/* 基础样式、页头页脚、通用组件。各页面共用 */
*,
*::before,
*::after {
  box-sizing: border-box;
}

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

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font);
  font-size: var(--fs-body);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

img {
  max-width: 100%;
  height: auto;
  vertical-align: middle;
}

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

h1, h2, h3, p {
  margin: 0;
}

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

:focus-visible {
  outline: 3px solid var(--accent);
  outline-offset: 2px;
  border-radius: 4px;
}

.container {
  width: 100%;
  max-width: calc(var(--container) + var(--gutter) * 2);
  margin: 0 auto;
  padding: 0 var(--gutter);
}

.skip-link {
  position: absolute;
  left: -9999px;
  top: 8px;
  z-index: 200;
  padding: 8px 16px;
  border-radius: var(--radius-s);
  color: #fff;
  background: var(--primary-dark);
}

.skip-link:focus {
  left: 8px;
}

/* ============ 页头与导航（固定 6 项） ============ */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.96);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--line);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: var(--header-h);
}

.brand-link {
  display: flex;
  align-items: center;
  gap: 12px;
  min-height: var(--tap);
}

.brand-bar {
  width: 6px;
  height: 28px;
  border-radius: 6px;
  background: linear-gradient(180deg, var(--primary), var(--accent));
}

.brand-text {
  font-size: 22px;
  font-weight: 700;
  letter-spacing: 3px;
  color: var(--primary-dark);
}

.nav-toggle {
  display: none;
  align-items: center;
  justify-content: center;
  width: var(--tap);
  height: var(--tap);
  padding: 0;
  border: none;
  border-radius: var(--radius-s);
  background: var(--primary-light);
  cursor: pointer;
}

.nav-toggle-bars,
.nav-toggle-bars::before,
.nav-toggle-bars::after {
  display: block;
  width: 20px;
  height: 2px;
  border-radius: 2px;
  background: var(--primary);
  transition: transform 0.2s, background 0.2s;
}

.nav-toggle-bars {
  position: relative;
}

.nav-toggle-bars::before,
.nav-toggle-bars::after {
  content: '';
  position: absolute;
  left: 0;
}

.nav-toggle-bars::before { top: -7px; }
.nav-toggle-bars::after { top: 7px; }

.nav-toggle[aria-expanded='true'] .nav-toggle-bars { background: transparent; }
.nav-toggle[aria-expanded='true'] .nav-toggle-bars::before { transform: translateY(7px) rotate(45deg); }
.nav-toggle[aria-expanded='true'] .nav-toggle-bars::after { transform: translateY(-7px) rotate(-45deg); }

.main-nav ul {
  display: flex;
  align-items: center;
  gap: 4px;
}

.main-nav a {
  display: flex;
  align-items: center;
  min-height: var(--tap);
  padding: 0 16px;
  border-radius: 999px;
  font-size: 17px;
  color: var(--text-2);
  transition: background 0.15s, color 0.15s;
}

.main-nav a:hover {
  color: var(--primary);
  background: var(--primary-light);
}

.main-nav a[aria-current='page'] {
  font-weight: 600;
  color: var(--primary);
  background: var(--primary-light);
}

/* 手机：导航收起，仍保持 6 项 */
@media (max-width: 899px) {
  .nav-toggle {
    display: inline-flex;
  }

  .main-nav {
    display: none;
    position: absolute;
    left: 0;
    right: 0;
    top: 100%;
    padding: 8px var(--gutter) 16px;
    background: #fff;
    border-bottom: 1px solid var(--line);
    box-shadow: 0 16px 24px rgba(var(--primary-dark-rgb), 0.1);
  }

  .main-nav.is-open {
    display: block;
  }

  .main-nav ul {
    flex-direction: column;
    align-items: stretch;
    gap: 2px;
  }

  .main-nav a {
    min-height: 52px;
    padding: 0 16px;
    border-radius: var(--radius-s);
    font-size: 18px;
  }

  /* 没有 JavaScript 时直接展开，保证能导航 */
  html:not(.js) .nav-toggle {
    display: none;
  }

  html:not(.js) .main-nav {
    display: block;
    position: static;
    padding: 0 0 8px;
    box-shadow: none;
    border: none;
  }

  html:not(.js) .main-nav ul {
    flex-direction: row;
    flex-wrap: wrap;
  }

  html:not(.js) .header-inner {
    flex-wrap: wrap;
  }
}

/* ============ 区块标题 ============ */
.section {
  padding-top: 36px;
}

.section-head {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 18px;
}

.section-title {
  position: relative;
  padding-left: 18px;
  font-size: 24px;
  font-weight: 700;
  line-height: 1.4;
}

.section-title::before {
  content: '';
  position: absolute;
  left: 0;
  top: 5px;
  bottom: 5px;
  width: 6px;
  border-radius: 6px;
  background: linear-gradient(180deg, var(--primary), var(--accent));
}

.section-desc {
  margin-top: 4px;
  padding-left: 18px;
  font-size: var(--fs-small);
  color: var(--text-3);
}

.more-link {
  display: inline-flex;
  align-items: center;
  flex-shrink: 0;
  min-height: var(--tap);
  gap: 6px;
  font-size: var(--fs-small);
  color: var(--primary);
}

