/* ===== 全局重置与变量 ===== */
*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --c-bg: #0B1A2E;
  --c-bg-secondary: #1A1A2E;
  --c-accent-red: #E63946;
  --c-accent-blue: #00B4D8;
  --c-accent-gold: #FFD700;
  --c-text: #F4F4F4;
  --c-text-secondary: #CCCCCC;
  --c-glass: rgba(255, 255, 255, 0.08);
  --c-glass-border: rgba(255, 255, 255, 0.12);
  --c-nav-bg: rgba(11, 26, 46, 0.96);
  --c-overlay: rgba(0, 0, 0, 0.6);
  --font-heading: 'Montserrat', 'Helvetica Neue', Arial, sans-serif;
  --font-body: 'Open Sans', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  --h1: clamp(36px, 6vw, 64px);
  --h2: clamp(28px, 4.5vw, 48px);
  --h3: clamp(22px, 3vw, 32px);
  --h4: clamp(18px, 2.2vw, 24px);
  --body: clamp(14px, 1.2vw, 16px);
  --caption: clamp(11px, 0.9vw, 12px);
  --space-xs: 4px;
  --space-sm: 8px;
  --space-md: 16px;
  --space-lg: 32px;
  --space-xl: 64px;
  --radius: 8px;
  --radius-sm: 4px;
  --transition: 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94);
  --nav-width: 240px;
  --nav-collapsed: 56px;
  --header-height: 80px;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: var(--font-body);
  font-size: var(--body);
  line-height: 1.6;
  color: var(--c-text);
  background: var(--c-bg);
  min-height: 100vh;
  display: grid;
  grid-template-columns: var(--nav-width) 1fr;
  grid-template-rows: auto 1fr auto;
  grid-template-areas:
    "header header"
    "nav main"
    "footer footer";
  transition: grid-template-columns var(--transition);
}

body.b-sidebar-collapsed {
  grid-template-columns: var(--nav-collapsed) 1fr;
}

/* ===== 跳过链接 ===== */
.b-skip {
  position: fixed;
  top: -100%;
  left: 50%;
  transform: translateX(-50%);
  z-index: 10000;
  background: var(--c-accent-red);
  color: #fff;
  padding: var(--space-sm) var(--space-lg);
  border-radius: 0 0 var(--radius) var(--radius);
  font-weight: 700;
  text-decoration: none;
  font-size: var(--body);
  transition: top var(--transition);
}
.b-skip:focus {
  top: 0;
}

/* ===== 头部 ===== */
.b-header {
  grid-area: header;
  position: relative;
  z-index: 1000;
  background: var(--c-nav-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--c-glass-border);
  height: var(--header-height);
  display: flex;
  align-items: center;
  justify-content: center;
}

.b-header__top {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  max-width: 1280px;
  padding: 0 var(--space-lg);
  position: relative;
}

.b-header__brand {
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.b-header__logo {
  font-family: var(--font-heading);
  font-weight: 900;
  font-size: var(--h3);
  color: var(--c-text);
  text-decoration: none;
  letter-spacing: 4px;
  text-transform: uppercase;
  background: linear-gradient(135deg, var(--c-accent-red), var(--c-accent-gold));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1.2;
}
.b-header__logo::after {
  content: "B体育";
  font-size: var(--caption);
  color: var(--c-text-secondary);
  -webkit-text-fill-color: var(--c-text-secondary);
  margin-left: var(--space-sm);
  font-weight: 400;
  letter-spacing: 1px;
}

.b-header__tagline {
  font-size: var(--caption);
  color: var(--c-text-secondary);
  letter-spacing: 6px;
  margin-top: var(--space-xs);
  text-transform: uppercase;
}

/* ===== 汉堡按钮 ===== */
.b-nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--space-sm);
  position: absolute;
  right: var(--space-lg);
  top: 50%;
  transform: translateY(-50%);
  z-index: 1100;
}
.b-nav-toggle__bar {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--c-text);
  margin: 5px 0;
  transition: var(--transition);
  border-radius: 2px;
}
.b-nav-toggle[aria-expanded="true"] .b-nav-toggle__bar:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}
.b-nav-toggle[aria-expanded="true"] .b-nav-toggle__bar:nth-child(2) {
  opacity: 0;
}
.b-nav-toggle[aria-expanded="true"] .b-nav-toggle__bar:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}

