/* ============================================
   数道 · 万象 — 交互式数学可视化
   全局样式
   ============================================ */

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

:root {
    /* 配色 */
    --ink-black: #0a0a0f;
    --ink-deep: #0d1117;
    --ink-mid: #161b22;
    --ink-light: #1c2333;
    --paper: #f4f1ea;
    --paper-warm: #ebe5d6;
    --gold: #d4a574;
    --gold-bright: #e8c499;
    --gold-dim: #8a7355;
    --vermilion: #c0392b;
    --vermilion-light: #e74c3c;
    --jade: #5c8a8a;
    --white: #ffffff;
    --text-dark: #1a1a2e;
    --text-light: #c9d1d9;
    --text-dim: #6e7681;
    --text-muted: #484f58;

    /* 字体 */
    --font-serif: 'Noto Serif SC', 'Cormorant Garamond', serif;
    --font-sans: 'Noto Sans SC', -apple-system, sans-serif;
    --font-mono: 'Courier New', monospace;

    /* 尺寸 */
    --nav-h: 64px;
    --max-w: 1400px;
    --radius: 12px;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: var(--font-sans);
    background: var(--ink-black);
    color: var(--text-light);
    overflow-x: hidden;
    line-height: 1.7;
    cursor: none;
}

/* ---- 自定义光标 ---- */
.cursor-dot {
    position: fixed;
    width: 6px;
    height: 6px;
    background: var(--gold);
    border-radius: 50%;
    pointer-events: none;
    z-index: 10002;
    transform: translate(-50%, -50%);
    transition: width 0.2s, height 0.2s;
}

.cursor-ring {
    position: fixed;
    width: 32px;
    height: 32px;
    border: 1px solid rgba(212, 165, 116, 0.4);
    border-radius: 50%;
    pointer-events: none;
    z-index: 10001;
    transform: translate(-50%, -50%);
    transition: width 0.3s, height 0.3s, border-color 0.3s;
}

.cursor-ring.expanded {
    width: 48px;
    height: 48px;
    border-color: var(--gold-bright);
}

/* ---- 加载动画 ---- */
.loader {
    position: fixed;
    inset: 0;
    background: var(--ink-black);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    z-index: 10000;
    transition: opacity 0.8s, visibility 0.8s;
}

.loader.hidden {
    opacity: 0;
    visibility: hidden;
}

.loader-taiji {
    width: 56px;
    height: 56px;
    border: 3px solid rgba(212, 165, 116, 0.12);
    border-top-color: var(--gold);
    border-right-color: var(--vermilion);
    border-radius: 50%;
    animation: taiji-spin 1s linear infinite;
    position: relative;
    margin-bottom: 24px;
}

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

/* 旋转太极图标：替换全站 AI 机器人图标 */
.taiji-icon {
    display: inline-block;
    width: 1em;
    height: 1em;
    border-radius: 50%;
    vertical-align: middle;
    margin-right: 0.15em;
    background:
        radial-gradient(circle at 50% 25%, #fff 12%, transparent 13%),
        radial-gradient(circle at 50% 75%, #000 12%, transparent 13%),
        radial-gradient(circle at 50% 25%, #000 25%, transparent 26%),
        radial-gradient(circle at 50% 75%, #fff 25%, transparent 26%),
        linear-gradient(to right, #000 50%, #fff 50%);
    box-shadow: 0 0 0 1px rgba(0,0,0,0.08);
    animation: taiji-spin 3s linear infinite;
}

.loader-text {
    font-family: var(--font-serif);
    color: var(--gold-dim);
    letter-spacing: 0.5em;
    font-size: 0.85rem;
    animation: text-fade 2s ease-in-out infinite;
}

@keyframes text-fade {
    0%, 100% { opacity: 0.4; }
    50% { opacity: 1; }
}

/* ---- 滚动进度条 ---- */
.scroll-progress {
    position: fixed;
    top: 0;
    left: 0;
    height: 2px;
    background: linear-gradient(90deg, var(--gold), var(--vermilion));
    z-index: 9999;
    width: 0%;
    transition: width 0.1s;
}

/* ---- 导航 ---- */
.nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--nav-h);
    z-index: 1000;
    transition: background 0.4s, backdrop-filter 0.4s, box-shadow 0.4s;
}

.nav.scrolled {
    background: rgba(10, 10, 15, 0.85);
    backdrop-filter: blur(20px);
    box-shadow: 0 1px 0 rgba(212, 165, 116, 0.1);
}

.nav-inner {
    max-width: var(--max-w);
    height: 100%;
    margin: 0 auto;
    padding: 0 32px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    text-decoration: none;
    color: var(--gold);
    font-family: var(--font-serif);
    font-weight: 600;
    font-size: 1.15rem;
    letter-spacing: 0.1em;
}

