/* ==========================================================================
   BSPORTS 数字竞技场 — 站点共享框架
   /assets/site.css
   框架式导航 · 数据叙事 · 数字竞技场
   ========================================================================== */

/* ---------- 1. Reset & Global ---------- */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

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

body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  font-family: var(--bsp-font-body);
  font-size: 16px;
  line-height: 1.6;
  background: var(--bsp-bg-deep);
  color: var(--bsp-text-main);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

main {
  flex: 1;
}

#main-content {
  scroll-margin-top: calc(var(--bsp-header-h) + 12px);
}

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

ul,
ol {
  list-style: none;
}

a {
  color: var(--bsp-info);
  text-decoration: underline;
  text-underline-offset: 2px;
  transition: color 0.2s ease;
}

a:hover {
  color: var(--bsp-green);
}

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

/* ---------- 2. Variables ---------- */
:root {
  --bsp-bg-deep: #0A1F44;
  --bsp-bg-navy: #0E2A5E;
  --bsp-bg-card: #122A50;
  --bsp-green: #39FF14;
  --bsp-orange: #FF4500;
  --bsp-info: #00BFFF;
  --bsp-text-main: #F0F4F8;
  --bsp-text-muted: #A0B0C0;
  --bsp-line: #1E3A5F;
  --bsp-overlay: rgba(0, 0, 0, 0.5);

  --bsp-font-head: Impact, 'Arial Black', 'Helvetica Neue', sans-serif;
  --bsp-font-body: 'Inter', system-ui, -apple-system, 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', sans-serif;

  --bsp-container: 1200px;
  --bsp-header-h: 72px;
  --bsp-gap: 24px;
  --bsp-radius: 0px;
  --bsp-ease: cubic-bezier(0.22, 1, 0.36, 1);
}

/* ---------- 3. Typography ---------- */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--bsp-font-head);
  font-weight: 900;
  line-height: 1.15;
  letter-spacing: 0.02em;
  text-transform: uppercase;
  color: var(--bsp-text-main);
  margin-bottom: 0.5em;
}

h1 { font-size: clamp(2.2rem, 5vw, 3.5rem); }
h2 { font-size: clamp(1.6rem, 3.5vw, 2.4rem); }
h3 { font-size: clamp(1.3rem, 2.5vw, 1.7rem); }
h4 { font-size: 1.2rem; }

p { margin-bottom: 16px; }

/* ---------- 4. Layout ---------- */
.container {
  width: 100%;
  max-width: var(--bsp-container);
  margin: 0 auto;
  padding: 0 24px;
}

.section {
  padding: 80px 0;
}

.section--tight {
  padding: 48px 0;
}

.split-hero {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: center;
}

.grid-2 {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--bsp-gap);
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--bsp-gap);
}

/* ---------- 5. Header ---------- */
.arena-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: rgba(10, 31, 68, 0.92);
  -webkit-backdrop-filter: blur(14px);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--bsp-line);
}

.arena-header__inner {
  position: relative;
  max-width: var(--bsp-container);
  margin: 0 auto;
  height: var(--bsp-header-h);
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.arena-header__inner::before {
  content: '';
  position: absolute;
  left: 0;
  top: 50%;
  transform: translateY(-50%);
  width: 3px;
  height: 36px;
  background: linear-gradient(180deg, var(--bsp-green), var(--bsp-orange));
}

/* 滚动进度 */
.match-progress {
  position: absolute;
  top: 0;
  left: 0;
  height: 3px;
  width: 0%;
  background: linear-gradient(90deg, var(--bsp-green), var(--bsp-orange));
  box-shadow: 0 0 12px rgba(57, 255, 20, 0.5);
  z-index: 5;
  will-change: width;
}

/* 品牌 Logo */
.arena-logo {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
}

