/* ============================================================
   /assets/site.css — 四季体育主站 共享外壳
   雪原灰白底 + 深墨夜间轨道 + 冰蓝索引 + 暖橙刻度
   ============================================================ */

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

html { -webkit-text-size-adjust: 100%; text-size-adjust: 100%; }

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

/* ---------- 2. 变量 ---------- */
:root {
  --snow: #F3F6F5;
  --paper: #FFFFFF;
  --ink: #0B1620;
  --ink-2: #132832;
  --ice: #8FE3F2;
  --cyan: #2FA8BD;
  --amber: #FF7A1A;
  --amber-deep: #C24A00;
  --pine: #1F4A3A;
  --grey: #A7B4B8;
  --grid: #2A3B44;
  --line: #D8E0E1;
  --text-mute: #5C6E74;

  --rail: 248px;
  --bar-h: 62px;
  --maxw: 1440px;
  --pad: clamp(18px, 4vw, 56px);

  --mono: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
  --sans: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --ease: cubic-bezier(.2, .7, .2, 1);
}

/* ---------- 3. 基础排版 ---------- */
body {
  min-height: 100vh;
  font-family: var(--sans);
  font-size: 17px;
  line-height: 1.75;
  letter-spacing: .012em;
  color: var(--ink);
  background-color: var(--snow);
  background-image: linear-gradient(to right, rgba(42, 59, 68, .055) 1px, transparent 1px);
  background-size: 88px 100%;
}

h1, h2, h3 { font-weight: 800; line-height: 1.16; letter-spacing: .05em; color: var(--ink); }
h1 { font-size: clamp(40px, 6vw, 88px); letter-spacing: .06em; }
h2 { font-size: clamp(28px, 3.4vw, 44px); }
h3 { font-size: clamp(20px, 2vw, 26px); }

a { transition: color .16s var(--ease); }

:focus-visible { outline: 2px solid var(--amber); outline-offset: 3px; }

@media (prefers-reduced-motion: no-preference) {
  html { scroll-behavior: smooth; }
}

/* ---------- 4. 跳转链 ---------- */
.skip-link {
  position: fixed;
  top: 8px;
  left: 8px;
  z-index: 300;
  transform: translateY(-180%);
  padding: 10px 18px;
  background: var(--ink);
  color: var(--ice);
  border: 1px solid var(--ice);
  font-size: 14px;
  letter-spacing: .06em;
  transition: transform .18s var(--ease);
}
.skip-link:focus { transform: translateY(0); }

/* ---------- 5. 按钮 ---------- */
.btn {
  --btn-bg: transparent;
  --btn-fg: var(--ink);
  --btn-bd: var(--grid);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 11px 18px;
  font-size: 14px;
  font-weight: 700;
  letter-spacing: .08em;
  line-height: 1.3;
  color: var(--btn-fg);
  background: var(--btn-bg);
  border: 1px solid var(--btn-bd);
  border-radius: 0;
  text-align: center;
  transition: background-color .16s var(--ease), color .16s var(--ease),
              border-color .16s var(--ease), box-shadow .16s var(--ease);
}
.btn:hover { box-shadow: 0 0 0 1px var(--ice); }
.btn--sm { padding: 9px 12px; font-size: 12.5px; letter-spacing: .12em; }
.btn--block { display: flex; width: 100%; }
.btn--amber { --btn-bg: var(--amber); --btn-fg: #1A0C02; --btn-bd: var(--amber); }
.btn--amber:hover { --btn-bg: #FF8C3D; }
.btn--ghost { --btn-bg: transparent; --btn-fg: var(--ice); --btn-bd: rgba(143, 227, 242, .45); }
.btn--ghost:hover { --btn-fg: #FFFFFF; --btn-bd: var(--ice); }

/* ---------- 6. 头部：桌面左侧轨道 ---------- */
.site-header {
  position: fixed;
  inset: 0 auto 0 0;
  width: var(--rail);
  z-index: 100;
  display: flex;
  flex-direction: column;
  overflow-y: auto;
  padding: 22px 22px 20px;
  color: #DCE7EA;
  background: linear-gradient(180deg, #0B1620 0%, #0B1620 58%, #0F2430 100%);
}
.site-header::after {
  content: "";
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  width: 1px;
  background: repeating-linear-gradient(180deg, rgba(143, 227, 242, .38) 0 1px, transparent 1px 14px);
}

