/* ==========================================================================
   完美体育厅 · 冰雪数据舱
   共享样式 /assets/site.css —— reset / 变量 / 排版 / 头尾 / 通用组件
   ========================================================================== */

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

html, body, h1, h2, h3, h4, h5, p, ul, ol, li, figure, blockquote, dl, dd, dt { margin: 0; padding: 0; }
ul, ol { list-style: none; }
img, svg, video { display: block; max-width: 100%; }
button { font: inherit; color: inherit; background: none; border: 0; padding: 0; cursor: pointer; }
a { color: inherit; text-decoration: none; }
table { border-collapse: collapse; width: 100%; }
[hidden] { display: none !important; }

/* ---------- 2. 变量 ---------- */
:root {
  /* 色板 */
  --ice: #CFE7F2;
  --frost: #F4FAFC;
  --ink: #0B2A25;
  --ink-2: #143C34;
  --cyan: #35E0C8;
  --orange: #FF8A3D;
  --orange-soft: #FFD9BF;
  --indigo: #2A5C7A;
  --steel: #6E8894;
  --text: #0F1F1D;

  /* 字体 */
  --font-sans: "Noto Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Source Han Sans SC", system-ui, -apple-system, sans-serif;
  --font-serif: Georgia, "Songti SC", "Times New Roman", "Noto Serif SC", serif;
  --font-mono: "JetBrains Mono", "IBM Plex Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;

  /* 尺度 */
  --maxw: 1200px;
  --gutter: clamp(20px, 5vw, 56px);
  --section-y: clamp(56px, 9vw, 128px);

  /* 切角 */
  --cut-sm: polygon(0 0, calc(100% - 10px) 0, 100% 10px, 100% 100%, 10px 100%, 0 calc(100% - 10px));
  --cut-nav: polygon(0 0, calc(100% - 14px) 0, 100% 14px, 100% 100%, 14px 100%, 0 calc(100% - 14px));
  --cut-panel: polygon(0 0, 100% 0, 100% calc(100% - 22px), calc(100% - 22px) 100%, 0 100%);
  --cut-shell: polygon(0 0, calc(100% - 16px) 0, 100% 16px, 100% 100%, 16px 100%, 0 calc(100% - 16px));

  --ease: cubic-bezier(.22, .61, .36, 1);
}

/* ---------- 3. 基础排版 ---------- */
html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.7;
  color: var(--text);
  background-color: var(--ice);
  background-image:
    linear-gradient(180deg, #E6F2F8 0%, var(--ice) 40%, #D8EBF4 100%);
  background-attachment: fixed;
  min-height: 100vh;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4 {
  font-weight: 800;
  line-height: 1.16;
  letter-spacing: -0.012em;
  color: var(--text);
  text-wrap: balance;
}
h1 { font-size: clamp(32px, 5.2vw, 56px); }
h2 { font-size: clamp(26px, 3.4vw, 40px); }
h3 { font-size: clamp(20px, 2.2vw, 28px); }
h4 { font-size: clamp(17px, 1.6vw, 20px); }
p  { text-wrap: pretty; }

.display-en {
  font-family: var(--font-serif);
  font-weight: 400;
  letter-spacing: 0.005em;
  line-height: 1.1;
}
.display-en--italic { font-style: italic; }

.num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-feature-settings: "tnum" 1;
  letter-spacing: -0.02em;
  line-height: 1.2;
}
.num--lg { font-size: clamp(24px, 3vw, 34px); }
.num--xl { font-size: clamp(32px, 4.6vw, 44px); }

.label {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.24em;
  text-transform: uppercase;
  color: var(--indigo);
}
.label::before {
  content: "";
  width: 22px;
  height: 1px;
  background: currentColor;
  flex: none;
}

.chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 5px 12px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  background: var(--orange-soft);
  color: var(--ink);
  clip-path: var(--cut-sm);
}
.chip--ink { background: var(--ink-2); color: var(--cyan); }

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

/* ---------- 4. 焦点 ---------- */
:focus-visible {
  outline: 2px solid var(--orange);
  outline-offset: 3px;
}
.btn:focus-visible,
.nav-link:focus-visible,
.lang-btn:focus-visible,
.nav-toggle:focus-visible,
.tab:focus-visible,
.skip-link:focus-visible {
  outline: none;
  box-shadow: inset 0 0 0 2px var(--orange);
}

