/* ============================================================
   5体育看台 · 共享样式 /assets/site.css
   夜间观赛指挥台：高原夜空深蓝 + 蓝图网格 + 聚光灯暖色
   ============================================================ */

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

html,
body { margin: 0; padding: 0; }

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

h1, h2, h3, h4, h5, p, ul, ol, figure, blockquote, dl, dd { margin: 0; }
ul, ol { padding: 0; list-style: none; }

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

a { color: inherit; text-decoration: none; }

button {
  font: inherit;
  color: inherit;
  background: none;
  border: 0;
  padding: 0;
  cursor: pointer;
}

input, select, textarea { font: inherit; }

/* ---------- tokens ---------- */
:root {
  --night: #0A1428;
  --panel: #101F3C;
  --surface-soft: rgba(16, 31, 60, 0.72);
  --turquoise: #2FD3B5;
  --coral: #FF7A59;
  --gold: #F2C14E;
  --snow: #F4F8FB;
  --mist: #A9BCCF;
  --line: #22375C;
  --turf: #1B4A42;
  --clay: #8C3B32;

  --radius-card: 20px;
  --radius-pill: 999px;

  --shell: min(1180px, calc(100% - 2.5rem));
  --gap: clamp(1rem, 2.2vw, 2rem);
  --pad-section: clamp(3rem, 7vw, 6rem);

  --font-sans: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei",
    "Source Han Sans SC", "Noto Sans SC", system-ui, -apple-system,
    "Helvetica Neue", Arial, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas,
    "Liberation Mono", monospace;

  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
}

/* ---------- base ---------- */
html {
  background-color: var(--night);
  background-image:
    linear-gradient(to right, rgba(34, 55, 92, 0.42) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(34, 55, 92, 0.42) 1px, transparent 1px);
  background-size: 88px 88px;
}

body {
  min-height: 100vh;
  background: transparent;
  color: var(--snow);
  font-family: var(--font-sans);
  font-size: 16.5px;
  line-height: 1.75;
  letter-spacing: 0.01em;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background:
    radial-gradient(120% 70% at 82% -8%, rgba(47, 211, 181, 0.14), transparent 62%),
    radial-gradient(80% 60% at 4% 10%, rgba(255, 122, 89, 0.09), transparent 60%),
    linear-gradient(180deg, rgba(10, 20, 40, 0) 40%, rgba(10, 20, 40, 0.88) 100%);
}

::selection {
  background: rgba(47, 211, 181, 0.32);
  color: var(--snow);
}

:focus-visible {
  outline: 2px solid var(--turquoise);
  outline-offset: 3px;
  border-radius: 6px;
}

#main-content { scroll-margin-top: 104px; }

/* ---------- utilities ---------- */
.shell {
  width: var(--shell);
  margin-inline: auto;
}

.section { padding-block: var(--pad-section); }
.section--tight { padding-block: calc(var(--pad-section) * 0.6); }

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

.rule {
  height: 1px;
  border: 0;
  background: linear-gradient(90deg, var(--line), rgba(34, 55, 92, 0));
}

.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;
}

.num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  letter-spacing: -0.01em;
}

.stat-figure {
  display: inline-block;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 1.8em;
  font-weight: 600;
  line-height: 1;
  color: var(--gold);
  letter-spacing: -0.02em;
}

/* ---------- typography ---------- */
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 0.6em;
  font-size: 10.5px;
  font-weight: 600;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--turquoise);
}

.eyebrow::before {
  content: "";
  width: 18px;
  height: 1px;
  background: currentColor;
  opacity: 0.75;
}

.display-title {
  display: inline-block;
  font-size: clamp(2.1rem, 5.4vw, 4rem);
  font-weight: 800;
  line-height: 1.06;
  letter-spacing: -0.012em;
  color: var(--snow);
  transform: skewX(-2deg);
  transform-origin: 0 100%;
  text-wrap: balance;
}

.display-title--lg {
  font-size: clamp(2.6rem, 7vw, 5rem);
}

.lede {
  max-width: 34em;
  font-size: clamp(1rem, 1.4vw, 1.15rem);
  line-height: 1.8;
  color: rgba(244, 248, 251, 0.82);
}

.prose {
  max-width: 64ch;
  color: rgba(244, 248, 251, 0.86);
}

.prose > * + * { margin-top: 1.15em; }

.prose h2,
.prose h3 {
  font-size: 1.15rem;
  font-weight: 700;
  letter-spacing: 0.01em;
  color: var(--snow);
}