.logo-mark {
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--gold), var(--vermilion));
    color: var(--ink-black);
    border-radius: 6px;
    font-size: 1.1rem;
    font-weight: 900;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 36px;
}

.nav-links a {
    color: var(--text-dim);
    text-decoration: none;
    font-size: 0.9rem;
    font-family: var(--font-serif);
    letter-spacing: 0.15em;
    transition: color 0.3s;
    position: relative;
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -6px;
    left: 0;
    width: 0;
    height: 1px;
    background: var(--gold);
    transition: width 0.3s;
}

.nav-links a:hover,
.nav-links a.active {
    color: var(--gold);
}

.nav-links a:hover::after,
.nav-links a.active::after {
    width: 100%;
}

.nav-menu-btn {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: none;
    padding: 8px;
}

.nav-menu-btn span {
    width: 22px;
    height: 2px;
    background: var(--gold);
    transition: 0.3s;
}

/* ---- 首屏 ---- */
.hero {
    position: relative;
    height: 100vh;
    min-height: 600px;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
    background: radial-gradient(ellipse at center, var(--ink-deep) 0%, var(--ink-black) 70%);
}

.taiji-canvas {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 1;
}

.hero-content {
    position: relative;
    z-index: 2;
    text-align: center;
    padding: 0 24px;
}

.hero-vertical {
    position: absolute;
    top: 50%;
    left: 5%;
    transform: translateY(-50%);
    display: flex;
    flex-direction: column;
    gap: 12px;
    font-family: var(--font-serif);
    font-size: 1.5rem;
    color: rgba(212, 165, 116, 0.15);
    letter-spacing: 0.3em;
    writing-mode: vertical-rl;
}

.hero-title {
    font-family: var(--font-serif);
    font-size: clamp(3rem, 9vw, 7rem);
    font-weight: 900;
    letter-spacing: 0.15em;
    margin-bottom: 1.5rem;
    line-height: 1;
}

.title-char {
    display: inline-block;
    opacity: 0;
    transform: translateY(40px);
    animation: char-rise 1s forwards;
    background: linear-gradient(180deg, var(--gold-bright) 0%, var(--gold) 50%, var(--gold-dim) 100%);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

.title-sep {
    display: inline-block;
    opacity: 0;
    color: var(--vermilion);
    animation: char-rise 1s 0.4s forwards;
    margin: 0 0.1em;
}

@keyframes char-rise {
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.hero-subtitle {
    font-family: var(--font-serif);
    font-size: clamp(1rem, 2vw, 1.4rem);
    color: var(--text-light);
    letter-spacing: 0.3em;
    margin-bottom: 2rem;
    opacity: 0;
    animation: fade-up 1s 1s forwards;
}

.hero-quote {
    font-family: var(--font-serif);
    font-style: italic;
    font-size: clamp(0.85rem, 1.5vw, 1.1rem);
    color: var(--gold-dim);
    letter-spacing: 0.2em;
    margin-bottom: 3rem;
    opacity: 0;
    animation: fade-up 1s 1.3s forwards;
}

@keyframes fade-up {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.hero-scroll {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 12px;
    opacity: 0;
    animation: fade-up 1s 1.6s forwards;
}

.hero-scroll span {
    font-size: 0.75rem;
    color: var(--text-muted);
    letter-spacing: 0.5em;
}

.scroll-line {
    width: 1px;
    height: 50px;
    background: linear-gradient(to bottom, var(--gold), transparent);
    position: relative;
    overflow: hidden;
}

.scroll-line::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 50%;
    background: var(--gold-bright);
    animation: scroll-down 2s ease-in-out infinite;
}

@keyframes scroll-down {
    0% { top: -50%; }
    100% { top: 100%; }
}

.hero-meta {
    position: absolute;
    bottom: 40px;
    left: 50%;
    transform: translateX(-50%);
    z-index: 2;
    display: flex;
    align-items: center;
    gap: 14px;
    font-size: 0.75rem;
    color: var(--text-muted);
    letter-spacing: 0.15em;
    white-space: nowrap;
}

.meta-dot {
    width: 4px;
    height: 4px;
    border-radius: 50%;
    background: var(--gold-dim);
}

/* ---- Section 通用 ---- */
.section {
    min-height: 100vh;
    padding: 120px 32px 80px;
    display: flex;
    flex-direction: column;
    align-items: center;
    position: relative;
}

.section-dark {
    background: linear-gradient(180deg, var(--ink-black) 0%, var(--ink-deep) 50%, var(--ink-black) 100%);
}

.section-light {
    background: linear-gradient(180deg, var(--paper) 0%, var(--paper-warm) 100%);
    color: var(--text-dark);
}

.section-header {
    max-width: 700px;
    text-align: center;
    margin-bottom: 60px;
}

.section-num {
    display: inline-block;
    font-family: var(--font-serif);
    font-size: 1.8rem;
    color: var(--vermilion);
    margin-bottom: 16px;
    letter-spacing: 0.1em;
    position: relative;
}

