/* ═══════════════════════════════════════════
   智答 — Premium Chat UI
   ═══════════════════════════════════════════ */

/* ── Reset ── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

/* ── Tokens ── */
:root {
    --c-primary: #2563eb;
    --c-primary-h: #1d4ed8;
    --c-primary-light: #3b82f6;
    --c-primary-bg: #eff6ff;
    --c-primary-glow: rgba(37,99,235,.12);

    --c-bg: #f8f9fb;
    --c-surface: #ffffff;
    --c-surface2: #f1f3f7;
    --c-border: #e2e5ea;
    --c-border-light: #eef0f4;
    --c-text: #0f172a;
    --c-text2: #475569;
    --c-text3: #94a3b8;

    --c-user-bg: linear-gradient(135deg, #2563eb, #3b82f6);
    --c-user-fg: #ffffff;
    --c-ai-bg: #ffffff;
    --c-ai-fg: #0f172a;

    --c-accent: #8b5cf6;
    --c-success: #10b981;

    --shadow-sm: 0 1px 2px rgba(0,0,0,.04);
    --shadow-md: 0 2px 8px rgba(0,0,0,.06);
    --shadow-lg: 0 4px 16px rgba(0,0,0,.08);
    --shadow-bubble: 0 1px 4px rgba(0,0,0,.05);

    --radius: 20px;
    --radius-sm: 14px;
    --radius-xs: 8px;

    --safe-t: env(safe-area-inset-top, 0px);
    --safe-b: env(safe-area-inset-bottom, 0px);

    --font: -apple-system, "SF Pro Display", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
    --transition: .2s cubic-bezier(.4,0,.2,1);
}

[data-theme="dark"] {
    --c-bg: #0c0f17;
    --c-surface: #141825;
    --c-surface2: #1c2030;
    --c-border: #252a3a;
    --c-border-light: #1e2235;
    --c-text: #e8ecf4;
    --c-text2: #8892a8;
    --c-text3: #4a5268;
    --c-primary-bg: rgba(37,99,235,.12);
    --c-user-bg: linear-gradient(135deg, #1d4ed8, #2563eb);
    --c-ai-bg: #141825;
    --c-ai-fg: #e8ecf4;
    --c-primary-h: #3b82f6;
    --c-primary-glow: rgba(59,130,246,.15);

    --shadow-sm: 0 1px 2px rgba(0,0,0,.2);
    --shadow-md: 0 2px 8px rgba(0,0,0,.25);
    --shadow-lg: 0 4px 16px rgba(0,0,0,.3);
    --shadow-bubble: 0 1px 4px rgba(0,0,0,.2);
}

/* ── Base ── */
html { height: 100%; -webkit-text-size-adjust: 100%; }
body {
    height: 100dvh;
    font-family: var(--font);
    background: var(--c-bg);
    color: var(--c-text);
    font-size: 16px;
    line-height: 1.5;
    overflow: hidden;
    -webkit-tap-highlight-color: transparent;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

.hidden { display: none !important; }

/* ── Header ── */
#header {
    position: fixed;
    top: 0; left: 0; right: 0;
    z-index: 100;
    padding-top: var(--safe-t);
    height: calc(58px + var(--safe-t));
    background: var(--c-surface);
    border-bottom: 1px solid var(--c-border-light);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding-left: 14px;
    padding-right: 10px;
    box-shadow: var(--shadow-sm);
}

.h-left { display: flex; align-items: center; gap: 12px; }

.h-logo {
    width: 36px; height: 36px;
    background: var(--c-user-bg);
    border-radius: 11px;
    display: grid; place-items: center;
    color: #fff; flex-shrink: 0;
    box-shadow: 0 2px 8px rgba(37,99,235,.25);
}
.h-logo svg { width: 18px; height: 18px; }

.h-name {
    display: block;
    font-size: 18px;
    font-weight: 700;
    line-height: 1.2;
    letter-spacing: .2px;
    color: var(--c-text);
}

