/* 海角社区 HAI JIAO - 全站样式 */
/* 品牌色系 */
:root {
  --brand-blue: #1677EE;
  --bright-blue: #3395FF;
  --deep-blue: #075FC6;
  --dark-blue: #08488D;
  --navy: #0A315E;
  --footer-bg: #071D37;
  --white: #FFFFFF;
  --light-bg: #F7FAFF;
  --soft-blue: #EDF5FF;
  --pale-blue: #E5F1FF;
  --title: #16243A;
  --text: #3C485A;
  --secondary: #6B7787;
  --muted: #929BA8;
  --light-text: #DCEEFF;
  --border: rgba(22,119,238,0.12);
  --dark-border: rgba(255,255,255,0.12);
  --shadow: 0 12px 34px rgba(30,72,120,0.08);
  --brand-shadow: 0 14px 40px rgba(22,119,238,0.14);
  --btn-gradient: linear-gradient(135deg, #3998FF 0%, #1677EE 55%, #075FC6 100%);
  --max-width: 1320px;
  --content-width: 1100px;
  --article-width: 800px;
}

*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  color: var(--text);
  background: var(--white);
  line-height: 1.7;
  overflow-x: hidden;
  min-height: 100vh;
}

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

a {
  color: var(--brand-blue);
  text-decoration: none;
  transition: color 0.2s ease;
}

a:hover {
  color: var(--deep-blue);
}

a:focus-visible {
  outline: 2px solid var(--brand-blue);
  outline-offset: 2px;
}

ul, ol {
  list-style: none;
}

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

/* ========== 顶部导航 ========== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: var(--white);
  border-bottom: 1px solid var(--border);
  box-shadow: 0 2px 12px rgba(30,72,120,0.04);
}

.header-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
  height: 72px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
  min-width: 0;
}

.brand a {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--title);
  text-decoration: none;
}

.brand-logo {
  height: 36px;
  width: auto;
  object-fit: contain;
}

.brand-name {
  font-size: 18px;
  font-weight: 600;
  color: var(--title);
  white-space: nowrap;
}

.desktop-nav {
  display: flex;
  align-items: center;
  gap: 4px;
  flex: 1;
  justify-content: center;
  min-width: 0;
}

.desktop-nav a {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 8px 14px;
  font-size: 15px;
  color: var(--text);
  border-radius: 8px;
  min-height: 44px;
  white-space: nowrap;
  position: relative;
}

.desktop-nav a:hover {
  color: var(--brand-blue);
  background: var(--soft-blue);
}

.desktop-nav a.active {
  color: var(--brand-blue);
  background: var(--pale-blue);
  font-weight: 500;
}

.desktop-nav a.active::after {
  content: "";
  position: absolute;
  bottom: 6px;
  left: 50%;
  transform: translateX(-50%);
  width: 5px;
  height: 5px;
  background: var(--brand-blue);
  border-radius: 50%;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-shrink: 0;
}

.header-actions a,
.header-actions button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 44px;
  min-height: 44px;
  padding: 8px 12px;
  font-size: 14px;
  color: var(--text);
  border-radius: 8px;
}

.header-actions a:hover,
.header-actions button:hover {
  color: var(--brand-blue);
  background: var(--soft-blue);
}

.btn-app {
  background: var(--btn-gradient) !important;
  color: var(--white) !important;
  padding: 8px 16px !important;
  border-radius: 20px !important;
  font-weight: 500;
}

.btn-app:hover {
  opacity: 0.92;
  color: var(--white) !important;
}

.menu-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 44px;
  height: 44px;
  padding: 10px;
}

.menu-toggle span {
  display: block;
  width: 20px;
  height: 2px;
  background: var(--title);
  border-radius: 1px;
  transition: 0.2s;
}

/* 手机顶部 */
.mobile-header {
  display: none;
  height: 62px;
  padding: 0 16px;
  align-items: center;
  justify-content: space-between;
  background: var(--white);
  border-bottom: 1px solid var(--border);
}

.mobile-header .brand-logo {
  height: 30px;
}

.mobile-header .brand-name {
  font-size: 16px;
}

/* ========== Mega Menu / 频道抽屉 ========== */
.mega-overlay {
  position: fixed;
  inset: 0;
  background: rgba(7, 29, 55, 0.45);
  z-index: 1100;
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transition: opacity 0.25s ease, visibility 0.25s ease;
}