/* ===== 导航 ===== */
.b-nav {
  grid-area: nav;
  position: fixed;
  top: var(--header-height);
  left: 0;
  width: var(--nav-width);
  height: calc(100vh - var(--header-height));
  background: var(--c-nav-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-right: 1px solid var(--c-glass-border);
  z-index: 900;
  display: flex;
  flex-direction: column;
  transition: width var(--transition), transform var(--transition);
  overflow-y: auto;
  overflow-x: hidden;
}

.b-sidebar-toggle {
  background: none;
  border: none;
  color: var(--c-text-secondary);
  cursor: pointer;
  padding: var(--space-md);
  text-align: right;
  font-size: var(--caption);
  transition: var(--transition);
  border-bottom: 1px solid var(--c-glass-border);
  flex-shrink: 0;
}
.b-sidebar-toggle:hover {
  color: var(--c-accent-gold);
}
.b-sidebar-toggle__icon {
  display: inline-block;
  transition: transform var(--transition);
}

body.b-sidebar-collapsed .b-nav {
  width: var(--nav-collapsed);
}
body.b-sidebar-collapsed .b-sidebar-toggle__icon {
  transform: rotate(180deg);
}

.b-nav__list {
  list-style: none;
  padding: var(--space-md) 0;
  flex: 1;
}

.b-nav__item {
  margin: 0 var(--space-xs);
}

.b-nav__link {
  display: flex;
  align-items: center;
  padding: var(--space-md) var(--space-lg);
  color: var(--c-text-secondary);
  text-decoration: none;
  font-size: var(--body);
  font-weight: 500;
  border-radius: var(--radius);
  transition: var(--transition);
  position: relative;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.b-nav__link::before {
  content: "";
  position: absolute;
  left: 0;
  top: 50%;
  transform: translateY(-50%);
  width: 3px;
  height: 0;
  background: var(--c-accent-red);
  transition: height var(--transition);
  border-radius: 0 3px 3px 0;
}
.b-nav__link:hover,
.b-nav__link:focus-visible {
  color: var(--c-text);
  background: var(--c-glass);
}
.b-nav__link:hover::before,
.b-nav__link:focus-visible::before {
  height: 60%;
}
.b-nav__link[aria-current="page"] {
  color: var(--c-accent-red);
  background: rgba(230, 57, 70, 0.08);
  font-weight: 700;
}
.b-nav__link[aria-current="page"]::before {
  height: 70%;
}

body.b-sidebar-collapsed .b-nav__link {
  padding: var(--space-md) var(--space-sm);
  justify-content: center;
  font-size: 0;
}
body.b-sidebar-collapsed .b-nav__link::after {
  content: attr(data-short);
  font-size: var(--body);
  font-weight: 700;
  color: var(--c-text-secondary);
}
body.b-sidebar-collapsed .b-nav__link:hover::after,
body.b-sidebar-collapsed .b-nav__link:focus-visible::after {
  color: var(--c-accent-red);
}

.b-nav__footer {
  padding: var(--space-md) var(--space-lg);
  border-top: 1px solid var(--c-glass-border);
  flex-shrink: 0;
}

.b-nav__trust {
  font-size: var(--caption);
  color: var(--c-text-secondary);
  line-height: 1.4;
  display: block;
}

body.b-sidebar-collapsed .b-nav__footer {
  display: none;
}

/* ===== 主内容 ===== */
.b-main {
  grid-area: main;
  min-height: calc(100vh - var(--header-height));
  padding: var(--space-xl) var(--space-lg);
  max-width: 100%;
  overflow-x: hidden;
}

/* ===== 页脚 ===== */
.b-footer {
  grid-area: footer;
  background: var(--c-bg-secondary);
  border-top: 1px solid var(--c-glass-border);
  padding: var(--space-xl) var(--space-lg) var(--space-lg);
}

.b-footer__inner {
  max-width: 1280px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: var(--space-lg);
}

.b-footer__logo {
  font-family: var(--font-heading);
  font-weight: 900;
  font-size: var(--h4);
  color: var(--c-text);
  text-decoration: none;
  letter-spacing: 2px;
  background: linear-gradient(135deg, var(--c-accent-red), var(--c-accent-gold));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.b-footer__desc {
  font-size: var(--caption);
  color: var(--c-text-secondary);
  margin-top: var(--space-sm);
}

.b-footer__links {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
  align-items: center;
}

.b-footer__link {
  color: var(--c-text-secondary);
  text-decoration: none;
  font-size: var(--body);
  transition: var(--transition);
  padding: var(--space-xs) 0;
}
.b-footer__link:hover,
.b-footer__link:focus-visible {
  color: var(--c-accent-blue);
}

