/* ================================================================
   QuillBot 中文指南 — 样式表
   设计基调：编辑刊物风 · 不对称布局 · 衬线大标题 · 暖米白底
   ================================================================ */

:root {
    --ink: #1A2B27;
    --ink-soft: #4A5752;
    --green: #1E5A4D;
    --green-deep: #143E35;
    --green-soft: #2E8B6E;
    --orange: #E8843C;
    --paper: #FAF7EE;
    --paper-warm: #F4E5C2;
    --paper-deep: #EFE7D2;
    --line: #D9CFB6;

    --serif: 'Noto Serif SC', 'Source Han Serif SC', 'Songti SC', serif;
    --serif-en: 'Cormorant Garamond', 'Noto Serif SC', serif;
    --sans: 'Noto Sans SC', -apple-system, 'PingFang SC', 'Microsoft YaHei', sans-serif;

    --max-w: 1200px;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; -webkit-font-smoothing: antialiased; }

body {
    font-family: var(--sans);
    color: var(--ink);
    background: var(--paper);
    line-height: 1.75;
    font-size: 16px;
    overflow-x: hidden;
}

/* 装饰性背景纹理 */
body::before {
    content: '';
    position: fixed;
    inset: 0;
    background-image:
        radial-gradient(circle at 12% 18%, rgba(232,132,60,0.04) 0, transparent 35%),
        radial-gradient(circle at 88% 70%, rgba(30,90,77,0.05) 0, transparent 40%);
    pointer-events: none;
    z-index: 0;
}

.container {
    max-width: var(--max-w);
    margin: 0 auto;
    padding: 0 32px;
    position: relative;
    z-index: 1;
}

/* ============ 排版基础 ============ */
h1, h2, h3, h4 {
    font-family: var(--serif);
    color: var(--green-deep);
    line-height: 1.25;
    letter-spacing: -0.01em;
}

h1 { font-weight: 900; }
h2 {
    font-weight: 700;
    font-size: clamp(1.8rem, 3vw, 2.6rem);
    margin-bottom: 1.2rem;
}
h3 {
    font-weight: 600;
    font-size: 1.25rem;
    margin-bottom: 0.6rem;
    color: var(--green);
}
h4 {
    font-weight: 600;
    font-size: 1.1rem;
    margin-bottom: 0.4rem;
}

p { margin-bottom: 1rem; color: var(--ink-soft); }
em { font-style: italic; color: var(--green); font-weight: 500; }
strong { color: var(--ink); font-weight: 600; }

a { color: var(--green); text-decoration: none; transition: color .25s ease; }
a:hover { color: var(--orange); }

/* ============ 顶部导航 ============ */
.site-header {
    position: sticky;
    top: 0;
    z-index: 100;
    background: rgba(250, 247, 238, 0.85);
    backdrop-filter: saturate(180%) blur(14px);
    -webkit-backdrop-filter: saturate(180%) blur(14px);
    border-bottom: 1px solid rgba(217, 207, 182, 0.5);
}

.nav-wrap {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: 18px;
    padding-bottom: 18px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
    color: var(--green-deep);
}
.logo-mark { width: 40px; height: 40px; flex-shrink: 0; }
.logo-mark.small { width: 32px; height: 32px; }
.logo-text { display: flex; flex-direction: column; line-height: 1.1; }
.logo-zh {
    font-family: var(--serif);
    font-weight: 700;
    font-size: 1.15rem;
    color: var(--green-deep);
}
.logo-sub {
    font-size: 0.68rem;
    color: var(--ink-soft);
    letter-spacing: 0.08em;
    white-space: nowrap;
}

.main-nav {
    display: flex;
    gap: 28px;
    align-items: center;
    font-size: 0.9rem;
}
.main-nav a { color: var(--ink); position: relative; padding: 4px 0; }
.main-nav a:not(.nav-cta)::after {
    content: '';
    position: absolute;
    left: 0;
    bottom: 0;
    width: 0;
    height: 1.5px;
    background: var(--orange);
    transition: width .3s ease;
}
.main-nav a:not(.nav-cta):hover::after { width: 100%; }

