/* =====================================================================
   华体CN — 共享样式表 /assets/site.css
   设计语汇：极简文字建筑 · 纸张叠层 · 印刷边框 · 坐标索引 · 球场几何
   ===================================================================== */

/* ---------- 1. Reset ---------- */
*,
*::before,
*::after { box-sizing: border-box; }

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: 104px;
}

body {
  margin: 0;
  font-family: var(--font-body);
  font-size: var(--step-17);
  line-height: 1.75;
  color: var(--ink);
  background: var(--paper);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

h1, h2, h3, h4, h5, h6, p, figure, blockquote, dl, dd, ul, ol {
  margin: 0;
}

ul, ol { padding: 0; }

img, svg, video {
  max-width: 100%;
  display: block;
}

button {
  font: inherit;
  color: inherit;
}

a { color: inherit; }

table {
  border-collapse: collapse;
  width: 100%;
}

/* ---------- 2. 变量 ---------- */
:root {
  /* 色彩 */
  --navy: #0E2740;
  --navy-deep: #071A2C;
  --navy-soft: #173A5A;
  --vermilion: #E8552B;
  --vermilion-light: #FF7A4D;
  --grass: #1F8A5B;
  --grass-light: #5FBF8C;
  --sand: #D9A93C;
  --paper: #F5F1E8;
  --paper-edge: #E3DBCB;
  --ink: #12181F;
  --slate: #55606E;

  /* 字体 */
  --font-display: "Source Han Sans Heavy", "Noto Sans SC", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  --font-headline: "Source Han Serif SC", "Noto Serif SC", "Songti SC", "SimSun", Georgia, serif;
  --font-body: "Source Han Sans SC", "Noto Sans SC", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  --font-mono: "IBM Plex Mono", "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  --font-label: "Source Han Serif SC", "Noto Serif SC", "Songti SC", "SimSun", Georgia, serif;

  /* 字号阶梯 */
  --step-12: 12px;
  --step-14: 14px;
  --step-17: 17px;
  --step-22: 22px;
  --step-34: 34px;
  --step-56: 56px;
  --step-88: 88px;

  /* 间距 */
  --space-1: 8px;
  --space-2: 16px;
  --space-3: 24px;
  --space-4: 40px;
  --space-5: 72px;

  /* 结构 */
  --max: 1280px;
  --print-bar: 4px;
  --rule: 1px solid var(--paper-edge);
  --header-offset: 92px;
}

/* ---------- 3. 可访问性基础 ---------- */
:focus-visible {
  outline: 2px solid var(--vermilion-light);
  outline-offset: 3px;
}

::selection {
  background: var(--vermilion);
  color: #fff;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: fixed;
  top: 12px;
  left: 12px;
  z-index: 200;
  padding: 11px 20px;
  background: var(--vermilion);
  color: #fff;
  font-size: var(--step-14);
  font-weight: 600;
  border-radius: 999px;
  text-decoration: none;
  transform: translateY(-220%);
  transition: transform .22s ease;
}

.skip-link:focus {
  transform: translateY(0);
}

/* 主内容区默认让开固定头部，页面可用 --header-offset 覆盖 */
#main-content {
  padding-top: var(--header-offset);
}

/* ---------- 4. 容器 / 网格 ---------- */
.container {
  width: 100%;
  max-width: var(--max);
  margin-inline: auto;
  padding-inline: clamp(16px, 3vw, 28px);
}

.grid {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: var(--space-3);
}

.grid--tight { gap: var(--space-2); }
.grid--wide { gap: var(--space-4); }

.col-2  { grid-column: span 2; }
.col-3  { grid-column: span 3; }
.col-4  { grid-column: span 4; }
.col-5  { grid-column: span 5; }
.col-6  { grid-column: span 6; }
.col-7  { grid-column: span 7; }
.col-8  { grid-column: span 8; }
.col-9  { grid-column: span 9; }
.col-10 { grid-column: span 10; }
.col-12 { grid-column: span 12; }

@media (max-width: 1024px) {
  .grid { grid-template-columns: repeat(8, minmax(0, 1fr)); }
}

@media (max-width: 640px) {
  .grid { grid-template-columns: repeat(4, minmax(0, 1fr)); gap: var(--space-2); }
  [class*="col-"] { grid-column: 1 / -1; }
}

