/* ==========================================================================
   四季体育主站 · 共享样式 /assets/site.css
   深空蓝底 + 四季分区色 + 印刷边框 + 纸张叠层
   ========================================================================== */

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

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

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

ul, ol { margin: 0; padding: 0; list-style: none; }

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

button, input, select, textarea { font: inherit; color: inherit; }

a { color: inherit; -webkit-tap-highlight-color: transparent; }

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

/* ---------- 变量 ---------- */
:root {
  --bg: #0A1120;
  --panel: #14224A;
  --ink: #F2F6FA;
  --ink-dim: #9BAAC4;
  --blue: #2E9BFF;
  --orange: #FF6A1A;
  --spring: #34D07F;
  --sprout: #E4F25C;
  --autumn-red: #C8382C;
  --amber: #E8A33D;
  --line: #2A3550;
  --mint: #7CF0C8;

  --season-accent: #2E9BFF;
  --season-alt: #FF6A1A;
  --season-wash: rgba(46, 155, 255, 0.14);

  --font-body: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Source Han Sans SC", "Noto Sans CJK SC", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --font-num: "JetBrains Mono", "SFMono-Regular", Menlo, Consolas, "Liberation Mono", "Courier New", monospace;

  --shell: 1360px;
  --gutter: clamp(18px, 4.2vw, 56px);
  --header-h: 78px;
  --radius: 2px;
  --ease: cubic-bezier(0.22, 0.7, 0.25, 1);
}

html[data-season="spring"] {
  --season-accent: #34D07F;
  --season-alt: #E4F25C;
  --season-wash: rgba(52, 208, 127, 0.14);
}
html[data-season="summer"] {
  --season-accent: #2E9BFF;
  --season-alt: #FF6A1A;
  --season-wash: rgba(46, 155, 255, 0.14);
}
html[data-season="autumn"] {
  --season-accent: #C8382C;
  --season-alt: #E8A33D;
  --season-wash: rgba(200, 56, 44, 0.16);
}
html[data-season="winter"] {
  --season-accent: #F2F6FA;
  --season-alt: #2E9BFF;
  --season-wash: rgba(242, 246, 250, 0.12);
}

/* ---------- 中文排版基座 ---------- */
html {
  background: var(--bg);
  scroll-behavior: smooth;
}

body {
  min-height: 100vh;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 17px;
  line-height: 1.75;
  letter-spacing: 0.01em;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

main { display: block; padding-top: var(--header-h); }

#main-content { scroll-margin-top: calc(var(--header-h) + 16px); }

h1, h2, h3, h4 { line-height: 1.22; font-weight: 600; }

p { max-width: 40em; }

a { text-decoration: none; }

.num,
[data-num] {
  font-family: var(--font-num);
  font-variant-numeric: tabular-nums;
  font-feature-settings: "tnum" 1;
  letter-spacing: -0.01em;
}

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

/* ---------- 跳至主内容 ---------- */
.skip-link {
  position: fixed;
  top: 10px;
  left: var(--gutter);
  z-index: 300;
  transform: translateY(-240%);
  background: var(--orange);
  color: #180901;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.08em;
  padding: 10px 16px;
  border-radius: var(--radius);
  transition: transform 220ms var(--ease);
}
.skip-link:focus { transform: translateY(0); }

/* ==========================================================================
   头部
   ========================================================================== */
.site-header {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 120;
  background: transparent;
  border-bottom: 1px solid transparent;
  transition: background-color 320ms var(--ease),
              border-color 320ms var(--ease),
              box-shadow 320ms var(--ease);
}

.site-header[data-stuck="true"] {
  background: #0A1120;
  border-bottom-color: var(--line);
  box-shadow: 0 20px 44px -30px rgba(0, 0, 0, 0.95);
}

.progress-rail {
  position: absolute;
  left: 0; right: 0; bottom: 0;
  height: 2px;
  overflow: hidden;
}