.h-sub {
    display: block;
    font-size: 11px;
    color: var(--c-text3);
    margin-top: 1px;
    letter-spacing: .3px;
}

.h-right { display: flex; gap: 2px; }

.h-btn {
    width: 40px; height: 40px;
    border: none; background: none;
    color: var(--c-text2);
    border-radius: 12px;
    display: grid; place-items: center;
    cursor: pointer;
    transition: all var(--transition);
}
.h-btn:active { background: var(--c-surface2); color: var(--c-primary); }
.h-btn svg { width: 20px; height: 20px; }

[data-theme="light"] .ico-moon { display: none; }
[data-theme="dark"]  .ico-sun  { display: none; }

/* ── Chat Area ── */
#chat {
    position: fixed;
    top: calc(58px + var(--safe-t));
    left: 0; right: 0;
    bottom: 0;
    overflow-y: auto;
    -webkit-overflow-scrolling: touch;
    overscroll-behavior: contain;
}

#msgs {
    padding: 20px 16px 140px;
    max-width: 740px;
    margin: 0 auto;
}

/* ── Welcome ── */
.welcome {
    text-align: center;
    padding: 56px 24px 36px;
}

.w-icon {
    width: 72px; height: 72px;
    background: var(--c-primary-bg);
    border-radius: 24px;
    display: grid; place-items: center;
    margin: 0 auto 20px;
    color: var(--c-primary);
    box-shadow: 0 4px 20px var(--c-primary-glow);
}
.w-icon svg { width: 36px; height: 36px; }

.w-title {
    font-size: 28px;
    font-weight: 800;
    letter-spacing: 1px;
    margin-bottom: 10px;
    background: linear-gradient(135deg, var(--c-primary), var(--c-accent));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.w-desc {
    font-size: 14px;
    color: var(--c-text2);
    max-width: 340px;
    margin: 0 auto 32px;
    line-height: 1.65;
}

.w-chips {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    justify-content: center;
}

.chip {
    padding: 10px 18px;
    border: 1px solid var(--c-border);
    border-radius: 24px;
    background: var(--c-surface);
    color: var(--c-text);
    font-size: 14px;
    font-family: var(--font);
    cursor: pointer;
    transition: all var(--transition);
    -webkit-tap-highlight-color: transparent;
    box-shadow: var(--shadow-sm);
}
.chip:active {
    background: var(--c-primary-bg);
    border-color: var(--c-primary);
    color: var(--c-primary);
    transform: scale(.97);
    box-shadow: var(--shadow-md);
}

/* ── Messages ── */
.msg {
    display: flex;
    gap: 10px;
    margin-bottom: 18px;
    animation: msgIn .3s cubic-bezier(.4,0,.2,1);
}

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

.msg.user { flex-direction: row-reverse; }

.msg-avatar {
    width: 32px; height: 32px;
    border-radius: 50%;
    display: grid; place-items: center;
    font-size: 11px; font-weight: 700;
    flex-shrink: 0;
    margin-top: 2px;
}
.msg.user .msg-avatar {
    background: var(--c-user-bg);
    color: #fff;
    box-shadow: 0 2px 6px rgba(37,99,235,.2);
}
.msg.ai   .msg-avatar {
    background: var(--c-primary-bg);
    color: var(--c-primary);
}

.msg-body { max-width: min(82%, 520px); }

.msg-bubble {
    padding: 12px 16px;
    border-radius: var(--radius);
    font-size: 15px;
    line-height: 1.7;
    word-break: break-word;
    white-space: pre-wrap;
}

.msg.user .msg-bubble {
    background: var(--c-user-bg);
    color: var(--c-user-fg);
    border-bottom-right-radius: 6px;
    box-shadow: 0 2px 10px rgba(37,99,235,.18);
}

.msg.ai .msg-bubble {
    background: var(--c-ai-bg);
    color: var(--c-ai-fg);
    border: 1px solid var(--c-border);
    border-bottom-left-radius: 6px;
    box-shadow: var(--shadow-bubble);
}

