/* ============================================================
   四季体育赛场 · 共享样式表  /assets/site.css
   reset → 变量 → 排版 → 工具 → 页头 → 页脚 → 通用组件 → 响应式
   ============================================================ */

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

html {
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
  scroll-behavior: smooth;
  background: #1C1C1E;
}

body,
h1, h2, h3, h4, h5, h6,
p, ul, ol, li, figure, figcaption, blockquote, dl, dd,
section, article, aside, header, footer, nav, main {
  margin: 0;
  padding: 0;
}

ul, ol { list-style: none; }
img, picture, svg, video { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
button, input, select, textarea { font: inherit; color: inherit; background: none; border: 0; }
button { cursor: pointer; }
table { border-collapse: collapse; width: 100%; }

/* ---------- 2. 变量 ---------- */
:root {
  /* 品牌色板 */
  --ink: #1C1C1E;            /* 赛场深灰：全站主背景 */
  --paper: #F5F3EE;          /* 看台纸白：长文与卡带底色 */
  --white: #FFFFFF;          /* 纯净白：深灰底上的正文与数字 */
  --muted: #6B6B70;          /* 次级灰：纸白底上的辅助说明 */
  --dim: #9A9AA0;            /* 次级灰在深灰底上的提升档，仅用于辅助文字 */
  --spring: #2E7D32;
  --summer: #EF6C00;
  --autumn: #F9A825;
  --winter: #1565C0;
  --live: #D32F2F;           /* 比分高亮红：全站唯一定点强调色 */
  --card-gold: #E8B10A;
  --deep: #0F0F11;           /* 深黑窄底：页头页脚与窄条 */

  /* 当前赛季锚点（由 html[data-season] 切换） */
  --accent: var(--spring);
  --accent-ink: #FFFFFF;

  /* 结构 */
  --shell: 1280px;
  --gutter: clamp(16px, 4vw, 40px);
  --line: 2px solid rgba(255, 255, 255, 0.16);
  --line-strong: 2px solid var(--ink);
  --dur: 240ms;
  --shadow-hard: 6px 6px 0 0 var(--ink);

  /* 字体 */
  --f-serif: "Songti SC", "Source Han Serif SC", "Noto Serif SC", "SimSun", Georgia, "Times New Roman", serif;
  --f-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", Arial, sans-serif;
  --f-num: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, "Courier New", monospace;
}

html[data-season="summer"] { --accent: var(--summer); }
html[data-season="autumn"] { --accent: var(--autumn); --accent-ink: #1C1C1E; }
html[data-season="winter"] { --accent: var(--winter); }

/* ---------- 3. 排版 ---------- */
body {
  min-height: 100vh;
  background: var(--ink);
  color: var(--white);
  font-family: var(--f-sans);
  font-size: 17px;
  font-weight: 400;
  line-height: 1.75;
  letter-spacing: 0.01em;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4 {
  font-family: var(--f-serif);
  font-weight: 700;
  line-height: 1.25;
  letter-spacing: -0.01em;
}
h1 { font-size: clamp(32px, 5.2vw, 56px); }
h2 { font-size: clamp(24px, 3.4vw, 38px); }
h3 { font-size: clamp(19px, 2.2vw, 26px); }
h4 { font-size: 18px; }

strong, b { font-weight: 700; }
small { font-size: 13px; }

.num,
.time-num,
.stat-num {
  font-variant-numeric: tabular-nums;
  font-feature-settings: "tnum" 1;
}

:focus-visible {
  outline: 3px solid var(--accent);
  outline-offset: 3px;
  border-radius: 0;
}

/* ---------- 4. 工具类与容器 ---------- */
.shell {
  width: 100%;
  max-width: var(--shell);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

#main-content { display: block; scroll-margin-top: 120px; }

.section { padding-block: clamp(40px, 6vw, 80px); }
.section--tight { padding-block: clamp(24px, 3vw, 40px); }

.stack > * + * { margin-top: var(--stack, 20px); }

.rule { height: 2px; background: rgba(255, 255, 255, 0.14); border: 0; }
.rule--accent { background: var(--accent); }

.eyebrow {
  display: block;
  font-family: var(--f-num);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--dim);
}