.mega-overlay.open {
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
}

.mega-menu {
  position: fixed;
  top: 0;
  right: 0;
  width: min(920px, 100%);
  height: 100%;
  background: var(--white);
  z-index: 1200;
  transform: translateX(100%);
  transition: transform 0.3s ease;
  overflow-y: auto;
  box-shadow: -8px 0 40px rgba(7, 29, 55, 0.12);
}

.mega-menu.open {
  transform: translateX(0);
}

.mega-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 20px 28px;
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  background: var(--white);
  z-index: 2;
}

.mega-brand {
  display: flex;
  align-items: center;
  gap: 10px;
}

.mega-brand img {
  height: 32px;
  object-fit: contain;
}

.mega-brand span {
  font-size: 17px;
  font-weight: 600;
  color: var(--title);
}

.mega-close {
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 24px;
  color: var(--secondary);
  border-radius: 8px;
}

.mega-close:hover {
  background: var(--soft-blue);
  color: var(--brand-blue);
}

.mega-body {
  padding: 28px 32px 48px;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px 40px;
}

.mega-group h3 {
  font-size: 13px;
  font-weight: 600;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.04em;
  margin-bottom: 14px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border);
}

.mega-group a {
  display: block;
  padding: 10px 0;
  font-size: 15px;
  color: var(--text);
  min-height: 44px;
  line-height: 1.4;
}

.mega-group a:hover {
  color: var(--brand-blue);
}

/* 搜索面板 */
.search-panel {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  background: var(--white);
  z-index: 1300;
  padding: 24px;
  box-shadow: var(--shadow);
  transform: translateY(-100%);
  transition: transform 0.3s ease;
  visibility: hidden;
  pointer-events: none;
}

.search-panel.open {
  transform: translateY(0);
  visibility: visible;
  pointer-events: auto;
}

.search-inner {
  max-width: 640px;
  margin: 0 auto;
  display: flex;
  gap: 12px;
  align-items: center;
}

.search-inner input {
  flex: 1;
  height: 48px;
  padding: 0 18px;
  border: 1px solid var(--border);
  border-radius: 12px;
  font-size: 16px;
  color: var(--title);
  background: var(--light-bg);
}

.search-inner input:focus {
  outline: none;
  border-color: var(--brand-blue);
  box-shadow: 0 0 0 3px rgba(22,119,238,0.15);
}

.search-close {
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 22px;
  color: var(--secondary);
  border-radius: 8px;
}

.search-close:hover {
  background: var(--soft-blue);
  color: var(--brand-blue);
}

/* ========== 主内容区 ========== */
main {
  min-height: 60vh;
}

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

.section {
  padding: 56px 0;
}

.section-title {
  font-size: 28px;
  font-weight: 650;
  color: var(--title);
  margin-bottom: 8px;
  line-height: 1.3;
}

.section-desc {
  font-size: 15px;
  color: var(--secondary);
  margin-bottom: 28px;
  max-width: 640px;
}

/* ========== 首页 Hero ========== */
.hero-banner {
  position: relative;
  width: 100%;
  aspect-ratio: 16 / 7;
  max-height: 520px;
  background: linear-gradient(135deg, #0A315E 0%, #1677EE 50%, #3395FF 100%);
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
}

.hero-banner img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  position: absolute;
  inset: 0;
}

.hero-content {
  position: relative;
  z-index: 2;
  text-align: center;
  padding: 40px 24px;
  max-width: 800px;
}

.hero-content .hero-title {
  font-size: 48px;
  font-weight: 700;
  color: var(--white);
  line-height: 1.2;
  margin-bottom: 16px;
  text-shadow: 0 2px 12px rgba(0,0,0,0.25);
}

.hero-content .hero-sub {
  font-size: 18px;
  color: var(--light-text);
  margin-bottom: 28px;
  line-height: 1.6;
}

.hero-actions {
  display: flex;
  gap: 14px;
  justify-content: center;
  flex-wrap: wrap;
}

