
    gap: 6px;
}

.account-button,
.sync-now-button {
    min-height: 40px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    background: transparent;
    color: var(--text-color);
    transition: border-color var(--dur-fast) ease, background var(--dur-fast) ease;
}

.account-button {
    display: flex;
    align-items: center;
    gap: 9px;
    min-width: 0;
    padding: 8px 11px;
    text-align: left;
    font-size: 0.88em;
}

.account-button span:last-child {
    min-width: 0;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.sync-now-button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 38px;
    padding: 0;
    color: var(--text-secondary);
}

.sync-now-button svg {
    width: 16px;
    height: 16px;
    stroke: currentColor;
    fill: none;
    stroke-width: 1.75;
    stroke-linecap: round;
    stroke-linejoin: round;
}

.sync-now-button.syncing svg {
    animation: sync-spin 0.9s linear infinite;
}

.account-indicator {
    width: 8px;
    height: 8px;
    flex: none;
    border-radius: 50%;
    background: var(--text-faint);
    box-shadow: 0 0 0 3px rgba(110, 118, 129, 0.18);
}

.account-indicator.online {
    background: var(--prompt-color);
    box-shadow: 0 0 0 3px var(--prompt-soft);
}

.account-indicator.pending {
    background: var(--warning-color);
    box-shadow: 0 0 0 3px var(--warning-soft);
}

.account-indicator.error {
    background: var(--error-color);
    box-shadow: 0 0 0 3px var(--error-soft);
}

.sync-status {
    min-height: 16px;
    color: var(--text-muted);
    font-size: 0.76em;
    line-height: 1.4;
    padding: 0 2px;
}

@keyframes sync-spin {
    to { transform: rotate(360deg); }
}

/* ---------- Workspace ---------- */

.workspace {
    position: relative;
    display: flex;
    flex: 1;
    min-width: 0;
    min-height: 0;
    flex-direction: column;
    background: transparent;
}

.toolbar {
    position: sticky;
    top: 0;
    z-index: 2;
    background: color-mix(in srgb, var(--bg-deep) 72%, transparent);
    border-bottom: 1px solid var(--border-soft);
    backdrop-filter: blur(18px);
    -webkit-backdrop-filter: blur(18px);
}

.workspace-topbar {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: max(12px, var(--safe-top)) calc(clamp(16px, 2.4vw, 28px) + var(--safe-right)) 12px calc(clamp(16px, 2.4vw, 28px) + var(--safe-left));
}

.workspace-heading {
    min-width: 0;
    flex: 1;
}

.workspace-title {
    font-size: 1.02em;
    font-weight: 650;
    letter-spacing: -0.01em;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.workspace-meta {
    margin-top: 2px;
    color: var(--text-muted);
    font-size: 0.8em;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.sidebar-overlay {
    position: fixed;
    inset: 0;
    z-index: 3;
    border: none;
    background: rgba(2, 6, 12, 0.55);
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.22s ease;
    backdrop-filter: blur(2px);
}

.sidebar-overlay.show {
    opacity: 1;
    pointer-events: auto;
}

#sidebar-toggle-button {
    display: none;
}

/* ---------- Switch ---------- */

.switch-container {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 8px 11px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    background: rgba(255, 255, 255, 0.015);
    transition: border-color var(--dur-fast) ease;
}

.switch-container:hover {
    border-color: var(--accent-mid);
}

.switch-container label {
    cursor: pointer;
    user-select: none;
    font-size: 0.86em;
    color: var(--text-secondary);
}

.switch {
    position: relative;
    display: inline-block;
    width: 36px;
    height: 20px;
    flex-shrink: 0;
}

.switch input {
    opacity: 0;
    width: 0;
    height: 0;
}

.slider {
    position: absolute;
    cursor: pointer;
    inset: 0;
    background-color: var(--border-color);
    transition: 0.25s ease;
    border-radius: 20px;
}

.slider:before {
    position: absolute;
    content: "";
    height: 14px;
    width: 14px;
    left: 3px;
    bottom: 3px;
    background-color: #fff;
    transition: 0.25s ease;
    border-radius: 50%;
    box-shadow: 0 1px 2px rgba(0, 0, 0, 0.25);
}

input:checked + .slider {
    background-color: var(--accent-color);
}

input:checked + .slider:before {
    transform: translateX(16px);
}

/* ---------- Chat stage / log ---------- */

.chat-stage {
    position: relative;
    display: flex;
    flex: 1;
    min-height: 0;
    flex-direction: column;
}

#chat-log {
    flex-grow: 1;
    display: flex;
    flex-direction: column;
    gap: 2px;
    padding: 18px clamp(16px, 3vw, 28px) 18px;
    overflow-y: auto;
    scroll-behavior: smooth;
    word-wrap: break-word;
    min-height: 0;
    scrollbar-gutter: stable;
    overscroll-behavior: contain;
}

.scroll-bottom-button {
    position: absolute;
    right: calc(clamp(16px, 3vw, 28px) + var(--safe-right));
    bottom: 14px;
    z-index: 5;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    padding: 0;
    border: 1px solid var(--border-strong);
    border-radius: 50%;
    background: color-mix(in srgb, var(--bg-elevated) 92%, transparent);
    color: var(--text-secondary);
    box-shadow: var(--shadow-md);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    opacity: 0;
    pointer-events: none;
    transform: translateY(8px) scale(0.96);
    transition: opacity var(--dur-fast) ease, transform var(--dur-fast) var(--ease-out), background var(--dur-fast) ease, color var(--dur-fast) ease, border-color var(--dur-fast) ease;
}

.scroll-bottom-button svg {
    width: 18px;
    height: 18px;
    stroke: currentColor;
    fill: none;
    stroke-width: 1.8;
    stroke-linecap: round;
    stroke-linejoin: round;
}

.scroll-bottom-button.is-visible {
    opacity: 1;
    pointer-events: auto;
    transform: translateY(0) scale(1);
}

.scroll-bottom-button:hover {
    color: var(--accent-color);
    border-color: var(--accent-mid);
    background: var(--bg-soft);
}

.chat-empty {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 10px;
    min-height: 240px;
    padding: 32px 20px;
    text-align: center;
    color: var(--text-muted);
    animation: empty-in 0.35s var(--ease-out) both;
}

.chat-empty-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 56px;
    height: 56px;
    margin-bottom: 6px;
    border-radius: 18px;
    background: linear-gradient(145deg, rgba(88, 166, 255, 0.16), rgba(88, 166, 255, 0.04));
    border: 1px solid var(--accent-mid);
    color: var(--accent-color);
    box-shadow: 0 12px 32px rgba(0, 0, 0, 0.2);
}

.chat-empty-icon svg {
    width: 26px;
    height: 26px;
    stroke: currentColor;
    fill: none;
    stroke-width: 1.5;
    stroke-linecap: round;
    stroke-linejoin: round;
}

.chat-empty-title {
    margin: 0;
    color: var(--text-color);
    font-size: clamp(1.25rem, 2.6vw, 1.65rem);
    font-weight: 600;
    letter-spacing: -0.02em;
    line-height: 1.2;
}

.chat-empty-desc {
    margin: 0;
    max-width: 28rem;
    color: var(--text-muted);
    font-size: 0.92em;
    line-height: 1.55;
}

@keyframes empty-in {
    from {
        opacity: 0;
        transform: translateY(8px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ---------- Messages ---------- */