.nav-cta {
    background: var(--green-deep);
    color: var(--paper-warm) !important;
    padding: 9px 18px !important;
    border-radius: 999px;
    transition: all .25s ease;
}
.nav-cta:hover { background: var(--orange); color: #fff !important; transform: translateY(-1px); }

/* ============ HERO ============ */
.hero {
    padding: 80px 0 60px;
    position: relative;
    overflow: hidden;
}

.hero-grid {
    display: grid;
    grid-template-columns: 1.15fr 1fr;
    gap: 64px;
    align-items: center;
}

.eyebrow {
    font-family: var(--serif-en);
    font-style: italic;
    color: var(--orange);
    font-size: 1rem;
    letter-spacing: 0.04em;
    margin-bottom: 28px;
}

h1 {
    font-size: clamp(2.4rem, 4.8vw, 4.4rem);
    line-height: 1.1;
    margin-bottom: 32px;
    color: var(--green-deep);
}
.h1-line { display: block; }
.h1-line.italic {
    font-family: var(--serif-en);
    font-style: italic;
    font-weight: 500;
    color: var(--orange);
    transform: translateX(40px);
}

.hero-lede {
    font-size: 1.1rem;
    line-height: 1.85;
    color: var(--ink-soft);
    max-width: 520px;
    margin-bottom: 36px;
}

.hero-cta { display: flex; gap: 16px; flex-wrap: wrap; margin-bottom: 48px; }

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 14px 28px;
    border-radius: 999px;
    font-weight: 500;
    font-size: 0.95rem;
    transition: all .25s ease;
    border: 1.5px solid transparent;
    letter-spacing: 0.02em;
}
.btn-primary {
    background: var(--green-deep);
    color: var(--paper-warm);
}
.btn-primary:hover {
    background: var(--orange);
    color: #fff;
    transform: translateY(-2px);
    box-shadow: 0 12px 24px -8px rgba(232,132,60,0.4);
}
.btn-ghost {
    border-color: var(--green-deep);
    color: var(--green-deep);
}
.btn-ghost:hover { background: var(--green-deep); color: var(--paper-warm); }
.btn.large { padding: 18px 36px; font-size: 1.05rem; }

.hero-meta {
    display: flex;
    gap: 48px;
    list-style: none;
    padding-top: 32px;
    border-top: 1px solid var(--line);
}
.hero-meta li { display: flex; flex-direction: column; }
.hero-meta strong {
    font-family: var(--serif);
    font-size: 2.2rem;
    color: var(--green-deep);
    line-height: 1;
    margin-bottom: 4px;
}
.hero-meta span { font-size: 0.85rem; color: var(--ink-soft); }

.hero-art {
    position: relative;
}
.hero-art svg { width: 100%; height: auto; max-width: 480px; display: block; margin: 0 auto; }

.scroll-hint {
    position: absolute;
    bottom: 20px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    color: var(--ink-soft);
}
.scroll-hint span {
    font-family: var(--serif-en);
    font-style: italic;
    font-size: 0.78rem;
    letter-spacing: 0.3em;
}
.scroll-line {
    width: 1px;
    height: 36px;
    background: var(--green-deep);
    animation: scrollPulse 2s ease-in-out infinite;
}
@keyframes scrollPulse {
    0%, 100% { transform: scaleY(0.4); transform-origin: top; opacity: 0.4; }
    50% { transform: scaleY(1); opacity: 1; }
}

/* ============ 通用章节 ============ */
.section {
    padding: 100px 0;
    position: relative;
}

.two-col {
    display: grid;
    grid-template-columns: 240px 1fr;
    gap: 80px;
    align-items: start;
}
.two-col.reverse {
    grid-template-columns: 1fr 240px;
}
.two-col.reverse .chapter-tag { order: 2; text-align: right; }
.two-col.reverse .section-body { order: 1; }