.prose {
  max-width: 70ch;
  font-size: 17px;
  line-height: 1.75;
}
.prose > * + * { margin-top: 1.1em; }
.prose ul { display: grid; gap: 0.5em; }
.prose li { position: relative; padding-left: 1.4em; }
.prose li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.72em;
  width: 12px;
  height: 2px;
  background: var(--accent);
}

.grid { display: grid; gap: clamp(16px, 2.4vw, 28px); }
.grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }

.layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 240px;
  gap: clamp(20px, 3vw, 36px);
  align-items: start;
}

.visually-hidden {
  position: absolute !important;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  clip-path: inset(50%);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: fixed;
  top: 10px;
  left: 10px;
  z-index: 300;
  transform: translateY(-220%);
  background: var(--white);
  color: var(--ink);
  border: 2px solid var(--ink);
  padding: 10px 18px;
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.04em;
  transition: transform var(--dur) ease;
}
.skip-link:focus { transform: translateY(0); }

/* ---------- 5. 页头：紧凑命令栏 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--deep);
  border-bottom: 2px solid rgba(255, 255, 255, 0.14);
  transition: border-color var(--dur) ease, box-shadow var(--dur) ease;
}
.site-header[data-scrolled] {
  border-bottom-color: var(--accent);
  box-shadow: 0 10px 26px rgba(0, 0, 0, 0.45);
}

.season-strip {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  width: 100%;
  height: 4px;
}
.season-strip--footer { height: 3px; }
.season-strip__seg { display: block; height: 100%; }
.season-strip__seg--spring { background: var(--spring); }
.season-strip__seg--summer { background: var(--summer); }
.season-strip__seg--autumn { background: var(--autumn); }
.season-strip__seg--winter { background: var(--winter); }

.scroll-progress {
  position: absolute;
  left: 0;
  right: 0;
  bottom: -2px;
  height: 2px;
  overflow: hidden;
  pointer-events: none;
}
.scroll-progress__bar {
  display: block;
  width: 100%;
  height: 100%;
  background: var(--live);
  transform: scaleX(0);
  transform-origin: left center;
  will-change: transform;
}

.header__inner {
  position: relative;
  display: flex;
  align-items: center;
  gap: clamp(12px, 1.8vw, 26px);
  padding-block: 10px;
}

.brand {
  display: flex;
  flex-direction: column;
  gap: 3px;
  flex: 0 0 auto;
  padding-block: 2px;
}
.brand__mark {
  font-family: var(--f-serif);
  font-weight: 700;
  font-size: 21px;
  line-height: 1.1;
  letter-spacing: 0.02em;
  color: var(--white);
  border-bottom: 3px solid var(--accent);
  padding-bottom: 3px;
  transition: border-color var(--dur) ease;
}
.brand:hover .brand__mark,
.brand:focus-visible .brand__mark { border-bottom-color: var(--live); }
.brand__tag {
  font-size: 11px;
  line-height: 1.2;
  letter-spacing: 0.08em;
  color: var(--dim);
}

.site-nav {
  flex: 1 1 auto;
  display: flex;
  justify-content: center;
  min-width: 0;
}
.site-nav__list {
  display: flex;
  align-items: center;
  gap: 2px;
}
.site-nav__item { flex: 0 0 auto; }
.site-nav__link {
  display: inline-flex;
  align-items: baseline;
  gap: 6px;
  padding: 7px 10px;
  font-size: 14px;
  font-weight: 600;
  letter-spacing: 0.02em;
  color: rgba(255, 255, 255, 0.72);
  border-bottom: 2px solid transparent;
  transition: color var(--dur) ease, border-color var(--dur) ease, background-color var(--dur) ease;
}
.site-nav__link:hover {
  color: var(--white);
  border-bottom-color: var(--accent);
  background: rgba(255, 255, 255, 0.05);
}
.site-nav__link[aria-current="page"] {
  color: var(--white);
  border-bottom-color: var(--accent);
  background: rgba(255, 255, 255, 0.08);
}
.site-nav__index {
  font-family: var(--f-num);
  font-size: 10px;
  letter-spacing: 0.1em;
  color: rgba(255, 255, 255, 0.42);
}
.site-nav__link[aria-current="page"] .site-nav__index { color: var(--accent); }

.header__tools {
  display: flex;
  align-items: center;
  gap: 12px;
  flex: 0 0 auto;
}

