/* ============================================================
   GoPrep v3 · 共享设计系统
   页面专属样式留在各页 <style>；这里只放全站共用层。
   ============================================================ */

:root {
    --paper: #F4EFE6;
    --paper-light: #FBF9F4;
    --ink: #122B20;
    --ink-body: #34483F;
    --ink-muted: #5F6C66;
    --umber: #A84A2A;
    --umber-deep: #8A3B20;
    --hairline: #D8D1C6;
    --deep: #14281F;
    --deep-text: rgba(255,255,255,.68);
    --deep-hairline: rgba(255,255,255,.14);
    --serif: 'Source Serif 4', 'Noto Serif SC', 'Songti SC', serif;
    --serif-sc: 'Noto Serif SC', 'Source Serif 4', 'Songti SC', serif;
    --sans: 'Source Sans 3', 'Noto Sans SC', 'PingFang SC', sans-serif;
    --sec-pad: clamp(72px, 10vw, 144px);
    --gutter: 24px;
}
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
    font-family: var(--sans);
    background: var(--paper);
    color: var(--ink-body);
    font-size: 17px;
    line-height: 1.9;
    letter-spacing: 0.01em;
    -webkit-font-smoothing: antialiased;
}
::selection { background: rgba(168,74,42,.18); }

/* ---------- 网格 ---------- */
.wrap { max-width: 1240px; margin: 0 auto; padding: 0 clamp(20px, 4vw, 48px); }
.grid { display: grid; grid-template-columns: repeat(12, 1fr); gap: var(--gutter); }

/* ---------- 字级 ---------- */
h1, h2, h3, h4 { font-family: var(--serif-sc); font-weight: 600; color: var(--ink); }
h1 { font-size: clamp(34px, 4.2vw, 54px); line-height: 1.28; letter-spacing: -0.01em; }
h2 { font-size: clamp(28px, 3.4vw, 44px); line-height: 1.28; letter-spacing: -0.015em; }
h3 { font-size: clamp(20px, 1.8vw, 24px); line-height: 1.4; }
h1 em, h2 em { font-style: normal; color: var(--umber); }
h1, h2 { text-wrap: balance; }
.w { display: inline-block; }
/* 导语=论点句：升档 + 墨色，与 17px 论证正文拉开层级 */
.lede { font-size: clamp(19px, 1.6vw, 21px); max-width: 660px; color: var(--ink); }
/* 标题→副题 全站统一间距：hero 24px，区块 20px */
h1 + .lede, h1 + .hero-sub { margin-top: 24px; }
h2 + .lede { margin-top: 20px; }
.small { font-size: 13.5px; color: var(--ink-muted); }
.num { font-family: var(--serif); font-weight: 400; }
.eyebrow {
    font-size: 12.5px; font-weight: 600; letter-spacing: 0.12em;
    text-transform: uppercase; color: var(--umber); margin-bottom: 14px;
}
.eyebrow .zh { letter-spacing: 0.06em; }
.sec { padding: var(--sec-pad) 0; }
.hairline-top { border-top: 1px solid var(--hairline); }

/* ---------- 导航 ---------- */
nav { position: fixed; top: 0; width: 100%; z-index: 100; padding: 16px 0; background: transparent; transition: background .3s, border-color .3s; border-bottom: 1px solid transparent; }
nav.scrolled { background: rgba(244,239,230,.92); -webkit-backdrop-filter: blur(14px); backdrop-filter: blur(14px); border-bottom-color: var(--hairline); }
.nav-inner { display: flex; justify-content: space-between; align-items: center; }
.logo img { height: 32px; width: auto; display: block; }
.nav-links { display: flex; gap: 30px; align-items: center; list-style: none; }
.nav-links a { text-decoration: none; color: var(--ink-body); font-size: 15px; font-weight: 500; transition: color .25s; }
.nav-links a:hover { color: var(--umber); }
.nav-links a.active { color: var(--ink); border-bottom: 1.5px solid var(--umber); padding-bottom: 2px; }
.nav-links a.lang { color: var(--ink-muted); font-size: 13.5px; letter-spacing: 0.08em; }
a, button { touch-action: manipulation; -webkit-tap-highlight-color: transparent; }
.mobile-toggle { display: none; background: none; border: none; cursor: pointer; padding: 12px; margin: -12px -4px -12px 0; }
.mobile-toggle span { display: block; width: 22px; height: 1.5px; background: var(--ink); margin: 6px 0; transition: .3s; }