.b-footer__meta {
  text-align: right;
}

.b-footer__copyright {
  font-size: var(--caption);
  color: var(--c-text-secondary);
}

.b-footer__icp {
  font-size: var(--caption);
  color: var(--c-text-secondary);
  margin-top: var(--space-xs);
}

.b-footer__contact {
  font-size: var(--caption);
  color: var(--c-text-secondary);
  margin-top: var(--space-sm);
}

.b-footer__address {
  font-size: var(--caption);
  color: var(--c-text-secondary);
  margin-top: var(--space-xs);
}

/* ===== 通用组件 ===== */
.b-container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 var(--space-md);
}

.b-section {
  padding: var(--space-xl) 0;
}

.b-card {
  background: var(--c-bg-secondary);
  border-radius: var(--radius);
  padding: var(--space-lg);
  border: 1px solid var(--c-glass-border);
  transition: var(--transition);
}
.b-card:hover {
  border-color: var(--c-accent-blue);
  box-shadow: 0 4px 24px rgba(0, 180, 216, 0.15);
}

.b-bento {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: var(--space-lg);
  align-items: start;
}

.b-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-sm) var(--space-lg);
  border-radius: var(--radius);
  font-family: var(--font-body);
  font-size: var(--body);
  font-weight: 600;
  text-decoration: none;
  border: none;
  cursor: pointer;
  transition: var(--transition);
  line-height: 1.4;
}
.b-btn:focus-visible {
  outline: 2px solid var(--c-accent-gold);
  outline-offset: 2px;
}
.b-btn--primary {
  background: var(--c-accent-red);
  color: #fff;
}
.b-btn--primary:hover {
  background: #c52e3a;
  box-shadow: 0 4px 16px rgba(230, 57, 70, 0.4);
}
.b-btn--secondary {
  background: transparent;
  color: var(--c-accent-blue);
  border: 1px solid var(--c-accent-blue);
}
.b-btn--secondary:hover {
  background: rgba(0, 180, 216, 0.1);
}

.b-badge {
  display: inline-block;
  padding: 2px var(--space-sm);
  border-radius: var(--radius-sm);
  font-size: var(--caption);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1px;
}
.b-badge--red {
  background: var(--c-accent-red);
  color: #fff;
}
.b-badge--gold {
  background: var(--c-accent-gold);
  color: #0B1A2E;
}

.b-data {
  font-size: 1.2em;
  font-weight: 700;
  color: var(--c-accent-red);
}
.b-data--gold {
  color: var(--c-accent-gold);
}

.b-tag {
  display: inline-block;
  padding: 2px var(--space-sm);
  background: var(--c-glass);
  border-radius: var(--radius-sm);
  font-size: var(--caption);
  color: var(--c-text-secondary);
  border: 1px solid var(--c-glass-border);
}

/* ===== 滚动进度条 ===== */
.b-progress {
  position: fixed;
  top: var(--header-height);
  left: 0;
  width: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--c-accent-red), var(--c-accent-gold));
  z-index: 1100;
  transition: width 0.1s linear;
  pointer-events: none;
}

/* ===== 滚动显现 ===== */
.b-reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}
.b-reveal[data-reveal-visible] {
  opacity: 1;
  transform: translateY(0);
}
@media (prefers-reduced-motion: reduce) {
  .b-reveal {
    opacity: 1;
    transform: none;
    transition: none;
  }
}

/* ===== 图片容器基础规则 ===== */
.b-img {
  display: block;
  width: 100%;
  height: auto;
  border-radius: var(--radius);
  background: var(--c-bg-secondary);
  aspect-ratio: 16 / 9;
  object-fit: cover;
}
.b-img--portrait {
  aspect-ratio: 3 / 4;
}
.b-img--square {
  aspect-ratio: 1 / 1;
}
.b-img--wide {
  aspect-ratio: 21 / 9;
}
.b-img-placeholder {
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--c-glass);
  border: 1px dashed var(--c-glass-border);
  color: var(--c-text-secondary);
  font-size: var(--caption);
  border-radius: var(--radius);
  aspect-ratio: 16 / 9;
  width: 100%;
}

/* ===== 移动端适配 ===== */
@media (max-width: 768px) {
  body {
    grid-template-columns: 1fr;
    grid-template-areas:
      "header"
      "main"
      "footer";
  }

  .b-header {
    height: auto;
    min-height: 60px;
  }

  .b-header__top {
    padding: var(--space-sm) var(--space-md);
    justify-content: space-between;
  }