/* ---------- 5. 正文与标题 ---------- */
.prose {
  max-width: 38em;
  font-size: var(--step-17);
  line-height: 1.75;
  color: var(--ink);
}

.prose p + p { margin-top: var(--space-2); }

.prose h2,
.prose h3 {
  font-family: var(--font-headline);
  font-weight: 600;
  line-height: 1.35;
  margin-top: var(--space-4);
}

.prose h2 { font-size: var(--step-34); letter-spacing: -0.01em; }
.prose h3 { font-size: var(--step-22); }

.prose a {
  color: var(--navy);
  text-decoration: none;
  border-bottom: 1px solid var(--vermilion);
}

.prose a:hover { color: var(--vermilion); }

.prose ul,
.prose ol {
  padding-left: 1.3em;
  margin-top: var(--space-2);
}

.prose li + li { margin-top: 6px; }

.prose strong { font-weight: 700; color: var(--navy); }

/* ---------- 6. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 46px;
  padding: 0 22px;
  border: 1px solid transparent;
  border-radius: 999px;
  font-family: var(--font-body);
  font-size: var(--step-14);
  font-weight: 600;
  line-height: 1;
  text-decoration: none;
  cursor: pointer;
  transition: background-color .2s ease, color .2s ease, border-color .2s ease;
}

.btn--primary {
  background: var(--vermilion);
  color: #fff;
}

.btn--primary:hover { background: var(--vermilion-light); }

.btn--ghost {
  background: transparent;
  color: var(--navy);
  border-color: var(--navy);
}

.btn--ghost:hover {
  background: var(--navy);
  color: var(--paper);
}

.btn--on-dark {
  background: transparent;
  color: var(--paper);
  border-color: rgba(245, 241, 232, .42);
}

.btn--on-dark:hover {
  background: rgba(245, 241, 232, .14);
  border-color: var(--paper);
}

/* ---------- 7. 站点头部：三岛浮岛导航 ---------- */
.site-header {
  --header-gutter: max(16px, calc((100vw - 1440px) / 2 + 24px));
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 120;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 14px var(--header-gutter) 0;
  pointer-events: none;
  transition: padding-top .24s ease;
}

.site-header > * { pointer-events: auto; }

.header-island {
  display: flex;
  align-items: center;
  min-height: 52px;
  border-radius: 999px;
  transition: min-height .24s ease;
}

/* 品牌岛 */
.header-island--brand {
  flex: 0 0 auto;
  padding: 0 20px;
  background: var(--navy);
  border: 1px solid rgba(245, 241, 232, .14);
  box-shadow: 0 12px 28px -20px rgba(7, 26, 44, .95);
}

.brand {
  display: flex;
  align-items: baseline;
  gap: 10px;
  text-decoration: none;
  color: var(--paper);
  white-space: nowrap;
}

.brand__name {
  font-family: var(--font-display);
  font-size: 22px;
  font-weight: 900;
  letter-spacing: -0.02em;
  line-height: 1;
}

.brand__name::after {
  content: "";
  display: inline-block;
  width: 7px;
  height: 7px;
  margin-left: 7px;
  background: var(--vermilion);
  transform: translateY(-1px);
}

.brand__line {
  font-family: var(--font-label);
  font-size: var(--step-12);
  letter-spacing: .14em;
  color: rgba(245, 241, 232, .62);
  padding-left: 12px;
  border-left: 1px solid rgba(245, 241, 232, .2);
}

/* 导航岛 */
.header-island--nav {
  flex: 1 1 auto;
  max-width: 720px;
  min-width: 0;
  justify-content: center;
  padding: 0 8px;
  background: rgba(14, 39, 64, .94);
  border: 1px solid rgba(245, 241, 232, .14);
}

.nav-list {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 4px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.nav-item { list-style: none; }

.nav-link {
  display: block;
  padding: 9px 14px;
  border-radius: 999px;
  font-size: var(--step-14);
  font-weight: 500;
  line-height: 1.35;
  white-space: nowrap;
  text-decoration: none;
  color: rgba(245, 241, 232, .8);
  transition: background-color .2s ease, color .2s ease;
}

.nav-link:hover {
  background: rgba(245, 241, 232, .1);
  color: #fff;
}

.nav-link[aria-current="page"] {
  background: var(--vermilion);
  color: #fff;
  font-weight: 700;
}