.message {
    position: relative;
    width: min(100%, var(--content-max));
    margin: 0 auto;
    padding: 14px 4px;
    border: 0;
    border-radius: 0;
    background: transparent;
    box-shadow: none;
    animation: message-in 0.28s var(--ease-out) both;
}

.message:last-child {
    margin-bottom: 4px;
}

@keyframes message-in {
    from {
        opacity: 0;
        transform: translateY(6px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.message-header {
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 6px 10px;
    margin-bottom: 8px;
}

.message-header-actions {
    margin-left: auto;
    display: inline-flex;
    align-items: center;
    gap: 4px;
    opacity: 0.35;
    transition: opacity var(--dur-fast) ease;
}

.message:hover .message-header-actions,
.message:focus-within .message-header-actions,
.message.is-active .message-header-actions {
    opacity: 1;
}

.message-header .role {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    font-weight: 650;
    font-size: 0.88em;
    letter-spacing: -0.01em;
}

.message-header .role::before {
    content: "";
    display: inline-block;
    width: 24px;
    height: 24px;
    border-radius: 8px;
    background-size: 14px 14px;
    background-repeat: no-repeat;
    background-position: center;
    flex-shrink: 0;
}

.user .message-header .role {
    color: var(--prompt-color);
}

.user .message-header .role::before {
    background-color: var(--prompt-soft);
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%233fb950' stroke-width='1.8' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M20 21a8 8 0 0 0-16 0'/%3E%3Ccircle cx='12' cy='7' r='4'/%3E%3C/svg%3E");
}

.assistant .message-header .role {
    color: var(--accent-color);
}

.assistant .message-header .role::before {
    background-color: var(--accent-soft);
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%2358a6ff' stroke-width='1.8' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M12 3l1.8 5.4L19 10l-5.2 1.6L12 17l-1.8-5.4L5 10l5.2-1.6L12 3z'/%3E%3C/svg%3E");
}

.search-badge {
    display: inline-flex;
    align-items: center;
    margin-left: 2px;
    font-size: 0.85em;
    opacity: 0.85;
}

.message-time {
    color: var(--text-faint);
    font-size: 0.76em;
    font-variant-numeric: tabular-nums;
}

.message-action-button,
.branch-switch-button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 28px;
    padding: 4px 10px;
    border: 1px solid transparent;
    border-radius: var(--radius-pill);
    background: transparent;
    color: var(--text-muted);
    cursor: pointer;
    font-size: 0.78em;
    line-height: 1;
    transition: background var(--dur-fast) ease, color var(--dur-fast) ease, border-color var(--dur-fast) ease;
}

.message-delete-button {
    color: var(--error-color);
}

.branch-switcher {
    display: flex;
    align-items: center;
    gap: 6px;
    margin-top: 10px;
    padding-top: 10px;
    border-top: 1px solid var(--divider);
}

.branch-selector {
    min-width: 0;
    max-width: min(340px, 62vw);
    height: 30px;
    padding: 4px 10px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-pill);
    background: var(--bg-elevated);
    color: var(--text-color);
    font-family: inherit;
    font-size: 0.8em;
    outline: none;
}

.branch-count {
    flex-shrink: 0;
    color: var(--text-faint);
    font-size: 0.78em;
    font-variant-numeric: tabular-nums;
}

/* User bubble */
.message.user {
    padding: 8px 4px;
}

.message.user .message-content {
    display: inline-block;
    max-width: min(100%, 640px);
    padding: 12px 16px;
    border-radius: 18px 18px 6px 18px;
    background: linear-gradient(180deg, rgba(63, 185, 80, 0.14), rgba(63, 185, 80, 0.07));
    border: 1px solid rgba(63, 185, 80, 0.18);
    color: var(--text-color);
    white-space: pre-wrap;
}

/* Assistant open layout */
.message.assistant {
    padding: 12px 4px 16px;
}

.message.assistant .message-content {
    padding: 0 2px 0 32px;
}

.message-content {
    white-space: normal;
    overflow-wrap: anywhere;
    line-height: 1.65;
    max-width: 100%;
    color: var(--text-color);
}

.message-content p {
    margin: 0 0 0.7em;
}

.message-content p:last-child {
    margin-bottom: 0;
}

.message-content h1,
.message-content h2,
.message-content h3 {
    border-bottom: 1px solid var(--divider);
    padding-bottom: 0.25em;
    margin: 1.1em 0 0.55em;
    font-weight: 650;
    letter-spacing: -0.015em;
    line-height: 1.3;
}

.message-content h1 { font-size: 1.35em; }
.message-content h2 { font-size: 1.18em; }
.message-content h3 { font-size: 1.05em; }

.message-content code {
    background-color: rgba(255, 255, 255, 0.05);
    padding: 0.15em 0.4em;
    margin: 0;
    font-size: 0.88em;
    border-radius: 5px;
    border: 1px solid var(--border-soft);
    font-family: var(--font-mono);
    color: #9ecbff;
}

.message-content pre {
    background-color: var(--bg-elevated);
    padding: 14px 16px;
    border-radius: var(--radius-md);
    border: 1px solid var(--border-soft);
    overflow-x: auto;
    position: relative;
    white-space: pre;
    max-width: 100%;
    margin: 0.85em 0;
    box-shadow: var(--shadow-sm);
}

.message-content pre code {
    padding: 0;
    background: none;
    border: 0;
    white-space: pre;
    color: #c9d1d9;
    font-size: 0.86em;
    line-height: 1.55;
}

.message-content blockquote {
    border-left: 3px solid var(--accent-mid);
    padding: 0.15em 0 0.15em 14px;
    color: var(--text-secondary);
    margin: 0.8em 0;
}

.message-content ul,
.message-content ol {
    padding-left: 1.35em;
    margin: 0.5em 0 0.8em;
}

.message-content li + li {
    margin-top: 0.25em;
}

.message-content img {
    max-width: min(100%, 420px);
    height: auto;
    border-radius: var(--radius-md);
    margin-top: 8px;
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow-sm);
}

.message-content table {
    display: block;
    width: max-content;
    max-width: 100%;
    overflow-x: auto;
    border-collapse: collapse;
    margin: 10px 0;
    border-radius: var(--radius-sm);
}

.message-content table th,
.message-content table td {
    border: 1px solid var(--border-color);
    padding: 8px 12px;
    text-align: left;
}

.message-content table th {
    background-color: var(--bg-soft);
    font-weight: 650;
}

.katex {
    font-size: 1.08em;
}

.katex-display {
    margin: 1em 0;
    overflow-x: auto;
    overflow-y: hidden;
}

.error-message {
    color: var(--error-color);
    background-color: var(--error-soft);
    padding: 12px 14px;
    border-radius: var(--radius-sm);
    border-left: 3px solid var(--error-color);
}

.answer-body {
    min-width: 0;
}

.stream-plain,
.markdown-fallback {
    margin: 0;
    white-space: pre-wrap;
    overflow-wrap: anywhere;
    font: inherit;
    color: inherit;
}

.markdown-fallback {
    padding: 0;
    border: 0;
    background: transparent;
    box-shadow: none;
}

/* ---------- Composer ---------- */

.input-container {
    padding: 0 calc(clamp(12px, 2vw, 20px) + var(--safe-right)) calc(14px + var(--safe-bottom)) calc(clamp(12px, 2vw, 20px) + var(--safe-left));
    background: linear-gradient(180deg, transparent, color-mix(in srgb, var(--bg-deep) 88%, transparent) 28%);
}

