/* ============================================================
   博业体育 — Site Kit / /assets/site.css
   共享层：变量、重置、排版、头部、页脚、通用组件、响应式
   ============================================================ */

/* ---------- 1. Design Tokens ---------- */
:root {
  --c-bg: #0C1612;
  --c-surface: #14261F;
  --c-primary: #1B3A2D;
  --c-primary-high: #22503C;
  --c-gold: #C9A45C;
  --c-gold-bright: #D8B56E;
  --c-border: #2A4A3A;
  --c-text: #E8E6DE;
  --c-text-dim: #9FAFA6;

  --font-serif: 'Noto Serif SC', 'Source Han Serif CN', 'Songti SC', 'SimSun', serif;
  --font-sans: 'Noto Sans SC', 'Source Han Sans CN', 'PingFang SC', 'Microsoft YaHei', sans-serif;

  --border-w: 3px;
  --shadow-hard: 5px 5px 0 rgba(0, 0, 0, .42);
  --shadow-mid: 3px 3px 0 rgba(0, 0, 0, .35);

  --container-max: 1240px;
  --page-pad: 20px;
}

/* ---------- 2. Reset & Base ---------- */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

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

body {
  min-height: 100vh;
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.75;
  color: var(--c-text);
  background-color: var(--c-bg);
  background-image: linear-gradient(180deg, var(--c-bg) 0%, var(--c-primary) 190%);
  background-repeat: no-repeat;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

main {
  display: block;
}

#main-content:focus {
  outline: none;
}

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

ul,
ol {
  list-style: none;
}

a {
  color: inherit;
}

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

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

/* ---------- 3. Typography ---------- */
h1,
h2,
h3,
h4,
h5,
h6 {
  font-family: var(--font-serif);
  font-weight: 900;
  line-height: 1.3;
  color: var(--c-text);
}

h1 {
  font-size: clamp(32px, 5vw, 48px);
}

h2 {
  font-size: clamp(24px, 4vw, 32px);
}

h3 {
  font-size: 22px;
}

p {
  text-wrap: pretty;
}

[data-year] {
  font-variant-numeric: tabular-nums;
}

/* ---------- 4. Layout Containers & Grid ---------- */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin-right: auto;
  margin-left: auto;
  padding-right: var(--page-pad);
  padding-left: var(--page-pad);
}

.grid-2,
.grid-3,
.grid-4 {
  display: grid;
  gap: 24px;
}

@media (min-width: 640px) {
  .grid-2 {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .grid-3,
  .grid-4 {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

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

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

/* ---------- 5. Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 28px;
  font-family: var(--font-sans);
  font-size: 15px;
  font-weight: 700;
  letter-spacing: .04em;
  color: var(--c-text);
  background: var(--c-surface);
  border: var(--border-w) solid var(--c-border);
  box-shadow: var(--shadow-mid);
  text-decoration: none;
  cursor: pointer;
  transition: background .22s ease-out, color .22s ease-out, border-color .22s ease-out, box-shadow .22s ease-out, transform .22s ease-out;
}

.btn:hover {
  background: var(--c-primary);
  border-color: var(--c-gold);
  box-shadow: 6px 6px 0 rgba(0, 0, 0, .4);
  transform: translate(-2px, -2px);
}

.btn:active {
  transform: translate(2px, 2px);
  box-shadow: 1px 1px 0 rgba(0, 0, 0, .3);
}

.btn-gold {
  background: var(--c-gold);
  border-color: var(--c-gold);
  color: var(--c-bg);
}

.btn-gold:hover {
  background: var(--c-gold-bright);
  border-color: var(--c-gold-bright);
  color: var(--c-bg);
}

.btn-outline {
  background: transparent;
  border-color: var(--c-gold);
  color: var(--c-gold);
}

.btn-outline:hover {
  background: rgba(201, 164, 92, .12);
  color: var(--c-gold-bright);
}

/* ---------- 6. Breadcrumb ---------- */
.breadcrumb {
  padding: 14px 0;
  font-size: 13px;
  color: var(--c-text-dim);
}

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

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

.breadcrumb li + li::before {
  content: '/';
  margin-right: 8px;
  color: var(--c-border);
}