.chapter-tag {
    position: sticky;
    top: 120px;
    border-top: 2px solid var(--green-deep);
    padding-top: 18px;
}
.chapter-num {
    font-family: var(--serif-en);
    font-style: italic;
    font-size: 3rem;
    color: var(--orange);
    line-height: 1;
    display: block;
}
.chapter-num.large {
    font-size: 5rem;
    display: inline-block;
    margin-right: 24px;
    vertical-align: middle;
}
.chapter-label {
    display: block;
    margin-top: 10px;
    color: var(--ink-soft);
    font-size: 0.85rem;
    letter-spacing: 0.2em;
    text-transform: uppercase;
    font-family: var(--serif-en);
}

.section-body p { font-size: 1.02rem; line-height: 1.85; }
.section-body .lede {
    font-size: 1.2rem;
    color: var(--ink);
    font-weight: 400;
    line-height: 1.75;
    margin-bottom: 1.5rem;
    font-family: var(--serif);
}

.section-body h3 {
    margin-top: 2rem;
    padding-left: 16px;
    border-left: 3px solid var(--orange);
}

.pull-quote {
    margin: 2.5rem 0 0;
    padding: 32px 0 0;
    border-top: 1px solid var(--line);
    font-family: var(--serif-en);
    font-style: italic;
    font-size: 1.5rem;
    line-height: 1.5;
    color: var(--green-deep);
}

.section-head {
    text-align: center;
    margin-bottom: 60px;
}
.section-head.left { text-align: left; }
.section-head h2 { display: inline-block; vertical-align: middle; margin-bottom: 0; }
.section-head .section-sub {
    margin-top: 16px;
    color: var(--ink-soft);
    font-size: 1.05rem;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}
.section-head.left .section-sub { margin-left: 0; }

/* ============ 关于章节 ============ */
.section-about { background: linear-gradient(180deg, var(--paper) 0%, var(--paper-deep) 100%); }

/* ============ 九种模式 ============ */
.section-modes {
    background: var(--green-deep);
    color: var(--paper-warm);
}
.section-modes h2, .section-modes h3 { color: var(--paper-warm); }
.section-modes .chapter-num.large { color: var(--orange); }
.section-modes .section-sub { color: rgba(244, 229, 194, 0.7); }
.section-modes p { color: rgba(244, 229, 194, 0.85); }

.modes-art {
    margin: 0 -32px 60px;
    overflow: hidden;
}
.modes-art svg { width: 100%; height: auto; }
.section-modes .modes-art text { fill: var(--paper-warm) !important; }

.modes-list {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1px;
    background: rgba(244, 229, 194, 0.15);
    border: 1px solid rgba(244, 229, 194, 0.15);
}
.mode-item {
    background: var(--green-deep);
    padding: 32px 28px;
    transition: background .3s ease;
}
.mode-item:hover { background: var(--green); }
.mode-item h3 {
    color: var(--paper-warm);
    margin-bottom: 12px;
    font-size: 1.15rem;
}
.mode-item p {
    color: rgba(244, 229, 194, 0.75);
    font-size: 0.93rem;
    line-height: 1.7;
    margin-bottom: 0;
}

/* ============ 中文支持 ============ */
.section-chinese { background: var(--paper); }

/* ============ 工具矩阵 ============ */
.section-tools { background: var(--paper-deep); }

.tools-grid {
    display: grid;
    grid-template-columns: repeat(6, 1fr);
    grid-auto-rows: 1fr;
    gap: 24px;
}
.tool-card {
    grid-column: span 2;
    background: var(--paper);
    padding: 36px 32px;
    border-radius: 4px;
    border: 1px solid var(--line);
    transition: all .3s ease;
    position: relative;
}
.tool-card.tool-lg { grid-column: span 3; background: var(--paper-warm); }
.tool-card:nth-child(2) { grid-column: span 3; }
.tool-card:hover {
    transform: translateY(-4px);
    border-color: var(--green);
    box-shadow: 0 16px 32px -16px rgba(30,90,77,0.2);
}
.tool-icon {
    width: 56px;
    height: 56px;
    margin-bottom: 20px;
    background: rgba(30,90,77,0.08);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 12px;
}
.tool-icon svg { width: 100%; height: 100%; }
.tool-card h3 { margin-bottom: 10px; font-size: 1.15rem; }
.tool-card p { font-size: 0.93rem; margin-bottom: 0; line-height: 1.7; }