.arena-logo__mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  background: var(--bsp-green);
  color: var(--bsp-bg-deep);
  font-family: var(--bsp-font-head);
  font-size: 16px;
  font-weight: 900;
  letter-spacing: 0.02em;
  clip-path: polygon(0 0, 100% 0, 100% 72%, 72% 100%, 0 100%);
  flex-shrink: 0;
  text-shadow: none;
}

.arena-logo__text {
  font-family: var(--bsp-font-head);
  font-size: 20px;
  font-weight: 900;
  line-height: 1;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--bsp-text-main);
  text-decoration: none;
}

.arena-logo__text em {
  font-style: normal;
  display: block;
  font-size: 11px;
  letter-spacing: 0.22em;
  color: var(--bsp-orange);
  margin-top: 2px;
}

/* 主导航 */
.arena-nav {
  display: flex;
  align-items: center;
  gap: 28px;
}

.arena-nav__link {
  position: relative;
  display: inline-block;
  padding: 6px 2px;
  font-family: var(--bsp-font-body);
  font-size: 14px;
  font-weight: 500;
  letter-spacing: 0.06em;
  color: var(--bsp-text-main);
  text-decoration: none;
  transition: color 0.3s var(--bsp-ease);
}

.arena-nav__link::after {
  content: '';
  position: absolute;
  left: 0;
  bottom: 0;
  width: 100%;
  height: 2px;
  background: linear-gradient(90deg, var(--bsp-green), var(--bsp-orange));
  transform: scaleX(0);
  transform-origin: right center;
  transition: transform 0.35s var(--bsp-ease);
}

.arena-nav__link:hover {
  color: var(--bsp-green);
}

.arena-nav__link:hover::after,
.arena-nav__link[aria-current="page"]::after {
  transform: scaleX(1);
  transform-origin: left center;
}

.arena-nav__link[aria-current="page"] {
  color: var(--bsp-green);
  text-shadow: 0 0 14px rgba(57, 255, 20, 0.4);
}

/* 汉堡按钮 */
.arena-nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 44px;
  height: 44px;
  padding: 10px;
  background: transparent;
  border: 1px solid var(--bsp-line);
  border-radius: 4px;
  cursor: pointer;
  transition: border-color 0.3s;
}

.arena-nav-toggle:hover {
  border-color: var(--bsp-green);
}

.arena-nav-toggle__bar {
  display: block;
  width: 100%;
  height: 2px;
  background: var(--bsp-text-main);
  transition: transform 0.3s var(--bsp-ease), opacity 0.2s;
}

.arena-nav-toggle[aria-expanded="true"] .arena-nav-toggle__bar:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.arena-nav-toggle[aria-expanded="true"] .arena-nav-toggle__bar:nth-child(2) {
  opacity: 0;
  transform: scaleX(0.4);
}

.arena-nav-toggle[aria-expanded="true"] .arena-nav-toggle__bar:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

.arena-nav-toggle__sr {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
}

/* Skip link */
.skip-link {
  position: fixed;
  top: -100px;
  left: 16px;
  z-index: 3000;
  background: var(--bsp-green);
  color: var(--bsp-bg-deep);
  font-weight: 700;
  font-size: 14px;
  padding: 10px 20px;
  border-radius: 0 0 6px 6px;
  text-decoration: none;
  transition: top 0.3s var(--bsp-ease);
}

.skip-link:focus {
  top: 0;
}

/* 返回顶部 */
.back-to-top {
  position: fixed;
  right: 24px;
  bottom: 24px;
  z-index: 900;
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--bsp-bg-card);
  border: 1px solid var(--bsp-line);
  color: var(--bsp-green);
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transform: translateY(8px);
  transition: opacity 0.3s var(--bsp-ease), visibility 0.3s, transform 0.3s var(--bsp-ease), background 0.3s, border-color 0.3s;
  clip-path: polygon(0 0, 100% 0, 100% 80%, 80% 100%, 0 100%);
}

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

.back-to-top:hover {
  background: var(--bsp-green);
  color: var(--bsp-bg-deep);
  border-color: var(--bsp-green);
}