#attachment-preview {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 10px;
    width: min(100%, var(--composer-max));
    margin: 0 auto 8px;
    padding: 9px 12px;
    background: linear-gradient(180deg, rgba(88, 166, 255, 0.08), var(--bg-elevated));
    border: 1px solid var(--accent-mid);
    border-radius: var(--radius-md);
    font-size: 0.88em;
    color: var(--text-secondary);
    animation: message-in 0.22s var(--ease-out) both;
}

#attachment-preview span {
    flex: 1;
    min-width: 0;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

#remove-attachment-button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 32px;
    min-height: 32px;
    background: none;
    border: none;
    color: var(--error-color);
    cursor: pointer;
    font-size: 1.15em;
    padding: 0 5px;
    border-radius: var(--radius-xs);
}

#remove-attachment-button:hover {
    background: var(--error-soft);
}

.input-area {
    display: grid;
    grid-template-columns: auto minmax(0, 1fr) auto;
    grid-template-areas:
        "textarea textarea textarea"
        "tools meta send";
    gap: 6px 10px;
    align-items: end;
    width: min(100%, var(--composer-max));
    margin: 0 auto;
    padding: 12px 12px 10px;
    border: 1px solid var(--border-strong);
    border-radius: var(--radius-xl);
    background:
        linear-gradient(180deg, rgba(20, 27, 36, 0.96), rgba(13, 17, 23, 0.98));
    box-shadow: var(--shadow-md), inset 0 1px 0 rgba(255, 255, 255, 0.03);
    transition: border-color var(--dur-fast) ease, box-shadow var(--dur-fast) ease, background var(--dur-fast) ease;
}

.input-area:focus-within {
    border-color: var(--accent-mid);
    box-shadow: var(--shadow-glow);
}

.input-area.is-drop-active {
    border-color: var(--accent-strong);
    background:
        linear-gradient(180deg, rgba(88, 166, 255, 0.1), rgba(13, 17, 23, 0.98));
    box-shadow: var(--shadow-glow);
}

.composer-tools {
    grid-area: tools;
    display: inline-flex;
    align-items: center;
    gap: 4px;
}

/* ---------- Reasoning level picker ---------- */

.reasoning-picker {
    position: relative;
    display: inline-flex;
}

.reasoning-level-button {
    width: auto !important;
    min-width: 36px;
    height: 36px;
    gap: 5px;
    padding: 0 9px 0 8px !important;
    border: 1px solid transparent;
    color: var(--text-muted);
    font-size: 0.78rem !important;
    font-weight: 600;
    letter-spacing: 0.01em;
    white-space: nowrap;
}

.reasoning-level-label {
    max-width: 3.2em;
    overflow: hidden;
    text-overflow: ellipsis;
    line-height: 1;
}

.reasoning-level-button:hover:not(:disabled) {
    background: rgba(255, 255, 255, 0.05);
    border-color: var(--border-strong);
    color: var(--text-color);
}

.reasoning-level-button:focus-visible {
    outline: none;
    border-color: var(--accent-mid);
    box-shadow: 0 0 0 3px var(--accent-soft);
}

.reasoning-level-button[aria-expanded="true"] {
    background: var(--accent-soft);
    border-color: var(--accent-mid);
    color: var(--accent-color);
}

.reasoning-level-button[aria-expanded="true"] .reasoning-level-caret {
    transform: rotate(180deg);
}

.reasoning-level-button.is-active:not([aria-expanded="true"]) {
    background: rgba(88, 166, 255, 0.1);
    border-color: rgba(88, 166, 255, 0.22);
    color: var(--accent-color);
}

.reasoning-level-button.is-off:not(:disabled) {
    color: var(--text-faint);
}

.reasoning-level-button:disabled {
    opacity: 0.45;
    cursor: not-allowed;
}

.reasoning-level-menu {
    position: absolute;
    left: 0;
    bottom: calc(100% + 8px);
    z-index: 40;
    width: min(248px, calc(100vw - 32px));
    padding: 8px;
    border: 1px solid var(--border-strong);
    border-radius: var(--radius-md);
    background:
        linear-gradient(180deg, rgba(26, 35, 48, 0.98), rgba(16, 22, 30, 0.99));
    box-shadow: var(--shadow-lg), 0 0 0 1px rgba(88, 166, 255, 0.06);
    backdrop-filter: blur(14px);
    -webkit-backdrop-filter: blur(14px);
    transform-origin: bottom left;
    animation: reasoning-menu-in 0.16s var(--ease-out) both;
}

.reasoning-level-menu[hidden] {
    display: none !important;
}

@keyframes reasoning-menu-in {
    from {
        opacity: 0;
        transform: translateY(6px) scale(0.97);
    }
    to {
        opacity: 1;
        transform: translateY(0) scale(1);
    }
}

.reasoning-level-menu-head {
    display: flex;
    flex-direction: column;
    gap: 2px;
    padding: 6px 10px 10px;
    border-bottom: 1px solid var(--border-soft);
    margin-bottom: 6px;
}

.reasoning-level-menu-title {
    color: var(--text-color);
    font-size: 0.82rem;
    font-weight: 650;
    letter-spacing: 0.01em;
}

.reasoning-level-menu-sub {
    color: var(--text-faint);
    font-size: 0.72rem;
}

.reasoning-level-options {
    display: flex;
    flex-direction: column;
    gap: 2px;
    max-height: min(320px, 48dvh);
    overflow-y: auto;
}

.reasoning-level-option {
    display: grid;
    grid-template-columns: 1fr auto;
    grid-template-areas:
        "label meter"
        "desc meter";
    column-gap: 12px;
    row-gap: 2px;
    align-items: center;
    width: 100%;
    margin: 0;
    padding: 8px 10px;
    border: 1px solid transparent;
    border-radius: var(--radius-sm);
    background: transparent;
    color: var(--text-secondary);
    text-align: left;
    cursor: pointer;
    transition: background var(--dur-fast) ease, border-color var(--dur-fast) ease, color var(--dur-fast) ease;
}

.reasoning-level-option:hover,
.reasoning-level-option:focus-visible {
    outline: none;
    background: rgba(255, 255, 255, 0.04);
    border-color: var(--border-soft);
    color: var(--text-color);
}

.reasoning-level-option[aria-selected="true"] {
    background: var(--accent-soft);
    border-color: rgba(88, 166, 255, 0.22);
    color: var(--text-color);
}

.reasoning-level-option-label {
    grid-area: label;
    font-size: 0.84rem;
    font-weight: 600;
    line-height: 1.2;
}

.reasoning-level-option-desc {
    grid-area: desc;
    color: var(--text-faint);
    font-size: 0.7rem;
    line-height: 1.3;
}

.reasoning-level-option[aria-selected="true"] .reasoning-level-option-desc {
    color: var(--text-muted);
}

.reasoning-level-meter {
    grid-area: meter;
    display: inline-flex;
    align-items: center;
    gap: 3px;
    height: 18px;
}

.reasoning-level-meter span {
    display: block;
    width: 3px;
    border-radius: 99px;
    background: rgba(230, 237, 243, 0.12);
    transition: background var(--dur-fast) ease, box-shadow var(--dur-fast) ease;
}

.reasoning-level-meter span:nth-child(1) { height: 6px; }
.reasoning-level-meter span:nth-child(2) { height: 9px; }
.reasoning-level-meter span:nth-child(3) { height: 12px; }
.reasoning-level-meter span:nth-child(4) { height: 15px; }
.reasoning-level-meter span:nth-child(5) { height: 18px; }