/* ============ 适用人群 ============ */
.section-audience { background: var(--paper); }

.audience-collage {
    display: grid;
    grid-template-columns: 1fr 1.4fr;
    gap: 64px;
    align-items: center;
}
.audience-art svg { width: 100%; height: auto; max-width: 360px; }

.audience-list { list-style: none; }
.audience-list li {
    padding: 24px 0;
    border-bottom: 1px solid var(--line);
}
.audience-list li:last-child { border-bottom: none; }
.audience-list h4 { color: var(--green-deep); margin-bottom: 6px; }
.audience-list p { margin-bottom: 0; font-size: 0.96rem; }

/* ============ 价格 ============ */
.section-price { background: linear-gradient(180deg, var(--paper) 0%, var(--paper-deep) 100%); }

.price-cards {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 24px;
    margin-top: 40px;
}
.price-card {
    padding: 36px 32px;
    background: var(--paper);
    border: 1px solid var(--line);
    border-radius: 4px;
    position: relative;
}
.price-card.featured {
    background: var(--green-deep);
    color: var(--paper-warm);
    border-color: var(--green-deep);
    transform: translateY(-12px);
}
.price-card.featured::before {
    content: '推 荐';
    position: absolute;
    top: -12px;
    left: 32px;
    background: var(--orange);
    color: #fff;
    padding: 4px 14px;
    font-size: 0.72rem;
    letter-spacing: 0.2em;
    border-radius: 3px;
}
.price-tier {
    display: block;
    font-family: var(--serif);
    font-size: 0.95rem;
    color: var(--ink-soft);
    letter-spacing: 0.1em;
    margin-bottom: 16px;
}
.price-card.featured .price-tier { color: rgba(244,229,194,0.7); }
.price-num {
    display: block;
    font-family: var(--serif);
    font-size: 3rem;
    font-weight: 700;
    color: var(--green-deep);
    margin-bottom: 24px;
    line-height: 1;
}
.price-num small { font-size: 0.9rem; font-weight: 400; color: var(--ink-soft); margin-left: 6px; }
.price-card.featured .price-num { color: var(--paper-warm); }
.price-card.featured .price-num small { color: rgba(244,229,194,0.7); }
.price-card ul { list-style: none; }
.price-card ul li {
    padding: 8px 0;
    font-size: 0.95rem;
    color: var(--ink-soft);
    border-top: 1px dashed var(--line);
}
.price-card.featured ul li {
    color: rgba(244,229,194,0.85);
    border-top-color: rgba(244,229,194,0.2);
}
.price-card ul li:first-child { border-top: none; }
.price-card.featured ul li:first-child { border-top: none; }

/* ============ FAQ ============ */
.section-faq { background: var(--paper); }

.faq-list {
    max-width: 820px;
    margin: 0 auto;
}
.faq-list details {
    border-bottom: 1px solid var(--line);
    padding: 24px 0;
}
.faq-list details[open] summary h3 { color: var(--orange); }
.faq-list summary {
    cursor: pointer;
    list-style: none;
    display: flex;
    justify-content: space-between;
    align-items: center;
    position: relative;
    padding-right: 40px;
}
.faq-list summary::-webkit-details-marker { display: none; }
.faq-list summary::after {
    content: '+';
    position: absolute;
    right: 0;
    font-family: var(--serif-en);
    font-size: 1.8rem;
    color: var(--green);
    transition: transform .3s ease;
}
.faq-list details[open] summary::after { transform: rotate(45deg); color: var(--orange); }
.faq-list summary h3 {
    margin: 0;
    font-size: 1.15rem;
    color: var(--green-deep);
    transition: color .25s ease;
    display: inline;
}
.faq-list details p {
    margin-top: 16px;
    line-height: 1.85;
    color: var(--ink-soft);
}

