/* ==========================================================================
   Design tokens — taken from the DesignSystem (Color / Typography / Border)
   ========================================================================== */
:root {
    --color-background-primary: #FFFFFF;
    --color-background-secondary: #F5F4ED;
    --color-background-tertiary: #FAF9F5;
    --color-background-inverse: #141413;
    --color-background-ghost: rgba(255, 255, 255, 0);
    --color-background-info: #D6E4F6;
    --color-background-danger: #F7ECEC;
    --color-background-warning: #FAEFDF;

    --color-text-primary: #141413;
    --color-text-secondary: #3D3D3A;
    --color-text-tertiary: #73726C;
    --color-text-inverse: #FFFFFF;
    --color-text-info: #2C84DB;
    --color-text-danger: #B53333;
    --color-text-warning: #805C1F;

    --color-border-primary: rgba(31, 30, 29, 0.40);
    --color-border-secondary: rgba(31, 30, 29, 0.30);
    --color-border-tertiary: rgba(31, 30, 29, 0.15);
    --color-ring-primary: rgba(20, 20, 19, 0.70);
    --color-ring-info: #3266AD;

    --color-accent: #D97757;
    --color-user-bubble: #F0EEE6;
    --color-hover: rgba(31, 30, 29, 0.06);

    --font-sans: "Anthropic Sans", "Vazirmatn", ui-sans-serif, system-ui, -apple-system, "Segoe UI", sans-serif;
    --font-mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, monospace;

    --font-weight-normal: 400;
    --font-weight-medium: 500;
    --font-weight-semibold: 600;
    --font-weight-bold: 700;

    --font-text-xs-size: 12px;  --font-text-xs-line-height: 16px;
    --font-text-sm-size: 14px;  --font-text-sm-line-height: 20px;
    --font-text-md-size: 16px;  --font-text-md-line-height: 28px;
    --font-text-lg-size: 18px;  --font-text-lg-line-height: 30px;
    --font-heading-sm-size: 16px;
    --font-heading-md-size: 20px;
    --font-heading-lg-size: 24px;
    --font-heading-xl-size: 30px;

    --border-radius-xs: 4px;
    --border-radius-sm: 6px;
    --border-radius-md: 8px;
    --border-radius-lg: 12px;
    --border-radius-xl: 20px;
    --border-radius-full: 9999px;
    --border-width-regular: 0.5px;

    --shadow-composer: 0 4px 20px rgba(0, 0, 0, 0.035), 0 0 0 0.5px var(--color-border-tertiary);
    --sidebar-width: 288px;
    --thread-width: 760px;

    color-scheme: light;
}

@media (prefers-color-scheme: dark) {
    :root:not([data-theme="light"]) {
        --color-background-primary: #30302E;
        --color-background-secondary: #262624;
        --color-background-tertiary: #141413;
        --color-background-inverse: #FAF9F5;
        --color-background-info: #253E5F;
        --color-background-danger: #4A2423;
        --color-background-warning: #483A1F;
        --color-text-primary: #FAF9F5;
        --color-text-secondary: #C2C0B6;
        --color-text-tertiary: #9C9A92;
        --color-text-inverse: #141413;
        --color-text-info: #80AADD;
        --color-text-danger: #EF8D89;
        --color-text-warning: #D5A34C;
        --color-border-primary: rgba(222, 220, 209, 0.40);
        --color-border-secondary: rgba(222, 220, 209, 0.30);
        --color-border-tertiary: rgba(222, 220, 209, 0.15);
        --color-ring-primary: rgba(250, 249, 245, 0.70);
        --color-user-bubble: #3D3D3A;
        --color-hover: rgba(250, 249, 245, 0.07);
        --shadow-composer: 0 4px 20px rgba(0, 0, 0, 0.15), 0 0 0 0.5px var(--color-border-tertiary);
        color-scheme: dark;
    }
}