.progress-bar {
  display: block;
  height: 100%;
  width: 100%;
  transform: scaleX(0);
  transform-origin: 0 50%;
  background: linear-gradient(90deg, var(--season-accent), var(--season-alt));
  transition: transform 140ms linear, background 400ms var(--ease);
}

.header-inner {
  max-width: var(--shell);
  margin: 0 auto;
  padding: 0 var(--gutter);
  min-height: var(--header-h);
  display: flex;
  align-items: center;
  gap: clamp(14px, 2vw, 32px);
}

/* 品牌 */
.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  flex: 0 0 auto;
}

.brand-mark {
  font-family: var(--font-num);
  font-size: 12px;
  font-weight: 700;
  line-height: 1;
  letter-spacing: 0.06em;
  padding: 8px 8px;
  color: #08111f;
  border-radius: var(--radius);
  background: linear-gradient(135deg, var(--season-accent), var(--season-alt));
  transition: background 400ms var(--ease);
}

.brand-text { display: flex; flex-direction: column; gap: 2px; }

.brand-line {
  font-size: 17px;
  font-weight: 600;
  line-height: 1.1;
  letter-spacing: 0.1em;
  color: var(--ink);
}

.brand-note {
  font-size: 10px;
  line-height: 1.3;
  letter-spacing: 0.2em;
  color: var(--ink-dim);
}

/* 主导航 */
.primary-nav {
  flex: 1 1 auto;
  min-width: 0;
}

.nav-list {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: clamp(6px, 1.5vw, 26px);
}

.nav-list a {
  position: relative;
  display: inline-block;
  padding: 9px 2px;
  font-size: 14.5px;
  letter-spacing: 0.05em;
  color: var(--ink-dim);
  transition: color 220ms var(--ease);
}

.nav-list a::after {
  content: "";
  position: absolute;
  left: 0; right: 0; bottom: 3px;
  height: 2px;
  background: var(--blue);
  transform: scaleX(0);
  transform-origin: 50% 50%;
  transition: transform 260ms var(--ease), background-color 400ms var(--ease);
}

.nav-list a:hover { color: var(--ink); }
.nav-list a:hover::after { transform: scaleX(1); }

.nav-list a[aria-current="page"] { color: var(--ink); }
.nav-list a[aria-current="page"]::after {
  transform: scaleX(1);
  background: var(--season-accent);
}

/* 工具区 */
.header-tools {
  display: flex;
  align-items: center;
  gap: 10px;
  flex: 0 0 auto;
}

.season-switch {
  display: inline-flex;
  align-items: center;
  gap: 2px;
  padding: 3px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: rgba(10, 17, 32, 0.45);
}

.season-btn {
  appearance: none;
  border: 0;
  background: transparent;
  display: inline-flex;
  align-items: center;
  gap: 5px;
  padding: 7px 9px;
  border-radius: var(--radius);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--ink-dim);
  cursor: pointer;
  transition: background-color 240ms var(--ease), color 240ms var(--ease), box-shadow 240ms var(--ease);
}

.season-btn:hover { color: var(--ink); }

.season-btn[aria-pressed="true"] {
  background: var(--panel);
  color: var(--ink);
}

.season-dot {
  width: 8px;
  height: 8px;
  flex: 0 0 auto;
  border-radius: 50%;
  background: currentColor;
  opacity: 0.85;
}

.season-btn[data-season-set="spring"] .season-dot { background: var(--spring); }
.season-btn[data-season-set="summer"] .season-dot { background: var(--blue); }
.season-btn[data-season-set="autumn"] .season-dot { background: var(--autumn-red); }
.season-btn[data-season-set="winter"] .season-dot { background: var(--ink); }