/* ---------- 按钮 ---------- */
.btn {
    display: inline-flex; align-items: center; justify-content: center; gap: 8px;
    min-height: 50px; padding: 0 26px; border-radius: 5px;
    background: var(--umber); color: #fff !important;
    font-family: var(--sans); font-size: 16px; font-weight: 600;
    text-decoration: none; border: none; cursor: pointer; transition: background .25s;
}
.btn:hover { background: var(--umber-deep); }
.btn-nav { min-height: 40px; padding: 0 20px; font-size: 14.5px; }
.textlink {
    display: inline-flex; align-items: baseline; gap: 6px;
    color: var(--ink); font-weight: 600; font-size: 16px; text-decoration: none;
    border-bottom: 1px solid var(--ink); padding-bottom: 2px;
    transition: color .25s, border-color .25s; cursor: pointer; background: none; font-family: var(--sans);
}
.textlink:hover { color: var(--umber); border-color: var(--umber); }

/* ---------- 数据列（hero proof / founder nums）---------- */
.proof-row { display: flex; align-items: baseline; gap: 18px; padding: 17px 0; border-bottom: 1px solid var(--hairline); }
.proof-row:first-child { border-top: 1px solid var(--hairline); }
.proof-num { font-family: var(--serif); font-size: clamp(28px, 2.5vw, 38px); font-weight: 400; color: var(--ink); line-height: 1; min-width: 100px; letter-spacing: -0.02em; }
.proof-label { font-size: 14.5px; color: var(--ink-muted); }

/* ---------- 岔路口分隔 ---------- */
.fork-divider { display: flex; align-items: center; gap: 18px; max-width: 1240px; margin: 0 auto; padding: 0 clamp(20px, 4vw, 48px); }
.fork-divider::before, .fork-divider::after { content: ''; flex: 1; height: 1px; background: var(--hairline); }
.fork-divider svg { width: 52px; height: 22px; flex-shrink: 0; }

/* ---------- 深绿收尾 ---------- */
.final { background: var(--deep); color: var(--deep-text); padding: var(--sec-pad) 0; }
.final .eyebrow { color: rgba(255,255,255,.5); }
.final h2 { color: #fff; max-width: 640px; }
.final .lede { color: var(--deep-text); margin-top: 18px; }
.final-actions { margin-top: 36px; display: flex; gap: 28px; align-items: center; flex-wrap: wrap; }
.final .textlink { color: #fff; border-color: rgba(255,255,255,.5); }
.final .textlink:hover { color: #fff; border-color: #fff; }
.final .contact-line { margin-top: 28px; font-size: 14.5px; color: rgba(255,255,255,.45); }

/* ---------- 页脚 ---------- */
footer { background: var(--deep); border-top: 1px solid var(--deep-hairline); padding: 36px 0; font-size: 13.5px; color: rgba(255,255,255,.4); }
.footer-inner { display: flex; justify-content: space-between; align-items: center; gap: 16px; flex-wrap: wrap; }
.footer-links { display: flex; gap: 24px; }
footer a { color: rgba(255,255,255,.6); text-decoration: none; transition: color .25s; }
footer a:hover { color: #fff; }
.footer-note { margin-top: 6px; font-size: 12px; color: rgba(255,255,255,.3); }

/* ---------- 预约 Modal ---------- */
.modal-mask { position: fixed; inset: 0; z-index: 200; background: rgba(18,43,32,.5); display: none; align-items: center; justify-content: center; padding: 20px; }
.modal-mask.open { display: flex; }
.modal { background: var(--paper-light); border-radius: 8px; max-width: 420px; width: 100%; padding: 40px 36px; position: relative; border: 1px solid var(--hairline); }
.modal h3 { margin-bottom: 4px; }
.modal .modal-sub { font-size: 14.5px; color: var(--ink-muted); margin-bottom: 18px; }
.modal-close { position: absolute; top: 14px; right: 18px; background: none; border: none; font-size: 22px; color: var(--ink-muted); cursor: pointer; line-height: 1; }
.contact-row { display: flex; justify-content: space-between; align-items: center; gap: 12px; padding: 15px 0; border-bottom: 1px solid var(--hairline); }
.contact-row .label { display: block; color: var(--ink-muted); font-size: 12.5px; letter-spacing: 0.06em; }
.contact-row .value { font-weight: 600; color: var(--ink); font-size: 16.5px; }
.copy-btn { background: none; border: 1px solid var(--hairline); border-radius: 4px; padding: 4px 14px; font-size: 13px; font-family: var(--sans); color: var(--ink-body); cursor: pointer; transition: all .2s; flex-shrink: 0; }
.copy-btn:hover { border-color: var(--umber); color: var(--umber); }