.section-light .section-num {
    color: var(--vermilion);
}

.section-dark .section-num {
    color: var(--gold);
}

.section-num::before,
.section-num::after {
    content: '';
    position: absolute;
    top: 50%;
    width: 30px;
    height: 1px;
    background: currentColor;
    opacity: 0.3;
}

.section-num::before { right: 100%; margin-right: 12px; }
.section-num::after { left: 100%; margin-left: 12px; }

.section-title {
    font-family: var(--font-serif);
    font-size: clamp(2rem, 5vw, 3.5rem);
    font-weight: 600;
    letter-spacing: 0.25em;
    margin-bottom: 20px;
}

.section-dark .section-title {
    background: linear-gradient(180deg, var(--white), var(--gold));
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

.section-light .section-title {
    color: var(--text-dark);
}

.section-desc {
    font-size: 0.95rem;
    line-height: 2;
    letter-spacing: 0.05em;
    max-width: 600px;
    margin: 0 auto;
}

.section-dark .section-desc {
    color: var(--text-dim);
}

.section-light .section-desc {
    color: #555;
}

/* ---- 模块容器 ---- */
.module-container {
    max-width: var(--max-w);
    width: 100%;
    display: flex;
    gap: 40px;
    align-items: stretch;
}

.canvas-wrapper {
    flex: 1;
    position: relative;
    border-radius: var(--radius);
    overflow: hidden;
    min-height: 500px;
    background: var(--ink-mid);
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.4);
}

.section-light .canvas-wrapper {
    background: #fff;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.12);
    border: 1px solid rgba(0, 0, 0, 0.05);
}

.canvas-wrapper canvas {
    display: block;
    width: 100%;
    height: 100%;
}

/* ---- 控制面板 ---- */
.control-panel {
    width: 300px;
    flex-shrink: 0;
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.control-group {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.control-group label {
    font-size: 0.8rem;
    letter-spacing: 0.1em;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.section-dark .control-group label {
    color: var(--text-dim);
}

.section-light .control-group label {
    color: #666;
}

.control-group label span {
    font-family: var(--font-mono);
    color: var(--gold);
    font-weight: 600;
}

.section-light .control-group label span {
    color: var(--vermilion);
}

/* 滑块 */
input[type="range"] {
    -webkit-appearance: none;
    appearance: none;
    width: 100%;
    height: 4px;
    border-radius: 2px;
    background: var(--ink-light);
    outline: none;
    cursor: none;
}

.section-light input[type="range"] {
    background: #ddd;
}

input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 16px;
    height: 16px;
    border-radius: 50%;
    background: var(--gold);
    cursor: none;
    border: 2px solid var(--ink-black);
    transition: transform 0.2s;
}

input[type="range"]::-webkit-slider-thumb:hover {
    transform: scale(1.2);
}

.section-light input[type="range"]::-webkit-slider-thumb {
    background: var(--vermilion);
    border-color: var(--paper);
}

input[type="range"]::-moz-range-thumb {
    width: 16px;
    height: 16px;
    border-radius: 50%;
    background: var(--gold);
    cursor: none;
    border: 2px solid var(--ink-black);
}

/* 按钮 */
.action-btn {
    padding: 14px 24px;
    border: 1px solid var(--gold);
    background: transparent;
    color: var(--gold);
    font-family: var(--font-serif);
    font-size: 0.95rem;
    letter-spacing: 0.3em;
    cursor: none;
    border-radius: var(--radius);
    transition: all 0.3s;
    position: relative;
    overflow: hidden;
}

.action-btn::before {
    content: '';
    position: absolute;
    inset: 0;
    background: var(--gold);
    transform: scaleX(0);
    transform-origin: left;
    transition: transform 0.3s;
    z-index: -1;
}

.action-btn:hover {
    color: var(--ink-black);
}

.action-btn:hover::before {
    transform: scaleX(1);
}

.action-btn.secondary {
    border-color: var(--text-muted);
    color: var(--text-dim);
}

.action-btn.secondary::before {
    background: var(--text-muted);
}

.action-btn.secondary:hover {
    color: var(--white);
}

.section-light .action-btn {
    border-color: var(--vermilion);
    color: var(--vermilion);
}

.section-light .action-btn::before {
    background: var(--vermilion);
}

.section-light .action-btn:hover {
    color: var(--paper);
}

/* 切换按钮 */
.toggle-btn {
    padding: 8px 16px;
    border: 1px solid var(--ink-light);
    background: transparent;
    color: var(--text-dim);
    border-radius: var(--radius);
    cursor: none;
    font-size: 0.85rem;
    transition: all 0.3s;
}

.toggle-btn.active {
    border-color: var(--gold);
    color: var(--gold);
    background: rgba(212, 165, 116, 0.1);
}