.reasoning-level-meter[data-level="0"] span,
.reasoning-level-meter[data-level="1"] span:nth-child(-n+1),
.reasoning-level-meter[data-level="2"] span:nth-child(-n+2),
.reasoning-level-meter[data-level="3"] span:nth-child(-n+3),
.reasoning-level-meter[data-level="4"] span:nth-child(-n+4),
.reasoning-level-meter[data-level="5"] span:nth-child(-n+5),
.reasoning-level-meter[data-level="max"] span {
    background: linear-gradient(180deg, #79c0ff, #58a6ff);
    box-shadow: 0 0 8px rgba(88, 166, 255, 0.28);
}

.reasoning-level-meter[data-level="0"] span {
    background: rgba(230, 237, 243, 0.14);
    box-shadow: none;
}

.reasoning-level-meter[data-level="max"] span,
.reasoning-level-meter.is-max span {
    background: linear-gradient(180deg, #f2cc60, var(--warning-color));
    box-shadow: 0 0 8px rgba(210, 153, 34, 0.38);
}

.reasoning-level-meter.is-auto span {
    background: linear-gradient(180deg, rgba(121, 192, 255, 0.55), rgba(88, 166, 255, 0.28));
    box-shadow: none;
    opacity: 0.85;
}

.reasoning-level-meter.is-auto span:nth-child(odd) {
    opacity: 0.55;
}

.reasoning-level-option[aria-selected="true"] .reasoning-level-meter[data-level="0"] span {
    background: rgba(88, 166, 255, 0.28);
}

.reasoning-level-option[aria-selected="true"] .reasoning-level-meter.is-auto span {
    background: linear-gradient(180deg, #79c0ff, rgba(88, 166, 255, 0.55));
    opacity: 1;
}

.reasoning-level-option[aria-selected="true"] .reasoning-level-meter.is-auto span:nth-child(odd) {
    opacity: 0.7;
}

.reasoning-level-option[aria-selected="true"] .reasoning-level-meter[data-level="max"] span,
.reasoning-level-option[aria-selected="true"] .reasoning-level-meter.is-max span {
    background: linear-gradient(180deg, #ffd666, #e3a008);
    box-shadow: 0 0 10px rgba(210, 153, 34, 0.45);
}

.reasoning-level-button.is-max {
    background: var(--warning-soft);
    border-color: rgba(210, 153, 34, 0.32);
    color: var(--warning-color);
}

.reasoning-level-button.is-max:hover:not(:disabled) {
    background: rgba(210, 153, 34, 0.18);
    border-color: rgba(210, 153, 34, 0.42);
    color: #f2cc60;
}

@media (max-width: 640px) {
    .reasoning-level-button .reasoning-level-label {
        max-width: 2.8em;
    }

    .reasoning-level-menu {
        left: 0;
        right: auto;
        width: min(236px, calc(100vw - 24px));
    }

    #search-button .tool-button-label {
        max-width: 4.5em;
    }
}

.composer-meta {
    grid-area: meta;
    min-width: 0;
    display: flex;
    align-items: center;
    justify-content: flex-end;
    padding: 0 4px 2px;
    pointer-events: none;
}

.composer-hint {
    color: var(--text-faint);
    font-size: 0.74em;
    letter-spacing: 0.01em;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

#user-input {
    grid-area: textarea;
    width: 100%;
    min-height: 44px;
    max-height: 33dvh;
    background: transparent;
    color: var(--text-color);
    border: 0;
    border-radius: 0;
    padding: 4px 6px 2px;
    font-family: inherit;
    font-size: 16px;
    line-height: 1.5;
    resize: none;
    overflow-y: auto;
    outline: none;
    box-shadow: none;
}

#user-input::placeholder {
    color: var(--text-faint);
}

#user-input:focus {
    border: 0;
    box-shadow: none;
    outline: none;
}

.icon-tool-button,
#upload-button,
#search-button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    padding: 0;
    border: 1px solid transparent;
    border-radius: var(--radius-sm);
    background: transparent;
    color: var(--text-muted);
    font-size: 0;
    transition: background var(--dur-fast) ease, color var(--dur-fast) ease, border-color var(--dur-fast) ease;
}

.icon-tool-button svg,
#upload-button svg,
#search-button svg {
    width: 18px;
    height: 18px;
    stroke: currentColor;
    fill: none;
    stroke-width: 1.75;
    stroke-linecap: round;
    stroke-linejoin: round;
}

#reasoning-level-button svg {
    width: auto;
    height: auto;
}

#reasoning-level-button .reasoning-level-icon {
    width: 15px;
    height: 15px;
    flex-shrink: 0;
    stroke-width: 1.6;
}

#reasoning-level-button .reasoning-level-caret {
    width: 12px;
    height: 12px;
    flex-shrink: 0;
    opacity: 0.7;
    stroke-width: 2;
    transition: transform var(--dur-fast) var(--ease-out);
}

#search-button {
    width: auto !important;
    min-width: 36px;
    gap: 5px;
    padding: 0 10px 0 8px !important;
    font-size: 0.78rem !important;
    font-weight: 600;
    letter-spacing: 0.01em;
    white-space: nowrap;
}

#search-button .tool-button-label {
    max-width: 5.5em;
    overflow: hidden;
    text-overflow: ellipsis;
    line-height: 1;
}

#search-button:hover:not(:disabled):not(.active) {
    background: rgba(255, 255, 255, 0.05);
    border-color: var(--border-strong);
    color: var(--text-color);
}

#search-button.active {
    background: var(--prompt-soft);
    border-color: rgba(63, 185, 80, 0.28);
    color: var(--prompt-color);
    box-shadow: 0 0 0 3px rgba(63, 185, 80, 0.08);
}

#send-button {
    grid-area: send;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    min-height: 38px;
    min-width: 84px;
    padding: 8px 14px;
    border: 1px solid var(--accent-mid);
    border-radius: var(--radius-pill);
    background: linear-gradient(180deg, rgba(88, 166, 255, 0.32), rgba(88, 166, 255, 0.16));
    color: #f0f6fc;
    font-weight: 650;
    font-size: 0.88em;
    box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.1);
    transition: background var(--dur-fast) ease, border-color var(--dur-fast) ease, transform var(--dur-fast) ease, opacity var(--dur-fast) ease, filter var(--dur-fast) ease;
}

#send-button:disabled:not(.is-stop) {
    opacity: 0.42;
    filter: grayscale(0.15);
    box-shadow: none;
}

#send-button svg {
    width: 15px;
    height: 15px;
    stroke: currentColor;
    fill: none;
    stroke-width: 2;
    stroke-linecap: round;
    stroke-linejoin: round;
}

#send-button .btn-icon-stop {
    display: none;
}

#send-button.is-stop {
    background: linear-gradient(180deg, rgba(248, 81, 73, 0.28), rgba(248, 81, 73, 0.14));
    border-color: rgba(248, 81, 73, 0.4);
}

#send-button.is-stop .btn-icon-send {
    display: none;
}

#send-button.is-stop .btn-icon-stop {
    display: block;
}

/* ---------- Modal ---------- */

.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    padding: max(16px, var(--safe-top)) max(16px, var(--safe-right)) max(16px, var(--safe-bottom)) max(16px, var(--safe-left));
    background-color: rgba(2, 6, 12, 0.62);
    align-items: center;
    justify-content: center;
    overscroll-behavior: contain;
    backdrop-filter: blur(6px);
    -webkit-backdrop-filter: blur(6px);
}