:root[data-theme="dark"] {
    --color-background-primary: #30302E;
    --color-background-secondary: #262624;
    --color-background-tertiary: #141413;
    --color-background-inverse: #FAF9F5;
    --color-background-info: #253E5F;
    --color-background-danger: #4A2423;
    --color-background-warning: #483A1F;
    --color-text-primary: #FAF9F5;
    --color-text-secondary: #C2C0B6;
    --color-text-tertiary: #9C9A92;
    --color-text-inverse: #141413;
    --color-text-info: #80AADD;
    --color-text-danger: #EF8D89;
    --color-text-warning: #D5A34C;
    --color-border-primary: rgba(222, 220, 209, 0.40);
    --color-border-secondary: rgba(222, 220, 209, 0.30);
    --color-border-tertiary: rgba(222, 220, 209, 0.15);
    --color-ring-primary: rgba(250, 249, 245, 0.70);
    --color-user-bubble: #3D3D3A;
    --color-hover: rgba(250, 249, 245, 0.07);
    --shadow-composer: 0 4px 20px rgba(0, 0, 0, 0.15), 0 0 0 0.5px var(--color-border-tertiary);
    color-scheme: dark;
}

/* ==========================================================================
   Base
   ========================================================================== */
*, *::before, *::after { box-sizing: border-box; }
html, body { height: 100%; }
body {
    margin: 0;
    font-family: var(--font-sans);
    font-size: var(--font-text-md-size);
    line-height: var(--font-text-md-line-height);
    color: var(--color-text-primary);
    background: var(--color-background-tertiary);
    -webkit-font-smoothing: antialiased;
}
button, textarea, input { font: inherit; color: inherit; }
button { cursor: pointer; background: none; border: 0; padding: 0; }
a { color: inherit; text-decoration: none; }
svg { width: 18px; height: 18px; flex: none; }
[hidden] { display: none !important; }
:focus-visible { outline: 2px solid var(--color-ring-info); outline-offset: 2px; }

.only-dark { display: none; }
:root[data-theme="dark"] .only-dark { display: block; }
:root[data-theme="dark"] .only-light { display: none; }
@media (prefers-color-scheme: dark) {
    :root:not([data-theme="light"]) .only-dark { display: block; }
    :root:not([data-theme="light"]) .only-light { display: none; }
}

/* ==========================================================================
   Controls
   ========================================================================== */
.icon-btn {
    display: inline-grid; place-items: center;
    width: 32px; height: 32px;
    border-radius: var(--border-radius-md);
    color: var(--color-text-tertiary);
    transition: background .15s, color .15s;
}
.icon-btn:hover { background: var(--color-hover); color: var(--color-text-primary); }
.icon-btn.sm { width: 28px; height: 28px; }
.icon-btn.sm svg { width: 16px; height: 16px; }

.btn {
    display: inline-flex; align-items: center; gap: 6px;
    height: 32px; padding: 0 12px;
    border-radius: var(--border-radius-md);
    font-size: var(--font-text-sm-size);
    font-weight: var(--font-weight-medium);
    transition: background .15s;
}
.btn svg { width: 16px; height: 16px; }
.btn-outline {
    background: var(--color-background-primary);
    border: var(--border-width-regular) solid var(--color-border-primary);
}
.btn-outline:hover { background: var(--color-background-secondary); }
.btn-primary { background: var(--color-background-inverse); color: var(--color-text-inverse); }
.btn-danger { background: var(--color-text-danger); color: #fff; }

/* ==========================================================================
   Layout
   ========================================================================== */
.app { display: flex; height: 100dvh; overflow: hidden; }

.sidebar {
    width: var(--sidebar-width);
    flex: none;
    display: flex; flex-direction: column;
    background: var(--color-background-secondary);
    border-inline-end: var(--border-width-regular) solid var(--color-border-tertiary);
    transition: margin .25s ease;
}
.sidebar-closed .sidebar { margin-inline-start: calc(-1 * var(--sidebar-width)); }
.sidebar-open { display: none; }
.sidebar-closed .sidebar-open { display: inline-grid; }