.breadcrumb a {
  color: var(--c-text);
  text-decoration: none;
  transition: color .2s;
}

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

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

/* ---------- 7. Section / Chapter / Card ---------- */
.section {
  padding: 56px 0;
}

.section-head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: 8px 16px;
  margin-bottom: 28px;
  padding-bottom: 14px;
  border-bottom: 2px solid var(--c-border);
}

.section-index {
  font-family: var(--font-serif);
  font-size: 14px;
  font-weight: 900;
  letter-spacing: .18em;
  color: var(--c-gold);
}

.section-title {
  font-family: var(--font-serif);
  font-size: clamp(24px, 4vw, 36px);
  font-weight: 900;
  line-height: 1.25;
}

.section-label {
  font-size: 13px;
  letter-spacing: .14em;
  color: var(--c-text-dim);
}

.chapter {
  position: relative;
  padding: 40px 0;
  border-top: var(--border-w) solid var(--c-border);
}

.chapter-num {
  display: block;
  margin-bottom: 4px;
  font-family: var(--font-serif);
  font-size: 34px;
  font-weight: 900;
  line-height: 1;
  letter-spacing: .08em;
  color: var(--c-gold);
}

.chapter-title {
  font-family: var(--font-serif);
  font-size: 28px;
  font-weight: 900;
  line-height: 1.3;
  margin-bottom: 12px;
}

.card {
  background: var(--c-surface);
  border: var(--border-w) solid var(--c-border);
  padding: 24px;
  box-shadow: var(--shadow-hard);
}

.card-title {
  font-family: var(--font-serif);
  font-size: 20px;
  font-weight: 900;
  margin-bottom: 8px;
}

/* ---------- 8. Page Hero ---------- */
.page-hero {
  position: relative;
  padding: 48px 0 42px;
  background: linear-gradient(135deg, var(--c-primary) 0%, var(--c-bg) 75%);
  border-bottom: var(--border-w) solid var(--c-border);
}

.page-hero-title {
  font-family: var(--font-serif);
  font-size: clamp(32px, 6vw, 56px);
  font-weight: 900;
  line-height: 1.15;
}

.page-hero-desc {
  margin-top: 12px;
  max-width: 640px;
  font-size: 16px;
  color: var(--c-text-dim);
}

/* ---------- 9. Image Containers ---------- */
.img-box {
  position: relative;
  display: block;
  overflow: hidden;
  background: var(--c-surface);
  border: var(--border-w) solid var(--c-border);
  box-shadow: var(--shadow-hard);
  aspect-ratio: 16 / 10;
}

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

.img-box::after {
  content: '';
  position: absolute;
  inset: 0;
  border: 2px solid rgba(201, 164, 92, .25);
  opacity: 0;
  transition: opacity .3s;
}

.img-box:hover::after {
  opacity: 1;
}

.img-cover {
  aspect-ratio: 16 / 9;
}

.img-portrait {
  aspect-ratio: 4 / 5;
}

.img-action {
  clip-path: polygon(6% 0, 100% 0, 100% 94%, 94% 100%, 0 100%, 0 6%);
}

.img-skeleton::before {
  content: '';
  position: absolute;
  inset: 0;
  z-index: 1;
  background: linear-gradient(100deg, transparent 20%, rgba(232, 230, 222, .07) 45%, rgba(201, 164, 92, .08) 55%, transparent 80%);
  background-size: 220% 100%;
  animation: skeleton-shimmer 2.2s ease-in-out infinite;
}

@keyframes skeleton-shimmer {
  0% {
    background-position: 120% 0;
  }

  100% {
    background-position: -120% 0;
  }
}

.img-caption {
  margin-top: 8px;
  font-size: 13px;
  color: var(--c-text-dim);
}

/* ---------- 10. Tabs ---------- */
.tabs {
  border: var(--border-w) solid var(--c-border);
  background: var(--c-surface);
  box-shadow: var(--shadow-hard);
}

.tablist {
  display: flex;
  flex-wrap: wrap;
  background: var(--c-primary);
  border-bottom: var(--border-w) solid var(--c-border);
}