/* ---------- 5. 布局容器 ---------- */
.container {
  width: 100%;
  max-width: var(--maxw);
  margin-inline: auto;
  padding-inline: var(--gutter);
}
.container--wide { max-width: 1440px; }
.container--narrow { max-width: 820px; }

.section { padding-block: var(--section-y); }
.section--tight { padding-block: clamp(32px, 5vw, 64px); }
.section--flush { padding-block: 0; }

.section--dark {
  background: var(--ink);
  color: var(--frost);
  background-image: linear-gradient(118deg, rgba(53, 224, 200, .10) 0%, rgba(11, 42, 37, 0) 44%, rgba(255, 138, 61, .10) 100%);
}
.section--ink2 {
  background: var(--ink-2);
  color: var(--frost);
}
.section--dark h1, .section--dark h2, .section--dark h3, .section--dark h4,
.section--ink2 h1, .section--ink2 h2, .section--ink2 h3, .section--ink2 h4 {
  color: var(--frost);
}
.section--dark .label, .section--ink2 .label { color: var(--cyan); }

.grid-12 {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: clamp(16px, 2.4vw, 32px);
}

/* ---------- 6. 头部 ---------- */
.skip-link {
  position: fixed;
  top: 10px;
  left: 50%;
  z-index: 200;
  transform: translate(-50%, -260%);
  padding: 12px 22px;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.06em;
  background: var(--ink);
  color: var(--cyan);
  clip-path: var(--cut-sm);
  pointer-events: auto;
  transition: transform .2s var(--ease);
}
.skip-link:focus { transform: translate(-50%, 0); }

.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  z-index: 99;
  width: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--cyan) 0%, var(--indigo) 46%, var(--orange) 100%);
  pointer-events: none;
  transition: width .12s linear;
}

.site-header {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 90;
  padding: clamp(10px, 1.6vw, 18px) clamp(12px, 3vw, 28px);
  pointer-events: none;
}

.header-shell {
  position: relative;
  pointer-events: auto;
  width: min(100%, 1320px);
  margin-inline: auto;
  display: flex;
  align-items: center;
  gap: clamp(8px, 1.4vw, 16px);
}

/* 品牌岛 */
.brand-island {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 10px 22px 10px 16px;
  background: var(--ink);
  color: var(--frost);
  clip-path: var(--cut-shell);
  flex: none;
  transition: background .2s var(--ease);
}
.brand-island:hover { background: var(--ink-2); }

.brand-mark {
  width: 13px;
  height: 13px;
  flex: none;
  background: linear-gradient(140deg, var(--cyan) 0%, var(--indigo) 100%);
  clip-path: polygon(50% 0, 100% 50%, 50% 100%, 0 50%);
}
.brand-text { display: flex; flex-direction: column; min-width: 0; }
.brand-name {
  font-size: 15px;
  font-weight: 800;
  letter-spacing: 0.06em;
  line-height: 1.25;
  white-space: nowrap;
}
.brand-sub {
  font-family: var(--font-mono);
  font-size: 9.5px;
  letter-spacing: 0.14em;
  color: rgba(207, 231, 242, .62);
  white-space: nowrap;
}

/* 栏目胶囊 */
.site-nav {
  margin-inline: auto;
  padding: 6px;
  background: rgba(244, 250, 252, .84);
  -webkit-backdrop-filter: blur(16px) saturate(150%);
  backdrop-filter: blur(16px) saturate(150%);
  clip-path: var(--cut-nav);
}
.nav-list { display: flex; align-items: center; gap: 2px; }
.nav-item { display: flex; }

.nav-link {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1px;
  padding: 8px 15px;
  color: var(--text);
  clip-path: var(--cut-sm);
  transition: background .2s var(--ease), color .2s var(--ease);
}
.nav-link:hover { background: rgba(42, 92, 122, .14); }
.nav-link[aria-current="page"] { background: var(--ink); }
.nav-link[aria-current="page"] .nav-cn { color: var(--frost); }
.nav-link[aria-current="page"] .nav-en { color: var(--cyan); }

.nav-cn {
  font-size: 13.5px;
  font-weight: 700;
  letter-spacing: 0.02em;
  white-space: nowrap;
  transition: opacity .2s var(--ease);
}
.nav-en {
  font-family: var(--font-mono);
  font-size: 9.5px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--steel);
  white-space: nowrap;
  transition: color .2s var(--ease), font-size .2s var(--ease);
}