.site-header__bar { display: block; }

/* 品牌 */
.brand {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  padding-bottom: 22px;
  border-bottom: 1px solid rgba(143, 227, 242, .18);
}
.brand__glyph {
  flex: 0 0 auto;
  width: 14px;
  height: 14px;
  margin-top: 6px;
  background: linear-gradient(135deg, var(--ice) 0 50%, var(--amber) 50% 100%);
}
.brand__text { display: block; }
.brand__name {
  display: block;
  font-size: 22px;
  font-weight: 800;
  letter-spacing: .16em;
  color: #FFFFFF;
  line-height: 1.2;
}
.brand__sub {
  display: block;
  margin-top: 6px;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .14em;
  color: var(--ice);
}
.brand:hover .brand__name { color: var(--ice); }

/* 导航 */
.rail-nav {
  display: flex;
  flex-direction: column;
  flex: 1 1 auto;
  padding-top: 20px;
}
.rail-nav__hint {
  margin-bottom: 12px;
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: .22em;
  color: rgba(167, 180, 184, .8);
}
.rail-nav__list { display: flex; flex-direction: column; gap: 2px; }
.rail-nav__link {
  position: relative;
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 11px 8px 11px 18px;
  font-size: 15px;
  letter-spacing: .06em;
  color: #BFD1D6;
  transition: color .16s var(--ease), background-color .16s var(--ease);
}
.rail-nav__link::before {
  content: "";
  position: absolute;
  left: 0;
  top: 50%;
  width: 2px;
  height: 0;
  background: var(--amber);
  transform: translateY(-50%);
  transition: height .16s var(--ease), background-color .16s var(--ease);
}
.rail-nav__link:hover { color: #FFFFFF; background: rgba(143, 227, 242, .07); }
.rail-nav__link:hover::before { height: 18px; background: var(--cyan); }
.rail-nav__link[aria-current="page"] { color: var(--ice); background: rgba(143, 227, 242, .09); }
.rail-nav__link[aria-current="page"]::before { height: 26px; background: var(--amber); }
.rail-nav__idx {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .1em;
  color: rgba(143, 227, 242, .6);
}
.rail-nav__link[aria-current="page"] .rail-nav__idx { color: var(--amber); }
.rail-nav__label { white-space: nowrap; }

.rail-nav__cta {
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin-top: auto;
  padding-top: 18px;
  border-top: 1px solid rgba(143, 227, 242, .16);
}

/* 坐标刻度 */
.rail-ruler { display: flex; flex-direction: column; gap: 7px; margin-top: 22px; }
.rail-ruler__ticks {
  display: block;
  height: 9px;
  background: repeating-linear-gradient(90deg, rgba(143, 227, 242, .45) 0 1px, transparent 1px 11px);
}
.rail-ruler__coord {
  display: block;
  font-family: var(--mono);
  font-size: 9.5px;
  letter-spacing: .2em;
  color: rgba(143, 227, 242, .55);
}

/* 移动抽屉按钮与遮罩：桌面隐藏 */
.nav-toggle { display: none; }
.rail-scrim { display: none; }

@media (min-width: 1024px) {
  body { padding-left: var(--rail); }
}

/* ---------- 7. 头部：移动/平板抽屉 ---------- */
@media (max-width: 1023px) {
  html { scroll-padding-top: calc(var(--bar-h) + 14px); }
  html[data-nav="open"] { overflow: hidden; }

  .site-header {
    position: sticky;
    inset: auto;
    top: 0;
    width: 100%;
    padding: 0;
    overflow: visible;
    background: var(--ink);
  }
  .site-header::after { display: none; }

  .site-header__bar {
    position: relative;
    z-index: 90;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    height: var(--bar-h);
    padding: 0 16px;
    background: var(--ink);
    border-bottom: 1px solid var(--grid);
  }

  .brand { align-items: center; gap: 10px; padding: 0; border-bottom: 0; }
  .brand__glyph { width: 12px; height: 12px; margin-top: 0; }
  .brand__name { font-size: 18px; letter-spacing: .12em; }
  .brand__sub { margin-top: 2px; font-size: 9.5px; letter-spacing: .12em; }

  .nav-toggle {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    padding: 8px 12px;
    border: 1px solid rgba(143, 227, 242, .4);
    color: var(--ice);
    font-family: var(--mono);
    font-size: 11px;
    letter-spacing: .18em;
  }
  .nav-toggle:hover { border-color: var(--ice); }
  .nav-toggle__bars { display: flex; flex-direction: column; gap: 3px; width: 18px; }
  .nav-toggle__bars span {
    display: block;
    height: 2px;
    background: currentColor;
    transition: transform .2s var(--ease), opacity .2s var(--ease);
  }
  .site-header[data-open] .nav-toggle__bars span:nth-child(1) { transform: translateY(5px) rotate(45deg); }
  .site-header[data-open] .nav-toggle__bars span:nth-child(2) { opacity: 0; }
  .site-header[data-open] .nav-toggle__bars span:nth-child(3) { transform: translateY(-5px) rotate(-45deg); }