.btn-primary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 28px;
  background: var(--btn-gradient);
  color: var(--white) !important;
  font-size: 15px;
  font-weight: 500;
  border-radius: 24px;
  min-height: 48px;
  box-shadow: var(--brand-shadow);
  transition: opacity 0.2s, transform 0.2s;
}

.btn-primary:hover {
  opacity: 0.92;
  transform: translateY(-1px);
  color: var(--white) !important;
}

.btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 28px;
  background: rgba(255,255,255,0.18);
  color: var(--white) !important;
  font-size: 15px;
  font-weight: 500;
  border-radius: 24px;
  min-height: 48px;
  border: 1px solid rgba(255,255,255,0.35);
  backdrop-filter: blur(8px);
}

.btn-secondary:hover {
  background: rgba(255,255,255,0.28);
  color: var(--white) !important;
}

/* 四格导航 */
.nav-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  margin-top: -40px;
  position: relative;
  z-index: 5;
  padding: 0 24px;
  max-width: var(--max-width);
  margin-left: auto;
  margin-right: auto;
}

.nav-card {
  background: var(--white);
  border-radius: 16px;
  padding: 28px 22px;
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
  text-align: center;
  transition: transform 0.2s, box-shadow 0.2s;
}

.nav-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--brand-shadow);
}

.nav-card h3 {
  font-size: 17px;
  font-weight: 600;
  color: var(--title);
  margin-bottom: 8px;
}

.nav-card p {
  font-size: 13px;
  color: var(--secondary);
  line-height: 1.5;
}

.nav-card a {
  display: block;
  color: inherit;
}

/* ========== 通用内容块 ========== */
.feature-row {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 48px;
  align-items: center;
}

.feature-row.reverse {
  grid-template-columns: 0.9fr 1.1fr;
}

.feature-row.reverse .feature-text {
  order: 2;
}

.feature-row.reverse .feature-media {
  order: 1;
}

.feature-text h2 {
  font-size: 30px;
  font-weight: 650;
  color: var(--title);
  margin-bottom: 14px;
  line-height: 1.3;
}

.feature-text p {
  font-size: 16px;
  color: var(--text);
  margin-bottom: 12px;
  line-height: 1.75;
}

.feature-media {
  position: relative;
  border-radius: 16px;
  overflow: hidden;
  background: linear-gradient(145deg, #EDF5FF, #F7FAFF);
  aspect-ratio: 4 / 3;
}

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

.city-feature-image {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* 卡片网格 */
.card-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.card {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 24px;
  transition: box-shadow 0.2s, border-color 0.2s;
}

.card:hover {
  box-shadow: var(--shadow);
  border-color: rgba(22,119,238,0.22);
}

.card h3 {
  font-size: 17px;
  font-weight: 600;
  color: var(--title);
  margin-bottom: 10px;
  line-height: 1.4;
}

.card p {
  font-size: 14px;
  color: var(--secondary);
  line-height: 1.65;
}

.card a {
  color: inherit;
  display: block;
}

/* 今日值得看 特殊布局 */
.today-layout {
  display: grid;
  grid-template-columns: 1.4fr 1fr;
  gap: 24px;
}

.today-main {
  background: var(--soft-blue);
  border-radius: 16px;
  padding: 32px;
  border: 1px solid var(--border);
}

.today-main h3 {
  font-size: 22px;
  font-weight: 650;
  color: var(--title);
  margin-bottom: 12px;
  line-height: 1.35;
}

.today-main p {
  font-size: 15px;
  color: var(--text);
  line-height: 1.7;
  margin-bottom: 16px;
}

.today-side {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.today-item {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 18px 20px;
}

.today-item h4 {
  font-size: 16px;
  font-weight: 600;
  color: var(--title);
  margin-bottom: 6px;
}

.today-item p {
  font-size: 13px;
  color: var(--secondary);
  line-height: 1.55;
}

.today-short {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  margin-top: 24px;
}

.today-short .item {
  background: var(--light-bg);
  border-radius: 10px;
  padding: 16px;
  border: 1px solid var(--border);
}

.today-short .item h5 {
  font-size: 14px;
  font-weight: 600;
  color: var(--title);
  margin-bottom: 4px;
}

.today-short .item p {
  font-size: 13px;
  color: var(--secondary);
}

/* 时间板 */
.time-boards {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.time-board {
  background: var(--light-bg);
  border-radius: 14px;
  padding: 24px 20px;
  border: 1px solid var(--border);
}