/* 右侧工具岛 */
.header-tools {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-left: auto;
  flex: none;
}

.lang-switch {
  display: flex;
  gap: 2px;
  padding: 3px;
  background: rgba(11, 42, 37, .10);
  clip-path: var(--cut-sm);
}
.lang-btn {
  padding: 6px 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--indigo);
  clip-path: var(--cut-sm);
  transition: background .2s var(--ease), color .2s var(--ease);
}
.lang-btn[aria-pressed="true"] { background: var(--ink); color: var(--cyan); }
.lang-btn:hover { color: var(--ink); }
.lang-btn[aria-pressed="true"]:hover { color: var(--cyan); }

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 22px;
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.04em;
  line-height: 1.2;
  clip-path: var(--cut-sm);
  transition: background .2s var(--ease), color .2s var(--ease), transform .18s var(--ease);
}
.btn:active { transform: translateY(1px); }
.btn--orange { background: var(--orange); color: var(--ink); }
.btn--orange:hover { background: #FFA063; }
.btn--ink { background: var(--ink); color: var(--frost); }
.btn--ink:hover { background: var(--ink-2); color: var(--cyan); }
.btn--ghost {
  background: transparent;
  color: var(--ink);
  box-shadow: inset 0 0 0 1px var(--indigo);
}
.btn--ghost:hover { background: rgba(42, 92, 122, .12); }
.header-cta { padding: 11px 18px; }

.nav-toggle {
  display: none;
  align-items: center;
  gap: 9px;
  padding: 11px 14px;
  background: var(--frost);
  color: var(--ink);
  clip-path: var(--cut-sm);
}
.nav-toggle-bars {
  position: relative;
  width: 16px;
  height: 2px;
  background: currentColor;
  flex: none;
}
.nav-toggle-bars::before,
.nav-toggle-bars::after {
  content: "";
  position: absolute;
  left: 0;
  width: 16px;
  height: 2px;
  background: currentColor;
  transition: transform .2s var(--ease), opacity .16s var(--ease);
}
.nav-toggle-bars::before { top: -5px; }
.nav-toggle-bars::after { top: 5px; }
.nav-toggle[aria-expanded="true"] .nav-toggle-bars { background: transparent; }
.nav-toggle[aria-expanded="true"] .nav-toggle-bars::before { transform: translateY(5px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle-bars::after { transform: translateY(-5px) rotate(-45deg); }
.nav-toggle-label {
  font-size: 12.5px;
  font-weight: 700;
  letter-spacing: 0.08em;
}

/* 滚动收窄 */
.site-header.is-condensed .brand-sub { display: none; }
.site-header.is-condensed .brand-island { padding: 11px 18px 11px 14px; }
.site-header.is-condensed .nav-en { display: none; }
.site-header.is-condensed .nav-link { padding-block: 9px; }

/* 中英强调切换 */
.site-header[data-lang-mode="en"] .nav-en { color: var(--indigo); font-size: 10.5px; }
.site-header[data-lang-mode="en"] .nav-cn { opacity: .58; }
.site-header[data-lang-mode="en"] .nav-link[aria-current="page"] .nav-cn { opacity: 1; }

/* ---------- 7. 页脚 ---------- */
.site-footer {
  position: relative;
  margin-top: clamp(48px, 7vw, 104px);
  background: var(--ink);
  color: var(--frost);
  overflow: hidden;
}
.site-footer::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    linear-gradient(118deg, rgba(53, 224, 200, .12) 0%, rgba(11, 42, 37, 0) 40%, rgba(255, 138, 61, .12) 100%);
  pointer-events: none;
}
.site-footer > * { position: relative; }

.footer-grid {
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr 1.25fr;
  gap: clamp(24px, 3vw, 48px);
  padding-block: clamp(48px, 7vw, 88px) clamp(32px, 4vw, 56px);
}

.footer-col { min-width: 0; }
.footer-col--brand { max-width: 34ch; }

.footer-brand {
  font-size: clamp(22px, 2.4vw, 30px);
  font-weight: 800;
  letter-spacing: 0.04em;
  color: var(--frost);
}
.footer-tagline {
  margin-top: 12px;
  font-size: 13.5px;
  line-height: 1.8;
  color: rgba(207, 231, 242, .66);
}
.footer-mark {
  display: block;
  width: 72px;
  height: 3px;
  margin-top: 22px;
  background: linear-gradient(90deg, var(--cyan) 0%, var(--indigo) 52%, var(--orange) 100%);
}