/* 行动岛 */
.header-island--action {
  flex: 0 0 auto;
  gap: 8px;
  background: transparent;
  border: 0;
  padding: 0;
}

.header-cta {
  min-height: 48px;
  padding: 0 20px;
  box-shadow: 0 12px 24px -18px rgba(232, 85, 43, .95);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 4px;
  width: 48px;
  height: 48px;
  padding: 0;
  border: 1px solid rgba(245, 241, 232, .26);
  border-radius: 999px;
  background: var(--navy);
  color: var(--paper);
  cursor: pointer;
  transition: border-color .2s ease, background-color .2s ease;
}

.nav-toggle:hover { border-color: var(--vermilion); }

.nav-toggle__bar {
  display: block;
  width: 18px;
  height: 2px;
  background: currentColor;
  transition: transform .22s ease, opacity .22s ease;
}

.nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(1) { transform: translateY(6px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(3) { transform: translateY(-6px) rotate(-45deg); }

/* 滚动后收窄 */
.site-header[data-scrolled] { padding-top: 8px; }

.site-header[data-scrolled] .header-island { min-height: 46px; }

.site-header[data-scrolled] .header-cta { min-height: 42px; }

.site-header[data-scrolled] .nav-toggle {
  width: 42px;
  height: 42px;
}

@media (max-width: 1180px) and (min-width: 981px) {
  .header-island--nav { max-width: none; }
  .nav-link { padding: 9px 10px; font-size: 13px; }
}

@media (max-width: 1080px) {
  .brand__line { display: none; }
}

/* 移动端与平板：导航岛转为下拉面板 */
@media (max-width: 980px) {
  .nav-toggle { display: inline-flex; }

  .header-island--nav {
    position: absolute;
    top: calc(100% + 10px);
    left: var(--header-gutter);
    right: var(--header-gutter);
    max-width: none;
    flex-direction: column;
    align-items: stretch;
    justify-content: flex-start;
    padding: 12px;
    background: var(--navy);
    border-radius: 22px;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-8px);
    transition: opacity .22s ease, transform .22s ease, visibility .22s;
    box-shadow: 0 26px 60px -30px rgba(0, 0, 0, .9);
  }

  .header-island--nav[data-open] {
    opacity: 1;
    visibility: visible;
    transform: none;
  }

  .nav-list {
    flex-direction: column;
    align-items: stretch;
    justify-content: flex-start;
    width: 100%;
    gap: 4px;
  }

  .nav-link {
    padding: 13px 16px;
    border-radius: 14px;
    font-size: 15px;
  }
}

@media (max-width: 560px) {
  .header-island { min-height: 48px; }
  .header-island--brand { padding: 0 15px; }
  .brand__name { font-size: 19px; }
  .header-cta { min-height: 44px; padding: 0 14px; font-size: 13px; }
  .nav-toggle { width: 44px; height: 44px; }
}

@media (max-width: 440px) {
  .header-cta { display: none; }
}

/* ---------- 8. 站点页脚 ---------- */
.site-footer {
  position: relative;
  margin-top: var(--space-5);
  background: var(--navy-deep);
  color: rgba(245, 241, 232, .78);
  border-top: var(--print-bar) solid var(--vermilion);
}

.site-footer::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: repeating-linear-gradient(90deg, var(--sand) 0 24px, transparent 24px 34px);
  opacity: .55;
  pointer-events: none;
}

.footer-shell {
  max-width: var(--max);
  margin-inline: auto;
  padding: 60px clamp(16px, 3vw, 28px) 34px;
}

.footer-top {
  display: grid;
  grid-template-columns: minmax(220px, 1.05fr) 2fr;
  gap: 40px;
  padding-bottom: 34px;
  border-bottom: 1px solid rgba(245, 241, 232, .14);
}

.footer-brand__name {
  font-family: var(--font-display);
  font-size: var(--step-34);
  font-weight: 900;
  letter-spacing: -0.02em;
  line-height: 1;
  color: var(--paper);
}

.footer-brand__line {
  margin-top: 12px;
  font-family: var(--font-label);
  font-size: 13px;
  letter-spacing: .2em;
  color: rgba(245, 241, 232, .6);
}