.prose ul,
.prose ol {
  display: grid;
  gap: 0.5em;
  padding-left: 1.15em;
  list-style: disc;
}

.prose ol { list-style: decimal; }

.prose a {
  color: var(--turquoise);
  border-bottom: 1px solid rgba(47, 211, 181, 0.4);
}

.prose a:hover { border-bottom-color: var(--turquoise); }

/* ---------- buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5em;
  padding: 0.72em 1.35em;
  border: 1px solid transparent;
  border-radius: var(--radius-pill);
  font-family: var(--font-sans);
  font-size: 13.5px;
  font-weight: 700;
  line-height: 1.4;
  letter-spacing: 0.04em;
  text-align: center;
  transition: transform 0.2s var(--ease), background 0.2s var(--ease),
    border-color 0.2s var(--ease), color 0.2s var(--ease),
    box-shadow 0.2s var(--ease);
}

.btn--accent {
  background: var(--turquoise);
  color: #06121F;
  box-shadow: 0 12px 26px -16px rgba(47, 211, 181, 0.9);
}

.btn--accent:hover {
  background: #3EE6C8;
  transform: translateY(-1px);
}

.btn--coral {
  background: var(--coral);
  color: #210B05;
  box-shadow: 0 12px 26px -16px rgba(255, 122, 89, 0.9);
}

.btn--coral:hover {
  background: #FF8F73;
  transform: translateY(-1px);
}

.btn--ghost {
  border-color: var(--line);
  background: rgba(16, 31, 60, 0.6);
  color: var(--snow);
}

.btn--ghost:hover {
  border-color: rgba(47, 211, 181, 0.6);
  color: var(--turquoise);
}

.btn--quiet {
  padding: 0.5em 1em;
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--mist);
  border-color: transparent;
}

.btn--quiet:hover { color: var(--turquoise); }

/* ---------- chips ---------- */
.chip {
  display: inline-flex;
  align-items: center;
  gap: 0.4em;
  padding: 0.32em 0.85em;
  border: 1px solid var(--line);
  border-radius: var(--radius-pill);
  background: rgba(16, 31, 60, 0.75);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.12em;
  color: var(--mist);
  transition: color 0.2s var(--ease), border-color 0.2s var(--ease),
    background 0.2s var(--ease);
}

.chip:hover { color: var(--snow); }

.chip[aria-pressed="true"],
.chip[data-active] {
  border-color: rgba(47, 211, 181, 0.65);
  background: rgba(47, 211, 181, 0.14);
  color: var(--turquoise);
}

.chip--coral {
  border-color: rgba(255, 122, 89, 0.45);
  background: rgba(255, 122, 89, 0.12);
  color: var(--coral);
}

.chip--gold {
  border-color: rgba(242, 193, 78, 0.45);
  background: rgba(242, 193, 78, 0.12);
  color: var(--gold);
}

/* ---------- breadcrumb ---------- */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.5rem;
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--mist);
}

.breadcrumb a:hover { color: var(--turquoise); }

.breadcrumb__sep {
  color: var(--line);
  opacity: 0.9;
}

.breadcrumb [aria-current="page"] { color: var(--snow); }

/* ---------- panel ---------- */
.panel {
  padding: clamp(1.1rem, 2.4vw, 1.75rem);
  border: 1px solid var(--line);
  border-radius: var(--radius-card);
  background: linear-gradient(180deg, rgba(16, 31, 60, 0.92), rgba(13, 25, 48, 0.72));
  transition: transform 0.24s var(--ease), border-color 0.24s var(--ease),
    box-shadow 0.24s var(--ease);
}

.panel:hover {
  transform: translateY(-4px);
  border-color: rgba(47, 211, 181, 0.45);
  box-shadow: 0 24px 48px -32px rgba(0, 0, 0, 0.95);
}

/* ---------- media frame ---------- */
.media-frame {
  position: relative;
  isolation: isolate;
  overflow: hidden;
  aspect-ratio: 16 / 9;
  border: 1px solid var(--line);
  border-radius: var(--radius-card);
  background:
    linear-gradient(160deg, var(--turf), #0d2136 58%, var(--panel));
}