.back-to-top__icon {
  display: block;
  width: 14px;
  height: 14px;
  border-top: 2px solid currentColor;
  border-left: 2px solid currentColor;
  transform: rotate(45deg);
  margin-top: 6px;
}

/* ---------- 6. Footer ---------- */
.arena-footer {
  position: relative;
  background: var(--bsp-bg-navy);
  border-top: 1px solid var(--bsp-line);
  margin-top: auto;
}

.arena-footer::before {
  content: '';
  position: absolute;
  top: -2px;
  left: 0;
  width: 160px;
  height: 2px;
  background: linear-gradient(90deg, var(--bsp-green), var(--bsp-orange));
}

.arena-footer__grid {
  max-width: var(--bsp-container);
  margin: 0 auto;
  padding: 56px 24px 40px;
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1.5fr;
  gap: 40px;
}

.arena-footer__brand {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.arena-logo--footer .arena-logo__mark {
  width: 36px;
  height: 36px;
  font-size: 14px;
}

.arena-footer__about {
  font-size: 14px;
  color: var(--bsp-text-muted);
  max-width: 36em;
}

.arena-footer__trust {
  font-size: 12px;
  color: var(--bsp-text-muted);
  border-left: 2px solid var(--bsp-orange);
  padding-left: 12px;
  max-width: 36em;
  line-height: 1.5;
}

.arena-footer__heading {
  font-family: var(--bsp-font-head);
  font-size: 14px;
  font-weight: 900;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--bsp-text-main);
  margin-bottom: 16px;
  padding-bottom: 8px;
  position: relative;
}

.arena-footer__heading::after {
  content: '';
  position: absolute;
  left: 0;
  bottom: 0;
  width: 24px;
  height: 2px;
  background: var(--bsp-orange);
}

.arena-footer__list {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.arena-footer__list a {
  color: var(--bsp-text-muted);
  font-size: 14px;
  text-decoration: none;
  transition: color 0.25s, padding-left 0.25s;
}

.arena-footer__list a:hover {
  color: var(--bsp-green);
  padding-left: 4px;
}

.arena-footer__contact .arena-footer__list li {
  color: var(--bsp-text-muted);
  font-size: 14px;
  line-height: 1.7;
}

.arena-footer__bottom {
  border-top: 1px solid var(--bsp-line);
  padding: 20px 24px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
  max-width: var(--bsp-container);
  margin: 0 auto;
  font-size: 13px;
  color: var(--bsp-text-muted);
}

/* ---------- 7. Components ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 28px;
  font-family: var(--bsp-font-body);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  text-decoration: none;
  line-height: 1.4;
  border: 1px solid transparent;
  cursor: pointer;
  transition: all 0.3s var(--bsp-ease);
  text-align: center;
}

.btn--primary {
  background: var(--bsp-green);
  color: var(--bsp-bg-deep);
}

.btn--primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 10px 32px rgba(57, 255, 20, 0.3);
  background: #54f938;
  color: var(--bsp-bg-deep);
}

.btn--outline {
  background: transparent;
  color: var(--bsp-text-main);
  border-color: var(--bsp-line);
}

.btn--outline:hover {
  background: rgba(255, 69, 0, 0.12);
  border-color: var(--bsp-orange);
  color: var(--bsp-orange);
  transform: translateY(-2px);
}

.card {
  background: var(--bsp-bg-card);
  border: 1px solid var(--bsp-line);
  padding: 28px;
  position: relative;
  transition: transform 0.35s var(--bsp-ease), box-shadow 0.35s var(--bsp-ease), border-color 0.35s;
}

.card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 3px;
  height: 0;
  background: var(--bsp-green);
  transition: height 0.35s var(--bsp-ease);
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: 0 16px 40px rgba(0, 0, 0, 0.4);
  border-color: rgba(57, 255, 20, 0.3);
}