.sidebar-head {
    display: flex; align-items: center; justify-content: space-between;
    padding: 12px 12px 8px 12px;
}
.brand {
    display: flex; align-items: center; gap: 8px;
    font-weight: var(--font-weight-semibold);
    font-size: var(--font-heading-sm-size);
    padding-inline-start: 6px;
}
.brand-spark { width: 20px; height: 20px; color: var(--color-accent); }

.nav-item {
    display: flex; align-items: center; gap: 10px;
    margin: 4px 8px;
    padding: 8px 10px;
    border-radius: var(--border-radius-md);
    font-size: var(--font-text-sm-size);
    font-weight: var(--font-weight-medium);
}
.nav-item:hover { background: var(--color-hover); }
.nav-new svg { color: var(--color-accent); }

.sidebar-label {
    padding: 16px 18px 6px;
    font-size: var(--font-text-xs-size);
    color: var(--color-text-tertiary);
    font-weight: var(--font-weight-medium);
}
.conv-list { flex: 1; overflow-y: auto; padding: 0 8px 8px; }
.conv-item {
    display: block;
    padding: 7px 10px;
    border-radius: var(--border-radius-md);
    font-size: var(--font-text-sm-size);
    line-height: var(--font-text-sm-line-height);
    color: var(--color-text-secondary);
}
.conv-item:hover { background: var(--color-hover); color: var(--color-text-primary); }
.conv-item.is-active { background: var(--color-background-primary); color: var(--color-text-primary); box-shadow: 0 0 0 var(--border-width-regular) var(--color-border-tertiary); }
.conv-title { display: block; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; text-align: start; }
.conv-empty { margin: 4px 10px; font-size: var(--font-text-sm-size); color: var(--color-text-tertiary); }

.sidebar-foot {
    display: flex; align-items: center; justify-content: space-between; gap: 8px;
    padding: 10px 12px;
    border-top: var(--border-width-regular) solid var(--color-border-tertiary);
}
.scrim { display: none; }

.main {
    flex: 1; min-width: 0;
    display: flex; flex-direction: column;
    background: var(--color-background-tertiary);
}

/* Chat titlebar */
.titlebar {
    display: flex; align-items: center; gap: 8px;
    height: 52px; padding: 0 12px;
    flex: none;
}
.title-menu { position: relative; min-width: 0; }
.title-btn {
    display: flex; align-items: center; gap: 4px;
    max-width: 100%;
    height: 32px; padding: 0 10px;
    border-radius: var(--border-radius-md);
    font-size: var(--font-text-sm-size);
    font-weight: var(--font-weight-medium);
}
.title-btn span { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.title-btn svg { width: 14px; height: 14px; color: var(--color-text-tertiary); }
.title-btn:hover { background: var(--color-hover); }
.titlebar-new { margin-inline-start: auto; }

.menu {
    position: absolute; top: 38px; inset-inline-start: 0; z-index: 20;
    min-width: 180px; padding: 4px;
    background: var(--color-background-primary);
    border: var(--border-width-regular) solid var(--color-border-tertiary);
    border-radius: var(--border-radius-lg);
    box-shadow: 0 8px 24px rgba(0, 0, 0, .08);
}
.menu button {
    display: flex; align-items: center; gap: 8px; width: 100%;
    padding: 7px 10px;
    border-radius: var(--border-radius-md);
    font-size: var(--font-text-sm-size);
    text-align: start;
}
.menu button svg { width: 16px; height: 16px; }
.menu button:hover { background: var(--color-hover); }
.menu .danger { color: var(--color-text-danger); }

/* ==========================================================================
   Thread
   ========================================================================== */
.thread { flex: 1; overflow-y: auto; scroll-behavior: smooth; }
.thread-inner {
    max-width: var(--thread-width);
    margin: 0 auto;
    padding: 24px 24px 40px;
    display: flex; flex-direction: column; gap: 24px;
}