.time-board .time-label {
  font-size: 13px;
  font-weight: 600;
  color: var(--brand-blue);
  margin-bottom: 10px;
}

.time-board h3 {
  font-size: 17px;
  font-weight: 600;
  color: var(--title);
  margin-bottom: 8px;
}

.time-board p {
  font-size: 14px;
  color: var(--secondary);
  line-height: 1.6;
}

/* 兴趣墙 */
.interest-wall {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 16px;
}

.interest-item {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 20px 16px;
  text-align: center;
  transition: border-color 0.2s, box-shadow 0.2s;
}

.interest-item:hover {
  border-color: rgba(22,119,238,0.3);
  box-shadow: var(--shadow);
}

.interest-item h3 {
  font-size: 16px;
  font-weight: 600;
  color: var(--title);
  margin-bottom: 6px;
}

.interest-item p {
  font-size: 13px;
  color: var(--secondary);
  line-height: 1.5;
}

/* 故事 */
.story-main {
  background: var(--soft-blue);
  border-radius: 16px;
  padding: 36px;
  margin-bottom: 28px;
  border: 1px solid var(--border);
}

.story-main h3 {
  font-size: 22px;
  font-weight: 650;
  color: var(--title);
  margin-bottom: 14px;
}

.story-main p {
  font-size: 16px;
  color: var(--text);
  line-height: 1.8;
  margin-bottom: 12px;
}

.story-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
}

.story-card {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 22px;
}

.story-card h4 {
  font-size: 16px;
  font-weight: 600;
  color: var(--title);
  margin-bottom: 8px;
}

.story-card p {
  font-size: 14px;
  color: var(--secondary);
  line-height: 1.65;
}

/* 影集槽位 */
.album-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  grid-template-rows: auto auto;
  gap: 16px;
}

.media-slot {
  background: linear-gradient(145deg, #EDF5FF 0%, #F7FAFF 50%, #FFFFFF 100%);
  border-radius: 12px;
  border: 1px solid var(--border);
  overflow: hidden;
  position: relative;
  aspect-ratio: 16 / 10;
}

.media-slot.wide {
  grid-row: span 2;
  aspect-ratio: 3 / 4;
}

.media-slot.medium {
  aspect-ratio: 4 / 3;
}

.media-slot.small {
  aspect-ratio: 1 / 1;
}

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

.media-slot .slot-label {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  padding: 12px 14px;
  background: linear-gradient(transparent, rgba(7,29,55,0.65));
  color: var(--white);
  font-size: 13px;
  font-weight: 500;
}

/* APP 预览 */
.app-section {
  background: var(--light-bg);
  border-radius: 20px;
  padding: 48px;
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 40px;
  align-items: center;
  border: 1px solid var(--border);
}

.app-preview-image {
  max-height: 480px;
  width: auto;
  margin: 0 auto;
  object-fit: contain;
}

.app-text h2 {
  font-size: 28px;
  font-weight: 650;
  color: var(--title);
  margin-bottom: 14px;
}

.app-text p {
  font-size: 15px;
  color: var(--text);
  margin-bottom: 12px;
  line-height: 1.7;
}

/* 安全中心深蓝 */
.security-banner {
  background: var(--navy);
  border-radius: 16px;
  padding: 40px 36px;
  color: var(--white);
}

.security-banner h2 {
  font-size: 26px;
  font-weight: 650;
  color: var(--white);
  margin-bottom: 12px;
}

.security-banner p {
  font-size: 15px;
  color: var(--light-text);
  line-height: 1.7;
  margin-bottom: 10px;
}

/* 隐私浅色 */
.privacy-box {
  background: var(--white);
  border: 1px solid rgba(22,119,238,0.18);
  border-radius: 14px;
  padding: 28px;
}

.privacy-box h3 {
  font-size: 17px;
  font-weight: 600;
  color: var(--title);
  margin-bottom: 10px;
}

.privacy-box p {
  font-size: 14px;
  color: var(--text);
  line-height: 1.65;
}

/* 脉搏信息条 */
.pulse-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.pulse-item {
  display: flex;
  align-items: flex-start;
  gap: 14px;
  padding: 16px 20px;
  background: var(--light-bg);
  border-radius: 10px;
  border: 1px solid var(--border);
}