/* ── Typing Dots ── */
.typing {
    display: flex; gap: 5px;
    padding: 4px 0;
}
.typing i {
    width: 7px; height: 7px;
    background: var(--c-text3);
    border-radius: 50%;
    animation: dot 1.2s infinite;
}
.typing i:nth-child(2) { animation-delay: .15s; }
.typing i:nth-child(3) { animation-delay: .3s; }

@keyframes dot {
    0%, 80%, 100% { opacity: .3; transform: scale(.8); }
    40% { opacity: 1; transform: scale(1); }
}

/* ── Sources ── */
.src-toggle {
    display: inline-flex;
    align-items: center;
    gap: 5px;
    margin-top: 10px;
    padding: 6px 12px;
    border: 1px solid var(--c-border);
    border-radius: var(--radius-xs);
    background: none;
    color: var(--c-text2);
    font-size: 12px;
    font-family: var(--font);
    cursor: pointer;
    -webkit-tap-highlight-color: transparent;
    transition: all var(--transition);
}
.src-toggle:active { background: var(--c-surface2); }
.src-toggle svg { width: 13px; height: 13px; transition: transform .25s; }
.src-toggle.open svg { transform: rotate(180deg); }

.src-list {
    max-height: 0;
    overflow: hidden;
    transition: max-height .35s cubic-bezier(.4,0,.2,1);
}
.src-list.open { max-height: 500px; }

.src-card {
    background: var(--c-surface2);
    border-radius: var(--radius-sm);
    padding: 12px 14px;
    margin-top: 8px;
    border-left: 3px solid var(--c-primary);
    transition: all var(--transition);
    cursor: pointer;
}
.src-card:active { transform: scale(.99); }
.src-card p { font-size: 13px; line-height: 1.55; }
.src-meta {
    display: flex;
    justify-content: space-between;
    margin-top: 6px;
    font-size: 11px;
    color: var(--c-text3);
}

/* ── Input Bar ── */
#bar {
    position: fixed;
    bottom: 0; left: 0; right: 0;
    z-index: 100;
    background: var(--c-surface);
    border-top: 1px solid var(--c-border-light);
    padding: 10px 12px calc(10px + var(--safe-b));
    box-shadow: 0 -2px 12px rgba(0,0,0,.04);
}

.bar-inner {
    max-width: 740px;
    margin: 0 auto;
    display: flex;
    align-items: flex-end;
    gap: 10px;
}

.bar-box {
    flex: 1;
    display: flex;
    align-items: flex-end;
    background: var(--c-surface2);
    border: 1.5px solid var(--c-border);
    border-radius: 24px;
    padding: 2px 4px 2px 16px;
    transition: all var(--transition);
}
.bar-box:focus-within {
    border-color: var(--c-primary);
    box-shadow: 0 0 0 3px var(--c-primary-glow);
}

#input {
    flex: 1;
    border: none;
    background: none;
    color: var(--c-text);
    font-size: 16px;
    font-family: var(--font);
    line-height: 1.45;
    padding: 9px 0;
    resize: none;
    max-height: 110px;
    outline: none;
}
#input::placeholder { color: var(--c-text3); }

.bar-icon {
    width: 36px; height: 36px;
    border: none; background: none;
    color: var(--c-text2);
    border-radius: 50%;
    display: grid; place-items: center;
    cursor: pointer;
    flex-shrink: 0;
    transition: all var(--transition);
}
.bar-icon:active { color: var(--c-primary); }
.bar-icon svg { width: 20px; height: 20px; }

.bar-icon.rec {
    background: #e53e3e;
    color: #fff;
    animation: pulse 1.4s infinite;
}
@keyframes pulse {
    0%,100% { opacity: 1; }
    50% { opacity: .45; }
}

