/* 小蓝视频官网 - 静态页样式 | 响应式 */

:root {
  --bg: #e8f2fc;
  --bg-card: #ffffff;
  --text: #1a2744;
  --text-muted: #5a6b85;
  --blue: #1e5a96;
  --blue-bright: #2b7fd4;
  --blue-soft: #e8f1fa;
  --accent: #5b21b6;
  --accent-soft: #ede9fe;
  --rainbow: linear-gradient(
    90deg,
    #e11d48 0%,
    #f97316 20%,
    #eab308 40%,
    #22c55e 60%,
    #3b82f6 80%,
    #a855f7 100%
  );
  --shadow: 0 12px 40px rgba(30, 90, 150, 0.08);
  --radius: 14px;
  --font: "PingFang SC", "Segoe UI", "Microsoft YaHei", Arial, "Helvetica Neue", sans-serif;
  --max: 1080px;
  /* 与轮播 #banner 的 Tailwind max-w-6xl + px-4 对齐 */
  --content-max: 72rem;
  --content-px: 1rem;
}

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

html {
  scroll-behavior: smooth;
  min-height: 100%;
  background: linear-gradient(
    165deg,
    #f0f9ff 0%,
    #dbeafe 38%,
    #e0f2fe 68%,
    #f8fafc 100%
  );
}

body {
  margin: 0;
  font-family: var(--font);
  font-size: clamp(15px, 2.8vw, 17px);
  line-height: 1.75;
  color: var(--text);
  min-height: 100%;
  background: transparent;
  -webkit-font-smoothing: antialiased;
}

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

a {
  color: var(--blue-bright);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  padding: 0.75rem 1rem;
  background: var(--blue);
  color: #fff;
  z-index: 100;
}

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

.sprite-defs {
  position: absolute;
  width: 0;
  height: 0;
  overflow: hidden;
}

/* 面包屑（SEO / 结构化导航） */
.breadcrumb-nav {
  max-width: var(--max);
  margin: 0 auto;
  padding: 0.5rem 1.25rem 0;
  font-size: 0.8125rem;
  color: var(--text-muted);
}

.breadcrumb-nav ol {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.35rem 0.5rem;
  list-style: none;
  margin: 0;
  padding: 0;
}

.breadcrumb-nav li:not(:last-child)::after {
  content: "/";
  margin-left: 0.5rem;
  color: #94a3b8;
  font-weight: 400;
}

.breadcrumb-nav a {
  color: var(--blue);
  text-decoration: none;
  font-weight: 500;
}

.breadcrumb-nav a:hover {
  text-decoration: underline;
  color: var(--blue-bright);
}

.breadcrumb-nav [aria-current="page"] {
  color: var(--text);
  font-weight: 600;
  text-decoration: none;
}

/* 站群内链扩展 + 实体自动链 */
.seo-pbn-footer {
  margin-top: 1.25rem;
  padding-top: 1rem;
  border-top: 1px solid rgba(30, 90, 150, 0.12);
}

.seo-pbn-footer:not([hidden]) {
  display: block;
}

.seo-pbn-footer__nav {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1rem;
  justify-content: center;
}

.seo-pbn-footer__nav a {
  font-size: 0.8125rem;
  color: var(--blue-bright);
  text-decoration: none;
}

.seo-pbn-footer__nav a:hover {
  text-decoration: underline;
}

a.pbn-entity-link {
  color: var(--blue-bright);
  text-decoration: underline;
  text-underline-offset: 2px;
}

a.pbn-entity-link:hover {
  color: var(--blue);
}

/* 顶部导航 */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid rgba(30, 90, 150, 0.1);
  box-shadow: 0 1px 0 rgba(255, 255, 255, 0.8);
}

.rainbow-bar {
  height: 3px;
  background: var(--rainbow);
  width: 100%;
}

.header-inner {
  max-width: var(--max);
  margin: 0 auto;
  padding: 0.65rem 1.25rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.logo {
  font-weight: 700;
  font-size: clamp(1rem, 4vw, 1.15rem);
  color: var(--blue);
  letter-spacing: -0.02em;
}

.logo span {
  color: var(--accent);
  font-weight: 600;
}

/* 移动端菜单 */
.menu-toggle {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.menu-btn {
  display: none;
  width: 44px;
  height: 44px;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--blue-soft);
  border-radius: 10px;
  background: var(--bg-card);
  cursor: pointer;
  padding: 0;
}

.menu-btn span,
.menu-btn span::before,
.menu-btn span::after {
  display: block;
  width: 20px;
  height: 2px;
  background: var(--blue);
  position: relative;
  transition: transform 0.2s, opacity 0.2s;
}