.pulse-item .tag {
  flex-shrink: 0;
  font-size: 12px;
  font-weight: 600;
  color: var(--brand-blue);
  background: var(--pale-blue);
  padding: 4px 10px;
  border-radius: 6px;
}

.pulse-item p {
  font-size: 14px;
  color: var(--text);
  line-height: 1.55;
}

/* 页脚 */
.site-footer {
  background: var(--footer-bg);
  color: var(--light-text);
  padding: 56px 0 32px;
  margin-top: 64px;
  border-top: 1px solid rgba(220, 238, 255, 0.12);
}

.footer-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 16px;
}

.footer-brand img {
  height: 32px;
  object-fit: contain;
}

.footer-brand .name {
  font-size: 18px;
  font-weight: 600;
  color: var(--white);
}

.footer-brand .en {
  font-size: 13px;
  color: var(--muted);
  margin-left: 6px;
}

.footer-desc {
  font-size: 14px;
  color: var(--muted);
  max-width: 520px;
  line-height: 1.7;
  margin-bottom: 36px;
}

.footer-cols {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 32px;
  margin-bottom: 40px;
}

.footer-col h4 {
  font-size: 14px;
  font-weight: 600;
  color: var(--white);
  margin-bottom: 14px;
}

.footer-col a {
  display: block;
  font-size: 14px;
  color: var(--muted);
  padding: 6px 0;
  min-height: 36px;
}

.footer-col a:hover {
  color: var(--light-text);
}

.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.08);
  padding-top: 24px;
  text-align: center;
  font-size: 13px;
  color: var(--muted);
}

/* 移动底部导航 */
.mobile-tabbar {
  display: none;
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  height: 56px;
  padding-bottom: env(safe-area-inset-bottom, 0);
  background: var(--white);
  border-top: 1px solid var(--border);
  z-index: 900;
  box-shadow: 0 -4px 20px rgba(30,72,120,0.06);
}

.mobile-tabbar a {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  font-size: 11px;
  color: var(--secondary);
  min-height: 54px;
  gap: 2px;
}

.mobile-tabbar a.active {
  color: var(--brand-blue);
  font-weight: 500;
}

.mobile-tabbar .tab-icon {
  width: 22px;
  height: 22px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 18px;
}

/* 页面内通用 */
.page-hero {
  padding: 48px 0 32px;
  background: var(--light-bg);
  border-bottom: 1px solid var(--border);
}

.page-hero h1 {
  font-size: 38px;
  font-weight: 700;
  color: var(--title);
  margin-bottom: 12px;
  line-height: 1.25;
}

.page-hero .lead {
  font-size: 16px;
  color: var(--secondary);
  max-width: 640px;
  line-height: 1.7;
}

.page-content {
  padding: 48px 0 64px;
}

.article-body {
  max-width: var(--article-width);
  margin: 0 auto;
}

.article-body h2 {
  font-size: 24px;
  font-weight: 650;
  color: var(--title);
  margin: 36px 0 14px;
  line-height: 1.35;
}

.article-body h3 {
  font-size: 19px;
  font-weight: 600;
  color: var(--title);
  margin: 28px 0 10px;
}

.article-body p {
  font-size: 16px;
  color: var(--text);
  margin-bottom: 14px;
  line-height: 1.8;
}

.article-body ul, .article-body ol {
  margin: 12px 0 20px 20px;
  list-style: disc;
}

.article-body li {
  font-size: 15px;
  color: var(--text);
  margin-bottom: 8px;
  line-height: 1.7;
}

.content-block {
  margin-bottom: 48px;
}

.content-block h2 {
  font-size: 26px;
  font-weight: 650;
  color: var(--title);
  margin-bottom: 16px;
}

/* FAQ */
.faq-list details {
  background: var(--light-bg);
  border: 1px solid var(--border);
  border-radius: 12px;
  margin-bottom: 12px;
  padding: 0 20px;
}

.faq-list summary {
  font-size: 16px;
  font-weight: 600;
  color: var(--title);
  padding: 18px 0;
  cursor: pointer;
  list-style: none;
  min-height: 52px;
  display: flex;
  align-items: center;
}