.welcome {
    display: flex; flex-direction: column; align-items: center; text-align: center;
    margin-top: 18vh; gap: 16px;
}
.welcome-spark { width: 40px; height: 40px; color: var(--color-accent); }
.welcome h1 {
    margin: 0;
    font-size: var(--font-heading-xl-size);
    line-height: 1.3;
    font-weight: var(--font-weight-medium);
    color: var(--color-text-secondary);
}
.suggestions { display: flex; flex-wrap: wrap; justify-content: center; gap: 8px; margin-top: 8px; }
.chip {
    padding: 6px 14px;
    border-radius: var(--border-radius-full);
    border: var(--border-width-regular) solid var(--color-border-secondary);
    background: var(--color-background-primary);
    font-size: var(--font-text-sm-size);
    color: var(--color-text-secondary);
    transition: background .15s;
}
.chip:hover { background: var(--color-background-secondary); color: var(--color-text-primary); }

/* User message */
.msg-user { display: flex; flex-direction: column; align-items: flex-end; gap: 6px; }
.msg-user .bubble {
    max-width: min(85%, 600px);
    padding: 10px 16px;
    background: var(--color-user-bubble);
    border-radius: var(--border-radius-lg);
    font-size: var(--font-text-md-size);
    line-height: 26px;
    white-space: pre-wrap;
    overflow-wrap: anywhere;
}

/* Attachments (in messages and in the composer) */
.msg-files { display: flex; flex-wrap: wrap; align-items: center; justify-content: flex-end; gap: 8px; max-width: min(85%, 600px); }
.file-thumb {
    position: relative; display: block; flex: none;
    width: 120px; height: 120px;
    border-radius: var(--border-radius-lg);
    overflow: hidden;
    border: var(--border-width-regular) solid var(--color-border-tertiary);
    background: var(--color-background-secondary);
}
.file-thumb img { width: 100%; height: 100%; object-fit: cover; display: block; }
.file-card {
    position: relative;
    display: flex; align-items: center; gap: 10px;
    width: 220px; padding: 8px 10px;
    border-radius: var(--border-radius-lg);
    background: var(--color-background-primary);
    border: var(--border-width-regular) solid var(--color-border-secondary);
}
a.file-card:hover { background: var(--color-background-secondary); }
.file-icon {
    display: grid; place-items: center; flex: none;
    width: 36px; height: 36px;
    border-radius: var(--border-radius-md);
    background: var(--color-background-secondary);
    color: var(--color-text-tertiary);
}
.file-meta { display: flex; flex-direction: column; min-width: 0; }
.file-name {
    font-size: var(--font-text-sm-size); line-height: var(--font-text-sm-line-height);
    font-weight: var(--font-weight-medium);
    overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
    text-align: start;
}
.file-size { font-size: var(--font-text-xs-size); line-height: var(--font-text-xs-line-height); color: var(--color-text-tertiary); direction: ltr; text-align: end; }

.composer-files { display: flex; flex-wrap: wrap; align-items: center; gap: 8px; margin-bottom: 10px; }
.composer-files .file-thumb { width: 64px; height: 64px; }
.composer-files .file-card { width: 200px; }
.file-remove {
    position: absolute; top: -6px; inset-inline-start: -6px;
    display: grid; place-items: center;
    width: 20px; height: 20px;
    border-radius: var(--border-radius-full);
    background: var(--color-background-inverse); color: var(--color-text-inverse);
    box-shadow: 0 0 0 2px var(--color-background-primary);
    opacity: 0; transition: opacity .15s;
}
.file-remove svg { width: 12px; height: 12px; }
.composer-files > :hover .file-remove, .file-remove:focus-visible { opacity: 1; }
@media (hover: none) { .file-remove { opacity: 1; } }
.composer-files .file-thumb { overflow: visible; }
.composer-files .file-thumb img { border-radius: var(--border-radius-lg); }

.composer-tools { display: flex; align-items: center; flex-wrap: wrap; gap: 4px; min-width: 0; }

