/* EvoForge — 新中式 · 锻造
   三色体系：宣纸暖白 / 墨 / 朱砂（用量 <5%，印章式用色）。
   宋体大标、竖排小字、汉字编号、细墨线、方角、大留白。
   无渐变、无阴影辉光、无跑马灯。 */

:root {
  --paper: #faf7f2;      /* 宣纸 */
  --paper-deep: #f3efe7; /* 覆一层茶渍 */
  --ink: #211f1c;        /* 墨 */
  --ink-soft: #55524c;   /* 淡墨 */
  --ink-faint: #98938a;  /* 飞白 */
  --hairline: #e3ddd2;   /* 界格线 */
  --vermilion: #c2401c;  /* 朱砂 */
  --vermilion-deep: #a83418;
  --serif: "Songti SC", "Noto Serif SC", "Source Han Serif SC", "STSong", "SimSun", serif;
  --sans: "PingFang SC", "Microsoft YaHei", "Segoe UI", system-ui, sans-serif;
  --maxw: 1060px;
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  font-family: var(--sans);
  background: var(--paper);
  color: var(--ink);
  line-height: 1.9;
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; text-decoration: none; }
h1, h2, h3, .motto, .sec-num, .row-num, .finale h2 { font-family: var(--serif); }

/* ───────── 印章 ───────── */
.seal {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: var(--vermilion);
  color: var(--paper);
  font-family: var(--serif);
  font-weight: 700;
  line-height: 1;
  user-select: none;
}
.seal-sm { width: 30px; height: 30px; font-size: 16px; border-radius: 4px; }
.seal-lg { width: 64px; height: 64px; font-size: 34px; border-radius: 7px; margin-bottom: 34px; }

/* ───────── 顶栏 ───────── */
.nav {
  position: fixed;
  inset: 0 0 auto;
  z-index: 40;
  display: flex;
  align-items: center;
  gap: 36px;
  height: 68px;
  padding: 0 clamp(24px, 5vw, 64px);
  background: color-mix(in srgb, var(--paper) 88%, transparent);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--hairline);
}
.brand { display: flex; align-items: center; gap: 12px; }
.brand-name { font-family: var(--serif); font-size: 19px; font-weight: 700; letter-spacing: 0.04em; }
.nav-links { margin-left: auto; display: flex; gap: 34px; }
.nav-actions { display: flex; align-items: center; gap: 14px; }
.language-toggle {
  border: 1px solid var(--hairline);
  border-radius: 2px;
  background: transparent;
  color: var(--ink-soft);
  cursor: pointer;
  font: 600 12px/1 var(--sans);
  letter-spacing: .08em;
  padding: 9px 10px;
  transition: color .18s, border-color .18s;
}
.language-toggle:hover { color: var(--vermilion); border-color: var(--vermilion); }
.nav-links a {
  font-size: 14.5px;
  color: var(--ink-soft);
  letter-spacing: 0.28em;
  padding-bottom: 3px;
  border-bottom: 1px solid transparent;
  transition: color .18s, border-color .18s;
}
.nav-links a:hover { color: var(--ink); border-color: var(--vermilion); }

/* ───────── 按钮：方角，墨与朱 ───────── */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 14px;
  letter-spacing: 0.22em;
  padding: 10px 26px;
  border-radius: 2px;
  transition: background .18s, color .18s, border-color .18s;
}
.btn-lg { padding: 15px 40px; font-size: 15px; }
.btn-solid { background: var(--ink); color: var(--paper); }
.btn-solid:hover { background: var(--vermilion); }
.btn-line { border: 1px solid var(--ink); color: var(--ink); }
.btn-line:hover { border-color: var(--vermilion); color: var(--vermilion); }

/* ───────── 首屏 ───────── */
.hero {
  position: relative;
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 200px 28px 96px;
  display: grid;
  grid-template-columns: 72px 1fr;
  gap: 12px;
}
.hero-side { position: relative; }
.vertical-text {
  writing-mode: vertical-rl;
  font-size: 13px;
  letter-spacing: 0.62em;
  color: var(--ink-faint);
  border-left: 1px solid var(--hairline);
  padding-left: 18px;
  height: 300px;
  display: inline-block;
}
.motto {
  font-size: 15px;
  letter-spacing: 0.5em;
  color: var(--ink-soft);
  margin-bottom: 30px;
}
.motto-dot { color: var(--vermilion); margin: 0 2px; }
h1 {
  font-size: clamp(46px, 7.2vw, 88px);
  font-weight: 700;
  line-height: 1.28;
  letter-spacing: 0.06em;
}
.vermilion { color: var(--vermilion); }
.lede {
  margin-top: 34px;
  max-width: 560px;
  font-size: 16.5px;
  color: var(--ink-soft);
}
.cta-row { display: flex; gap: 16px; margin-top: 44px; flex-wrap: wrap; }
.hero-meta {
  margin-top: 26px;
  font-size: 12px;
  letter-spacing: 0.3em;
  color: var(--ink-faint);
}