.card:hover::before {
  height: 100%;
}

.card--frag {
  clip-path: polygon(0 0, calc(100% - 20px) 0, 100% 20px, 100% 100%, 20px 100%, 0 calc(100% - 20px));
}

.img-frame {
  position: relative;
  overflow: hidden;
  background: linear-gradient(135deg, var(--bsp-bg-card), var(--bsp-bg-navy));
  border: 1px solid var(--bsp-line);
}

.img-frame--16-9 { aspect-ratio: 16 / 9; }
.img-frame--4-3 { aspect-ratio: 4 / 3; }
.img-frame--1-1 { aspect-ratio: 1 / 1; }

.img-frame img,
.img-frame svg {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.img-frame::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 3px;
  background: linear-gradient(90deg, var(--bsp-green), var(--bsp-orange));
  opacity: 0.6;
}

/* ---------- 8. Breadcrumb ---------- */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  padding: 16px 0;
  font-size: 13px;
  color: var(--bsp-text-muted);
}

.breadcrumb a {
  color: var(--bsp-text-muted);
  text-decoration: none;
  transition: color 0.2s;
}

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

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

.breadcrumb__item {
  display: inline-flex;
  align-items: center;
  gap: 8px;
}

/* ---------- 9. Utilities ---------- */
.text-muted { color: var(--bsp-text-muted); }
.text-green { color: var(--bsp-green); }
.text-orange { color: var(--bsp-orange); }
.text-center { text-align: center; }
.text-uppercase { text-transform: uppercase; }
.font-head { font-family: var(--bsp-font-head); font-weight: 900; }
.mt-0 { margin-top: 0; }
.mb-0 { margin-bottom: 0; }

/* ---------- 10. Responsive ---------- */
@media (max-width: 1023px) {
  .arena-header__inner {
    padding: 0 16px;
    gap: 16px;
  }

  .arena-nav {
    gap: 16px;
  }

  .arena-nav__link {
    font-size: 13px;
  }

  .arena-logo__text {
    font-size: 17px;
  }

  .arena-footer__grid {
    grid-template-columns: 1fr 1fr;
    gap: 32px;
  }

  .split-hero {
    grid-template-columns: 1fr;
    gap: 32px;
  }

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

@media (max-width: 767px) {
  .arena-nav-toggle {
    display: flex;
  }

  .arena-nav {
    position: fixed;
    top: var(--bsp-header-h);
    left: 0;
    right: 0;
    display: none;
    flex-direction: column;
    align-items: stretch;
    gap: 4px;
    background: rgba(14, 42, 94, 0.97);
    border-bottom: 2px solid var(--bsp-green);
    padding: 16px;
    box-shadow: 0 24px 48px rgba(0, 0, 0, 0.5);
  }

  .arena-nav[data-open] {
    display: flex;
    animation: navSlideIn 0.3s var(--bsp-ease);
  }

  .arena-nav__link {
    padding: 12px 16px;
    font-size: 16px;
    border-left: 3px solid transparent;
  }

  .arena-nav__link::after {
    display: none;
  }

  .arena-nav__link[aria-current="page"] {
    border-left-color: var(--bsp-green);
    background: rgba(57, 255, 20, 0.08);
  }

  .split-hero {
    padding: 40px 0;
  }

  .section {
    padding: 48px 0;
  }
}

@media (max-width: 567px) {
  .arena-footer__grid {
    grid-template-columns: 1fr;
    padding: 40px 20px 28px;
  }

  .arena-footer__bottom {
    flex-direction: column;
    text-align: center;
    padding: 16px 20px;
  }

  .grid-2,
  .grid-3 {
    grid-template-columns: 1fr;
  }

  .back-to-top {
    right: 16px;
    bottom: 16px;
  }
}

@keyframes navSlideIn {
  from {
    opacity: 0;
    transform: translateY(-12px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ---------- 11. Focus & Reduced Motion ---------- */
:focus-visible {
  outline: 2px solid var(--bsp-orange);
  outline-offset: 2px;
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}