/* Image generation mode */
.mode-btn {
    display: inline-flex; align-items: center; gap: 6px;
    height: 32px; padding: 0 10px;
    border-radius: var(--border-radius-full);
    border: var(--border-width-regular) solid transparent;
    font-size: var(--font-text-sm-size);
    color: var(--color-text-tertiary);
    transition: background .15s, color .15s, border-color .15s;
}
.mode-btn svg { width: 17px; height: 17px; }
.mode-btn:hover { background: var(--color-hover); color: var(--color-text-primary); }
.mode-btn[aria-pressed="true"] {
    color: var(--color-accent);
    background: color-mix(in srgb, var(--color-accent) 10%, transparent);
    border-color: color-mix(in srgb, var(--color-accent) 35%, transparent);
}
.image-options { display: flex; gap: 4px; }
.select select {
    height: 30px; padding: 0 10px;
    border-radius: var(--border-radius-md);
    border: var(--border-width-regular) solid var(--color-border-secondary);
    background: var(--color-background-primary);
    color: var(--color-text-secondary);
    font: inherit; font-size: var(--font-text-xs-size);
    cursor: pointer;
}
.select select:hover { border-color: var(--color-border-primary); }
.is-image-mode .composer-hint { display: none; }
.sr-only { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }

.msg-tag {
    display: inline-flex; align-items: center; gap: 6px;
    font-size: var(--font-text-xs-size); line-height: var(--font-text-xs-line-height);
    color: var(--color-accent);
}
.msg-tag svg { width: 14px; height: 14px; }
.msg-tag-meta { color: var(--color-text-tertiary); font-family: var(--font-mono); direction: ltr; }

.gen-image {
    position: relative; display: block;
    width: fit-content; max-width: min(100%, 512px);
    border-radius: var(--border-radius-lg);
    overflow: hidden;
    border: var(--border-width-regular) solid var(--color-border-tertiary);
    background: var(--color-background-secondary);
}
.gen-image img { display: block; max-width: 100%; height: auto; max-height: 512px; }
.gen-skeleton {
    width: min(100%, 384px); aspect-ratio: 1;
    border-radius: var(--border-radius-lg);
    border: var(--border-width-regular) solid var(--color-border-tertiary);
    background: linear-gradient(100deg, var(--color-background-secondary) 30%, var(--color-background-primary) 50%, var(--color-background-secondary) 70%) 0 0 / 300% 100%;
    animation: shimmer 1.6s linear infinite;
}
.gen-skeleton[data-size="1536x1024"] { aspect-ratio: 3 / 2; }
.gen-skeleton[data-size="1024x1536"] { aspect-ratio: 2 / 3; width: min(100%, 300px); }
.gen-image.is-partial img { filter: blur(6px) saturate(.9); transform: scale(1.03); transition: filter .4s; }
.gen-image.is-partial::after {
    content: ""; position: absolute; inset: 0;
    background: linear-gradient(100deg, transparent 35%, rgba(255, 255, 255, .25) 50%, transparent 65%) 0 0 / 300% 100%;
    animation: shimmer 1.6s linear infinite;
}
@keyframes shimmer { from { background-position: 100% 0; } to { background-position: -200% 0; } }
@media (prefers-reduced-motion: reduce) {
    .gen-skeleton, .gen-image.is-partial::after, .thinking svg { animation: none; }
}

.drop-overlay {
    position: fixed; inset: 0; z-index: 40;
    display: grid; place-items: center;
    background: rgba(20, 20, 19, .25);
    backdrop-filter: blur(2px);
    pointer-events: none;
}
.drop-box {
    display: flex; flex-direction: column; align-items: center; gap: 6px;
    padding: 28px 36px; max-width: calc(100vw - 32px);
    border-radius: var(--border-radius-xl);
    border: 1.5px dashed var(--color-accent);
    background: var(--color-background-primary);
    text-align: center;
}
.drop-box svg { width: 28px; height: 28px; color: var(--color-accent); }
.drop-box span { font-size: var(--font-text-sm-size); color: var(--color-text-tertiary); }

.toast {
    position: fixed; bottom: 24px; left: 50%; transform: translateX(-50%); z-index: 50;
    max-width: calc(100vw - 32px);
    padding: 10px 16px;
    border-radius: var(--border-radius-lg);
    background: var(--color-background-inverse); color: var(--color-text-inverse);
    font-size: var(--font-text-sm-size);
    box-shadow: 0 8px 24px rgba(0, 0, 0, .15);
}