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

.media-frame::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 1;
  pointer-events: none;
  background-image:
    linear-gradient(to right, rgba(34, 55, 92, 0.4) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(34, 55, 92, 0.4) 1px, transparent 1px);
  background-size: 48px 48px;
  opacity: 0.55;
  mix-blend-mode: screen;
}

.media-frame--wide { aspect-ratio: 21 / 9; }
.media-frame--tall { aspect-ratio: 4 / 5; }
.media-frame--square { aspect-ratio: 1 / 1; }

.media-frame__caption {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 2;
  padding: 0.85rem 1rem;
  font-size: 11.5px;
  letter-spacing: 0.04em;
  color: var(--mist);
  background: linear-gradient(0deg, rgba(8, 16, 32, 0.94), rgba(8, 16, 32, 0));
}

/* ---------- chapter link ---------- */
.chapter-link {
  display: flex;
  align-items: center;
  gap: 0.6em;
  padding: 0.5rem 0.7rem;
  border-left: 2px solid transparent;
  border-radius: 0 12px 12px 0;
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--mist);
  transition: color 0.2s var(--ease), background 0.2s var(--ease),
    border-color 0.2s var(--ease);
}

.chapter-link:hover {
  color: var(--snow);
  background: rgba(47, 211, 181, 0.08);
}

.chapter-link[aria-current="location"] {
  color: var(--turquoise);
  border-left-color: var(--turquoise);
  background: rgba(47, 211, 181, 0.1);
}

/* ---------- reveal ---------- */
.js [data-reveal] {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.3s var(--ease), transform 0.3s var(--ease);
}

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

/* ============================================================
   HEADER
   ============================================================ */
.skip-link {
  position: absolute;
  top: -100px;
  left: 50%;
  z-index: 200;
  padding: 0.7em 1.4em;
  border-radius: var(--radius-pill);
  background: var(--turquoise);
  color: #06121F;
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.04em;
  transform: translateX(-50%);
  transition: top 0.2s var(--ease);
}

.skip-link:focus { top: 12px; }

.stand-header {
  position: sticky;
  top: 0;
  z-index: 90;
  padding: 14px 0 0;
  transition: padding 0.28s var(--ease);
}

.stand-header[data-scrolled] { padding-top: 8px; }

.progress-rail {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  overflow: hidden;
  background: rgba(34, 55, 92, 0.55);
}

.progress-fill {
  display: block;
  width: 0;
  height: 100%;
  background: linear-gradient(90deg, var(--turquoise), var(--gold) 62%, var(--coral));
  transition: width 0.12s linear;
}

.stand-header__inner {
  position: relative;
  display: flex;
  align-items: center;
  gap: clamp(0.75rem, 2vw, 1.75rem);
  width: var(--shell);
  margin-inline: auto;
  padding: 0.55rem 0.55rem 0.55rem 1rem;
  border: 1px solid rgba(34, 55, 92, 0.9);
  border-radius: var(--radius-pill);
  background: linear-gradient(180deg, rgba(16, 31, 60, 0.94), rgba(10, 20, 40, 0.9));
  box-shadow: 0 18px 44px -28px rgba(0, 0, 0, 0.9),
    inset 0 1px 0 rgba(244, 248, 251, 0.05);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  transition: padding 0.28s var(--ease), background 0.28s var(--ease),
    box-shadow 0.28s var(--ease);
}

.stand-header[data-scrolled] .stand-header__inner {
  padding-block: 0.35rem;
  background: linear-gradient(180deg, rgba(13, 26, 50, 0.97), rgba(8, 16, 32, 0.95));
  box-shadow: 0 22px 50px -26px rgba(0, 0, 0, 0.95);
}

.brand-mark {
  display: flex;
  flex: 0 0 auto;
  align-items: center;
  gap: 0.65rem;
  min-width: 0;
}

.brand-mark__glyph {
  display: grid;
  flex: 0 0 auto;
  place-items: center;
  width: 34px;
  height: 34px;
  border: 1px solid rgba(47, 211, 181, 0.5);
  border-radius: 12px;
  background: radial-gradient(120% 120% at 30% 20%, rgba(47, 211, 181, 0.34), rgba(47, 211, 181, 0.06));
  color: var(--turquoise);
  font-family: var(--font-mono);
  font-size: 16px;
  font-weight: 700;
  line-height: 1;
}

.brand-mark__text {
  display: flex;
  flex-direction: column;
  min-width: 0;
  line-height: 1.2;
}