.header__entry {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--accent-ink);
  background: var(--accent);
  border: 2px solid var(--accent);
  transition: background-color var(--dur) ease, color var(--dur) ease;
}
.header__entry:hover,
.header__entry:focus-visible {
  background: transparent;
  color: var(--accent);
}
.header__entry-arrow {
  display: inline-block;
  transition: transform var(--dur) ease;
}
.header__entry:hover .header__entry-arrow { transform: translateX(3px); }

.season-switch {
  display: inline-flex;
  align-items: stretch;
  border: 2px solid rgba(255, 255, 255, 0.22);
  background: #131315;
}
.season-switch__key {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  padding: 5px 9px;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: rgba(255, 255, 255, 0.6);
  border-right: 1px solid rgba(255, 255, 255, 0.14);
  transition: color var(--dur) ease, background-color var(--dur) ease;
}
.season-switch__key:last-child { border-right: 0; }
.season-switch__key:hover {
  color: var(--white);
  background: rgba(255, 255, 255, 0.08);
}
.season-switch__key[data-season-key="spring"] { --key-c: var(--spring); }
.season-switch__key[data-season-key="summer"] { --key-c: var(--summer); }
.season-switch__key[data-season-key="autumn"] { --key-c: var(--autumn); }
.season-switch__key[data-season-key="winter"] { --key-c: var(--winter); }
.season-switch__key[aria-pressed="true"] {
  background: var(--key-c, var(--accent));
  color: var(--white);
}
.season-switch__key[data-season-key="autumn"][aria-pressed="true"] { color: var(--ink); }
.season-switch__dot {
  width: 8px;
  height: 8px;
  flex: 0 0 auto;
  background: var(--key-c, var(--accent));
  transition: background-color var(--dur) ease;
}
.season-switch__key[aria-pressed="true"] .season-switch__dot { background: currentColor; }
.season-switch__label { line-height: 1; }

.legend {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.1em;
  color: var(--dim);
  white-space: nowrap;
}
.legend__dot {
  width: 9px;
  height: 9px;
  flex: 0 0 auto;
  background: var(--live);
}

.nav-toggle {
  display: none;
  align-items: center;
  gap: 9px;
  padding: 8px 12px;
  border: 2px solid rgba(255, 255, 255, 0.28);
  color: var(--white);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.08em;
  transition: border-color var(--dur) ease, color var(--dur) ease;
}
.nav-toggle:hover,
.nav-toggle[aria-expanded="true"] {
  border-color: var(--accent);
  color: var(--accent);
}
.nav-toggle__bars {
  display: block;
  width: 16px;
  height: 2px;
  background: currentColor;
  box-shadow: 0 -5px 0 currentColor, 0 5px 0 currentColor;
}
.nav-toggle__label { line-height: 1; }

body[data-nav-open] { overflow: hidden; }

/* ---------- 6. 页脚 ---------- */
.site-footer {
  margin-top: clamp(48px, 7vw, 96px);
  background: var(--deep);
  border-top: 2px solid var(--accent);
  color: rgba(255, 255, 255, 0.82);
}
.footer__inner { padding-block: clamp(30px, 4vw, 54px) 26px; }

.footer__head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 10px 20px;
  padding-bottom: 22px;
  border-bottom: 2px solid rgba(255, 255, 255, 0.12);
}
.footer__mark {
  font-family: var(--f-serif);
  font-weight: 700;
  font-size: 25px;
  letter-spacing: 0.02em;
  color: var(--white);
}
.footer__tag {
  font-size: 14px;
  letter-spacing: 0.04em;
  color: var(--dim);
}
.footer__head .legend { margin-left: auto; }

.footer__cols {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: clamp(20px, 3vw, 40px);
  padding-block: 28px;
}
.footer__col { min-width: 0; }
.footer__title {
  font-family: var(--f-num);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.2em;
  color: var(--dim);
  margin-bottom: 12px;
}
.footer__list { display: grid; gap: 8px; }
.footer__link {
  position: relative;
  display: inline-block;
  font-size: 15px;
  color: rgba(255, 255, 255, 0.78);
  transition: color var(--dur) ease;
}
.footer__link::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -2px;
  width: 100%;
  height: 2px;
  background: var(--accent);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform var(--dur) ease;
}
.footer__link:hover { color: var(--white); }
.footer__link:hover::after,
.footer__link:focus-visible::after { transform: scaleX(1); }