/* 证明/算法选择器 */
.proof-selector {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.proof-btn {
    padding: 8px 14px;
    border: 1px solid var(--ink-light);
    background: transparent;
    color: var(--text-dim);
    border-radius: var(--radius);
    cursor: none;
    font-size: 0.8rem;
    transition: all 0.3s;
    font-family: var(--font-serif);
}

.proof-btn.active {
    border-color: var(--gold);
    color: var(--gold);
    background: rgba(212, 165, 116, 0.1);
}

.section-light .proof-btn {
    border-color: #ccc;
    color: #666;
}

.section-light .proof-btn.active {
    border-color: var(--vermilion);
    color: var(--vermilion);
    background: rgba(192, 57, 43, 0.08);
}

/* 信息盒 */
.info-box {
    padding: 14px 16px;
    border-radius: var(--radius);
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid rgba(255, 255, 255, 0.06);
}

.section-light .info-box {
    background: rgba(0, 0, 0, 0.03);
    border-color: rgba(0, 0, 0, 0.06);
}

.info-box.highlight {
    background: linear-gradient(135deg, rgba(212, 165, 116, 0.1), rgba(192, 57, 43, 0.08));
    border-color: rgba(212, 165, 116, 0.3);
}

.section-light .info-box.highlight {
    background: linear-gradient(135deg, rgba(212, 165, 116, 0.15), rgba(192, 57, 43, 0.1));
}

.info-label {
    font-size: 0.7rem;
    letter-spacing: 0.1em;
    color: var(--text-muted);
    margin-bottom: 4px;
}

.section-light .info-label {
    color: #888;
}

.info-value {
    font-family: var(--font-serif);
    font-size: 1.3rem;
    font-weight: 600;
    color: var(--gold);
}

.section-light .info-value {
    color: var(--vermilion);
}

.info-value.mono {
    font-family: var(--font-mono);
    font-size: 1.1rem;
}

.info-value.small-text {
    font-size: 0.95rem;
}

/* 引用盒 */
.quote-box {
    padding: 16px;
    border-left: 2px solid var(--gold);
    background: rgba(212, 165, 116, 0.05);
}

.quote-box p {
    font-family: var(--font-serif);
    font-style: italic;
    font-size: 0.9rem;
    color: var(--gold-dim);
    letter-spacing: 0.1em;
}

/* ---- 曼德博集合特殊样式 ---- */
.mandelbrot-wrapper {
    cursor: none;
}

.mandelbrot-info {
    position: absolute;
    top: 16px;
    left: 16px;
    display: flex;
    flex-direction: column;
    gap: 4px;
    font-family: var(--font-mono);
    font-size: 0.75rem;
    color: var(--gold);
    background: rgba(10, 10, 15, 0.7);
    padding: 8px 12px;
    border-radius: 8px;
    backdrop-filter: blur(10px);
}

.mandelbrot-hint {
    position: absolute;
    bottom: 16px;
    left: 50%;
    transform: translateX(-50%);
    font-size: 0.75rem;
    color: rgba(255, 255, 255, 0.4);
    letter-spacing: 0.1em;
    white-space: nowrap;
}

.color-schemes {
    display: flex;
    gap: 8px;
}

.color-scheme {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    border: 2px solid transparent;
    cursor: none;
    background: linear-gradient(135deg, var(--sc), var(--sc2));
    transition: border-color 0.3s, transform 0.2s;
}

.color-scheme.active {
    border-color: var(--gold);
    transform: scale(1.1);
}

.section-light .color-scheme.active {
    border-color: var(--vermilion);
}

/* ---- 斐波那契特殊样式 ---- */
.fibonacci-container {
    align-items: stretch;
}

.fibonacci-panel {
    gap: 16px;
}

.fib-sequence {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    padding: 12px;
    border-radius: var(--radius);
    background: rgba(255, 255, 255, 0.03);
    min-height: 60px;
}

.fib-sequence span {
    font-family: var(--font-mono);
    font-size: 0.8rem;
    color: var(--gold);
    padding: 2px 8px;
    background: rgba(212, 165, 116, 0.1);
    border-radius: 4px;
    animation: fib-appear 0.5s;
}

@keyframes fib-appear {
    from {
        opacity: 0;
        transform: scale(0);
    }
    to {
        opacity: 1;
        transform: scale(1);
    }
}

/* ---- Footer ---- */
.footer {
    background: var(--ink-black);
    padding: 100px 32px 60px;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.footer-content {
    max-width: 700px;
    margin: 0 auto;
    position: relative;
    z-index: 2;
}

.footer-taiji {
    width: 40px;
    height: 40px;
    margin: 0 auto 32px;
    border: 2px solid rgba(212, 165, 116, 0.12);
    border-top-color: var(--gold);
    border-right-color: var(--vermilion);
    border-radius: 50%;
    animation: taiji-spin 6s linear infinite;
}