.brand-mark__name {
  font-size: 15px;
  font-weight: 800;
  letter-spacing: 0.02em;
  color: var(--snow);
  white-space: nowrap;
}

.brand-mark__tag {
  font-size: 10px;
  font-weight: 500;
  letter-spacing: 0.16em;
  color: var(--mist);
  white-space: nowrap;
}

.nav-toggle {
  display: none;
  align-items: center;
  gap: 0.55rem;
  margin-left: auto;
  padding: 0.5rem 0.9rem;
  border: 1px solid var(--line);
  border-radius: var(--radius-pill);
  background: rgba(16, 31, 60, 0.7);
  color: var(--snow);
}

.nav-toggle__bars {
  display: grid;
  gap: 4px;
  width: 16px;
}

.nav-toggle__bars span {
  display: block;
  height: 1.5px;
  border-radius: 2px;
  background: currentColor;
  transition: transform 0.24s var(--ease), opacity 0.24s var(--ease);
}

.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:first-child {
  transform: translateY(2.75px) rotate(45deg);
}

.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:last-child {
  transform: translateY(-2.75px) rotate(-45deg);
}

.nav-toggle__label {
  font-size: 11.5px;
  font-weight: 600;
  letter-spacing: 0.16em;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 0.35rem;
  min-width: 0;
  margin-left: auto;
}

.site-nav__list {
  display: flex;
  align-items: center;
  gap: 0.15rem;
  flex-wrap: nowrap;
}

.site-nav__link {
  position: relative;
  display: inline-block;
  padding: 0.5rem 0.7rem;
  border-radius: var(--radius-pill);
  font-size: 11.5px;
  font-weight: 600;
  letter-spacing: 0.16em;
  color: var(--mist);
  white-space: nowrap;
  transition: color 0.2s var(--ease), background 0.2s var(--ease);
}

.site-nav__link:hover {
  color: var(--snow);
  background: rgba(47, 211, 181, 0.09);
}

.site-nav__link[aria-current="page"] {
  color: var(--turquoise);
  background: rgba(47, 211, 181, 0.12);
}

.site-nav__link[aria-current="page"]::after {
  content: "";
  position: absolute;
  left: 50%;
  bottom: 2px;
  width: 4px;
  height: 4px;
  border-radius: 50%;
  background: var(--turquoise);
  transform: translateX(-50%);
}

.site-nav__cta {
  flex: 0 0 auto;
  margin-left: 0.35rem;
  padding: 0.62em 1.15em;
  font-size: 12.5px;
  letter-spacing: 0.06em;
}

/* ============================================================
   FOOTER
   ============================================================ */
.stand-footer {
  position: relative;
  margin-top: clamp(3rem, 8vw, 7rem);
  border-top: 1px solid var(--line);
  background: linear-gradient(180deg, rgba(16, 31, 60, 0.55), rgba(10, 20, 40, 0) 58%),
    transparent;
}

.stand-footer::before {
  content: "";
  position: absolute;
  top: -1px;
  left: 0;
  right: 0;
  height: 10px;
  pointer-events: none;
  background-image: repeating-linear-gradient(90deg, var(--line) 0 1px, transparent 1px 44px);
  opacity: 0.85;
}

.stand-footer__inner {
  display: grid;
  grid-template-columns: minmax(220px, 1.1fr) minmax(0, 2fr);
  gap: clamp(2rem, 5vw, 4rem);
  width: var(--shell);
  margin-inline: auto;
  padding: clamp(2.5rem, 6vw, 4.5rem) 0 clamp(1.6rem, 4vw, 2.6rem);
}

.stand-footer__brand { min-width: 0; }

.stand-footer__wordmark {
  display: inline-block;
  font-size: clamp(1.35rem, 3vw, 1.8rem);
  font-weight: 800;
  letter-spacing: 0.01em;
  color: var(--snow);
  transform: skewX(-2deg);
  transform-origin: 0 100%;
}

.stand-footer__tagline {
  margin-top: 0.4rem;
  font-size: 10.5px;
  font-weight: 600;
  letter-spacing: 0.22em;
  color: var(--turquoise);
}

.stand-footer__lede {
  max-width: 24em;
  margin-top: 1rem;
  font-size: 12.5px;
  line-height: 1.85;
  color: var(--mist);
}