.footer__bottom {
  display: grid;
  gap: 8px;
  padding-top: 22px;
  border-top: 2px solid rgba(255, 255, 255, 0.12);
  font-size: 13px;
  color: var(--dim);
}
.footer__legal {
  font-family: var(--f-num);
  letter-spacing: 0.06em;
  color: rgba(255, 255, 255, 0.72);
}
.footer__contact { line-height: 1.7; }
.footer__note { color: var(--dim); }
.footer__copy { font-size: 12px; letter-spacing: 0.06em; }

/* ---------- 7. 通用组件 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 22px;
  border: 2px solid var(--white);
  color: var(--white);
  font-size: 15px;
  font-weight: 700;
  letter-spacing: 0.04em;
  background: transparent;
  transition: background-color var(--dur) ease, color var(--dur) ease, border-color var(--dur) ease;
}
.btn:hover { background: var(--white); color: var(--ink); }
.btn--solid {
  background: var(--accent);
  border-color: var(--accent);
  color: var(--accent-ink);
}
.btn--solid:hover {
  background: var(--white);
  border-color: var(--white);
  color: var(--ink);
}
.btn--ghost {
  border-color: rgba(255, 255, 255, 0.32);
  color: var(--white);
}
.btn--ghost:hover {
  background: transparent;
  border-color: var(--accent);
  color: var(--accent);
}
.btn:disabled { opacity: 0.5; cursor: not-allowed; }

.link-line {
  position: relative;
  display: inline-block;
  font-weight: 600;
}
.link-line::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: -2px;
  height: 2px;
  background: currentColor;
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform var(--dur) ease;
}
.link-line:hover::after,
.link-line:focus-visible::after,
.link-line[aria-current="page"]::after { transform: scaleX(1); }

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  letter-spacing: 0.04em;
  color: var(--dim);
}
.breadcrumb a { color: var(--dim); transition: color var(--dur) ease; }
.breadcrumb a:hover { color: var(--white); }
.breadcrumb__sep { color: rgba(255, 255, 255, 0.28); }
.breadcrumb [aria-current="page"] { color: var(--white); }

.panel {
  border: 2px solid rgba(255, 255, 255, 0.16);
  background: var(--deep);
  padding: clamp(20px, 3vw, 32px);
}
.panel--paper {
  background: var(--paper);
  color: var(--ink);
  border-color: var(--ink);
  box-shadow: 6px 6px 0 0 var(--accent);
}
.panel--paper .eyebrow,
.panel--paper .card__meta { color: var(--muted); }

.card {
  border: 2px solid rgba(255, 255, 255, 0.18);
  background: var(--deep);
  padding: 20px;
  transition: border-color var(--dur) ease, box-shadow var(--dur) ease;
}
.card:hover,
.card:focus-within {
  border-color: var(--accent);
  box-shadow: 6px 6px 0 0 var(--accent);
}
.card__head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
}
.card__meta {
  font-size: 13px;
  letter-spacing: 0.04em;
  color: var(--dim);
}
.card__title { font-size: 20px; margin-top: 10px; }

.band {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px 24px;
  padding: 14px 20px;
  background: var(--deep);
  border-left: 6px solid var(--accent);
}
.band--paper { background: var(--paper); color: var(--ink); }
.band--spring { border-left-color: var(--spring); }
.band--summer { border-left-color: var(--summer); }
.band--autumn { border-left-color: var(--autumn); }
.band--winter { border-left-color: var(--winter); }
.band__label {
  font-family: var(--f-num);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.2em;
  color: var(--dim);
}
.band--paper .band__label { color: var(--muted); }

.tape {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 2px;
  background: rgba(255, 255, 255, 0.16);
  border: 2px solid rgba(255, 255, 255, 0.16);
}
.tape__item {
  background: var(--deep);
  padding: 18px 20px;
  transition: opacity var(--dur) ease, background-color var(--dur) ease;
}
.tape:hover .tape__item { opacity: 0.55; }
.tape:hover .tape__item:hover { opacity: 1; background: #17171A; }