/* Assistant response */
.msg-assistant { display: flex; flex-direction: column; gap: 6px; }
.msg-actions { display: flex; align-items: center; gap: 2px; opacity: 0; transition: opacity .15s; }
.msg-assistant:hover .msg-actions,
.msg-assistant:last-child .msg-actions { opacity: 1; }
.msg-error {
    padding: 10px 14px;
    border-radius: var(--border-radius-lg);
    background: var(--color-background-danger);
    color: var(--color-text-danger);
    font-size: var(--font-text-sm-size);
}

.prose { font-size: var(--font-text-md-size); line-height: var(--font-text-md-line-height); overflow-wrap: anywhere; }
.prose > :first-child { margin-top: 0; }
.prose > :last-child { margin-bottom: 0; }
.prose p { margin: 0 0 12px; }
.prose h1, .prose h2, .prose h3, .prose h4 { line-height: 1.4; margin: 20px 0 8px; font-weight: var(--font-weight-semibold); }
.prose h1 { font-size: var(--font-heading-lg-size); }
.prose h2 { font-size: var(--font-heading-md-size); }
.prose h3, .prose h4 { font-size: var(--font-heading-sm-size); }
.prose ul, .prose ol { margin: 0 0 12px; padding-inline-start: 24px; }
.prose li { margin: 4px 0; }
.prose a { color: var(--color-text-info); text-decoration: underline; text-underline-offset: 2px; }
.prose blockquote { margin: 0 0 12px; padding-inline-start: 14px; border-inline-start: 3px solid var(--color-border-secondary); color: var(--color-text-secondary); }
.prose hr { border: 0; border-top: var(--border-width-regular) solid var(--color-border-secondary); margin: 20px 0; }
.prose code {
    font-family: var(--font-mono); font-size: .875em;
    font-variant-ligatures: none;
    background: var(--color-background-secondary);
    border: var(--border-width-regular) solid var(--color-border-tertiary);
    border-radius: var(--border-radius-xs);
    padding: 1px 5px;
    direction: ltr; unicode-bidi: isolate;
}
.prose pre {
    position: relative;
    margin: 0 0 12px;
    background: var(--color-background-secondary);
    border: var(--border-width-regular) solid var(--color-border-tertiary);
    border-radius: var(--border-radius-lg);
    padding: 14px 16px;
    overflow-x: auto;
    direction: ltr; text-align: left;
}
.prose pre code { background: none; border: 0; padding: 0; font-size: 13px; line-height: 21px; }
.prose table { border-collapse: collapse; margin: 0 0 12px; font-size: var(--font-text-sm-size); display: block; overflow-x: auto; }
.prose th, .prose td { border: var(--border-width-regular) solid var(--color-border-secondary); padding: 6px 10px; text-align: start; }
.prose th { background: var(--color-background-secondary); font-weight: var(--font-weight-semibold); }

.code-copy {
    position: absolute; top: 6px; right: 6px;
    font-family: var(--font-sans); font-size: var(--font-text-xs-size);
    padding: 2px 8px; border-radius: var(--border-radius-sm);
    background: var(--color-background-primary);
    border: var(--border-width-regular) solid var(--color-border-tertiary);
    color: var(--color-text-tertiary);
    opacity: 0; transition: opacity .15s;
}
.prose pre:hover .code-copy { opacity: 1; }

/* Streaming caret + thinking state (the "spark") */
.streaming .prose > :last-child::after {
    content: ""; display: inline-block;
    width: 8px; height: 8px; margin-inline-start: 4px;
    border-radius: 50%; background: var(--color-accent);
    vertical-align: middle;
    animation: pulse 1s ease-in-out infinite;
}
.thinking { display: flex; align-items: center; gap: 10px; color: var(--color-text-tertiary); font-size: var(--font-text-sm-size); font-style: italic; }
.thinking svg { width: 22px; height: 22px; color: var(--color-accent); animation: spin 2.4s linear infinite; }
@keyframes spin { to { transform: rotate(360deg); } }
@keyframes pulse { 50% { opacity: .3; } }