.season-btn[data-season-set="spring"][aria-pressed="true"] { box-shadow: inset 0 -2px 0 var(--spring); }
.season-btn[data-season-set="summer"][aria-pressed="true"] { box-shadow: inset 0 -2px 0 var(--blue); }
.season-btn[data-season-set="autumn"][aria-pressed="true"] { box-shadow: inset 0 -2px 0 var(--autumn-red); }
.season-btn[data-season-set="winter"][aria-pressed="true"] { box-shadow: inset 0 -2px 0 var(--ink); }

/* 移动端开关 */
.nav-toggle {
  display: none;
  width: 44px;
  height: 44px;
  padding: 0;
  align-items: center;
  justify-content: center;
  background: transparent;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  color: var(--ink);
  cursor: pointer;
  transition: border-color 220ms var(--ease), color 220ms var(--ease);
}

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

.nav-toggle-bars {
  position: relative;
  display: block;
  width: 20px;
  height: 12px;
}

.nav-toggle-bars span {
  position: absolute;
  left: 0; right: 0;
  height: 2px;
  background: currentColor;
  transition: transform 240ms var(--ease), opacity 200ms var(--ease);
}

.nav-toggle-bars span:nth-child(1) { top: 0; }
.nav-toggle-bars span:nth-child(2) { top: 5px; }
.nav-toggle-bars span:nth-child(3) { top: 10px; }

.nav-toggle[aria-expanded="true"] .nav-toggle-bars span:nth-child(1) {
  transform: translateY(5px) rotate(45deg);
}
.nav-toggle[aria-expanded="true"] .nav-toggle-bars span:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] .nav-toggle-bars span:nth-child(3) {
  transform: translateY(-5px) rotate(-45deg);
}

/* 抽屉内移动端栏目入口（桌面隐藏） */
.header-utility { display: none; }

/* ==========================================================================
   通用按钮 / 标签 / 卡片
   ========================================================================== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 11px 18px;
  border: 1px solid transparent;
  border-radius: var(--radius);
  font-size: 13px;
  letter-spacing: 0.1em;
  white-space: nowrap;
  cursor: pointer;
  transition: background-color 220ms var(--ease),
              color 220ms var(--ease),
              border-color 220ms var(--ease);
}

.btn-primary {
  background: var(--orange);
  color: #180901;
  font-weight: 700;
}
.btn-primary:hover { background: #FF8A45; }

.btn-ghost {
  background: transparent;
  border-color: var(--line);
  color: var(--ink);
}
.btn-ghost:hover {
  border-color: var(--season-accent);
  color: var(--season-accent);
}

.btn-quiet {
  background: var(--panel);
  border-color: var(--line);
  color: var(--ink-dim);
}
.btn-quiet:hover {
  color: var(--ink);
  border-color: var(--season-accent);
}

.btn-sm { padding: 8px 13px; font-size: 12px; }

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 5px 9px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  font-size: 11px;
  letter-spacing: 0.18em;
  color: var(--season-alt);
  background: var(--season-wash);
  transition: color 400ms var(--ease), background-color 400ms var(--ease);
}

.card {
  position: relative;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: clamp(18px, 2.4vw, 26px);
  box-shadow: 6px 6px 0 0 rgba(242, 246, 250, 0.07);
}

/* ==========================================================================
   布局容器
   ========================================================================== */
.shell {
  width: 100%;
  max-width: var(--shell);
  margin: 0 auto;
  padding: 0 var(--gutter);
}

.section { padding: clamp(56px, 8vw, 112px) 0; }

.section-head { max-width: 66ch; margin-bottom: clamp(24px, 3.6vw, 44px); }

.section-index {
  font-family: var(--font-num);
  font-size: 12px;
  letter-spacing: 0.22em;
  color: var(--ink-dim);
  margin-bottom: 10px;
  transition: color 400ms var(--ease), text-shadow 400ms var(--ease);
}

.section-index.is-live {
  color: var(--season-alt);
  text-shadow: 0 0 18px var(--season-wash);
}