.footer-title {
    font-family: var(--font-serif);
    font-size: clamp(1.5rem, 3vw, 2.2rem);
    font-weight: 600;
    letter-spacing: 0.25em;
    color: var(--gold);
    margin-bottom: 28px;
}

.footer-text {
    font-family: var(--font-serif);
    font-size: 0.95rem;
    line-height: 2.2;
    color: var(--text-dim);
    letter-spacing: 0.08em;
    margin-bottom: 24px;
}

.footer-quote {
    font-family: var(--font-serif);
    font-style: italic;
    font-size: 1.05rem;
    color: var(--gold-dim);
    letter-spacing: 0.15em;
    margin-bottom: 40px;
}

.footer-divider {
    width: 60px;
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--gold-dim), transparent);
    margin: 0 auto 32px;
}

.footer-meta {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 14px;
    font-size: 0.75rem;
    color: var(--text-muted);
    letter-spacing: 0.1em;
    flex-wrap: wrap;
}

/* ---- 滚动揭示动画 ---- */
.reveal {
    opacity: 0;
    transform: translateY(60px);
    transition: opacity 1s cubic-bezier(0.16, 1, 0.3, 1), transform 1s cubic-bezier(0.16, 1, 0.3, 1);
}

.reveal.visible {
    opacity: 1;
    transform: translateY(0);
}

/* ---- 响应式 ---- */
@media (max-width: 1024px) {
    .module-container {
        flex-direction: column;
    }

    .control-panel {
        width: 100%;
        flex-direction: row;
        flex-wrap: wrap;
        gap: 16px;
    }

    .control-group,
    .info-box,
    .proof-selector,
    .toggle-btn,
    .action-btn,
    .quote-box,
    .color-schemes {
        flex: 1;
        min-width: 140px;
    }

    .canvas-wrapper {
        min-height: 400px;
    }

    .hero-vertical {
        display: none;
    }
}

@media (max-width: 768px) {
    .nav-links {
        display: none;
    }

    .nav-links.mobile-open {
        display: flex;
        flex-direction: column;
        position: absolute;
        top: var(--nav-h);
        left: 0;
        right: 0;
        background: rgba(10, 10, 15, 0.95);
        backdrop-filter: blur(20px);
        padding: 24px;
        gap: 20px;
    }

    .nav-menu-btn {
        display: flex;
    }

    .section {
        padding: 100px 20px 60px;
    }

    .hero-meta {
        font-size: 0.65rem;
    }

    .control-panel {
        flex-direction: column;
    }

    .control-group,
    .info-box,
    .proof-selector,
    .action-btn,
    .quote-box,
    .color-schemes {
        min-width: 100%;
    }

    body {
        cursor: auto;
    }

    .cursor-dot,
    .cursor-ring {
        display: none;
    }
}

/* ---- 选中文本 ---- */
::selection {
    background: var(--gold);
    color: var(--ink-black);
}

.section-light ::selection {
    background: var(--vermilion);
    color: var(--paper);
}

/* ---- 滚动条 ---- */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: var(--ink-black);
}

::-webkit-scrollbar-thumb {
    background: var(--ink-light);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--gold-dim);
}

/* ---- 伪代码区 ---- */
.pseudocode-box {
    padding: 14px 16px;
    border-radius: var(--radius);
    background: rgba(0, 0, 0, 0.06);
    border: 1px solid rgba(0, 0, 0, 0.08);
}

.pseudocode {
    font-family: var(--font-mono);
    font-size: 0.72rem;
    line-height: 1.6;
    color: #555;
    white-space: pre-wrap;
    margin-top: 6px;
}

.section-dark .pseudocode-box {
    background: rgba(255, 255, 255, 0.03);
    border-color: rgba(255, 255, 255, 0.06);
}

.section-dark .pseudocode {
    color: var(--text-dim);
}

/* ---- 技术说明区 ---- */
.tech-section {
    padding-bottom: 100px;
}

.tech-grid {
    max-width: var(--max-w);
    width: 100%;
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 24px;
    margin-bottom: 48px;
}

.tech-card {
    padding: 32px 28px;
    border-radius: var(--radius);
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid rgba(255, 255, 255, 0.06);
    transition: all 0.4s cubic-bezier(0.16, 1, 0.3, 1);
    position: relative;
    overflow: hidden;
}

.tech-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--gold), transparent);
    transform: scaleX(0);
    transition: transform 0.4s;
}

.tech-card:hover {
    background: rgba(212, 165, 116, 0.05);
    border-color: rgba(212, 165, 116, 0.2);
    transform: translateY(-4px);
}

.tech-card:hover::before {
    transform: scaleX(1);
}

.tech-icon {
    font-family: var(--font-serif);
    font-size: 1.6rem;
    color: var(--gold);
    margin-bottom: 16px;
    font-weight: 600;
}