/* ==========================================================================
   Composer (Chat input)
   ========================================================================== */
.composer-wrap {
    flex: none;
    width: 100%; max-width: var(--thread-width);
    margin: 0 auto;
    padding: 0 24px 12px;
}
.composer {
    background: var(--color-background-primary);
    border: var(--border-width-regular) solid var(--color-border-secondary);
    border-radius: var(--border-radius-xl);
    box-shadow: var(--shadow-composer);
    padding: 14px 14px 10px 14px;
    transition: border-color .15s;
}
.composer:focus-within { border-color: var(--color-border-primary); }
.composer textarea {
    display: block; width: 100%;
    min-height: 28px; max-height: 240px;
    resize: none; border: 0; outline: 0; background: transparent;
    padding: 0 4px;
    font-size: var(--font-text-md-size);
    line-height: 26px;
}
.composer textarea::placeholder { color: var(--color-text-tertiary); }
.composer-row { display: flex; align-items: center; justify-content: space-between; margin-top: 8px; }
.composer-hint { font-size: var(--font-text-xs-size); color: var(--color-text-tertiary); padding-inline-start: 4px; }
.send-btn {
    display: grid; place-items: center;
    width: 34px; height: 34px;
    border-radius: var(--border-radius-md);
    background: var(--color-accent); color: #fff;
    transition: opacity .15s, background .15s;
}
.send-btn:disabled { opacity: .4; cursor: default; }
.send-btn .i-stop { display: none; }
.is-busy .send-btn { background: var(--color-background-inverse); color: var(--color-text-inverse); opacity: 1; cursor: pointer; }
.is-busy .send-btn .i-send { display: none; }
.is-busy .send-btn .i-stop { display: block; }

.disclaimer { margin: 8px 0 0; text-align: center; font-size: var(--font-text-xs-size); line-height: var(--font-text-xs-line-height); color: var(--color-text-tertiary); }
.notice {
    margin-bottom: 10px; padding: 10px 14px;
    border-radius: var(--border-radius-lg);
    background: var(--color-background-warning);
    color: var(--color-text-warning);
    font-size: var(--font-text-sm-size); line-height: var(--font-text-sm-line-height);
}
.notice code { font-family: var(--font-mono); font-size: 12px; }

/* ==========================================================================
   Dialog
   ========================================================================== */
dialog.modal {
    width: min(420px, calc(100vw - 32px));
    padding: 20px;
    border: var(--border-width-regular) solid var(--color-border-tertiary);
    border-radius: var(--border-radius-xl);
    background: var(--color-background-primary);
    color: var(--color-text-primary);
    box-shadow: 0 20px 50px rgba(0, 0, 0, .15);
}
dialog.modal::backdrop { background: rgba(20, 20, 19, .35); }
.modal h2 { margin: 0 0 8px; font-size: var(--font-heading-sm-size); font-weight: var(--font-weight-semibold); }
.modal p { margin: 0 0 16px; font-size: var(--font-text-sm-size); color: var(--color-text-secondary); }
.modal input {
    width: 100%; height: 38px; padding: 0 12px; margin-bottom: 16px;
    border-radius: var(--border-radius-md);
    border: var(--border-width-regular) solid var(--color-border-primary);
    background: var(--color-background-primary);
}
.modal input:focus { outline: 2px solid var(--color-ring-info); outline-offset: -1px; }
.modal-actions { display: flex; justify-content: flex-end; gap: 8px; }

/* ==========================================================================
   User section (sidebar footer)
   ========================================================================== */
.sidebar-foot form { display: contents; }
.user-chip { display: flex; align-items: center; gap: 10px; min-width: 0; flex: 1; }
.avatar {
    display: grid; place-items: center; flex: none;
    width: 32px; height: 32px;
    border-radius: var(--border-radius-full);
    background: var(--color-background-inverse); color: var(--color-text-inverse);
    font-size: var(--font-text-sm-size); font-weight: var(--font-weight-semibold);
}
.user-meta { display: flex; flex-direction: column; min-width: 0; }
.user-name, .user-email { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.user-name { font-size: var(--font-text-sm-size); line-height: var(--font-text-sm-line-height); font-weight: var(--font-weight-medium); text-align: start; }
.user-email { font-size: var(--font-text-xs-size); line-height: var(--font-text-xs-line-height); color: var(--color-text-tertiary); text-align: end; }