[data-tab] {
  -webkit-appearance: none;
  appearance: none;
  background: transparent;
  border: none;
  border-right: 2px solid var(--c-border);
  padding: 12px 24px;
  font-family: var(--font-sans);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: .06em;
  color: var(--c-text-dim);
  cursor: pointer;
  transition: color .2s, background .2s;
}

[data-tab]:hover {
  color: var(--c-text);
  background: rgba(27, 58, 45, .5);
}

[data-tab][aria-selected="true"] {
  color: var(--c-gold);
  background: var(--c-surface);
}

[data-tabpanel] {
  padding: 24px;
}

/* ---------- 11. Label / Note / Table ---------- */
.label-tag {
  display: inline-block;
  padding: 3px 12px;
  border: 2px solid var(--c-gold);
  color: var(--c-gold);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .14em;
  background: rgba(201, 164, 92, .08);
}

.note {
  padding: 12px 16px;
  border-left: 4px solid var(--c-gold);
  background: var(--c-surface);
  font-size: 14px;
  color: var(--c-text-dim);
}

.table-data {
  width: 100%;
  border-collapse: collapse;
  font-size: 14px;
  background: var(--c-surface);
  border: var(--border-w) solid var(--c-border);
}

.table-data th,
.table-data td {
  padding: 12px 16px;
  text-align: left;
  border-bottom: 1px solid var(--c-border);
}

.table-data th {
  background: var(--c-primary);
  color: var(--c-gold);
  font-weight: 700;
  letter-spacing: .06em;
}

.table-data tbody tr:hover {
  background: rgba(27, 58, 45, .5);
}

/* ---------- 12. Skip Link / Progress / Back to Top ---------- */
.skip-link {
  position: fixed;
  top: -100px;
  left: 16px;
  z-index: 2000;
  padding: 12px 20px;
  background: var(--c-gold);
  border: var(--border-w) solid var(--c-gold-bright);
  box-shadow: 4px 4px 0 rgba(0, 0, 0, .5);
  color: var(--c-bg);
  font-weight: 700;
  text-decoration: none;
  transition: top .2s;
}

.skip-link:focus {
  top: 16px;
}

.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  z-index: 1500;
  width: 0;
  height: 3px;
  background: var(--c-gold);
  box-shadow: 0 0 8px rgba(201, 164, 92, .5);
  pointer-events: none;
}

.back-to-top {
  position: fixed;
  right: 20px;
  bottom: 20px;
  z-index: 1200;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 48px;
  height: 48px;
  background: var(--c-surface);
  border: var(--border-w) solid var(--c-border);
  color: var(--c-gold);
  font-size: 20px;
  box-shadow: var(--shadow-mid);
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transform: translateY(8px);
  transition: opacity .25s, visibility .25s, transform .25s, background .2s;
}

.back-to-top:hover {
  background: var(--c-primary);
}

.back-to-top.is-visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

/* ---------- 13. Header ---------- */
.site-header {
  position: relative;
  background: var(--c-bg);
}

.masthead {
  position: relative;
  padding: 22px 20px 34px;
  text-align: center;
  overflow: hidden;
  background:
    radial-gradient(ellipse at 12% -20%, rgba(27, 58, 45, .55) 0%, transparent 55%),
    radial-gradient(ellipse at 88% 120%, rgba(27, 58, 45, .45) 0%, transparent 50%),
    var(--c-bg);
  border-bottom: var(--border-w) solid var(--c-border);
}

.masthead::before {
  content: '';
  position: absolute;
  inset: 0;
  background: repeating-linear-gradient(115deg, transparent 0, transparent 16px, rgba(201, 164, 92, .04) 17px, transparent 18px);
  pointer-events: none;
}

.masthead::after {
  content: '';
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 26px;
  background: var(--c-surface);
  clip-path: polygon(0 100%, 0 60%, 7% 48%, 14% 68%, 23% 28%, 34% 62%, 43% 46%, 55% 70%, 64% 36%, 76% 64%, 86% 42%, 100% 70%, 100% 100%);
  opacity: .72;
  pointer-events: none;
}

.masthead-meta {
  position: relative;
  z-index: 1;
  max-width: var(--container-max);
  margin: 0 auto 18px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--c-border);
  font-size: 12px;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--c-text-dim);
}