.menu-btn span::before,
.menu-btn span::after {
  content: "";
  position: absolute;
  left: 0;
}

.menu-btn span::before {
  top: -6px;
}

.menu-btn span::after {
  top: 6px;
}

.nav-cluster {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: flex-end;
  gap: 0.75rem 1.25rem;
}

.nav-links {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.35rem 1.25rem;
}

.nav-links a {
  color: var(--text);
  font-size: 0.92rem;
  font-weight: 500;
  text-decoration: none;
  padding: 0.35rem 0;
}

.nav-links a:hover {
  color: var(--blue-bright);
  text-decoration: none;
}

.header-search {
  display: flex;
  align-items: stretch;
  flex-shrink: 0;
  border: 1px solid rgba(30, 90, 150, 0.2);
  border-radius: 10px;
  overflow: hidden;
  background: var(--bg-card);
  box-shadow: 0 1px 2px rgba(30, 90, 150, 0.06);
}

.header-search input[type="search"] {
  -webkit-appearance: none;
  appearance: none;
  border: none;
  padding: 0.4rem 0.65rem;
  font-size: 0.88rem;
  font-family: inherit;
  min-width: 6.5rem;
  width: 9.5rem;
  max-width: 12rem;
  background: transparent;
  color: var(--text);
}

.header-search input[type="search"]::placeholder {
  color: var(--text-muted);
}

.header-search input[type="search"]:focus {
  outline: none;
}

.header-search:focus-within {
  border-color: var(--blue-bright);
  box-shadow: 0 0 0 2px rgba(43, 127, 212, 0.2);
}

.header-search__btn {
  display: flex;
  align-items: center;
  justify-content: center;
  border: none;
  border-left: 1px solid rgba(30, 90, 150, 0.15);
  padding: 0 0.6rem;
  background: rgba(30, 90, 150, 0.07);
  color: var(--blue);
  cursor: pointer;
}

.header-search__btn:hover {
  background: rgba(30, 90, 150, 0.12);
  color: var(--blue-bright);
}

@media (max-width: 768px) {
  .menu-btn {
    display: flex;
  }

  .menu-toggle:checked ~ .nav-wrap {
    max-height: 520px;
    opacity: 1;
    padding: 0.75rem 0 0.5rem;
    visibility: visible;
  }

  .menu-toggle:checked ~ .menu-btn span {
    background: transparent;
  }

  .menu-toggle:checked ~ .menu-btn span::before {
    top: 0;
    transform: rotate(45deg);
  }

  .menu-toggle:checked ~ .menu-btn span::after {
    top: 0;
    transform: rotate(-45deg);
  }

  .nav-wrap {
    width: 100%;
    order: 3;
    border-top: 1px solid var(--blue-soft);
    margin-top: 0.5rem;
    padding-top: 0;
    max-height: 0;
    opacity: 0;
    overflow: hidden;
    visibility: hidden;
    transition: max-height 0.35s ease, opacity 0.25s ease, visibility 0.25s ease;
  }

  .nav-cluster {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
  }

  .nav-links {
    flex-direction: column;
    align-items: flex-start;
    width: 100%;
    padding-top: 0.25rem;
  }

  .header-search {
    width: 100%;
    margin-top: 0.75rem;
  }

  .header-search input[type="search"] {
    flex: 1;
    width: auto;
    min-width: 0;
    max-width: none;
  }

  .header-inner {
    flex-wrap: wrap;
  }
}

@media (min-width: 769px) {
  .nav-wrap {
    display: contents;
  }
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* 顶部轮播：Tailwind CDN + 页内脚本；避免全站链接样式覆盖轮播 CTA */
.tw-banner a,
.tw-banner a:hover,
.tw-promo-grid a,
.tw-promo-grid a:hover {
  text-decoration: none;
}

@media (prefers-reduced-motion: reduce) {
  .tw-promo-grid .group:hover img {
    transform: scale(1) !important;
  }

  .landing-platform-module .tw-promo-grid > .group {
    transition: none;
  }

  .landing-platform-module .tw-promo-grid > .group:hover {
    transform: none;
  }
}

/* 轮播下方：热门内容推荐（仅作用于 .hot-section，避免与全站 .card 冲突） */
.hot-section {
  width: 100%;
  max-width: 1200px;
  margin: 40px auto;
  padding: 0 1.25rem;
  box-sizing: border-box;
}

.hot-section .section-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 20px;
  flex-wrap: wrap;
  gap: 0.5rem 1rem;
}