/* 锻铁三横 */
.ingot {
  grid-column: 1 / -1;
  margin-top: 110px;
  padding-top: 56px;
  border-top: 1px solid var(--hairline);
  display: flex;
  flex-direction: column;
  gap: 22px;
}
.ingot .bar { height: 14px; border-radius: 7px; background: var(--ink); position: relative; }
.ingot .bar-hot { width: 62%; background: var(--vermilion); }
.ingot .bar-mid { width: 46%; }
.ingot .bar-cold { width: 62%; }
.spark {
  position: absolute;
  right: -26px;
  top: -8px;
  width: 10px; height: 10px;
  background: var(--vermilion);
  clip-path: polygon(50% 0, 62% 38%, 100% 50%, 62% 62%, 50% 100%, 38% 62%, 0 50%, 38% 38%);
}
.ingot figcaption {
  font-size: 12px;
  letter-spacing: 0.34em;
  color: var(--ink-faint);
  margin-top: 6px;
}

/* ───────── 章节骨架 ───────── */
.section {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 140px 28px 0;
}
.sec-head {
  display: flex;
  align-items: flex-start;
  gap: 34px;
  margin-bottom: 72px;
}
.sec-num {
  font-size: 60px;
  line-height: 1;
  color: var(--vermilion);
  font-weight: 700;
  border-bottom: 3px solid var(--vermilion);
  padding-bottom: 10px;
}
.sec-head h2 {
  font-size: clamp(30px, 4vw, 46px);
  font-weight: 700;
  letter-spacing: 0.08em;
}
.sec-sub { margin-top: 12px; color: var(--ink-soft); font-size: 15.5px; letter-spacing: 0.04em; }

/* ───────── 进化 · 三联屏 ───────── */
.triptych {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
}
.panel {
  border-left: 1px solid var(--hairline);
  padding: 8px 34px 8px 30px;
}
.panel:first-child { border-left: none; padding-left: 0; }
.panel h3 {
  font-size: 24px;
  font-weight: 700;
  letter-spacing: 0.1em;
  display: flex;
  align-items: baseline;
  gap: 12px;
}
.panel h3 .en {
  font-family: var(--sans);
  font-size: 11px;
  letter-spacing: 0.3em;
  color: var(--ink-faint);
  font-weight: 500;
}
.panel p { margin-top: 18px; font-size: 14.5px; color: var(--ink-soft); }

/* ───────── 工坊 · 账页式列表 ───────── */
.ledger { border-top: 1px solid var(--hairline); }
.row {
  display: grid;
  grid-template-columns: 120px 260px 1fr;
  gap: 24px;
  padding: 46px 0;
  border-bottom: 1px solid var(--hairline);
  align-items: baseline;
  transition: background .2s;
}
.row:hover { background: color-mix(in srgb, var(--paper-deep) 60%, transparent); }
.row-num {
  font-size: 30px;
  color: var(--ink-faint);
  font-weight: 700;
  transition: color .2s;
}
.row:hover .row-num { color: var(--vermilion); }
.row h3 { font-size: 22px; font-weight: 700; letter-spacing: 0.08em; }
.row p { color: var(--ink-soft); font-size: 14.5px; max-width: 560px; }

/* ───────── 边界 ───────── */
.section-bounds {
  max-width: none;
  background: var(--paper-deep);
  border-block: 1px solid var(--hairline);
  margin-top: 140px;
  padding: 120px 28px;
}
.section-bounds .sec-head,
.section-bounds .bounds-grid { max-width: var(--maxw); margin-inline: auto; }
.section-bounds .sec-head { margin-bottom: 64px; }
.bounds-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1px;
  background: var(--hairline);
  border: 1px solid var(--hairline);
}
.bound { background: var(--paper-deep); padding: 40px 38px; }
.bound h3 {
  font-size: 20px;
  font-weight: 700;
  letter-spacing: 0.1em;
  padding-left: 16px;
  border-left: 3px solid var(--vermilion);
}
.bound p { margin-top: 16px; color: var(--ink-soft); font-size: 14.5px; }

/* ───────── 尾声 ───────── */
.finale {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 160px 28px 140px;
  text-align: center;
}
.finale h2 {
  font-size: clamp(32px, 4.6vw, 54px);
  font-weight: 700;
  line-height: 1.5;
  letter-spacing: 0.06em;
}
.finale em { font-style: normal; color: var(--vermilion); }
.finale .cta-row { justify-content: center; margin-top: 48px; }

/* ───────── 页脚 ───────── */
.footer {
  border-top: 1px solid var(--hairline);
  padding: 44px 28px 40px;
  text-align: center;
  font-size: 13.5px;
  color: var(--ink-soft);
  letter-spacing: 0.2em;
}
.footer-fine { margin-top: 10px; font-size: 11.5px; color: var(--ink-faint); }

/* ───────── 显现（渐进增强：无 JS 时全部可见） ───────── */
html.js .reveal { opacity: 0; transform: translateY(18px); transition: opacity .8s ease, transform .8s ease; }
html.js .reveal.in { opacity: 1; transform: none; }
@media (prefers-reduced-motion: reduce) {
  html.js .reveal { opacity: 1; transform: none; transition: none; }
}

/* ───────── 响应式 ───────── */
@media (max-width: 860px) {
  .nav-links { display: none; }
  .nav { gap: 14px; }
  .hero { grid-template-columns: 1fr; padding-top: 150px; }
  .hero-side { display: none; }
  .triptych { grid-template-columns: 1fr; gap: 40px; }
  .panel { border-left: none; padding: 0; }
  .row { grid-template-columns: 56px 1fr; }
  .row p { grid-column: 2; }
  .bounds-grid { grid-template-columns: 1fr; }
  .sec-head { flex-direction: column; gap: 18px; }
}