.modal.show {
    display: flex;
    animation: modal-fade 0.18s ease both;
}

@keyframes modal-fade {
    from { opacity: 0; }
    to { opacity: 1; }
}

.modal-content {
    background: linear-gradient(180deg, rgba(20, 27, 36, 0.99), rgba(13, 17, 23, 0.99));
    padding: 22px;
    border-radius: var(--radius-lg);
    border: 1px solid var(--border-strong);
    box-shadow: var(--shadow-lg);
    max-width: 640px;
    width: min(100%, 640px);
    max-height: min(84dvh, 860px);
    overflow-y: auto;
    overscroll-behavior: contain;
    animation: modal-pop 0.22s var(--ease-out) both;
}

@keyframes modal-pop {
    from {
        opacity: 0;
        transform: translateY(8px) scale(0.98);
    }
    to {
        opacity: 1;
        transform: translateY(0) scale(1);
    }
}

.modal-header {
    font-weight: 700;
    margin-bottom: 16px;
    font-size: 1.12em;
    letter-spacing: -0.015em;
    color: var(--text-color);
}

.app-dialog {
    z-index: 2100;
}

.app-dialog-content {
    width: min(100%, 460px);
    max-width: 460px;
}

.password-modal-content {
    width: min(100%, 460px);
    max-width: 460px;
}

.password-security-hint {
    margin-top: 2px !important;
}

.password-modal .modal-footer button:disabled {
    cursor: wait;
    opacity: 0.62;
}

.onboarding-modal {
    z-index: 2050;
}

.onboarding-content {
    width: min(100%, 480px);
    max-width: 480px;
    padding: 24px;
    overflow: hidden;
}

.onboarding-brand {
    display: flex;
    align-items: center;
    gap: 9px;
    margin-bottom: 24px;
    color: var(--text-secondary);
    font-size: 0.82rem;
    font-weight: 700;
    letter-spacing: 0;
}

.onboarding-brand .brand-logo {
    width: 28px;
    height: 28px;
    border-radius: var(--radius-sm);
    font-size: 0.8rem;
}

.onboarding-heading {
    margin-bottom: 18px;
}

.onboarding-heading.compact {
    margin: 16px 0 20px;
}

.onboarding-title {
    color: var(--text-color);
    font-size: 1.25rem;
    font-weight: 750;
    line-height: 1.3;
    letter-spacing: 0;
}

.onboarding-description {
    margin-top: 5px;
    color: var(--text-muted);
    font-size: 0.88rem;
    line-height: 1.55;
}

.onboarding-choice-list {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.onboarding-choice-button {
    display: grid;
    grid-template-columns: 38px minmax(0, 1fr) 18px;
    align-items: center;
    gap: 12px;
    width: 100%;
    min-height: 68px;
    padding: 11px 13px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    background: rgba(255, 255, 255, 0.02);
    color: var(--text-color);
    text-align: left;
}

.onboarding-choice-button:hover,
.onboarding-choice-button:focus-visible {
    outline: none;
    border-color: var(--border-strong);
    background: var(--bg-hover);
}

.onboarding-choice-button.primary-choice {
    border-color: rgba(88, 166, 255, 0.3);
    background: var(--accent-soft);
}

.onboarding-choice-button.primary-choice:hover,
.onboarding-choice-button.primary-choice:focus-visible {
    border-color: var(--accent-mid);
    background: rgba(88, 166, 255, 0.16);
}

.onboarding-choice-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 38px;
    height: 38px;
    border-radius: var(--radius-sm);
    background: rgba(255, 255, 255, 0.045);
    color: var(--text-secondary);
}

.primary-choice .onboarding-choice-icon {
    background: rgba(88, 166, 255, 0.14);
    color: var(--accent-color);
}

.onboarding-choice-icon svg,
.onboarding-choice-arrow,
.onboarding-back-button svg {
    width: 18px;
    height: 18px;
    fill: none;
    stroke: currentColor;
    stroke-width: 1.8;
    stroke-linecap: round;
    stroke-linejoin: round;
}

.onboarding-choice-copy {
    display: flex;
    min-width: 0;
    flex-direction: column;
    gap: 3px;
}

.onboarding-choice-copy strong {
    font-size: 0.92rem;
    font-weight: 700;
}

.onboarding-choice-copy > span {
    color: var(--text-muted);
    font-size: 0.76rem;
    line-height: 1.4;
}

.onboarding-choice-arrow {
    width: 15px;
    height: 15px;
    color: var(--text-faint);
}

.onboarding-skip-button {
    display: block;
    margin: 14px auto 0;
    padding: 6px 10px;
    border: 0;
    background: transparent;
    color: var(--text-muted);
    font-size: 0.78rem;
}

.onboarding-skip-button:hover,
.onboarding-skip-button:focus-visible,
.onboarding-back-button:hover,
.onboarding-back-button:focus-visible {
    outline: none;
    color: var(--text-color);
}

.onboarding-back-button {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    margin: -4px 0 0 -6px;
    padding: 5px 6px;
    border: 0;
    background: transparent;
    color: var(--text-muted);
    font-size: 0.78rem;
}

.onboarding-back-button svg {
    width: 15px;
    height: 15px;
}

#onboarding-api-panel > label {
    display: block;
    margin-bottom: 6px;
    color: var(--text-secondary);
    font-size: 0.82rem;
    font-weight: 600;
}

#onboarding-api-key-input {
    width: 100%;
    margin-bottom: 12px;
    padding: 11px 12px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    background: var(--bg-deep);
    color: var(--text-color);
    font-family: inherit;
    font-size: 16px;
}

#onboarding-api-key-input:focus {
    outline: none;
    border-color: var(--accent-mid);
    box-shadow: 0 0 0 3px var(--accent-soft);
}

.onboarding-save-button {
    width: 100%;
    margin-top: 12px;
}

.onboarding-save-button:disabled {
    cursor: wait;
    opacity: 0.62;
}

@media (max-width: 520px) {
    .onboarding-content {
        padding: 20px;
    }

    .onboarding-choice-button {
        grid-template-columns: 34px minmax(0, 1fr) 16px;
        min-height: 64px;
        gap: 10px;
        padding: 10px 11px;
    }

    .onboarding-choice-icon {
        width: 34px;
        height: 34px;
    }
}

.app-dialog-heading {
    display: grid;
    grid-template-columns: 42px minmax(0, 1fr);
    align-items: start;
    gap: 13px;
    margin-bottom: 20px;
}

.app-dialog-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 42px;
    height: 42px;
    border-radius: 50%;
    background: var(--accent-soft);
    color: var(--accent-color);
    font-size: 1rem;
    font-weight: 800;
}

.app-dialog[data-tone="danger"] .app-dialog-icon {
    background: var(--error-soft);
    color: var(--error-color);
}

.app-dialog[data-tone="warning"] .app-dialog-icon {
    background: var(--warning-soft);
    color: var(--warning-color);
}

.app-dialog-heading-copy {
    min-width: 0;
}

.app-dialog-title {
    color: var(--text-color);
    font-size: 1.05rem;
    font-weight: 700;
    line-height: 1.35;
    overflow-wrap: anywhere;
}

.app-dialog-message {
    margin-top: 5px;
    color: var(--text-secondary);
    font-size: 0.88rem;
    line-height: 1.55;
    overflow-wrap: anywhere;
    white-space: pre-line;
}

.app-dialog-input-group {
    margin: 0 0 20px;
}

.app-dialog-input-group[hidden] {
    display: none;
}

.app-dialog-input-group label {
    display: block;
    margin-bottom: 7px;
    color: var(--text-secondary);
    font-size: 0.86rem;
}