.masthead-meta-accent {
  color: var(--c-gold);
}

.masthead-brand {
  position: relative;
  z-index: 1;
  display: inline-flex;
  align-items: center;
  gap: 14px;
  text-decoration: none;
  color: var(--c-text);
}

.masthead-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: clamp(44px, 7vw, 64px);
  height: clamp(44px, 7vw, 64px);
  border: clamp(3px, .5vw, 4px) solid var(--c-gold);
  background: var(--c-primary);
  color: var(--c-gold);
  font-family: var(--font-serif);
  font-size: clamp(28px, 5vw, 40px);
  font-weight: 900;
  line-height: 1;
  box-shadow: var(--shadow-hard);
  transform: rotate(-3deg);
  transition: transform .25s;
}

.masthead-brand:hover .masthead-mark {
  transform: rotate(0deg);
}

.masthead-name {
  font-family: var(--font-serif);
  font-size: clamp(44px, 9vw, 88px);
  font-weight: 900;
  line-height: 1.08;
  letter-spacing: .06em;
}

.masthead-desc {
  position: relative;
  z-index: 1;
  margin-top: 12px;
  font-size: 13px;
  letter-spacing: .18em;
  color: var(--c-text-dim);
}

.site-nav {
  background: var(--c-surface);
  border-top: var(--border-w) solid var(--c-border);
  border-bottom: var(--border-w) solid var(--c-border);
}

.site-nav-inner {
  max-width: var(--container-max);
  margin: 0 auto;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  min-height: 56px;
  padding: 0 var(--page-pad);
}

.site-nav-list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: 4px 8px;
}

.site-nav-link {
  display: inline-block;
  padding: 16px 6px;
  font-size: 15px;
  font-weight: 600;
  letter-spacing: .08em;
  color: var(--c-text);
  text-decoration: none;
  border-bottom: 3px solid transparent;
  transition: color .2s, border-color .2s;
}

.site-nav-link:hover {
  color: var(--c-gold);
}

.site-nav-link[aria-current="page"] {
  color: var(--c-gold);
  border-bottom-color: var(--c-gold);
}

.nav-toggle {
  display: none;
}

/* ---------- 14. Footer ---------- */
.site-footer {
  position: relative;
  margin-top: 72px;
  background:
    radial-gradient(ellipse at 15% 0%, rgba(27, 58, 45, .5) 0%, transparent 60%),
    linear-gradient(180deg, var(--c-bg) 0%, var(--c-surface) 100%);
}

.footer-topline {
  height: 4px;
  background: linear-gradient(90deg, var(--c-gold) 0%, var(--c-gold) 35%, var(--c-border) 35.1%, var(--c-border) 60%, var(--c-gold) 60.1%, var(--c-gold) 100%);
}

.footer-cols {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 48px var(--page-pad) 36px;
  display: grid;
  grid-template-columns: 1fr;
  gap: 36px;
}

.footer-brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  margin-bottom: 16px;
}

.footer-brand-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 46px;
  height: 46px;
  border: 3px solid var(--c-gold);
  background: var(--c-primary);
  color: var(--c-gold);
  font-family: var(--font-serif);
  font-size: 26px;
  font-weight: 900;
  box-shadow: var(--shadow-mid);
  transform: rotate(-2deg);
  transition: transform .25s;
}

.footer-brand:hover .footer-brand-mark {
  transform: rotate(0deg);
}

.footer-brand-name {
  font-family: var(--font-serif);
  font-size: 26px;
  font-weight: 900;
  letter-spacing: .08em;
}

.footer-desc {
  max-width: 340px;
  margin-bottom: 14px;
  font-size: 14px;
  line-height: 1.7;
  color: var(--c-text-dim);
}

.footer-stamp {
  display: inline-block;
  padding: 4px 12px;
  border: 2px solid var(--c-border);
  font-size: 11px;
  letter-spacing: .22em;
  text-transform: uppercase;
  color: var(--c-gold);
  opacity: .8;
}

.footer-title {
  margin-bottom: 14px;
  padding-bottom: 8px;
  border-bottom: 2px solid var(--c-border);
  font-family: var(--font-serif);
  font-size: 16px;
  font-weight: 900;
  letter-spacing: .12em;
}