/* ==========================================================================
   Auth pages (login / register)
   ========================================================================== */
.auth-page {
    min-height: 100dvh;
    display: grid; place-items: center;
    padding: 32px 16px;
    background: var(--color-background-tertiary);
}
.auth-card {
    width: 100%; max-width: 400px;
    padding: 32px;
    background: var(--color-background-primary);
    border: var(--border-width-regular) solid var(--color-border-tertiary);
    border-radius: var(--border-radius-xl);
    box-shadow: var(--shadow-composer);
}
.auth-brand {
    display: inline-flex; align-items: center; gap: 8px;
    font-weight: var(--font-weight-semibold);
    margin-bottom: 24px;
}
.auth-brand svg { width: 24px; height: 24px; color: var(--color-accent); }
.auth-card h1 { margin: 0 0 4px; font-size: var(--font-heading-lg-size); line-height: 1.4; font-weight: var(--font-weight-semibold); }
.auth-sub { margin: 0 0 24px; font-size: var(--font-text-sm-size); line-height: var(--font-text-sm-line-height); color: var(--color-text-tertiary); }
.auth-form { display: flex; flex-direction: column; gap: 16px; }
.field { display: flex; flex-direction: column; gap: 6px; }
.field label { font-size: var(--font-text-sm-size); font-weight: var(--font-weight-medium); color: var(--color-text-secondary); }
.field input {
    height: 40px; padding: 0 12px;
    border-radius: var(--border-radius-md);
    border: var(--border-width-regular) solid var(--color-border-primary);
    background: var(--color-background-primary);
    color: var(--color-text-primary);
    font-size: var(--font-text-md-size);
}
.field input:focus { outline: 2px solid var(--color-ring-info); outline-offset: -1px; }
.field input[aria-invalid="true"] { border-color: var(--color-text-danger); }
.field input[dir="ltr"] { text-align: left; }
.field-hint, .field-error { margin: 0; font-size: var(--font-text-xs-size); line-height: var(--font-text-xs-line-height); }
.field-hint { color: var(--color-text-tertiary); }
.field-error { color: var(--color-text-danger); }
.check { display: flex; align-items: center; gap: 8px; font-size: var(--font-text-sm-size); color: var(--color-text-secondary); cursor: pointer; }
.check input { width: 16px; height: 16px; accent-color: var(--color-background-inverse); }
.btn-block { justify-content: center; height: 40px; font-size: var(--font-text-md-size); }
.btn-primary:hover { opacity: .9; }
.auth-switch { margin: 20px 0 0; text-align: center; font-size: var(--font-text-sm-size); color: var(--color-text-tertiary); }
.auth-switch a { color: var(--color-text-info); font-weight: var(--font-weight-medium); }
.auth-switch a:hover { text-decoration: underline; }

/* ==========================================================================
   Mobile
   ========================================================================== */
@media (max-width: 800px) {
    .sidebar { position: fixed; inset-block: 0; inset-inline-start: 0; z-index: 30; margin-inline-start: 0; box-shadow: 0 0 40px rgba(0, 0, 0, .15); }
    .sidebar-closed .sidebar, :root:not(.sidebar-open-mobile) .sidebar { margin-inline-start: calc(-1 * var(--sidebar-width)); box-shadow: none; }
    .sidebar-open { display: inline-grid; }
    .sidebar-open-mobile .scrim { display: block; position: fixed; inset: 0; z-index: 25; background: rgba(20, 20, 19, .3); }
    .thread-inner { padding: 16px 16px 32px; }
    .composer-wrap { padding: 0 12px 10px; }
    .composer-hint { display: none; }
    .welcome { margin-top: 10vh; }
    .welcome h1 { font-size: var(--font-heading-lg-size); }
    .titlebar-new span { display: none; }
}