  .b-header__brand {
    flex-direction: row;
    align-items: center;
    gap: var(--space-sm);
  }

  .b-header__logo {
    font-size: var(--h4);
  }
  .b-header__logo::after {
    font-size: 10px;
  }

  .b-header__tagline {
    display: none;
  }

  .b-nav-toggle {
    display: block;
  }

  .b-nav {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100vh;
    height: 100dvh;
    transform: translateX(-100%);
    background: var(--c-nav-bg);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-right: none;
    z-index: 2000;
    padding-top: 60px;
  }
  .b-nav[data-open] {
    transform: translateX(0);
  }

  body.b-sidebar-collapsed .b-nav {
    width: 100%;
  }

  .b-sidebar-toggle {
    display: none;
  }

  .b-nav__link {
    font-size: var(--h4);
    padding: var(--space-md) var(--space-lg);
    justify-content: flex-start;
  }
  body.b-sidebar-collapsed .b-nav__link {
    font-size: var(--h4);
  }
  body.b-sidebar-collapsed .b-nav__link::after {
    display: none;
  }

  .b-nav__footer {
    display: block;
  }

  .b-main {
    padding: var(--space-lg) var(--space-md);
  }

  .b-footer__inner {
    grid-template-columns: 1fr;
    text-align: center;
    gap: var(--space-md);
  }

  .b-footer__meta {
    text-align: center;
  }

  .b-footer__links {
    flex-direction: row;
    justify-content: center;
    gap: var(--space-md);
  }

  .b-bento {
    grid-template-columns: 1fr;
  }
}

@media (min-width: 769px) and (max-width: 1024px) {
  body {
    grid-template-columns: var(--nav-collapsed) 1fr;
  }
  .b-nav {
    width: var(--nav-collapsed);
  }
  .b-nav__link {
    padding: var(--space-md) var(--space-sm);
    justify-content: center;
    font-size: 0;
  }
  .b-nav__link::after {
    content: attr(data-short);
    font-size: var(--body);
    font-weight: 700;
    color: var(--c-text-secondary);
  }
  .b-nav__footer {
    display: none;
  }
  .b-sidebar-toggle {
    display: none;
  }
  .b-nav__trust {
    display: none;
  }
}

/* ===== 焦点样式与可访问性 ===== */
:focus-visible {
  outline: 2px solid var(--c-accent-gold);
  outline-offset: 2px;
}

/* ===== 减少动效 ===== */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
  }
  html {
    scroll-behavior: auto;
  }
  .b-nav {
    transition: transform 0.01ms;
  }
  .b-nav-toggle__bar {
    transition: 0.01ms;
  }
}

/* ===== 滚动条 ===== */
.b-nav::-webkit-scrollbar {
  width: 4px;
}
.b-nav::-webkit-scrollbar-track {
  background: transparent;
}
.b-nav::-webkit-scrollbar-thumb {
  background: var(--c-glass-border);
  border-radius: 4px;
}
.b-nav::-webkit-scrollbar-thumb:hover {
  background: var(--c-text-secondary);
}

/* ===== 选中状态 ===== */
::selection {
  background: var(--c-accent-red);
  color: #fff;
}

/* ===== 数据高亮容器 ===== */
.b-data-group {
  display: flex;
  gap: var(--space-lg);
  flex-wrap: wrap;
}

.b-data-item {
  display: flex;
  flex-direction: column;
  align-items: center;
}

.b-data-value {
  font-size: var(--h2);
  font-weight: 900;
  color: var(--c-accent-red);
  line-height: 1;
}

.b-data-value--gold {
  color: var(--c-accent-gold);
}

.b-data-label {
  font-size: var(--caption);
  color: var(--c-text-secondary);
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-top: var(--space-xs);
}

/* ===== 分隔装饰 ===== */
.b-divider {
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--c-accent-red), var(--c-accent-gold), transparent);
  margin: var(--space-xl) 0;
  border: none;
  opacity: 0.4;
}

.b-speed-line {
  position: relative;
  overflow: hidden;
}
.b-speed-line::after {
  content: "";
  position: absolute;
  top: 0;
  right: 0;
  width: 120%;
  height: 100%;
  background: repeating-linear-gradient(
    45deg,
    transparent,
    transparent 20px,
    rgba(255, 255, 255, 0.02) 20px,
    rgba(255, 255, 255, 0.02) 21px
  );
  pointer-events: none;
}