/* ============ CTA Band ============ */
.cta-band {
    background: var(--green-deep);
    padding: 80px 0;
    position: relative;
    overflow: hidden;
}
.cta-band::before {
    content: '';
    position: absolute;
    inset: 0;
    background-image:
        radial-gradient(circle at 80% 30%, rgba(232,132,60,0.18) 0, transparent 45%),
        radial-gradient(circle at 15% 80%, rgba(46,139,110,0.25) 0, transparent 50%);
}
.cta-inner {
    text-align: center;
    position: relative;
    z-index: 1;
}
.cta-band h2 {
    color: var(--paper-warm);
    margin-bottom: 36px;
    font-size: clamp(1.6rem, 3vw, 2.4rem);
}
.cta-band .btn-primary {
    background: var(--orange);
    color: #fff;
}
.cta-band .btn-primary:hover {
    background: var(--paper-warm);
    color: var(--green-deep);
}

/* ============ 页脚 ============ */
.site-footer {
    background: var(--ink);
    color: var(--paper-deep);
    padding: 60px 0 32px;
}
.footer-grid {
    display: grid;
    grid-template-columns: 1.5fr 1fr;
    gap: 48px;
    align-items: start;
}
.footer-brand { display: flex; flex-direction: column; gap: 16px; }
.footer-brand p { color: rgba(239,231,210,0.7); font-size: 0.92rem; margin: 0; }
.footer-nav {
    display: flex;
    gap: 24px;
    flex-wrap: wrap;
    justify-content: flex-end;
}
.footer-nav a { color: var(--paper-deep); font-size: 0.9rem; }
.footer-nav a:hover { color: var(--orange); }
.copyright {
    grid-column: 1 / -1;
    border-top: 1px solid rgba(239,231,210,0.15);
    padding-top: 24px;
    margin-top: 16px;
    color: rgba(239,231,210,0.5);
    font-size: 0.82rem;
    margin-bottom: 0;
}

/* ============ 响应式 ============ */
@media (max-width: 960px) {
    .hero-grid, .two-col, .two-col.reverse, .audience-collage {
        grid-template-columns: 1fr !important;
        gap: 40px;
    }
    .two-col.reverse .chapter-tag { order: 0; text-align: left; }
    .two-col.reverse .section-body { order: 1; }
    .chapter-tag { position: static; }
    .h1-line.italic { transform: none; }
    .modes-list { grid-template-columns: repeat(2, 1fr); }
    .tools-grid { grid-template-columns: repeat(2, 1fr); }
    .tool-card, .tool-card.tool-lg, .tool-card:nth-child(2) { grid-column: span 1; }
    .price-cards { grid-template-columns: 1fr; }
    .price-card.featured { transform: none; }
    .footer-grid { grid-template-columns: 1fr; }
    .footer-nav { justify-content: flex-start; }
    .main-nav { display: none; }
    .section { padding: 70px 0; }
    .hero { padding: 50px 0 40px; }
    .hero-meta { gap: 32px; flex-wrap: wrap; }
    .scroll-hint { display: none; }
}

@media (max-width: 600px) {
    .container { padding: 0 20px; }
    .modes-list, .tools-grid { grid-template-columns: 1fr; }
    .hero-meta strong { font-size: 1.6rem; }
    .chapter-num.large { font-size: 3.5rem; margin-right: 16px; }
}

/* ================================================================
   ✦ 视觉升级层 v2 ✦
   ① 颗粒纹理 ② 入场/滚动动画 ③ 装饰大字 ④ 手写感修饰
   ================================================================ */