.footer-brand__meta {
  display: inline-block;
  margin-top: 18px;
  padding: 4px 10px;
  font-family: var(--font-mono);
  font-size: var(--step-12);
  letter-spacing: .06em;
  color: var(--sand);
  border: 1px solid rgba(217, 169, 60, .45);
}

.footer-nav {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 24px;
}

.footer-col { min-width: 0; }

.footer-title {
  display: inline-block;
  margin-bottom: 16px;
  padding-bottom: 8px;
  font-family: var(--font-headline);
  font-size: var(--step-14);
  font-weight: 600;
  letter-spacing: .12em;
  color: var(--paper);
  border-bottom: 1px solid rgba(232, 85, 43, .55);
}

.footer-links {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.footer-link {
  font-size: var(--step-14);
  color: rgba(245, 241, 232, .72);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color .2s ease, border-color .2s ease;
}

.footer-link:hover {
  color: var(--paper);
  border-bottom-color: var(--vermilion);
}

.footer-contact {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 14px 32px;
  padding: 28px 0;
  border-bottom: 1px solid rgba(245, 241, 232, .14);
}

.footer-contact__item {
  display: flex;
  align-items: baseline;
  gap: 10px;
  font-size: var(--step-14);
  line-height: 1.75;
  color: rgba(245, 241, 232, .78);
}

.footer-contact__item--wide { grid-column: 1 / -1; }

.footer-tag {
  flex: none;
  padding: 2px 8px;
  font-family: var(--font-label);
  font-size: var(--step-12);
  letter-spacing: .12em;
  color: var(--navy-deep);
  background: var(--sand);
  white-space: nowrap;
}

.footer-note {
  max-width: 62ch;
  margin-top: 20px;
  font-size: 13px;
  line-height: 1.85;
  color: rgba(245, 241, 232, .55);
}

.footer-base {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 12px 32px;
  margin-top: 28px;
  padding-top: 20px;
  border-top: 1px solid rgba(245, 241, 232, .1);
  font-size: var(--step-12);
  color: rgba(245, 241, 232, .5);
}

.footer-legal {
  font-family: var(--font-mono);
  letter-spacing: .04em;
}

.footer-footnote { max-width: 60ch; }

/* 返回顶部：坐标样式 */
.to-top {
  position: fixed;
  right: clamp(14px, 3vw, 28px);
  bottom: clamp(16px, 3vw, 28px);
  z-index: 90;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 16px;
  background: var(--navy);
  border: 1px solid rgba(217, 169, 60, .55);
  color: var(--paper);
  font-family: var(--font-mono);
  font-size: var(--step-12);
  letter-spacing: .08em;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transform: translateY(8px);
  transition: opacity .22s ease, transform .22s ease, visibility .22s, border-color .2s ease, background-color .2s ease;
}

.to-top::before {
  content: "\2191";
  font-size: 14px;
  line-height: 1;
  color: var(--vermilion);
}

.to-top[data-visible] {
  opacity: 1;
  visibility: visible;
  transform: none;
}

.to-top:hover {
  background: var(--navy-soft);
  border-color: var(--vermilion);
  color: #fff;
}

@media (max-width: 900px) {
  .footer-top { grid-template-columns: 1fr; gap: 32px; }
}

@media (max-width: 640px) {
  .footer-shell { padding-top: 44px; }
  .footer-nav { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .footer-brand__name { font-size: 28px; }
}

@media (max-width: 400px) {
  .footer-nav { grid-template-columns: 1fr; }
}

/* ---------- 9. 面包屑 ---------- */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
  font-family: var(--font-mono);
  font-size: var(--step-12);
  letter-spacing: .06em;
  color: var(--slate);
}

.crumb { display: inline-flex; align-items: center; gap: 8px; }

.crumb + .crumb::before {
  content: "/";
  color: var(--paper-edge);
}

.crumb a {
  color: var(--slate);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color .2s ease, border-color .2s ease;
}

.crumb a:hover {
  color: var(--vermilion);
  border-bottom-color: var(--vermilion);
}

.crumb[aria-current="page"] {
  color: var(--ink);
  font-weight: 700;
}

/* ---------- 10. 图形语言组件 ---------- */
/* 坐标索引 */
.coord {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: var(--step-12);
  letter-spacing: .06em;
  color: var(--slate);
}