.bar-send {
    width: 42px; height: 42px;
    border: none;
    border-radius: 50%;
    background: var(--c-user-bg);
    color: #fff;
    display: grid; place-items: center;
    cursor: pointer;
    flex-shrink: 0;
    transition: all var(--transition);
    box-shadow: 0 2px 8px rgba(37,99,235,.25);
}
.bar-send:disabled {
    background: var(--c-border);
    color: var(--c-text3);
    box-shadow: none;
    pointer-events: none;
}
.bar-send:not(:disabled):active {
    background: var(--c-primary-h);
    transform: scale(.95);
}
.bar-send svg { width: 18px; height: 18px; }

.bar-voice {
    display: none;
    align-items: center;
    gap: 6px;
    padding: 4px 0 0;
    font-size: 13px;
    color: #e53e3e;
}
.bar-voice.on { display: flex; }
.v-dot {
    width: 8px; height: 8px;
    background: #e53e3e;
    border-radius: 50%;
    animation: pulse 1.4s infinite;
}

/* ── Overlay ── */
.overlay {
    position: fixed; inset: 0;
    background: rgba(0,0,0,.3);
    z-index: 200;
    opacity: 0;
    pointer-events: none;
    transition: opacity .3s;
    backdrop-filter: blur(2px);
}
.overlay.on { opacity: 1; pointer-events: auto; }

/* ── Drawer ── */
.drawer {
    position: fixed;
    top: 0; right: 0; bottom: 0;
    width: min(380px, 88vw);
    background: var(--c-surface);
    z-index: 201;
    transform: translateX(100%);
    transition: transform .32s cubic-bezier(.4,0,.2,1);
    display: flex;
    flex-direction: column;
    box-shadow: -4px 0 24px rgba(0,0,0,.1);
    overflow: hidden;
}
.drawer.on { transform: translateX(0); }

.d-head {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 18px 16px;
    border-bottom: 1px solid var(--c-border-light);
    padding-top: calc(18px + var(--safe-t));
}
.d-head h2 { font-size: 18px; font-weight: 700; letter-spacing: .2px; }

/* Upload Zone */
.d-upload { padding: 16px; }

.uz {
    border: 2px dashed var(--c-border);
    border-radius: var(--radius-sm);
    padding: 22px 16px;
    text-align: center;
    color: var(--c-text2);
    cursor: pointer;
    transition: all var(--transition);
    -webkit-tap-highlight-color: transparent;
}
.uz:active, .uz.drag {
    border-color: var(--c-primary);
    background: var(--c-primary-bg);
    box-shadow: 0 0 0 3px var(--c-primary-glow);
}

.uz-text { display: block; font-size: 14px; margin-top: 8px; font-weight: 500; }
.uz-hint  { display: block; font-size: 12px; color: var(--c-text3); margin-top: 3px; }

/* Form */
.d-form { padding: 0 16px 16px; }
.d-input, .d-select {
    width: 100%;
    padding: 11px 14px;
    border: 1px solid var(--c-border);
    border-radius: 12px;
    font-size: 14px;
    font-family: var(--font);
    background: var(--c-surface);
    color: var(--c-text);
    margin-bottom: 8px;
    outline: none;
    transition: all var(--transition);
}
.d-input:focus, .d-select:focus {
    border-color: var(--c-primary);
    box-shadow: 0 0 0 3px var(--c-primary-glow);
}

.d-form-row { display: flex; gap: 8px; }
.d-form-row .d-input { flex: 1; }
.d-form-row .d-select { width: 130px; flex-shrink: 0; }

.d-submit {
    width: 100%;
    padding: 12px;
    border: none;
    border-radius: 12px;
    background: var(--c-user-bg);
    color: #fff;
    font-size: 15px;
    font-weight: 600;
    font-family: var(--font);
    cursor: pointer;
    margin-top: 6px;
    transition: all var(--transition);
    box-shadow: 0 2px 8px rgba(37,99,235,.2);
}
.d-submit:disabled { background: var(--c-border); color: var(--c-text3); box-shadow: none; pointer-events: none; }
.d-submit:not(:disabled):active { transform: scale(.98); }