/* ---------- ① 全屏颗粒噪点（印刷品质感） ---------- */
body::after {
    content: '';
    position: fixed;
    inset: 0;
    pointer-events: none;
    z-index: 9999;
    opacity: 0.55;
    mix-blend-mode: multiply;
    background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='240' height='240'><filter id='n'><feTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='2' stitchTiles='stitch'/><feColorMatrix values='0 0 0 0 0  0 0 0 0 0  0 0 0 0 0  0 0 0 0.13 0'/></filter><rect width='100%' height='100%' filter='url(%23n)'/></svg>");
}

/* ---------- ② Hero 入场动画 ---------- */
@keyframes heroIn {
    from { opacity: 0; transform: translateY(24px); }
    to { opacity: 1; transform: translateY(0); }
}
@keyframes heroInItalic {
    from { opacity: 0; transform: translateY(24px) translateX(0); }
    to { opacity: 1; transform: translateY(0) translateX(40px); }
}
@keyframes heroArtIn {
    from { opacity: 0; transform: translateY(20px) rotate(-2deg); }
    to { opacity: 1; transform: translateY(0) rotate(0); }
}
@keyframes floatY {
    0%, 100% { transform: translateY(0) rotate(0); }
    50% { transform: translateY(-5px) rotate(-0.4deg); }
}
@keyframes inkFlow {
    0%, 100% { opacity: 0.5; }
    50% { opacity: 0.78; }
}
@keyframes inkPulse {
    0%, 100% { transform: scale(1); opacity: 1; }
    45% { transform: scale(1.18) translateY(0.5px); opacity: 0.92; }
    65% { transform: scale(1) translateY(1.2px); opacity: 0.78; }
}
@keyframes inkDropFade {
    0%, 100% { opacity: 0.85; transform: scale(1); }
    50% { opacity: 0.6; transform: scale(0.92); }
}

.hero .eyebrow      { opacity: 0; animation: heroIn .9s cubic-bezier(.22,.61,.36,1) both .1s; }
.hero h1 .h1-line:nth-child(1) { opacity: 0; animation: heroIn .9s cubic-bezier(.22,.61,.36,1) both .25s; }
.hero h1 .h1-line.italic       { opacity: 0; animation: heroInItalic .9s cubic-bezier(.22,.61,.36,1) both .45s; }
.hero h1 .h1-line:nth-child(3) { opacity: 0; animation: heroIn .9s cubic-bezier(.22,.61,.36,1) both .65s; }
.hero-lede          { opacity: 0; animation: heroIn .9s cubic-bezier(.22,.61,.36,1) both .85s; }
.hero-cta           { opacity: 0; animation: heroIn .9s cubic-bezier(.22,.61,.36,1) both 1.05s; }
.hero-meta          { opacity: 0; animation: heroIn .9s cubic-bezier(.22,.61,.36,1) both 1.25s; }
.hero-art           { opacity: 0; animation: heroArtIn 1.2s cubic-bezier(.22,.61,.36,1) both .55s; }
.hero-art svg       { animation: floatY 9s ease-in-out infinite 1.8s; transform-origin: 60% 50%; will-change: transform; }

/* 飘散文字呼吸 */
.hero-art svg g[font-family] text { animation: inkFlow 6s ease-in-out infinite; }
.hero-art svg g[font-family] text:nth-of-type(2) { animation-delay: 1.5s; }
.hero-art svg g[font-family] text:nth-of-type(3) { animation-delay: 3s; }
.hero-art svg g[font-family] text:nth-of-type(4) { animation-delay: 4.5s; }

/* 笔尖墨珠脉冲 */
.hero-art svg .ink-bead {
    transform-box: fill-box;
    transform-origin: center;
    animation: inkPulse 3.6s ease-in-out infinite 2.4s;
}
/* 纸上墨水滴呼吸 */
.hero-art svg .ink-drops {
    transform-box: fill-box;
    transform-origin: center;
    animation: inkDropFade 5s ease-in-out infinite 3s;
}