.coord__key {
  color: var(--vermilion);
  font-weight: 700;
}

.coord__val {
  font-weight: 700;
  color: var(--ink);
}

.coord--on-dark { color: rgba(245, 241, 232, .6); }
.coord--on-dark .coord__val { color: var(--paper); }

/* 胶带／贴纸标签 */
.tape-tag {
  display: inline-block;
  padding: 4px 12px;
  font-family: var(--font-label);
  font-size: var(--step-12);
  letter-spacing: .14em;
  color: var(--navy-deep);
  background: var(--sand);
  transform: rotate(-1.5deg);
}

.tape-tag--vermilion {
  background: var(--vermilion);
  color: #fff;
}

.tape-tag--grass {
  background: var(--grass);
  color: #fff;
}

/* 纸张叠层卡 */
.paper-stack {
  position: relative;
  display: block;
}

.paper-stack::before {
  content: "";
  position: absolute;
  inset: 0;
  background: var(--paper-edge);
  border: 1px solid var(--paper-edge);
  transform: translate(8px, 8px);
}

.paper-stack--tilt-l::before { transform: translate(-7px, 8px) rotate(-1.2deg); }
.paper-stack--tilt-r::before { transform: translate(9px, 6px) rotate(1.4deg); }

.paper-stack__face {
  position: relative;
  z-index: 1;
  padding: var(--space-3);
  background: var(--paper);
  border: 1px solid var(--paper-edge);
  border-left: var(--print-bar) solid var(--vermilion);
}

/* 图片容器（页面阶段放置 <img>） */
.figure-frame {
  position: relative;
  display: block;
  overflow: hidden;
  background: var(--navy);
  border: 1px solid var(--paper-edge);
  border-left: var(--print-bar) solid var(--vermilion);
}

.figure-frame[data-ratio="16x9"] { aspect-ratio: 16 / 9; }
.figure-frame[data-ratio="4x3"]  { aspect-ratio: 4 / 3; }
.figure-frame[data-ratio="1x1"]  { aspect-ratio: 1 / 1; }
.figure-frame[data-ratio="3x4"]  { aspect-ratio: 3 / 4; }
.figure-frame[data-ratio="21x9"] { aspect-ratio: 21 / 9; }

.figure-frame > img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.figure-frame__overlay {
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-color: rgba(14, 39, 64, .34);
  background-image: repeating-linear-gradient(-45deg, rgba(245, 241, 232, .07) 0 1px, transparent 1px 5px);
}

.figure-frame__caption {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  padding: 12px 16px;
  background: linear-gradient(180deg, rgba(7, 26, 44, 0), rgba(7, 26, 44, .9));
  color: var(--paper);
  font-family: var(--font-label);
  font-size: var(--step-12);
  letter-spacing: .06em;
}

/* 宽窄章节带 */
.section-band {
  padding: var(--space-5) 0;
  background: var(--navy);
  color: var(--paper);
}

.section-band--paper {
  background: var(--paper);
  color: var(--ink);
}

.section-band--deep {
  background: var(--navy-deep);
}

/* 印刷分隔线 */
.divider-rule {
  height: 1px;
  border: 0;
  margin: var(--space-4) 0;
  background: var(--paper-edge);
}

.divider-rule--bare {
  background: repeating-linear-gradient(90deg, var(--paper-edge) 0 18px, transparent 18px 26px);
}

/* 文本工具 */
.text-mono { font-family: var(--font-mono); }
.text-label {
  font-family: var(--font-label);
  letter-spacing: .12em;
  font-size: var(--step-12);
}
.text-slate { color: var(--slate); }
.text-vermilion { color: var(--vermilion); }
.text-grass { color: var(--grass); }
.text-sand { color: var(--sand); }

/* ---------- 11. 滚动显现协议 ---------- */
[data-reveal] {
  opacity: 0;
  transform: translateY(12px);
  transition: opacity .5s cubic-bezier(.22, .61, .36, 1), transform .5s cubic-bezier(.22, .61, .36, 1);
}

[data-reveal].is-revealed {
  opacity: 1;
  transform: none;
}

/* ---------- 12. 减少动态效果 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

  *,
  *::before,
  *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
    transition-delay: 0ms !important;
  }

  [data-reveal] {
    opacity: 1 !important;
    transform: none !important;
  }
}