.hot-section .section-header h2 {
  margin: 0;
  font-size: 22px;
  font-weight: bold;
  color: var(--text);
}

.hot-section .section-header a {
  color: #888;
  text-decoration: none;
  font-size: 14px;
}

.hot-section .section-header a:hover {
  color: #555;
  text-decoration: none;
}

.hot-section .card-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

@media (max-width: 1024px) {
  .hot-section .card-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 520px) {
  .hot-section {
    margin: 24px auto;
  }

  .hot-section .card-grid {
    grid-template-columns: 1fr;
  }
}

.hot-section .card {
  position: relative;
  padding: 0;
  background: linear-gradient(165deg, #fbfcff 0%, #ffffff 38%, #ffffff 100%);
  border-radius: 16px;
  overflow: hidden;
  transition: transform 0.3s ease, box-shadow 0.3s ease;
  box-shadow: 0 5px 20px rgba(0, 0, 0, 0.05);
  border: 1px solid rgba(255, 255, 255, 0.9);
}

/* 图片区底部渐变遮罩（高度与 .card-thumb 一致，避免盖住标题与正文） */
.hot-section .card::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  top: 0;
  height: 140px;
  z-index: 1;
  pointer-events: none;
  border-radius: 16px 16px 0 0;
  background: linear-gradient(to top, rgba(0, 0, 0, 0.3), transparent);
}

.hot-section .card:hover {
  transform: translateY(-5px);
  box-shadow: 0 12px 32px rgba(30, 90, 150, 0.12), 0 8px 24px rgba(0, 0, 0, 0.06);
}

.hot-section .card-thumb {
  position: relative;
  z-index: 0;
  height: 140px;
  overflow: hidden;
  background: linear-gradient(135deg, #e8edf7 0%, #dde8ff 42%, #ede9fe 100%);
}

.hot-section .card img {
  width: 100%;
  height: 140px;
  object-fit: cover;
  display: block;
  transition: transform 0.35s ease;
}

.hot-section .card:hover img {
  transform: scale(1.05);
}

.hot-section .card h3 {
  position: relative;
  z-index: 2;
  margin: 0;
  font-size: 16px;
  font-weight: bold;
  padding: 10px 12px 0;
  line-height: 1.35;
  color: var(--text);
}

.hot-section .card p {
  position: relative;
  z-index: 2;
  margin: 0;
  font-size: 13px;
  color: #666;
  padding: 6px 12px 14px;
  line-height: 1.5;
}

@media (prefers-reduced-motion: reduce) {
  .hot-section .card {
    transition: none;
  }

  .hot-section .card:hover {
    transform: none;
  }

  .hot-section .card img {
    transition: none;
  }

  .hot-section .card:hover img {
    transform: none;
  }
}

/* 轮播下方：居中标题 + 双栏白卡片 */
.landing-intro {
  background: transparent;
  padding: clamp(1.75rem, 5vw, 2.75rem) 0 clamp(2.25rem, 6vw, 3.5rem);
}

.landing-intro__wrap {
  max-width: var(--content-max);
  margin: 0 auto;
  padding: 0 var(--content-px);
}

.landing-intro__header {
  text-align: center;
  max-width: 52rem;
  margin: 0 auto clamp(1.75rem, 4vw, 2.5rem);
}

.landing-intro__title {
  margin: 0 0 1rem;
  font-size: clamp(1.35rem, 4.2vw, 2rem);
  line-height: 1.35;
  font-weight: 800;
  color: #3f36a3;
  letter-spacing: -0.02em;
}

.landing-intro__lead {
  margin: 0;
  font-size: clamp(0.95rem, 2.4vw, 1.05rem);
  line-height: 1.85;
  color: #5a6b85;
}

/* 「热门平台推荐」：无整块渐变紫底，与页面背景融为一体 */
.landing-platform-module {
  margin-top: clamp(1.35rem, 3.5vw, 2rem);
  text-align: left;
  background: transparent;
  border-radius: 0;
  box-shadow: none;
  border: none;
  outline: none;
  overflow: visible;
}

.landing-platform-module__intro {
  /* 横向不再缩进，与 #banner（max-w-6xl + px-4）内容区左右齐平 */
  padding: clamp(1.35rem, 4vw, 2.5rem) 0;
  background: transparent;
}

.landing-platform-module__promo {
  background: transparent;
  border-top: none;
}

.landing-platform-module__intro h2 {
  margin: 0 0 0.75rem;
  font-size: clamp(1.15rem, 3vw, 1.5rem);
  font-weight: 700;
  color: #3730a3;
  letter-spacing: -0.02em;
  text-align: center;
}