.rail {
  position: sticky;
  top: 96px;
  border: 2px solid rgba(255, 255, 255, 0.16);
  background: var(--deep);
}
.rail__head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  padding: 10px 12px;
  border-bottom: 2px solid rgba(255, 255, 255, 0.16);
  font-family: var(--f-num);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--dim);
}
.rail__body { padding: 12px; }

.media-frame {
  position: relative;
  overflow: hidden;
  aspect-ratio: 16 / 10;
  border: 2px solid var(--ink);
  background: #232326;
}
.media-frame img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 420ms ease;
}
.media-frame:hover img { transform: scale(1.03); }
.media-frame--wide { aspect-ratio: 21 / 9; }
.media-frame--tall { aspect-ratio: 3 / 4; }
.media-frame--paper { box-shadow: 6px 6px 0 0 var(--accent); }
.media-frame__cap {
  position: absolute;
  left: 0;
  bottom: 0;
  padding: 6px 12px;
  background: var(--deep);
  color: var(--white);
  font-size: 12px;
  letter-spacing: 0.08em;
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 3px 9px;
  border: 2px solid currentColor;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.08em;
  line-height: 1.5;
}
.tag--spring { color: var(--spring); }
.tag--summer { color: var(--summer); }
.tag--autumn { color: var(--autumn); }
.tag--winter { color: var(--winter); }
.tag--live { color: var(--live); }

.stat-num {
  font-family: var(--f-num);
  font-weight: 700;
  font-size: clamp(28px, 4vw, 44px);
  line-height: 1;
  letter-spacing: -0.02em;
}
.stat-num--live { color: var(--live); }
.time-num {
  font-family: var(--f-num);
  font-weight: 700;
  letter-spacing: 0.02em;
}

/* ---------- 8. 响应式 ---------- */
@media (max-width: 1180px) {
  .brand__tag { display: none; }
  .legend { display: none; }
}

@media (max-width: 1000px) {
  .header__inner { flex-wrap: wrap; gap: 12px 14px; padding-block: 10px 12px; }
  .brand { order: 1; }
  .header__tools { order: 2; margin-left: auto; gap: 10px; }
  .nav-toggle { order: 3; display: inline-flex; }
  .site-nav {
    order: 4;
    flex: 1 0 100%;
    display: none;
    flex-direction: column;
    justify-content: flex-start;
    margin-inline: calc(-1 * var(--gutter));
    padding: 6px var(--gutter) 14px;
    border-top: 2px solid rgba(255, 255, 255, 0.14);
    background: var(--deep);
  }
  .site-nav[data-open] { display: flex; }
  .site-nav__list { flex-direction: column; align-items: stretch; gap: 0; width: 100%; }
  .site-nav__item { width: 100%; }
  .site-nav__link {
    width: 100%;
    padding: 12px 8px;
    font-size: 16px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.12);
    border-left: 4px solid transparent;
  }
  .site-nav__link[aria-current="page"] {
    border-bottom-color: rgba(255, 255, 255, 0.12);
    border-left-color: var(--accent);
    background: rgba(255, 255, 255, 0.06);
  }
  .layout { grid-template-columns: minmax(0, 1fr); }
  .grid--3 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .rail { position: static; }
  .media-frame--tall { aspect-ratio: 4 / 3; }
}

@media (max-width: 860px) {
  body { font-size: 16px; }
  .footer__cols { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 760px) {
  .header__entry { display: none; }
  .grid--2,
  .grid--3 { grid-template-columns: minmax(0, 1fr); }
  .tape { grid-template-columns: minmax(0, 1fr); }
  .tape:hover .tape__item { opacity: 1; }
}

@media (max-width: 560px) {
  .season-switch__label { display: none; }
  .season-switch__key { padding: 6px 9px; }
  .brand__mark { font-size: 18px; }
  .footer__cols { grid-template-columns: minmax(0, 1fr); }
  .footer__head .legend { margin-left: 0; }
  .stat-num { font-size: clamp(24px, 9vw, 34px); }
  .tape__item { padding: 14px 16px; }
}

/* ---------- 9. 无障碍与动效偏好 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *,
  *::before,
  *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }
  .media-frame:hover img { transform: none; }
  .header__entry:hover .header__entry-arrow { transform: none; }
  .scroll-progress { display: none; }
}