.footer-title {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 8px;
  margin-bottom: 18px;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--cyan);
}
.footer-title-en {
  font-size: 10px;
  letter-spacing: 0.2em;
  color: rgba(207, 231, 242, .42);
}

.footer-list > li + li { margin-top: 11px; }

.footer-link {
  display: block;
  font-size: 14px;
  line-height: 1.5;
  color: rgba(244, 250, 252, .80);
  transition: color .18s var(--ease);
}
.footer-link:hover { color: var(--cyan); }
.footer-link-en {
  display: block;
  margin-top: 2px;
  font-family: var(--font-mono);
  font-size: 9.5px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: rgba(207, 231, 242, .38);
}

.footer-contact li {
  font-size: 13.5px;
  line-height: 1.7;
  color: rgba(244, 250, 252, .82);
  word-break: break-word;
}
.footer-key {
  display: block;
  margin-bottom: 2px;
  font-family: var(--font-mono);
  font-size: 9.5px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--steel);
}
.footer-value { display: block; }

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 12px 28px;
  padding-block: 22px;
  border-top: 1px solid rgba(207, 231, 242, .14);
  font-size: 12px;
  color: rgba(207, 231, 242, .58);
}
.footer-legal { font-family: var(--font-mono); letter-spacing: 0.06em; }
.footer-note { line-height: 1.6; }
.footer-minor { display: flex; flex-wrap: wrap; gap: 8px 20px; }
.footer-minor a {
  color: rgba(207, 231, 242, .76);
  transition: color .18s var(--ease);
}
.footer-minor a:hover { color: var(--cyan); }

/* ---------- 8. 通用组件 ---------- */
.panel {
  position: relative;
  padding: clamp(20px, 2.6vw, 34px);
  background: var(--frost);
  clip-path: var(--cut-panel);
}
.panel--tl { clip-path: polygon(22px 0, 100% 0, 100% 100%, 0 100%, 0 22px); }
.panel--ink { background: var(--ink-2); color: var(--frost); }
.panel--ink h2, .panel--ink h3, .panel--ink h4 { color: var(--frost); }
.panel--ink .label { color: var(--cyan); }
.panel--ice { background: rgba(207, 231, 242, .72); }

.trajectory {
  position: relative;
  height: 1px;
  margin-block: clamp(20px, 3vw, 36px);
  background: linear-gradient(90deg,
    rgba(42, 92, 122, 0) 0%,
    rgba(42, 92, 122, .55) 12%,
    var(--cyan) 56%,
    var(--orange) 88%,
    rgba(255, 138, 61, 0) 100%);
}
.trajectory::after {
  content: "";
  position: absolute;
  top: -4px;
  left: 0;
  width: 9px;
  height: 9px;
  background: var(--cyan);
  clip-path: polygon(50% 0, 100% 50%, 50% 100%, 0 50%);
  animation: trajectory-run 11s linear infinite;
}
@keyframes trajectory-run {
  0% { left: 0; opacity: 0; }
  12% { opacity: 1; }
  88% { opacity: 1; }
  100% { left: calc(100% - 9px); opacity: 0; }
}

.breadcrumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.1em;
  color: var(--steel);
}
.breadcrumbs li { display: flex; align-items: center; gap: 8px; }
.breadcrumbs li + li::before { content: "／"; color: var(--indigo); }
.breadcrumbs a { color: var(--steel); transition: color .18s var(--ease); }
.breadcrumbs a:hover { color: var(--indigo); }
.section--dark .breadcrumbs,
.section--dark .breadcrumbs a { color: rgba(207, 231, 242, .62); }
.section--dark .breadcrumbs a:hover { color: var(--cyan); }

/* 图片容器基础规则（页面阶段放插图） */
.media-frame {
  position: relative;
  display: block;
  overflow: hidden;
  aspect-ratio: 16 / 10;
  background: linear-gradient(140deg, var(--ink-2) 0%, var(--indigo) 52%, var(--ice) 100%);
  clip-path: var(--cut-panel);
}
.media-frame img,
.media-frame > svg {
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.media-frame::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(162deg, rgba(53, 224, 200, .20) 0%, rgba(53, 224, 200, 0) 46%, rgba(255, 138, 61, .18) 100%);
  pointer-events: none;
}
.media-frame--wide { aspect-ratio: 21 / 9; }
.media-frame--tall { aspect-ratio: 3 / 4; }
.media-frame--square { aspect-ratio: 1 / 1; }