/* ---------- ② 滚动触发动画（现代浏览器） ---------- */
@keyframes revealUp {
    from { opacity: 0; transform: translateY(40px); }
    to { opacity: 1; transform: translateY(0); }
}
@keyframes revealLeft {
    from { opacity: 0; transform: translateX(-30px); }
    to { opacity: 1; transform: translateX(0); }
}

@supports (animation-timeline: view()) {
    .section-body,
    .section-head,
    .mode-item,
    .tool-card,
    .audience-list li,
    .price-card,
    .faq-list details,
    .modes-art,
    .audience-art,
    .pull-quote {
        animation: revealUp linear both;
        animation-timeline: view();
        animation-range: entry 5% cover 28%;
    }
    .chapter-tag {
        animation: revealLeft linear both;
        animation-timeline: view();
        animation-range: entry 5% cover 25%;
    }
    .mode-item:nth-child(2) { animation-range: entry 8% cover 30%; }
    .mode-item:nth-child(3) { animation-range: entry 11% cover 32%; }
    .tool-card:nth-child(2) { animation-range: entry 8% cover 30%; }
    .tool-card:nth-child(3) { animation-range: entry 11% cover 32%; }
}

/* 旧浏览器优雅降级：直接显示 */
@supports not (animation-timeline: view()) {
    .section-body, .section-head, .mode-item, .tool-card,
    .audience-list li, .price-card, .faq-list details {
        opacity: 1;
    }
}

/* 尊重无障碍偏好 */
@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* ---------- ③ 章节大装饰字 ---------- */
.section { overflow: hidden; }

.section::before {
    content: '';
    position: absolute;
    font-family: var(--serif-en);
    font-weight: 700;
    line-height: 0.85;
    pointer-events: none;
    user-select: none;
    z-index: 0;
    letter-spacing: -0.05em;
}

.section-about::before {
    content: 'Q';
    font-size: 32rem;
    color: var(--green-deep);
    opacity: 0.05;
    right: -4rem;
    top: -6rem;
}
.section-modes::before {
    content: 'IX';
    font-style: italic;
    font-size: 28rem;
    color: var(--paper-warm);
    opacity: 0.07;
    left: -3rem;
    bottom: -10rem;
}
.section-chinese::before {
    content: '中';
    font-family: var(--serif);
    font-size: 26rem;
    color: var(--green);
    opacity: 0.05;
    left: -2rem;
    top: -4rem;
}
.section-tools::before {
    content: '&';
    font-style: italic;
    font-size: 36rem;
    color: var(--orange);
    opacity: 0.06;
    right: -6rem;
    top: -8rem;
}
.section-audience::before {
    content: 'WHO';
    font-size: 18rem;
    color: var(--green-deep);
    opacity: 0.04;
    right: -3rem;
    bottom: -4rem;
}
.section-price::before {
    content: '$';
    font-size: 36rem;
    color: var(--green-deep);
    opacity: 0.05;
    left: -4rem;
    top: -10rem;
}
.section-faq::before {
    content: '?';
    font-style: italic;
    font-size: 32rem;
    color: var(--orange);
    opacity: 0.06;
    right: -2rem;
    top: -8rem;
}

.section .container { position: relative; z-index: 1; }

/* ---------- ④ 手写感装饰：标记笔色块 ---------- */
.mark-pen {
    background-image: linear-gradient(
        180deg,
        transparent 0%,
        transparent 55%,
        rgba(232, 132, 60, 0.32) 55%,
        rgba(232, 132, 60, 0.32) 92%,
        transparent 92%
    );
    padding: 0 4px;
    border-radius: 2px;
}
.mark-pen-green {
    background-image: linear-gradient(
        180deg,
        transparent 0%,
        transparent 55%,
        rgba(46, 139, 110, 0.28) 55%,
        rgba(46, 139, 110, 0.28) 92%,
        transparent 92%
    );
    padding: 0 4px;
}