.section-title {
  font-size: clamp(1.6rem, 3.2vw, 2.6rem);
  font-weight: 600;
  letter-spacing: 0.01em;
  color: var(--ink);
}

.section-lead {
  margin-top: 14px;
  font-size: 16px;
  line-height: 1.75;
  color: var(--ink-dim);
}

/* ---------- 网格 ---------- */
.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)); }
.grid-4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }

@media (max-width: 1024px) {
  .grid-4 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .grid-3 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 680px) {
  .grid-2,
  .grid-3,
  .grid-4 { grid-template-columns: minmax(0, 1fr); }
}

/* ---------- 图片容器（页面阶段放图用） ---------- */
.media {
  position: relative;
  display: block;
  overflow: hidden;
  aspect-ratio: 16 / 9;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.media img,
.media picture,
.media video {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.media-wide { aspect-ratio: 21 / 9; }
.media-tall { aspect-ratio: 3 / 4; }
.media-square { aspect-ratio: 1 / 1; }

.media-shade::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: linear-gradient(180deg, rgba(10, 17, 32, 0) 42%, rgba(10, 17, 32, 0.88) 100%);
}

.media-cap {
  position: absolute;
  left: 14px;
  right: 14px;
  bottom: 12px;
  z-index: 2;
  font-size: 11px;
  letter-spacing: 0.18em;
  color: var(--ink);
}

/* ---------- 面包屑 ---------- */
.breadcrumb {
  padding: 20px 0 4px;
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--ink-dim);
}

.breadcrumb ol {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
}

.breadcrumb li { display: inline-flex; align-items: center; }

.breadcrumb li:not(:last-child)::after {
  content: "/";
  margin-left: 8px;
  color: var(--line);
}

.breadcrumb a { color: inherit; transition: color 200ms var(--ease); }
.breadcrumb a:hover { color: var(--ink); }

/* ==========================================================================
   页脚
   ========================================================================== */
.site-footer {
  position: relative;
  margin-top: clamp(64px, 10vw, 140px);
  background: var(--bg);
  border-top: 1px solid var(--line);
  color: var(--ink-dim);
}

.footer-rule {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  height: 4px;
}

.rule-seg { display: block; height: 100%; }
.rule-spring { background: var(--spring); }
.rule-summer { background: var(--blue); }
.rule-autumn { background: var(--autumn-red); }
.rule-winter { background: var(--ink); }

.footer-frame {
  max-width: var(--shell);
  margin: 0 auto;
  padding: clamp(38px, 5vw, 72px) var(--gutter) 8px;
  display: grid;
  grid-template-columns: minmax(240px, 1.6fr) repeat(3, minmax(120px, 1fr));
  gap: clamp(24px, 3.4vw, 48px);
}

.footer-frame--contact {
  padding-top: clamp(20px, 3vw, 36px);
  padding-bottom: clamp(28px, 4vw, 48px);
  grid-template-columns: minmax(0, 1fr);
}

.footer-mast { display: flex; flex-direction: column; gap: 14px; }

.footer-brand {
  font-size: 13px;
  letter-spacing: 0.22em;
  color: var(--ink);
  max-width: none;
}

.footer-tagline {
  font-size: clamp(1.5rem, 3vw, 2.3rem);
  font-weight: 200;
  line-height: 1.24;
  letter-spacing: -0.01em;
  color: var(--ink);
  max-width: 14em;
}

.footer-kicker {
  font-family: var(--font-num);
  font-size: 11px;
  letter-spacing: 0.2em;
  color: var(--season-alt);
  max-width: none;
  transition: color 400ms var(--ease);
}

.footer-col-title {
  font-size: 11px;
  letter-spacing: 0.2em;
  color: var(--ink);
  margin-bottom: 16px;
  max-width: none;
}

.footer-list { display: grid; gap: 11px; }

.footer-list a {
  font-size: 14.5px;
  color: var(--ink-dim);
  transition: color 220ms var(--ease);
}