/* 标签页 */
.tabs { display: block; }
.tab-list {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-bottom: clamp(18px, 2.4vw, 28px);
}
.tab {
  padding: 10px 18px;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--ink);
  background: rgba(42, 92, 122, .14);
  clip-path: var(--cut-sm);
  transition: background .2s var(--ease), color .2s var(--ease);
}
.tab:hover { background: rgba(42, 92, 122, .24); }
.tab[aria-selected="true"] { background: var(--ink); color: var(--cyan); }
.tab-panel { animation: tab-in .22s var(--ease); }
@keyframes tab-in {
  from { opacity: 0; transform: translateY(6px); }
  to { opacity: 1; transform: none; }
}

/* 显现 */
.reveal {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity .5s var(--ease), transform .5s var(--ease);
}
.reveal.is-visible { opacity: 1; transform: none; }

/* ---------- 9. 响应式 ---------- */
@media (max-width: 1180px) {
  .nav-en { display: none; }
  .site-header.is-condensed .brand-sub { display: none; }
}

@media (max-width: 960px) {
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .footer-col--brand { grid-column: 1 / -1; max-width: none; }
  .grid-12 { grid-template-columns: repeat(6, minmax(0, 1fr)); }
}

@media (max-width: 900px) {
  body { padding-bottom: 104px; }

  .site-header {
    top: auto;
    bottom: 0;
    padding: 10px clamp(10px, 3vw, 18px) calc(10px + env(safe-area-inset-bottom, 0px));
  }

  .header-shell { gap: 8px; }

  .brand-island { padding: 10px 16px 10px 13px; }
  .brand-sub { display: none; }
  .brand-name { font-size: 14px; }

  .site-nav {
    position: absolute;
    left: 0;
    right: 0;
    bottom: calc(100% + 10px);
    margin: 0;
    padding: 10px;
    background: rgba(11, 42, 37, .97);
    -webkit-backdrop-filter: blur(18px);
    backdrop-filter: blur(18px);
    clip-path: var(--cut-nav);
    opacity: 0;
    visibility: hidden;
    transform: translateY(14px);
    transition: opacity .22s var(--ease), transform .22s var(--ease), visibility .22s linear;
  }
  .site-nav[data-open] {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
  }

  .nav-list { flex-direction: column; align-items: stretch; gap: 4px; }
  .nav-item { display: block; }
  .nav-link {
    flex-direction: row;
    align-items: baseline;
    justify-content: space-between;
    gap: 12px;
    padding: 12px 14px;
    color: var(--frost);
  }
  .nav-link:hover { background: rgba(53, 224, 200, .12); }
  .nav-link[aria-current="page"] { background: var(--ink-2); }
  .nav-link[aria-current="page"] .nav-cn { color: var(--cyan); }
  .nav-cn { color: var(--frost); }
  .nav-en { display: inline; color: rgba(207, 231, 242, .5); }
  .nav-link[aria-current="page"] .nav-en { color: var(--cyan); }

  .site-header.is-condensed .nav-en { display: inline; }
  .site-header[data-lang-mode="en"] .nav-en { color: var(--cyan); }

  .nav-toggle { display: inline-flex; }
  .header-cta { padding: 10px 15px; font-size: 13px; }
}

@media (max-width: 620px) {
  .grid-12 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .footer-grid { grid-template-columns: 1fr; }
  .footer-bottom { flex-direction: column; align-items: flex-start; }
}

@media (max-width: 460px) {
  .lang-switch { display: none; }
  .nav-toggle-label { display: none; }
  .nav-toggle { padding: 11px 12px; }
  .brand-island { padding: 9px 13px 9px 11px; }
  .header-cta { padding: 9px 13px; font-size: 12.5px; }
}

/* ---------- 10. 减弱动效 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *,
  *::before,
  *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
  }
  .reveal { opacity: 1 !important; transform: none !important; }
  .trajectory::after { animation: none; left: 50%; opacity: 1; }
  .scroll-progress { transition: none; }
}