/* History */
.d-history {
    flex: 1;
    overflow-y: auto;
    padding: 16px;
    border-top: 1px solid var(--c-border-light);
}

.dh-head {
    display: flex;
    justify-content: space-between;
    margin-bottom: 12px;
}
.dh-label { font-size: 13px; font-weight: 600; color: var(--c-text2); letter-spacing: .2px; }
.dh-count { font-size: 12px; color: var(--c-text3); }

.dh-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 10px 0;
    border-bottom: 1px solid var(--c-border-light);
    font-size: 13px;
    transition: background var(--transition);
}
.dh-item:last-child { border-bottom: none; }
.dh-title {
    flex: 1;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    font-weight: 500;
    margin-right: 8px;
}
.dh-chunks {
    color: var(--c-success);
    font-size: 11px;
    background: rgba(16,185,129,.08);
    padding: 3px 10px;
    border-radius: 6px;
    flex-shrink: 0;
    font-weight: 500;
}

.dh-empty {
    text-align: center;
    color: var(--c-text3);
    font-size: 13px;
    padding: 28px 0;
}

/* ── Version ── */
.h-name small { font-size: 11px; font-weight: 400; color: var(--c-text3); margin-left: 3px; }

/* ── Citation inline ── */
.cite {
    display: inline;
    color: var(--c-primary);
    cursor: pointer;
    font-size: 0.8em;
    vertical-align: super;
    line-height: 0;
    font-weight: 600;
    transition: all var(--transition);
}
.cite:hover { color: var(--c-primary-h); text-decoration: underline; }

/* ── Markdown in AI bubble ── */
.msg.ai .msg-bubble p { margin: 0.3em 0; }
.msg.ai .msg-bubble p:first-child { margin-top: 0; }
.msg.ai .msg-bubble p:last-child { margin-bottom: 0; }
.msg.ai .msg-bubble h1, .msg.ai .msg-bubble h2, .msg.ai .msg-bubble h3 {
    font-size: 1.05em; font-weight: 700; margin: 0.6em 0 0.3em;
}
.msg.ai .msg-bubble blockquote {
    border-left: 3px solid var(--c-primary);
    padding-left: 12px; margin: 0.5em 0;
    color: var(--c-text2);
}
.msg.ai .msg-bubble ul, .msg.ai .msg-bubble ol {
    padding-left: 1.5em; margin: 0.4em 0;
}
.msg.ai .msg-bubble li { margin: 0.15em 0; }
.msg.ai .msg-bubble strong { font-weight: 700; }
.msg.ai .msg-bubble em { font-style: italic; }
.msg.ai .msg-bubble code {
    background: var(--c-surface2); padding: 2px 6px; border-radius: 4px;
    font-size: 0.9em;
}

/* ── Settings drawer ── */
.settings-form { padding: 16px; }
.s-label {
    display: block; font-size: 13px; font-weight: 600;
    color: var(--c-text2); margin-bottom: 8px; letter-spacing: .2px;
}
.s-model-group {
    display: flex; flex-wrap: wrap; gap: 8px; margin-top: 6px;
}
.s-model-btn {
    padding: 9px 18px; border: 1.5px solid var(--c-border);
    border-radius: 12px; background: var(--c-surface);
    color: var(--c-text); font-size: 14px; font-family: var(--font);
    cursor: pointer; transition: all var(--transition);
}
.s-model-btn:hover { border-color: var(--c-primary); }
.s-model-btn.active {
    background: var(--c-primary-bg); border-color: var(--c-primary);
    color: var(--c-primary); font-weight: 600;
    box-shadow: 0 0 0 3px var(--c-primary-glow);
}
.s-model-btn:disabled { opacity: .4; cursor: not-allowed; }