.faq-list summary::-webkit-details-marker {
  display: none;
}

.faq-list details[open] summary {
  border-bottom: 1px solid var(--border);
  margin-bottom: 12px;
}

.faq-list details p {
  font-size: 15px;
  color: var(--text);
  padding-bottom: 18px;
  line-height: 1.7;
}

/* 按钮组 */
.btn-group {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  margin-top: 20px;
}

/* 响应式 */
@media (max-width: 1280px) {
  .header-inner {
    padding: 0 20px;
  }
  .desktop-nav a {
    padding: 8px 10px;
    font-size: 14px;
  }
  .section-title {
    font-size: 26px;
  }
  .hero-content .hero-title {
    font-size: 42px;
  }
}

@media (max-width: 1024px) {
  .desktop-nav {
    display: none;
  }
  .menu-toggle {
    display: flex;
  }
  .header-actions .btn-app {
    display: none;
  }
  .nav-grid {
    grid-template-columns: repeat(2, 1fr);
    margin-top: -28px;
  }
  .feature-row,
  .feature-row.reverse {
    grid-template-columns: 1fr;
    gap: 28px;
  }
  .feature-row.reverse .feature-text,
  .feature-row.reverse .feature-media {
    order: unset;
  }
  .card-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .today-layout {
    grid-template-columns: 1fr;
  }
  .today-short {
    grid-template-columns: 1fr;
  }
  .time-boards {
    grid-template-columns: repeat(2, 1fr);
  }
  .interest-wall {
    grid-template-columns: repeat(3, 1fr);
  }
  .app-section {
    grid-template-columns: 1fr;
    padding: 36px 28px;
  }
  .app-preview-image {
    max-height: 360px;
    max-width: 280px;
  }
  .footer-cols {
    grid-template-columns: repeat(2, 1fr);
  }
  .mega-body {
    grid-template-columns: repeat(2, 1fr);
  }
  .album-grid {
    grid-template-columns: 1fr 1fr;
  }
  .media-slot.wide {
    grid-row: span 1;
    aspect-ratio: 16 / 10;
  }
  .story-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 768px) {
  .site-header .header-inner {
    display: none;
  }
  .mobile-header {
    display: flex;
  }
  .mobile-tabbar {
    display: flex;
  }
  main {
    padding-bottom: 70px;
  }
  .hero-banner {
    aspect-ratio: 16 / 10;
    max-height: 360px;
  }
  .hero-content .hero-title {
    font-size: 32px;
  }
  .hero-content .hero-sub {
    font-size: 15px;
  }
  .section {
    padding: 40px 0;
  }
  .section-title {
    font-size: 24px;
  }
  .page-hero h1 {
    font-size: 30px;
  }
  .page-hero {
    padding: 36px 0 24px;
  }
  .nav-grid {
    grid-template-columns: 1fr 1fr;
    gap: 14px;
    margin-top: -20px;
  }
  .nav-card {
    padding: 20px 16px;
  }
  .card-grid {
    grid-template-columns: 1fr;
  }
  .time-boards {
    grid-template-columns: 1fr;
  }
  .interest-wall {
    grid-template-columns: repeat(2, 1fr);
  }
  .footer-cols {
    grid-template-columns: 1fr 1fr;
    gap: 24px;
  }
  .mega-menu {
    width: 100%;
  }
  .mega-body {
    grid-template-columns: 1fr;
    gap: 24px;
    padding: 24px 20px 48px;
  }
  .container {
    padding: 0 16px;
  }
  .album-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 560px) {
  .hero-content .hero-title {
    font-size: 28px;
  }
  .nav-grid {
    grid-template-columns: 1fr;
  }
  .interest-wall {
    grid-template-columns: 1fr 1fr;
  }
  .footer-cols {
    grid-template-columns: 1fr;
  }
  .btn-group {
    flex-direction: column;
  }
  .btn-primary, .btn-secondary {
    width: 100%;
  }
}

/* 工具类 */
.text-center { text-align: center; }
.mt-24 { margin-top: 24px; }
.mb-16 { margin-bottom: 16px; }
.bg-light { background: var(--light-bg); }
.bg-soft { background: var(--soft-blue); }
.rounded { border-radius: 14px; }
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  border: 0;
}