  .rail-scrim {
    display: block;
    position: fixed;
    inset: 0;
    z-index: 60;
    background: rgba(6, 14, 20, .62);
    opacity: 0;
    pointer-events: none;
    transition: opacity .2s var(--ease);
  }
  .site-header[data-open] .rail-scrim { opacity: 1; pointer-events: auto; }

  .rail-nav {
    position: fixed;
    top: 0;
    left: 0;
    bottom: 0;
    z-index: 70;
    width: min(86vw, 340px);
    padding: calc(var(--bar-h) + 18px) 20px 24px;
    overflow-y: auto;
    background: #0B1620;
    border-right: 1px solid var(--grid);
    transform: translateX(-102%);
    transition: transform .22s var(--ease);
  }
  .site-header[data-open] .rail-nav { transform: translateX(0); }

  .rail-nav__cta { margin-top: 26px; }
  .rail-ruler { display: none; }
}

/* ---------- 8. 页脚 ---------- */
.site-footer {
  margin-top: clamp(40px, 6vw, 80px);
  background: var(--ink);
  color: #C6D5DA;
  border-top: 1px solid var(--grid);
}
.site-footer__inner { padding-block: clamp(36px, 5vw, 64px) 0; }

.footer__grid {
  display: grid;
  grid-template-columns: 1.6fr 1fr 1.5fr 1fr;
  gap: clamp(20px, 3vw, 40px);
  padding-bottom: clamp(28px, 4vw, 48px);
}
.footer__brand { min-width: 0; }
.footer__name { font-size: 26px; font-weight: 800; letter-spacing: .18em; color: #FFFFFF; }
.footer__desc { margin-top: 12px; max-width: 30ch; font-size: 13.5px; line-height: 1.8; color: #9FB3BA; }
.footer__stamp {
  margin-top: 16px;
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: .2em;
  color: var(--amber);
}

.footer__col {
  min-width: 0;
  padding-left: clamp(16px, 2vw, 28px);
  border-left: 1px solid rgba(42, 59, 68, .95);
}
.footer__ttl {
  margin-bottom: 14px;
  font-family: var(--mono);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: .24em;
  color: var(--ice);
}
.footer__list { display: flex; flex-direction: column; gap: 9px; }
.footer__link {
  position: relative;
  display: inline-block;
  padding-left: 12px;
  font-size: 13.5px;
  letter-spacing: .03em;
  color: #BFD1D6;
  transition: color .16s var(--ease);
}
.footer__link::before {
  content: "";
  position: absolute;
  left: 0;
  top: .82em;
  width: 6px;
  height: 1px;
  background: rgba(143, 227, 242, .55);
  transition: width .16s var(--ease), background-color .16s var(--ease);
}
.footer__link:hover { color: var(--ice); }
.footer__link:hover::before { width: 9px; background: var(--amber); }
.footer__link[aria-current="page"] { color: var(--ice); }
.footer__link[aria-current="page"]::before { background: var(--amber); }

.footer__list--plain li { display: flex; flex-direction: column; gap: 3px; }
.footer__k {
  font-family: var(--mono);
  font-size: 9.5px;
  letter-spacing: .2em;
  color: rgba(167, 180, 184, .85);
}
.footer__v { font-size: 13.5px; line-height: 1.6; color: #DCE7EA; word-break: break-word; }

.footer__base {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding-block: 18px 22px;
  border-top: 1px solid rgba(42, 59, 68, .95);
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .12em;
}
.footer__copy { color: #8A9CA3; }
.footer__mono { color: var(--amber); }

/* ---------- 9. 通用容器 ---------- */
.wrap {
  width: 100%;
  max-width: var(--maxw);
  margin-inline: auto;
  padding-inline: var(--pad);
}
.section { padding-block: clamp(40px, 6vw, 84px); }
.section--ink { background: var(--ink); color: #DCE7EA; }
.section--ink h1,
.section--ink h2,
.section--ink h3 { color: #FFFFFF; }