#app-dialog-input {
    width: 100%;
    min-height: 118px;
    max-height: 34dvh;
    padding: 12px 13px;
    resize: vertical;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    outline: none;
    background: var(--bg-deep);
    color: var(--text-color);
    font-size: 16px;
    line-height: 1.5;
}

#app-dialog-input:focus {
    border-color: var(--accent-mid);
    box-shadow: 0 0 0 3px var(--accent-soft);
}

.app-dialog-input-error {
    margin-top: 7px;
    color: var(--error-color);
    font-size: 0.82rem;
}

.app-dialog-actions button.danger {
    border-color: rgba(248, 81, 73, 0.5);
    background: rgba(248, 81, 73, 0.18);
    color: #ffc1bc;
}

.modal-body {
    margin-bottom: 15px;
}

.modal-body label {
    display: block;
    margin-bottom: 6px;
    color: var(--text-secondary);
    font-size: 0.88em;
    font-weight: 550;
}

.modal-body input,
.modal-body textarea,
.modal-body select {
    width: 100%;
    padding: 10px 12px;
    background-color: var(--bg-deep);
    color: var(--text-color);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    font-family: inherit;
    font-size: 16px;
    margin-bottom: 12px;
    transition: border-color var(--dur-fast) ease, box-shadow var(--dur-fast) ease;
}

.modal-body textarea {
    resize: vertical;
    min-height: 100px;
}

.modal-body input:focus,
.modal-body textarea:focus,
.modal-body select:focus {
    border-color: var(--accent-mid);
    box-shadow: 0 0 0 3px var(--accent-soft);
    outline: none;
}

.modal-body .hint {
    font-size: 0.82em;
    color: var(--text-muted);
    margin-top: -6px;
    margin-bottom: 12px;
    line-height: 1.45;
}

.modal-body .checkbox-row {
    display: flex;
    align-items: center;
    gap: 8px;
    cursor: pointer;
    margin-bottom: 6px;
}

.modal-body .checkbox-row input[type="checkbox"] {
    width: 16px;
    height: 16px;
    margin: 0;
    flex: none;
    accent-color: var(--accent-color);
}

.modal-body .checkbox-row span {
    font-size: 0.92em;
    color: var(--text-color);
}

.modal-body .checkbox-row {
    display: flex;
    align-items: center;
    gap: 8px;
    cursor: pointer;
    margin-bottom: 6px;
}

.modal-body .checkbox-row input[type="checkbox"] {
    width: 16px;
    height: 16px;
    margin: 0;
    flex: none;
    accent-color: var(--accent-color);
}

.modal-body .checkbox-row span {
    font-size: 0.92em;
    color: var(--text-color);
}

.modal-body .readonly-url {
    width: 100%;
    margin-bottom: 10px;
    padding: 10px 12px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    background: rgba(0, 0, 0, 0.2);
    color: var(--text-muted);
    font-size: 0.88em;
    word-break: break-all;
}

.modal-footer {
    display: flex;
    gap: 8px;
    justify-content: flex-end;
}

.modal-footer button {
    min-height: 42px;
    padding: 9px 16px;
    background-color: transparent;
    color: var(--text-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    cursor: pointer;
    font-family: inherit;
    font-size: 0.9em;
    transition: background var(--dur-fast) ease, border-color var(--dur-fast) ease, color var(--dur-fast) ease;
}

.modal-footer button.primary {
    background: linear-gradient(180deg, rgba(88, 166, 255, 0.28), rgba(88, 166, 255, 0.14));
    color: #f0f6fc;
    border-color: var(--accent-mid);
    font-weight: 600;
}

.account-modal-content {
    width: min(100%, 460px);
    max-width: 460px;
}

.auth-mode-tabs {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 4px;
    margin-bottom: 18px;
    padding: 4px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    background: var(--bg-deep);
}

.auth-mode-tab {
    min-height: 36px;
    border: 0;
    border-radius: 8px;
    background: transparent;
    color: var(--text-muted);
    cursor: pointer;
    font-weight: 550;
    transition: background var(--dur-fast) ease, color var(--dur-fast) ease;
}

.auth-mode-tab.active {
    background: var(--accent-soft);
    color: var(--text-color);
}

.auth-error {
    margin-top: 4px;
    padding: 10px 12px;
    border: 1px solid rgba(248, 81, 73, 0.35);
    border-radius: var(--radius-sm);
    background: var(--error-soft);
    color: #ffb4af;
    line-height: 1.45;
    font-size: 0.88em;
}

.account-summary {
    display: flex;
    align-items: center;
    gap: 14px;
    padding: 6px 0 24px;
}

.account-avatar {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 46px;
    height: 46px;
    flex: none;
    border: 1px solid var(--accent-mid);
    border-radius: 50%;
    background: var(--accent-soft);
    color: var(--text-color);
    font-size: 1.05rem;
    font-weight: 700;
}

.account-username {
    color: var(--text-color);
    font-size: 1.05em;
    font-weight: 700;
    overflow-wrap: anywhere;
}

.account-detail {
    margin-top: 4px;
    color: var(--text-muted);
    font-size: 0.88em;
}

.account-storage {
    margin: -6px 0 22px;
    padding: 16px 0;
    border-top: 1px solid var(--divider);
    border-bottom: 1px solid var(--divider);
}

.account-storage-header,
.account-storage-footer {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 14px;
}

.account-storage-footer {
    flex-wrap: wrap;
}

.account-storage-label {
    color: var(--text-color);
    font-size: 0.9em;
    font-weight: 650;
}

.account-storage-usage {
    min-width: 0;
    color: var(--text-secondary);
    font-size: 0.82em;
    font-variant-numeric: tabular-nums;
    overflow-wrap: anywhere;
    text-align: right;
}

.account-storage-progress-track {
    position: relative;
    width: 100%;
    height: 6px;
    margin: 10px 0 12px;
    overflow: hidden;
    border-radius: var(--radius-pill);
    background: rgba(110, 118, 129, 0.22);
}

.account-storage-progress-bar {
    display: block;
    width: 100%;
    height: 100%;
    border-radius: inherit;
    background: var(--prompt-color);
    transform: scaleX(0);
    transform-origin: left center;
    transition: transform 0.28s ease, background-color 0.2s ease;
}

.account-storage-available {
    min-width: 0;
    color: var(--text-muted);
    font-size: 0.8em;
    font-variant-numeric: tabular-nums;
    overflow-wrap: anywhere;
}

.storage-check-in-button {
    min-height: 34px;
    flex: none;
    padding: 6px 11px;
    border: 1px solid rgba(63, 185, 80, 0.32);
    border-radius: var(--radius-xs);
    background: var(--prompt-soft);
    color: #7ee787;
    cursor: pointer;
    font-family: inherit;
    font-size: 0.8em;
    font-weight: 650;
    transition: background-color var(--dur-fast) ease, border-color var(--dur-fast) ease, color var(--dur-fast) ease;
}

.storage-check-in-button:hover:not(:disabled) {
    border-color: rgba(63, 185, 80, 0.55);
    background: rgba(63, 185, 80, 0.2);
    color: #aff5b4;
}

.storage-check-in-button:disabled {
    cursor: default;
    opacity: 0.58;
}

.account-sync-progress {
    min-height: 66px;
    margin: -4px 0 22px;
}

.account-sync-progress[hidden] {
    display: none;
}

.account-sync-progress-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
    margin-bottom: 9px;
}