.more-link::after {
  content: '';
  width: 8px;
  height: 8px;
  border-top: 2px solid currentColor;
  border-right: 2px solid currentColor;
  transform: rotate(45deg);
}

.more-link:hover {
  color: var(--primary-dark);
}

/* ============ 通用组件 ============ */
.card {
  background: var(--surface);
  border-radius: var(--radius-m);
  box-shadow: var(--shadow-card);
}

.tag {
  display: inline-flex;
  align-items: center;
  height: 26px;
  padding: 0 10px;
  border-radius: 6px;
  font-size: 13px;
  line-height: 1;
  color: var(--primary);
  background: var(--primary-light);
}

.tag-accent { color: var(--accent-dark); background: var(--accent-light); }
.tag-muted { color: var(--text-3); background: var(--muted-bg); }

.state {
  display: inline-flex;
  align-items: center;
  flex-shrink: 0;
  height: 28px;
  padding: 0 12px;
  border-radius: 999px;
  font-size: 14px;
  line-height: 1;
}

.state-upcoming { color: var(--accent-dark); background: var(--accent-light); }
.state-replay { color: var(--primary); background: var(--primary-light); }
.state-ended { color: var(--text-3); background: var(--muted-bg); }

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 52px;
  padding: 0 32px;
  border: 2px solid transparent;
  border-radius: 999px;
  font-family: inherit;
  font-size: 18px;
  font-weight: 500;
  letter-spacing: 1px;
  cursor: pointer;
  transition: transform 0.15s, box-shadow 0.15s, background 0.15s;
}

.btn:hover {
  transform: translateY(-1px);
}

.btn-primary {
  color: #fff;
  background: linear-gradient(135deg, var(--primary-bright) 0%, var(--primary) 50%, var(--primary-dark) 100%);
  box-shadow: 0 8px 20px rgba(var(--primary-rgb), 0.28);
}

.btn-light {
  color: var(--primary-dark);
  background: #fff;
}

.btn-outline-light {
  color: #fff;
  border-color: rgba(255, 255, 255, 0.55);
  background: rgba(255, 255, 255, 0.08);
}

.btn-outline-light:hover {
  background: rgba(255, 255, 255, 0.18);
}

.btn-accent {
  color: #fff;
  background: var(--accent-mid);
}

/* 列表中的内容卡片（文章 / 视频 / FAQ 共用） */
.content-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
}

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

@media (min-width: 1024px) {
  .content-grid { grid-template-columns: repeat(3, 1fr); gap: 20px; }
}

.content-card {
  display: flex;
  flex-direction: column;
  padding: 22px 22px 18px;
  transition: transform 0.18s, box-shadow 0.18s;
}

.content-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-hover);
}

.content-card .tag {
  align-self: flex-start;
}

.content-card-title {
  margin-top: 12px;
  font-size: var(--fs-title);
  font-weight: 600;
  line-height: 1.5;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.content-card-summary {
  margin-top: 8px;
  font-size: var(--fs-small);
  color: var(--text-2);
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.content-card-meta {
  margin-top: auto;
  padding-top: 16px;
  font-size: 14px;
  color: var(--text-3);
}

/* ============ 页脚 ============ */
.site-footer {
  margin-top: 56px;
  color: rgba(255, 255, 255, 0.82);
  background: linear-gradient(160deg, var(--primary-dark) 0%, var(--primary-deepest) 100%);
}

.footer-inner {
  display: grid;
  gap: 28px;
  padding: 40px 0 28px;
}

@media (min-width: 900px) {
  .footer-inner {
    grid-template-columns: 1.4fr 1fr 1fr;
    gap: 48px;
  }
}

.footer-brand {
  font-size: 24px;
  font-weight: 700;
  letter-spacing: 3px;
  color: #fff;
}

.footer-full {
  margin-top: 6px;
  font-size: var(--fs-small);
}

.footer-org {
  margin-top: 14px;
  font-size: var(--fs-small);
  color: var(--accent-pale);
}

.footer-title {
  margin-bottom: 8px;
  font-size: 16px;
  font-weight: 600;
  color: #fff;
}

.footer-links a {
  display: inline-flex;
  align-items: center;
  min-height: 36px;
  font-size: var(--fs-small);
}

.footer-links a:hover {
  color: #fff;
  text-decoration: underline;
}

.footer-contact li {
  font-size: var(--fs-small);
  line-height: 2;
}

.footer-bottom {
  padding: 18px 0 24px;
  border-top: 1px solid rgba(255, 255, 255, 0.14);
  font-size: 13px;
  color: rgba(255, 255, 255, 0.6);
}

.footer-bottom p + p {
  margin-top: 4px;
}

.footer-stat-num {
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  color: var(--accent-pale);
}

.footer-icp a {
  color: inherit;
  text-decoration: underline;
  text-underline-offset: 3px;
}

/* 无障碍：用户偏好减少动效时关闭过渡 */
@media (prefers-reduced-motion: reduce) {
  * {
    transition: none !important;
    scroll-behavior: auto !important;
  }
}