.tech-card h3 {
    font-family: var(--font-serif);
    font-size: 1.05rem;
    font-weight: 600;
    color: var(--text-light);
    margin-bottom: 12px;
    letter-spacing: 0.05em;
}

.tech-card p {
    font-size: 0.82rem;
    line-height: 1.8;
    color: var(--text-dim);
    letter-spacing: 0.02em;
}

/* 技术标签 */
.tech-stack {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 12px;
}

.tech-tag {
    padding: 8px 20px;
    border-radius: 100px;
    border: 1px solid rgba(212, 165, 116, 0.3);
    color: var(--gold-dim);
    font-size: 0.8rem;
    font-family: var(--font-mono);
    letter-spacing: 0.05em;
    transition: all 0.3s;
}

.tech-tag:hover {
    border-color: var(--gold);
    color: var(--gold);
    background: rgba(212, 165, 116, 0.08);
}

/* ---- 回到顶部 ---- */
.back-to-top {
    position: fixed;
    bottom: 32px;
    right: 32px;
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background: rgba(10, 10, 15, 0.85);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(212, 165, 116, 0.3);
    color: var(--gold);
    font-family: var(--font-serif);
    font-size: 1.1rem;
    cursor: none;
    z-index: 999;
    opacity: 0;
    visibility: hidden;
    transform: translateY(20px);
    transition: all 0.4s;
    display: flex;
    align-items: center;
    justify-content: center;
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.back-to-top:hover {
    background: var(--gold);
    color: var(--ink-black);
    border-color: var(--gold);
}

/* ---- 键盘提示 ---- */
.kbd-hint {
    position: fixed;
    bottom: 32px;
    left: 32px;
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 0.7rem;
    color: var(--text-muted);
    letter-spacing: 0.1em;
    z-index: 999;
    opacity: 0;
    transition: opacity 0.6s;
}

.kbd-hint.visible {
    opacity: 0.6;
}

.kbd-hint kbd {
    display: inline-block;
    padding: 2px 8px;
    border-radius: 4px;
    border: 1px solid var(--ink-light);
    background: var(--ink-mid);
    font-family: var(--font-mono);
    font-size: 0.7rem;
    color: var(--gold-dim);
}

@media (max-width: 768px) {
    .back-to-top {
        bottom: 16px;
        right: 16px;
        width: 40px;
        height: 40px;
    }

    .kbd-hint {
        display: none;
    }

    .tech-grid {
        grid-template-columns: 1fr;
    }
}

/* ============================================
   使用指南页
   ============================================ */
.guide-section {
    padding-top: 100px;
}

.guide-intro {
    max-width: var(--max-w);
    width: 100%;
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
    margin-bottom: 56px;
}

.guide-intro-item {
    padding: 28px 24px;
    border-radius: var(--radius);
    background: #fff;
    border: 1px solid rgba(0, 0, 0, 0.08);
    text-align: center;
    transition: all 0.4s cubic-bezier(0.16, 1, 0.3, 1);
}

.guide-intro-item:hover {
    transform: translateY(-4px);
    border-color: var(--gold);
    box-shadow: 0 12px 32px rgba(212, 165, 116, 0.15);
}

.guide-intro-icon {
    display: block;
    font-size: 2rem;
    margin-bottom: 12px;
}

.guide-intro-item h3 {
    font-family: var(--font-serif);
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--text-dark);
    margin-bottom: 10px;
    letter-spacing: 0.05em;
}

.guide-intro-item p {
    font-size: 0.88rem;
    color: var(--text-muted);
    line-height: 1.7;
}

.guide-intro-item kbd {
    display: inline-block;
    padding: 1px 7px;
    margin: 0 2px;
    font-family: var(--font-mono);
    font-size: 0.8rem;
    color: var(--text-dark);
    background: var(--paper-warm);
    border: 1px solid rgba(0, 0, 0, 0.12);
    border-radius: 4px;
}

.guide-grid {
    max-width: var(--max-w);
    width: 100%;
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 20px;
}

.guide-card {
    display: block;
    text-decoration: none;
    color: inherit;
    padding: 28px 24px;
    border-radius: var(--radius);
    background: #fff;
    border: 1px solid rgba(0, 0, 0, 0.08);
    transition: all 0.4s cubic-bezier(0.16, 1, 0.3, 1);
    position: relative;
    overflow: hidden;
    cursor: pointer;
}

.guide-card-arrow {
    display: inline-block;
    margin-top: 10px;
    font-size: 0.82rem;
    color: var(--gold);
    font-weight: 500;
    transition: all 0.3s;
    opacity: 0.7;
}

.guide-card:hover .guide-card-arrow {
    color: var(--vermilion);
    transform: translateX(6px);
    opacity: 1;
}