.account-sync-phase {
    min-width: 0;
    color: var(--text-color);
    font-size: 0.9em;
    font-weight: 650;
    overflow-wrap: anywhere;
}

.account-sync-percent {
    flex: none;
    color: var(--accent-color);
    font-size: 0.82em;
    font-variant-numeric: tabular-nums;
}

.account-sync-progress-track {
    position: relative;
    width: 100%;
    height: 6px;
    overflow: hidden;
    border-radius: var(--radius-pill);
    background: rgba(110, 118, 129, 0.22);
}

.account-sync-progress-bar {
    display: block;
    width: 0;
    height: 100%;
    border-radius: inherit;
    background: var(--accent-color);
    box-shadow: 0 0 12px var(--accent-glow);
    transition: width 0.28s ease, background-color 0.2s ease, box-shadow 0.2s ease;
}

.account-sync-progress[data-state="complete"] .account-sync-progress-bar {
    background: var(--prompt-color);
    box-shadow: 0 0 12px rgba(63, 185, 80, 0.28);
}

.account-sync-progress[data-state="paused"] .account-sync-progress-bar {
    background: var(--warning-color);
    box-shadow: 0 0 12px rgba(88, 166, 255, 0.28);
}

.account-sync-progress[data-state="error"] .account-sync-progress-bar {
    background: var(--error-color);
    box-shadow: 0 0 12px rgba(248, 81, 73, 0.28);
}

.account-sync-progress[data-state="complete"] .account-sync-percent {
    color: var(--prompt-color);
}

.account-sync-progress[data-state="paused"] .account-sync-percent {
    color: var(--warning-color);
}

.account-sync-progress[data-state="error"] .account-sync-percent {
    color: var(--error-color);
}

.account-sync-progress-detail {
    min-height: 18px;
    margin-top: 8px;
    color: var(--text-muted);
    font-size: 0.8em;
    line-height: 1.4;
    overflow-wrap: anywhere;
}

.account-user-actions {
    flex-wrap: wrap;
}

.account-user-actions button:disabled {
    cursor: wait;
    opacity: 0.62;
}

.toggle-advanced-button {
    width: 100%;
    min-height: 42px;
    padding: 10px 14px;
    margin-bottom: 10px;
    background-color: transparent;
    color: var(--text-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    cursor: pointer;
    font-family: inherit;
    font-size: 0.9em;
    text-align: left;
    transition: background-color var(--dur-fast) ease, border-color var(--dur-fast) ease, color var(--dur-fast) ease;
}

.toggle-advanced-button:hover {
    background-color: rgba(255, 255, 255, 0.03);
    border-color: var(--accent-mid);
    color: var(--text-color);
}

#toggle-advanced-icon {
    display: inline-block;
    transition: transform 0.2s ease;
    margin-right: 6px;
}

#toggle-advanced-icon.expanded {
    transform: rotate(90deg);
}

#advanced-settings {
    margin-top: 10px;
}

.copy-code-button {
    position: absolute;
    top: 8px;
    right: 8px;
    min-height: 30px;
    padding: 5px 10px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-xs);
    background: rgba(20, 27, 36, 0.92);
    color: var(--text-secondary);
    font-size: 12px;
    cursor: pointer;
    opacity: 0;
    transition: opacity var(--dur-fast) ease, border-color var(--dur-fast) ease, background-color var(--dur-fast) ease, color var(--dur-fast) ease;
}

.message-content pre:hover .copy-code-button,
.copy-code-button:focus-visible {
    opacity: 1;
}

.copy-code-button:focus-visible {
    outline: none;
    border-color: var(--accent-mid);
    box-shadow: 0 0 0 3px var(--accent-soft);
}

/* ---------- Thinking & reasoning ---------- */

.thinking-indicator {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    color: var(--text-muted);
    font-size: 0.92em;
}

.thinking-indicator::before {
    content: "";
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background: var(--accent-color);
    box-shadow:
        10px 0 0 0 var(--accent-color),
        20px 0 0 0 var(--accent-color);
    animation: thinking-dots 1.1s ease-in-out infinite;
    margin-right: 18px;
}

@keyframes thinking-dots {
    0%, 100% {
        box-shadow:
            10px 0 0 0 rgba(88, 166, 255, 0.35),
            20px 0 0 0 rgba(88, 166, 255, 0.2);
        opacity: 1;
    }
    50% {
        box-shadow:
            10px 0 0 0 rgba(88, 166, 255, 1),
            20px 0 0 0 rgba(88, 166, 255, 0.55);
        opacity: 0.85;
    }
}

.reasoning-block {
    margin: 0 0 14px;
    border: 1px solid var(--border-soft);
    border-left: 3px solid var(--accent-color);
    border-radius: var(--radius-sm);
    background: rgba(88, 166, 255, 0.04);
    overflow: hidden;
}

.reasoning-summary {
    cursor: pointer;
    list-style: none;
    padding: 8px 12px;
    font-size: 0.84em;
    color: var(--text-muted);
    user-select: none;
    display: flex;
    align-items: center;
    gap: 6px;
    transition: color var(--dur-fast) ease, background var(--dur-fast) ease;
}

.reasoning-summary::-webkit-details-marker {
    display: none;
}

.reasoning-summary::after {
    content: "▸";
    margin-left: auto;
    transition: transform 0.15s ease;
    color: var(--text-faint);
}

.reasoning-block[open] > .reasoning-summary::after {
    transform: rotate(90deg);
}

.reasoning-summary:hover {
    color: var(--text-secondary);
    background: rgba(255, 255, 255, 0.02);
}

.reasoning-block[open] > .reasoning-summary {
    border-bottom: 1px solid var(--border-soft);
}

.reasoning-body {
    padding: 6px 14px 10px;
    font-size: 0.88em;
    line-height: 1.65;
    color: var(--text-muted);
}

.reasoning-body p:first-child {
    margin-top: 6px;
}

.reasoning-body p:last-child {
    margin-bottom: 4px;
}

.reasoning-body pre {
    background-color: rgba(0, 0, 0, 0.22);
}

/* ---------- Shortcuts ---------- */

.shortcuts-hint {
    position: fixed;
    bottom: calc(16px + var(--safe-bottom));
    right: calc(20px + var(--safe-right));
    background-color: var(--bg-elevated);
    border: 1px solid var(--border-strong);
    border-radius: var(--radius-md);
    padding: 12px 16px;
    font-size: 0.84em;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.25s ease;
    z-index: 999;
    max-width: 260px;
    box-shadow: var(--shadow-md);
    backdrop-filter: blur(12px);
}

.shortcuts-hint.show {
    opacity: 0.96;
}

.shortcuts-hint h4 {
    margin: 0 0 8px 0;
    color: var(--accent-color);
    font-size: 0.95em;
}

.shortcuts-hint ul {
    margin: 0;
    padding-left: 0;
    list-style: none;
}

.shortcuts-hint li {
    margin: 5px 0;
    color: var(--text-secondary);
}

.shortcuts-hint kbd {
    display: inline-block;
    background-color: var(--bg-deep);
    border: 1px solid var(--border-color);
    border-radius: 5px;
    padding: 1px 6px;
    font-size: 0.88em;
    font-family: var(--font-mono);
    color: var(--text-color);
    margin-right: 2px;
}