.footer-links li + li {
  margin-top: 8px;
}

.footer-links a {
  font-size: 14px;
  color: var(--c-text-dim);
  text-decoration: none;
  transition: color .2s;
}

.footer-links a:hover {
  color: var(--c-gold);
}

.footer-links-dense li {
  font-size: 14px;
  line-height: 1.65;
  color: var(--c-text-dim);
}

.footer-note {
  margin-top: 16px;
  padding: 10px 12px;
  border-left: 3px solid var(--c-gold);
  background: rgba(27, 58, 45, .4);
  font-size: 12px;
  line-height: 1.6;
  color: var(--c-text-dim);
}

.footer-bottom {
  background: rgba(0, 0, 0, .28);
  border-top: var(--border-w) solid var(--c-border);
}

.footer-bottom-inner {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 20px var(--page-pad);
  display: flex;
  flex-wrap: wrap;
  gap: 8px 24px;
  align-items: center;
  justify-content: space-between;
}

.footer-trust {
  max-width: 680px;
  font-size: 13px;
  color: var(--c-text-dim);
}

.footer-copy {
  font-size: 13px;
  color: var(--c-text-dim);
}

/* ---------- 15. Reveal ---------- */
[data-reveal] {
  opacity: 0;
  transform: translateY(22px);
  transition: opacity .55s ease-out, transform .55s ease-out;
}

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

/* ---------- 16. Responsive ---------- */
@media (max-width: 767px) {
  .masthead {
    padding: 14px 14px 24px;
  }

  .masthead-meta {
    font-size: 10px;
    letter-spacing: .1em;
    margin-bottom: 12px;
    padding-bottom: 8px;
  }

  .masthead-brand {
    gap: 10px;
  }

  .masthead-name {
    font-size: 40px;
    letter-spacing: .04em;
  }

  .masthead-desc {
    font-size: 11px;
    letter-spacing: .1em;
    margin-top: 10px;
  }

  .site-nav-inner {
    justify-content: space-between;
    align-items: center;
    min-height: 52px;
    padding: 8px 16px;
  }

  .nav-toggle {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    padding: 8px 14px;
    border: 2px solid var(--c-border);
    background: var(--c-bg);
    color: var(--c-text);
    transition: border-color .2s, color .2s;
  }

  .nav-toggle:hover {
    border-color: var(--c-gold);
    color: var(--c-gold);
  }

  .nav-toggle-box {
    display: flex;
    flex-direction: column;
    gap: 4px;
    width: 16px;
  }

  .nav-toggle-line {
    display: block;
    height: 2px;
    background: var(--c-gold);
  }

  .nav-toggle-label {
    font-size: 14px;
    font-weight: 700;
    letter-spacing: .1em;
  }

  .site-nav-list {
    display: none;
    flex: 1 1 100%;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    margin-top: 8px;
    padding-top: 4px;
    border-top: 2px solid var(--c-border);
  }

  .site-nav[data-open="true"] .site-nav-list {
    display: flex;
  }

  .site-nav-item + .site-nav-item {
    border-top: 1px solid var(--c-border);
  }

  .site-nav-link {
    width: 100%;
    padding: 13px 10px;
    font-size: 15px;
    border-bottom: none;
  }

  .site-nav-link[aria-current="page"] {
    border-bottom: none;
    border-left: 4px solid var(--c-gold);
    padding-left: 16px;
    background: rgba(201, 164, 92, .06);
  }

  .footer-cols {
    gap: 32px;
    padding-top: 40px;
  }

  .footer-bottom-inner {
    flex-direction: column;
    align-items: flex-start;
  }

  .back-to-top {
    right: 12px;
    bottom: 12px;
    width: 44px;
    height: 44px;
  }
}

@media (min-width: 640px) and (max-width: 1023px) {
  .footer-cols {
    grid-template-columns: 1fr 1fr;
  }

  .footer-brand-block {
    grid-column: 1 / -1;
  }
}

@media (min-width: 1024px) {
  .footer-cols {
    grid-template-columns: 5fr 2fr 2fr 3fr;
    align-items: start;
    gap: 48px;
  }

  .footer-brand-block {
    grid-column: auto;
  }
}

/* ---------- 17. 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;
    transition-delay: 0ms !important;
  }

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