.guide-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 2px;
    background: linear-gradient(90deg, var(--gold), var(--vermilion));
    transform: scaleX(0);
    transform-origin: left;
    transition: transform 0.4s;
}

.guide-card:hover {
    transform: translateY(-4px);
    border-color: rgba(212, 165, 116, 0.4);
    box-shadow: 0 12px 32px rgba(0, 0, 0, 0.08);
}

.guide-card:hover::before {
    transform: scaleX(1);
}

.guide-card-wide {
    grid-column: 1 / -1;
}

.guide-card-num {
    font-family: var(--font-serif);
    font-size: 1.4rem;
    font-weight: 900;
    color: var(--gold);
    margin-bottom: 8px;
}

.guide-card-title {
    font-family: var(--font-serif);
    font-size: 1.15rem;
    font-weight: 600;
    color: var(--text-dark);
    margin-bottom: 6px;
    letter-spacing: 0.05em;
}

.guide-card-field {
    font-size: 0.78rem;
    color: var(--vermilion);
    font-weight: 500;
    margin-bottom: 12px;
    letter-spacing: 0.03em;
}

.guide-card-desc {
    font-size: 0.88rem;
    color: var(--text-muted);
    line-height: 1.7;
    margin-bottom: 12px;
}

.guide-card-tip {
    font-size: 0.8rem;
    color: var(--gold-dim);
    line-height: 1.6;
    padding-top: 10px;
    border-top: 1px dashed rgba(0, 0, 0, 0.1);
    font-style: italic;
}

@media (max-width: 768px) {
    .guide-intro {
        grid-template-columns: 1fr;
    }

    .guide-grid {
        grid-template-columns: 1fr;
    }
}

/* ============================================
   提问区
   ============================================ */
.ask-area {
    max-width: var(--max-w);
    width: 100%;
    margin-bottom: 48px;
    padding: 36px 40px;
    background: #fff;
    border-radius: var(--radius);
    border: 1px solid rgba(0, 0, 0, 0.08);
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.04);
    transition: box-shadow 0.3s;
}

.ask-area:focus-within {
    box-shadow: 0 8px 32px rgba(212, 165, 116, 0.15);
    border-color: var(--gold);
}

.ask-input-row {
    display: flex;
    gap: 12px;
    align-items: stretch;
}

.ask-input {
    flex: 1;
    padding: 16px 20px;
    font-family: var(--font-sans);
    font-size: 1rem;
    color: var(--text-dark);
    background: var(--paper);
    border: 1px solid rgba(0, 0, 0, 0.1);
    border-radius: 8px;
    outline: none;
    transition: all 0.3s;
}

.ask-input:focus {
    border-color: var(--gold);
    background: #fff;
    box-shadow: 0 0 0 3px rgba(212, 165, 116, 0.12);
}

.ask-input::placeholder {
    color: var(--text-dim);
    font-size: 0.92rem;
}

.ask-btn {
    padding: 0 32px;
    font-family: var(--font-serif);
    font-size: 1.1rem;
    font-weight: 600;
    color: #fff;
    background: linear-gradient(135deg, var(--gold), var(--vermilion));
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s;
    letter-spacing: 0.1em;
    white-space: nowrap;
}

.ask-btn:hover {
    transform: translateY(-1px);
    box-shadow: 0 4px 16px rgba(192, 57, 43, 0.3);
}

.ask-btn:active {
    transform: translateY(0);
}

.ask-uploads {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 0 6px;
    border-left: 1px solid rgba(0, 0, 0, 0.08);
    border-right: 1px solid rgba(0, 0, 0, 0.08);
}

.ask-upload-btn {
    width: 38px;
    height: 38px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 8px;
    border: 1px solid transparent;
    background: transparent;
    color: #8a7355;
    cursor: pointer;
    transition: all 0.25s;
}

.ask-upload-btn:hover {
    background: rgba(212, 165, 116, 0.12);
    border-color: rgba(212, 165, 116, 0.35);
    color: var(--vermilion);
}

.ask-upload-btn svg {
    pointer-events: none;
}

.ask-attachment-preview {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin-top: 12px;
}

.ask-attachment-item {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 6px 10px;
    background: var(--paper);
    border: 1px solid rgba(212, 165, 116, 0.35);
    border-radius: 8px;
    font-size: 0.82rem;
    color: #5a4e3c;
}

.ask-attachment-item img {
    width: 40px;
    height: 40px;
    object-fit: cover;
    border-radius: 4px;
    border: 1px solid rgba(0, 0, 0, 0.08);
}

.ask-attachment-item .ask-attachment-remove {
    width: 18px;
    height: 18px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    border: none;
    background: rgba(192, 57, 43, 0.1);
    color: var(--vermilion);
    font-size: 0.75rem;
    cursor: pointer;
    line-height: 1;
}

.ask-examples {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 8px;
    margin-top: 16px;
}