.prose { max-width: 70ch; font-size: 17px; line-height: 1.8; }
.prose p + p { margin-top: 1em; }
.prose h2 { margin-top: 1.6em; margin-bottom: .5em; font-size: clamp(24px, 2.4vw, 32px); }
.prose h3 { margin-top: 1.4em; margin-bottom: .4em; }
.prose ul { display: flex; flex-direction: column; gap: .4em; }
.prose ul li { position: relative; padding-left: 20px; }
.prose ul li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .78em;
  width: 8px;
  height: 1px;
  background: var(--cyan);
}
.prose a { color: #0F5F6B; text-decoration: underline; text-underline-offset: 3px; }
.prose a:hover { color: var(--amber-deep); }

.kicker {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .22em;
  color: var(--cyan);
}
.kicker::before { content: ""; width: 22px; height: 1px; background: var(--cyan); }
.section--ink .kicker { color: var(--ice); }
.section--ink .kicker::before { background: var(--amber); }

.crumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  padding-block: 14px;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .14em;
  color: var(--text-mute);
}
.crumbs__link { color: #0F5F6B; }
.crumbs__link:hover { color: var(--amber-deep); text-decoration: underline; }
.crumbs__sep { color: var(--grey); }
.crumbs__current { color: var(--ink); }

/* ---------- 10. 网格与卡片 ---------- */
.grid {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: clamp(16px, 2vw, 28px);
}
.grid--auto { grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); }

.card {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: clamp(16px, 2vw, 24px);
  background: var(--paper);
  border: 1px solid var(--line);
  transition: border-color .18s var(--ease), box-shadow .18s var(--ease);
}
.card:hover { border-color: var(--cyan); box-shadow: 0 0 0 1px rgba(47, 168, 189, .25); }
.card__index { font-family: var(--mono); font-size: 11px; letter-spacing: .16em; color: var(--cyan); }
.card__title { font-size: 18px; font-weight: 800; line-height: 1.4; letter-spacing: .03em; }
.card__meta { font-family: var(--mono); font-size: 11px; letter-spacing: .1em; color: var(--text-mute); }

/* ---------- 11. 标签 ---------- */
.tag {
  display: inline-block;
  padding: 3px 9px;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .1em;
  color: #2A3B44;
  background: var(--paper);
  border: 1px solid var(--grid);
}
.tag--ice { color: #12626F; background: rgba(143, 227, 242, .28); border-color: var(--cyan); }
.tag--amber { color: var(--amber-deep); background: #FFF1E7; border-color: var(--amber); }
.tag--pine { color: #FFFFFF; background: var(--pine); border-color: var(--pine); }

/* ---------- 12. 图片容器基础规则 ---------- */
.media {
  position: relative;
  overflow: hidden;
  background: var(--ink-2);
  border: 1px solid var(--line);
}
.media img { width: 100%; height: 100%; object-fit: cover; }
.media--wide { aspect-ratio: 16 / 9; }
.media--tall { aspect-ratio: 3 / 4; }
.media--square { aspect-ratio: 1 / 1; }
.media__cap {
  position: absolute;
  left: 0;
  bottom: 0;
  padding: 6px 10px;
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: .14em;
  color: var(--ice);
  background: rgba(11, 22, 32, .82);
}

/* ---------- 13. 主题筛选 ---------- */
.filter-bar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  padding-block: 12px;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}
.filter-btn {
  padding: 6px 12px;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .14em;
  color: #31474E;
  background: var(--paper);
  border: 1px solid var(--line);
  transition: color .16s var(--ease), background-color .16s var(--ease), border-color .16s var(--ease);
}
.filter-btn:hover { border-color: var(--cyan); color: #0F5F6B; }
.filter-btn[aria-pressed="true"] { color: var(--ice); background: var(--ink); border-color: var(--ink); }
.filter-count {
  margin-left: auto;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .12em;
  color: var(--text-mute);
}
.filter-empty {
  display: none;
  padding: 24px;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--text-mute);
  border: 1px dashed var(--grey);
}

/* ---------- 14. 响应式 ---------- */
@media (max-width: 1023px) {
  body { font-size: 16px; }
  .footer__grid { grid-template-columns: 1fr 1fr; }
  .footer__brand { grid-column: 1 / -1; }
  .footer__col {
    padding-left: 0;
    padding-top: 20px;
    border-left: 0;
    border-top: 1px solid rgba(42, 59, 68, .95);
  }
}

@media (max-width: 640px) {
  .footer__grid { grid-template-columns: 1fr; }
  .footer__base { flex-direction: column; align-items: flex-start; gap: 6px; }
  .filter-count { margin-left: 0; width: 100%; }
  .card { padding: 16px; }
  .media--tall { aspect-ratio: 4 / 5; }
}

/* ---------- 15. 降低动效 ---------- */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
    scroll-behavior: auto !important;
  }
}