.stand-footer__contact {
  display: grid;
  gap: 0.3rem;
  margin-top: 1.1rem;
  font-size: 12.5px;
  color: var(--mist);
}

.stand-footer__contact strong {
  font-weight: 600;
  color: var(--snow);
}

.stand-footer__nav {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: clamp(1.2rem, 3vw, 2.5rem);
}

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

.footer-col__title {
  padding-bottom: 0.75rem;
  border-bottom: 1px solid var(--line);
  font-size: 10.5px;
  font-weight: 600;
  letter-spacing: 0.22em;
  color: var(--mist);
}

.footer-col__list {
  display: grid;
  gap: 0.5rem;
  margin-top: 0.9rem;
}

.footer-col__link {
  display: inline-block;
  font-size: 13.5px;
  color: rgba(244, 248, 251, 0.86);
  transition: color 0.2s var(--ease), padding 0.2s var(--ease);
}

.footer-col__link:hover {
  color: var(--turquoise);
  padding-left: 0.25rem;
}

.footer-col__link[aria-current="page"] { color: var(--gold); }

.stand-footer__meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem 1.5rem;
  width: var(--shell);
  margin-inline: auto;
  padding: 1.1rem 0 2rem;
  border-top: 1px solid var(--line);
  font-size: 11.5px;
  letter-spacing: 0.04em;
  color: var(--mist);
}

.stand-footer__meta-line {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.4rem 1.25rem;
}

.stand-footer__service {
  color: var(--gold);
  letter-spacing: 0.12em;
}

.stand-footer__icp {
  font-family: var(--font-mono);
  letter-spacing: 0.02em;
  color: rgba(244, 248, 251, 0.72);
}

.stand-footer__signoff {
  flex: 1 0 100%;
  padding-top: 1rem;
  border-top: 1px dashed rgba(34, 55, 92, 0.85);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: rgba(169, 188, 207, 0.78);
}

/* ============================================================
   RESPONSIVE
   ============================================================ */
@media (max-width: 1080px) and (min-width: 901px) {
  .site-nav__link {
    padding: 0.45rem 0.5rem;
    font-size: 11px;
    letter-spacing: 0.1em;
  }
  .brand-mark__tag { display: none; }
  .site-nav__cta { font-size: 12px; padding: 0.6em 1em; }
}

@media (max-width: 900px) {
  .stand-header__inner {
    flex-wrap: wrap;
    border-radius: 22px;
    padding: 0.55rem 0.6rem 0.55rem 0.85rem;
  }

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

  .site-nav {
    position: absolute;
    top: calc(100% + 8px);
    left: 0;
    right: 0;
    display: none;
    flex-direction: column;
    align-items: stretch;
    gap: 0.25rem;
    width: var(--shell);
    margin-inline: auto;
    padding: 0.85rem;
    border: 1px solid var(--line);
    border-radius: 22px;
    background: linear-gradient(180deg, rgba(16, 31, 60, 0.98), rgba(9, 18, 36, 0.98));
    box-shadow: 0 30px 60px -30px #000;
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
  }

  .site-nav[data-open] { display: flex; }

  .site-nav__list {
    flex-direction: column;
    align-items: stretch;
    gap: 0.15rem;
  }

  .site-nav__link {
    padding: 0.7rem 0.9rem;
    border-radius: 14px;
    font-size: 12px;
    letter-spacing: 0.14em;
  }

  .site-nav__link[aria-current="page"]::after { display: none; }

  .site-nav__cta {
    justify-content: center;
    margin: 0.5rem 0 0;
    padding: 0.8em 1.2em;
    font-size: 13px;
  }

  .stand-footer__inner {
    grid-template-columns: 1fr;
    gap: 2.25rem;
  }

  .stand-footer__nav {
    grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  }

  .stand-footer__meta { font-size: 11px; }
}

@media (max-width: 640px) {
  :root { --shell: calc(100% - 1.5rem); }

  body { font-size: 16px; }

  .stand-header { padding-top: 8px; }

  .brand-mark__tag { display: none; }

  .display-title { transform: skewX(-1.4deg); }

  .stand-footer__nav { grid-template-columns: repeat(2, minmax(0, 1fr)); }

  .stand-footer__meta-line { gap: 0.35rem 0.9rem; }
}

/* ---------- reduced motion ---------- */
@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;
  }

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

  .panel:hover { transform: none; }
  .btn:hover { transform: none; }
}