.ask-examples-label {
    font-size: 0.8rem;
    color: var(--text-muted);
    white-space: nowrap;
}

.ask-example {
    padding: 4px 14px;
    font-family: var(--font-sans);
    font-size: 0.78rem;
    color: var(--text-muted);
    background: var(--paper);
    border: 1px solid rgba(0, 0, 0, 0.08);
    border-radius: 20px;
    cursor: pointer;
    transition: all 0.25s;
    white-space: nowrap;
}

.ask-example:hover {
    color: var(--vermilion);
    border-color: var(--vermilion-light);
    background: #fff;
}

.ask-result {
    margin-top: 16px;
    padding: 20px 24px;
    border-radius: 8px;
    background: var(--paper);
    border: 1px solid rgba(0, 0, 0, 0.06);
    animation: ask-fadein 0.3s ease-out;
}

.ask-result-title {
    font-family: var(--font-serif);
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--gold-dim);
    margin-bottom: 8px;
    letter-spacing: 0.05em;
}

.ask-result-body {
    font-size: 0.95rem;
    line-height: 1.7;
    color: var(--text-dark);
}

.ask-result-body .highlight {
    color: var(--vermilion);
    font-weight: 500;
}

.ask-result-body .formula {
    font-family: var(--font-mono);
    font-size: 1.1rem;
    color: var(--vermilion);
    font-weight: 500;
}

.ask-result-link {
    display: inline-block;
    margin-top: 12px;
    padding: 6px 18px;
    font-size: 0.82rem;
    color: #fff;
    background: var(--gold);
    border-radius: 6px;
    text-decoration: none;
    transition: all 0.25s;
}

.ask-result-link:hover {
    background: var(--vermilion);
    transform: translateY(-1px);
}

.ask-result-help {
    padding: 0;
    list-style: none;
}

.ask-result-help li {
    padding: 4px 0;
    font-size: 0.85rem;
    color: var(--text-muted);
}

.ask-result-help code {
    display: inline-block;
    padding: 0 6px;
    font-family: var(--font-mono);
    font-size: 0.8rem;
    color: var(--text-dark);
    background: rgba(0, 0, 0, 0.04);
    border-radius: 3px;
}

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

.ask-canvas-wrap {
    margin-top: 16px;
    border-radius: 16px;
    overflow: hidden;
    background: #ffffff;
    border: 1px solid rgba(0, 0, 0, 0.06);
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.06), 0 1px 4px rgba(0, 0, 0, 0.04);
    animation: ask-fadein 0.3s ease-out;
    transition: box-shadow 0.3s;
}

.ask-canvas-wrap:hover {
    box-shadow: 0 12px 40px rgba(0, 0, 0, 0.1), 0 2px 6px rgba(0, 0, 0, 0.05);
}

.ask-canvas-card {
    width: 100%;
}

.ask-canvas-header {
    display: flex;
    gap: 8px;
    padding: 18px 24px 0;
    flex-wrap: wrap;
}

.ask-canvas-header .tag {
    display: inline-block;
    padding: 3px 12px;
    font-size: 0.72rem;
    color: #fff;
    border-radius: 12px;
    letter-spacing: 0.03em;
    font-weight: 500;
}

.ask-canvas-header .tag-t1 { background: #4A90D9; }
.ask-canvas-header .tag-t2 { background: #50B86C; }
.ask-canvas-header .tag-t3 { background: #E09D3E; }
.ask-canvas-header .tag-t4 { background: #9B6BBF; }
.ask-canvas-header .tag-t5 { background: #D9726A; }

.ask-canvas-question {
    padding: 12px 24px 8px;
    font-family: 'Noto Serif SC', serif;
    font-size: 1rem;
    font-weight: 600;
    color: #1a1a2e;
    letter-spacing: 0.02em;
    line-height: 1.5;
}

.ask-canvas-wrap canvas {
    display: block;
    width: calc(100% - 32px);
    margin: 4px 16px;
    height: 220px;
    border-radius: 10px;
    background: #faf8f4;
}

.ask-canvas-footer {
    padding: 10px 24px 18px;
    font-size: 0.75rem;
    color: #8a7355;
    text-align: center;
    border-top: 1px solid rgba(0, 0, 0, 0.04);
    letter-spacing: 0.04em;
}

.ask-thinking {
    display: inline-block;
    font-size: 2rem;
    line-height: 1;
    color: var(--gold);
    animation: ask-dot 1.2s ease-in-out infinite;
}

@keyframes ask-dot {
    0%, 100% { opacity: 0.2; content: '·'; }
    50% { opacity: 1; content: '···'; }
}

@media (max-width: 768px) {
    .ask-area {
        padding: 24px 20px;
    }

    .ask-input-row {
        flex-direction: column;
    }

    .ask-btn {
        padding: 12px;
    }

    .ask-examples {
        gap: 6px;
    }
}