/* ---------- 动效（内容默认可见，JS 只做增强）----------
   淡入只给桌面端（hover+fine pointer）：手机上内容永远直接可见，
   彻底杜绝 iOS 滚动/观察器怪癖导致的"透明空白"类故障。 */
@media (hover: hover) and (pointer: fine) {
    html.js .reveal { opacity: 0; transform: translateY(12px); transition: opacity .35s ease, transform .35s ease; }
    html.js .reveal.visible { opacity: 1; transform: none; }
}
@media (prefers-reduced-motion: reduce) {
    html.js .reveal { opacity: 1; transform: none; transition: none; }
    html { scroll-behavior: auto; }
}

/* ---------- 移动端导航 ---------- */
@media (max-width: 900px) {
    .nav-links { display: none; }
    .mobile-toggle { display: block; }
    /* 展开时必须关掉磨砂：backdrop-filter 会让 nav 成为 fixed 子元素的
       定位基准，菜单面板的 top/bottom 就不再相对视口，高度直接坍缩 */
    nav.open { background: var(--paper); -webkit-backdrop-filter: none; backdrop-filter: none; }
    nav.open .nav-links { display: flex; flex-direction: column; align-items: flex-start; gap: 0; position: fixed; top: 64px; left: 0; right: 0; bottom: 0; background: var(--paper); padding: 16px clamp(20px,4vw,48px); overflow-y: auto; }
    nav.open .nav-links li { width: 100%; border-bottom: 1px solid var(--hairline); }
    nav.open .nav-links a { display: block; padding: 18px 0; font-size: 18px; }
    nav.open .nav-links a.active { border-bottom: none; color: var(--umber); }
    nav.open .nav-links li:last-child { border-bottom: none; padding-top: 20px; }
    body.nav-locked { overflow: hidden; }
}
/* ---------- 手机端排印（不是桌面版压扁：字号/行距/细线节奏单独定）---------- */
@media (max-width: 600px) {
    body { font-size: 16px; line-height: 1.85; }
    h1 { font-size: clamp(32px, 9.6vw, 40px); line-height: 1.32; }
    h2 { font-size: clamp(26px, 7.6vw, 32px); line-height: 1.35; }
    h3 { font-size: 20px; }
    .lede { font-size: 17.5px; }
    .eyebrow { margin-bottom: 10px; }
    .sec { padding: clamp(64px, 18vw, 88px) 0; }
    .proof-row { padding: 13px 0; gap: 14px; }
    .proof-num { min-width: 82px; font-size: 27px; }
    .proof-label { font-size: 13.5px; }
    .fork-divider svg { width: 44px; height: 19px; }
    .btn { min-height: 48px; font-size: 15.5px; }
    .textlink { font-size: 15px; }
    .modal { padding: 32px 24px; }
    html[lang="en"] h1 { font-size: clamp(36px, 11vw, 44px); line-height: 1.1; }
    html[lang="en"] h2 { font-size: clamp(27px, 8vw, 32px); line-height: 1.18; }
    html[lang="en"] body { line-height: 1.6; }
}

/* ============================================================
   英文版排印覆写：<html lang="en"> 即生效
   中英共享视觉系统，但不共享行高/字距/断行节奏。
   ============================================================ */
html[lang="en"] { --serif-sc: 'Source Serif 4', 'Noto Serif SC', serif; }
html[lang="en"] body { line-height: 1.65; letter-spacing: -0.005em; }
html[lang="en"] h1 { line-height: 1.08; letter-spacing: -0.03em; font-size: clamp(38px, 4.8vw, 64px); }
html[lang="en"] h2 { line-height: 1.15; letter-spacing: -0.025em; }
html[lang="en"] h3, html[lang="en"] h4 { line-height: 1.25; letter-spacing: -0.015em; }
html[lang="en"] .lede { line-height: 1.6; }
html[lang="en"] .eyebrow { letter-spacing: 0.12em; }
html[lang="en"] blockquote em, html[lang="en"] .quote-it { font-style: italic; color: inherit; }