/* ── Document selection list ── */
.dd-item {
    display: flex; align-items: center; gap: 10px;
    padding: 10px 0; border-bottom: 1px solid var(--c-border-light);
}
.dd-item:last-child { border-bottom: none; }
.dd-check {
    width: 18px; height: 18px; flex-shrink: 0; accent-color: var(--c-primary);
}
.dd-info { flex: 1; min-width: 0; display: flex; justify-content: space-between; align-items: center; }
.dd-info .dd-title {
    flex: 1; overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
    font-size: 13px; font-weight: 500;
}

/* ── Viewer ── */
.viewer-overlay {
    position: fixed; inset: 0;
    background: rgba(0,0,0,.25);
    z-index: 300;
    opacity: 0; pointer-events: none;
    transition: opacity .3s;
    backdrop-filter: blur(2px);
}
.viewer-overlay.on { opacity: 1; pointer-events: auto; }
.viewer {
    position: fixed;
    top: 0; right: 0; bottom: 0;
    width: min(500px, 92vw);
    background: var(--c-surface);
    z-index: 301;
    transform: translateX(100%);
    transition: transform .32s cubic-bezier(.4,0,.2,1);
    display: flex; flex-direction: column;
    box-shadow: -6px 0 24px rgba(0,0,0,.1);
    overflow: hidden;
}
.viewer.on { transform: translateX(0); }
.viewer-head {
    display: flex; align-items: center; justify-content: space-between;
    padding: 16px; border-bottom: 1px solid var(--c-border-light);
    padding-top: calc(16px + var(--safe-t));
}
.viewer-head h3 { font-size: 17px; font-weight: 700; }
.viewer-meta {
    padding: 12px 16px; font-size: 13px;
    color: var(--c-text2); border-bottom: 1px solid var(--c-border-light);
}
.viewer-body {
    flex: 1; overflow-y: auto; padding: 16px;
    font-size: 14px; line-height: 1.75;
    white-space: pre-wrap;
    -webkit-overflow-scrolling: touch;
}
.viewer-body mark {
    background: rgba(37,99,235,.15);
    color: inherit;
    padding: 2px 1px;
    border-radius: 3px;
    font-weight: 500;
}
.v-ell { color: var(--c-text2); margin: 0 2px; }
.dd-meta {
    display: block; font-size: 12px; color: var(--c-text2); margin-top: 2px;
}
.dd-url { color: var(--c-primary); text-decoration: none; }
.dd-url:hover { text-decoration: underline; }

/* ── Scrollbar (desktop) ── */
@media (pointer: fine) {
    #chat::-webkit-scrollbar, .d-history::-webkit-scrollbar { width: 5px; }
    #chat::-webkit-scrollbar-thumb, .d-history::-webkit-scrollbar-thumb {
        background: var(--c-border); border-radius: 3px;
    }
    #chat::-webkit-scrollbar-track, .d-history::-webkit-scrollbar-track {
        background: transparent;
    }
}

/* ── Desktop Enhancements ── */
@media (min-width: 768px) {
    #msgs { padding: 28px 28px 140px; }
    .h-right { gap: 4px; }
    .h-btn { width: 38px; height: 38px; }
    .h-btn:hover { background: var(--c-surface2); color: var(--c-primary); }
    .chip:hover {
        background: var(--c-primary-bg);
        border-color: var(--c-primary);
        color: var(--c-primary);
        box-shadow: var(--shadow-md);
    }
    .src-toggle:hover { background: var(--c-surface2); }
    .bar-send:not(:disabled):hover {
        box-shadow: 0 4px 12px rgba(37,99,235,.3);
    }
    .d-submit:not(:disabled):hover {
        box-shadow: 0 4px 12px rgba(37,99,235,.3);
    }
    .uz:hover {
        border-color: var(--c-primary);
        background: var(--c-primary-bg);
        box-shadow: 0 0 0 3px var(--c-primary-glow);
    }
    .bar-icon:hover { color: var(--c-primary); }
    .src-card:hover { background: var(--c-primary-bg); transform: translateX(2px); }
    .msg.user .msg-bubble { box-shadow: 0 3px 12px rgba(37,99,235,.22); }
}