.footer-list a:hover { color: var(--season-accent); }

.footer-list--contact { gap: 12px; }

.footer-list--contact li {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 12px;
  font-size: 14.5px;
  color: var(--ink);
}

.contact-key {
  flex: 0 0 auto;
  min-width: 44px;
  font-size: 11px;
  letter-spacing: 0.18em;
  color: var(--ink-dim);
  padding-top: 4px;
}

.footer-contact-note {
  margin-top: 18px;
  max-width: 62ch;
  font-size: 13px;
  line-height: 1.8;
  color: var(--ink-dim);
}

.footer-base {
  max-width: var(--shell);
  margin: 0 auto;
  padding: 18px var(--gutter) 40px;
  border-top: 1px solid var(--line);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px 28px;
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--ink-dim);
}

.footer-base p { max-width: none; }

.footer-icp { color: var(--ink); }

.footer-domain {
  margin-left: auto;
  font-family: var(--font-num);
  letter-spacing: 0.06em;
  color: var(--line);
}

/* ==========================================================================
   响应式
   ========================================================================== */
@media (max-width: 1024px) {
  :root { --header-h: 66px; }

  .nav-toggle { display: inline-flex; }

  .primary-nav {
    position: fixed;
    top: var(--header-h);
    left: 0; right: 0; bottom: 0;
    z-index: 118;
    background: #0A1120;
    border-top: 1px solid var(--line);
    padding: 24px var(--gutter) 56px;
    overflow-y: auto;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-14px);
    transition: opacity 240ms var(--ease),
                transform 300ms var(--ease),
                visibility 0s linear 300ms;
  }

  .primary-nav[data-open] {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
    transition: opacity 240ms var(--ease),
                transform 300ms var(--ease),
                visibility 0s;
  }

  .nav-list {
    flex-direction: column;
    align-items: stretch;
    justify-content: flex-start;
    gap: 0;
  }

  .nav-list a {
    padding: 16px 0 16px 16px;
    font-size: 19px;
    letter-spacing: 0.06em;
    border-bottom: 1px solid var(--line);
  }

  .nav-list a::after { display: none; }

  .nav-list a:hover { color: var(--season-accent); }

  .nav-list a[aria-current="page"] { color: var(--season-alt); }

  .nav-list a[aria-current="page"]::before {
    content: "";
    position: absolute;
    left: 0;
    top: 50%;
    width: 4px;
    height: 20px;
    margin-top: -10px;
    background: var(--season-alt);
  }

  .header-utility {
    display: block;
    margin-top: 32px;
    padding-top: 22px;
    border-top: 1px solid var(--line);
  }

  .utility-label {
    font-size: 11px;
    letter-spacing: 0.2em;
    color: var(--ink-dim);
    margin-bottom: 14px;
    max-width: none;
  }

  .utility-links { display: grid; gap: 10px; }

  .utility-links a {
    display: block;
    padding: 13px 14px;
    font-size: 15px;
    color: var(--ink);
    background: var(--panel);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    transition: border-color 220ms var(--ease), color 220ms var(--ease);
  }

  .utility-links a:hover {
    border-color: var(--season-accent);
    color: var(--season-accent);
  }

  .footer-frame {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .footer-mast { grid-column: 1 / -1; }
}

@media (max-width: 900px) {
  .header-tools .btn-ghost { display: none; }
}

@media (max-width: 780px) {
  .season-label { display: none; }
  .season-btn { padding: 8px; }
}

@media (max-width: 680px) {
  body { font-size: 16px; }

  .brand-note { display: none; }

  .footer-frame { grid-template-columns: minmax(0, 1fr); }

  .footer-base { gap: 8px 18px; }

  .footer-domain { margin-left: 0; }
}

@media (max-width: 420px) {
  .header-tools .btn-primary { display: none; }
  .header-tools { gap: 8px; }
}

/* ---------- 动效降级 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}