/* ---------- ④ 手写感装饰：圆圈 / 弧线 / 下划波浪 ---------- */
.scribble {
    position: relative;
    display: inline-block;
}
.scribble svg {
    position: absolute;
    left: -8%;
    top: -10%;
    width: 116%;
    height: 130%;
    pointer-events: none;
    overflow: visible;
}
.scribble svg path {
    fill: none;
    stroke: var(--orange);
    stroke-width: 2.4;
    stroke-linecap: round;
    stroke-linejoin: round;
    stroke-dasharray: 600;
    stroke-dashoffset: 600;
}
.scribble.in-view svg path,
@supports (animation-timeline: view()) {
    .scribble svg path {
        animation: drawScribble 1.6s cubic-bezier(.6,.05,.3,1) forwards;
        animation-timeline: view();
        animation-range: entry 10% cover 40%;
    }
}
@keyframes drawScribble {
    to { stroke-dashoffset: 0; }
}

.underline-wave {
    position: relative;
    display: inline-block;
}
.underline-wave svg {
    position: absolute;
    left: -2%;
    bottom: -14px;
    width: 104%;
    height: 14px;
    pointer-events: none;
}
.underline-wave svg path {
    fill: none;
    stroke: var(--orange);
    stroke-width: 2.4;
    stroke-linecap: round;
    stroke-dasharray: 400;
    stroke-dashoffset: 400;
}
@supports (animation-timeline: view()) {
    .underline-wave svg path {
        animation: drawScribble 1.4s cubic-bezier(.6,.05,.3,1) forwards;
        animation-timeline: view();
        animation-range: entry 10% cover 40%;
    }
}
@supports not (animation-timeline: view()) {
    .underline-wave svg path,
    .scribble svg path {
        stroke-dashoffset: 0;
    }
}

/* ---------- ④ 手写感装饰：箭头 ---------- */
.hand-arrow {
    display: inline-block;
    vertical-align: middle;
    margin: 0 8px;
    color: var(--orange);
}

/* ---------- 按钮微动效升级 ---------- */
.btn-primary { position: relative; overflow: hidden; }
.btn-primary::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(120deg,
        transparent 30%,
        rgba(255, 255, 255, 0.35) 50%,
        transparent 70%);
    transform: translateX(-120%);
    transition: transform .8s ease;
}
.btn-primary:hover::before { transform: translateX(120%); }

/* ---------- 卡片浮起阴影更柔 ---------- */
.tool-card { will-change: transform; }
.tool-card:hover {
    box-shadow:
        0 20px 40px -20px rgba(30,90,77,0.25),
        0 4px 8px -4px rgba(30,90,77,0.08);
}

/* ---------- 数据展示加装饰圆环 ---------- */
.hero-meta li {
    position: relative;
    padding-left: 8px;
}
.hero-meta li::before {
    content: '';
    position: absolute;
    left: -10px;
    top: -4px;
    width: 36px;
    height: 36px;
    border: 1px solid var(--orange);
    border-radius: 50%;
    opacity: 0.45;
    z-index: -1;
}
.hero-meta li:nth-child(2)::before {
    border-color: var(--green);
    border-radius: 0;
    transform: rotate(45deg);
    width: 28px;
    height: 28px;
    top: 0;
    left: -6px;
}
.hero-meta li:nth-child(3)::before {
    border-color: var(--orange);
    border-style: dashed;
}

/* ---------- 移动端调整 ---------- */
@media (max-width: 960px) {
    .section-about::before { font-size: 18rem; right: -2rem; top: -3rem; }
    .section-modes::before { font-size: 16rem; }
    .section-chinese::before { font-size: 16rem; }
    .section-tools::before { font-size: 20rem; right: -3rem; }
    .section-audience::before { font-size: 12rem; }
    .section-price::before { font-size: 22rem; }
    .section-faq::before { font-size: 20rem; }
}
@media (max-width: 600px) {
    body::after { opacity: 0.4; }
    .section::before { display: none; }
}