/* ---------- Focus rings ---------- */

.session-item:focus-visible,
.session-item-main:focus-visible,
.primary-sidebar-button:focus-visible,
.sidebar-actions button:focus-visible,
.sidebar-icon-button:focus-visible,
.session-item-delete:focus-visible,
.message-action-button:focus-visible,
.branch-switch-button:focus-visible,
.branch-selector:focus-visible,
.account-button:focus-visible,
.sync-now-button:focus-visible,
.icon-tool-button:focus-visible,
#upload-button:focus-visible,
#search-button:focus-visible,
#send-button:focus-visible,
.scroll-bottom-button:focus-visible,
.storage-check-in-button:focus-visible,
.modal-footer button:focus-visible {
    outline: none;
    box-shadow: 0 0 0 3px var(--accent-soft);
}

/* ---------- Responsive ---------- */

@media (min-width: 1280px) {
    :root {
        --sidebar-width: 320px;
        --content-max: 880px;
        --composer-max: 880px;
    }

    .workspace-topbar {
        padding-left: clamp(24px, 3vw, 40px);
        padding-right: clamp(24px, 3vw, 40px);
    }

    #chat-log {
        padding-left: clamp(24px, 3vw, 40px);
        padding-right: clamp(24px, 3vw, 40px);
    }
}

@media (max-width: 900px) {
    .sidebar {
        position: fixed;
        top: 0;
        left: 0;
        bottom: 0;
        width: min(86vw, 340px);
        min-width: 0;
        padding-top: calc(14px + var(--safe-top));
        padding-bottom: calc(12px + var(--safe-bottom));
        transform: translateX(-100%);
        transition: transform 0.25s var(--ease-out);
        box-shadow: 20px 0 40px rgba(0, 0, 0, 0.35);
        background: var(--bg-elevated);
    }

    .sidebar.is-open {
        transform: translateX(0);
    }

    #sidebar-close-button,
    #sidebar-toggle-button {
        display: inline-flex;
    }

    .workspace-topbar {
        padding: max(12px, var(--safe-top)) calc(14px + var(--safe-right)) 12px calc(14px + var(--safe-left));
    }

    #chat-log {
        padding: 16px calc(14px + var(--safe-right)) 12px calc(14px + var(--safe-left));
    }

    .input-container {
        padding: 0 calc(12px + var(--safe-right)) calc(12px + var(--safe-bottom)) calc(12px + var(--safe-left));
    }

    .sidebar-icon-button {
        width: 40px;
        height: 40px;
    }

    .session-item-delete {
        opacity: 1;
        width: 32px;
        height: 32px;
    }

    .session-item-main {
        padding-right: 44px;
    }

    .message-header-actions {
        opacity: 1;
    }

    .message-action-button,
    .branch-switch-button {
        min-height: 34px;
        padding: 6px 12px;
    }

    .copy-code-button {
        opacity: 1;
        min-height: 34px;
    }

    #remove-attachment-button {
        min-width: 40px;
        min-height: 40px;
    }
}

@media (max-width: 600px) {
    .notification-region {
        top: calc(10px + var(--safe-top));
        right: calc(10px + var(--safe-right));
        width: calc(100vw - 20px - var(--safe-left) - var(--safe-right));
    }

    .workspace-topbar {
        align-items: flex-start;
        gap: 10px;
    }

    .workspace-title,
    .workspace-meta {
        white-space: normal;
    }

    .sidebar {
        padding: calc(14px + var(--safe-top)) calc(12px + var(--safe-right)) calc(12px + var(--safe-bottom)) calc(12px + var(--safe-left));
    }

    .sidebar-actions {
        grid-template-columns: 1fr;
    }

    .message.assistant .message-content {
        padding-left: 0;
    }

    .message-header-actions {
        margin-left: 0;
        width: 100%;
        flex-wrap: wrap;
        justify-content: flex-end;
    }

    .branch-switcher {
        flex-wrap: wrap;
    }

    .branch-selector {
        flex: 1;
        max-width: none;
    }

    .message-content pre {
        padding-top: 42px;
    }

    #attachment-preview {
        flex-wrap: wrap;
        gap: 8px;
    }

    .input-area {
        grid-template-columns: 1fr auto;
        grid-template-areas:
            "textarea textarea"
            "tools send";
        padding: 10px;
        border-radius: 18px;
        gap: 8px;
    }

    .composer-meta {
        display: none;
    }

    .scroll-bottom-button {
        right: calc(14px + var(--safe-right));
        bottom: 10px;
        width: 44px;
        height: 44px;
    }

    #user-input {
        min-height: 72px;
        max-height: 34dvh;
    }

    #send-button {
        min-width: 72px;
    }

    .modal-content {
        width: 100%;
        max-height: calc(100dvh - 16px);
        padding: 18px;
        border-radius: 16px;
    }

    .modal-footer {
        flex-direction: column-reverse;
    }

    .modal-footer button {
        width: 100%;
    }

    .shortcuts-hint {
        left: calc(12px + var(--safe-left));
        right: calc(12px + var(--safe-right));
        bottom: calc(12px + var(--safe-bottom));
        max-width: none;
    }
}

@media (max-width: 420px) {
    .sidebar {
        width: 100vw;
        border-right: none;
    }

    .workspace-topbar {
        padding-left: calc(12px + var(--safe-left));
        padding-right: calc(12px + var(--safe-right));
    }

    #chat-log {
        padding-left: calc(12px + var(--safe-left));
        padding-right: calc(12px + var(--safe-right));
    }

    .input-container {
        padding-left: calc(10px + var(--safe-left));
        padding-right: calc(10px + var(--safe-right));
    }
}

/* ---------- Hover (fine pointer) ---------- */

@media (hover: hover) and (pointer: fine) {
    .sidebar-icon-button:hover {
        border-color: var(--accent-mid);
        background: var(--accent-soft);
        color: var(--accent-color);
    }

    .primary-sidebar-button:hover {
        border-color: var(--accent-strong);
        background: linear-gradient(180deg, rgba(88, 166, 255, 0.3), rgba(88, 166, 255, 0.16));
    }

    .sidebar-actions button:hover,
    .account-button:hover,
    .sync-now-button:hover,
    .modal-footer button:hover {
        border-color: var(--accent-mid);
        background: rgba(255, 255, 255, 0.03);
        color: var(--text-color);
    }

    .session-item:hover .session-item-main:not(.is-active) {
        background: rgba(255, 255, 255, 0.03);
    }

    .icon-tool-button:hover,
    #upload-button:hover,
    #search-button:hover:not(.active) {
        background: rgba(255, 255, 255, 0.05);
        color: var(--text-color);
    }

    #send-button:hover:not(:disabled) {
        border-color: var(--accent-strong);
        filter: brightness(1.05);
    }

    .copy-code-button:hover {
        background: var(--bg-soft);
        color: var(--text-color);
        border-color: var(--accent-mid);
    }

    .message-action-button:hover,
    .branch-switch-button:hover {
        color: var(--accent-color);
        background: var(--accent-soft);
        border-color: transparent;
    }

    .message-delete-button:hover {
        color: #ff7b72;
        background: var(--error-soft);
    }

    .session-item-delete:hover {
        color: #ff7b72;
        background: var(--error-soft);
    }

    .modal-footer button.primary:hover {
        border-color: var(--accent-strong);
        filter: brightness(1.05);
    }
}

.session-item-main:active,
.primary-sidebar-button:active,
.sidebar-actions button:active,
.sidebar-icon-button:active,
#upload-button:active,
#search-button:active,
#send-button:active,
.modal-footer button:active,
.copy-code-button:active,
.message-action-button:active,
.branch-switch-button:active,
.session-item-delete:active {
    filter: brightness(1.06);
}

/* ---------- Reduced motion ---------- */

@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
    }
}