.landing-platform-module__intro p {
  margin: 0 auto;
  max-width: 56rem;
  font-size: clamp(0.95rem, 2.2vw, 1.05rem);
  line-height: 1.8;
  color: #5b5675;
  text-align: justify;
  text-justify: inter-ideograph;
}

.landing-platform-module__grid {
  padding: clamp(1.25rem, 4vw, 2.5rem) 0;
}

/* 推广宫格：双列等宽拉伸，避免通栏卡片缩窄 */
.landing-platform-module .tw-promo-grid {
  width: 100%;
}

/* 与 .hot-section 卡片一致：无紫/深色描边，轻阴影 + 悬停抬起 */
.landing-platform-module .tw-promo-grid > .group {
  border: none;
  box-shadow: 0 5px 20px rgba(0, 0, 0, 0.05);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.landing-platform-module .tw-promo-grid > .group:hover {
  transform: translateY(-5px);
  box-shadow: 0 12px 32px rgba(30, 90, 150, 0.12), 0 8px 24px rgba(0, 0, 0, 0.06);
}

.landing-card {
  background: linear-gradient(
    155deg,
    #eff6ff 0%,
    #dbeafe 38%,
    #e0f2fe 72%,
    #f0f9ff 100%
  );
  border-radius: 18px;
  box-shadow: 0 12px 48px rgba(30, 90, 150, 0.12), 0 2px 8px rgba(30, 90, 150, 0.06);
  border: 1px solid rgba(30, 90, 150, 0.12);
  padding: clamp(1.35rem, 4vw, 2.25rem) clamp(1.25rem, 4vw, 2.5rem);
}

.landing-card__grid {
  display: grid;
  gap: clamp(1.5rem, 4vw, 2.25rem);
  align-items: start;
}

@media (min-width: 900px) {
  .landing-card__grid {
    grid-template-columns: minmax(0, 1.65fr) minmax(0, 1fr);
    gap: clamp(1.75rem, 3vw, 2.75rem);
  }
}

.landing-card__title {
  margin: 0 0 1rem;
  font-size: clamp(1.1rem, 2.5vw, 1.35rem);
  font-weight: 700;
  color: #1e3a5f;
}

.landing-card__text {
  margin: 0 0 1rem;
  font-size: 0.98rem;
  line-height: 1.85;
  color: #4a5f78;
}

.landing-card__text:last-child {
  margin-bottom: 0;
}

.landing-card__aside {
  background: rgba(255, 255, 255, 0.88);
  border-radius: 14px;
  padding: clamp(1.1rem, 3vw, 1.5rem) clamp(1.1rem, 3vw, 1.35rem);
  border: 1px solid rgba(30, 90, 150, 0.1);
  box-shadow: 0 2px 14px rgba(30, 90, 150, 0.06);
}

.landing-card__aside-title {
  margin: 0 0 1rem;
  font-size: 0.95rem;
  font-weight: 700;
  color: #1e3a5f;
}

.landing-checklist {
  list-style: none;
  margin: 0;
  padding: 0;
}

.landing-checklist li {
  display: flex;
  align-items: flex-start;
  gap: 0.65rem;
  margin-bottom: 0.75rem;
  font-size: 0.92rem;
  line-height: 1.55;
  color: #4a5568;
}

.landing-checklist li:last-child {
  margin-bottom: 0;
}

.landing-checklist__icon {
  flex-shrink: 0;
  margin-top: 0.12rem;
}

/* 区块通用 */
.section {
  max-width: var(--max);
  margin: 0 auto;
  padding: clamp(2rem, 5vw, 3rem) 1.25rem;
}

.section-alt {
  background: linear-gradient(180deg, #dbeafe 0%, var(--bg) 100%);
}

.section h2 {
  margin: 0 0 1rem;
  font-size: clamp(1.25rem, 3.5vw, 1.6rem);
  color: var(--blue);
}

.section-intro {
  margin: 0 0 1.5rem;
  color: var(--text-muted);
  max-width: 52em;
}

/* 卡片网格 */
.cards {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.25rem;
}

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

@media (min-width: 960px) {
  .cards.three {
    grid-template-columns: repeat(3, 1fr);
  }
}

.card {
  background: var(--bg-card);
  border-radius: var(--radius);
  padding: 1.35rem 1.4rem;
  border: 1px solid rgba(30, 90, 150, 0.08);
  box-shadow: 0 4px 20px rgba(30, 90, 150, 0.05);
}

.card h3 {
  margin: 0 0 0.5rem;
  font-size: 1.05rem;
  color: var(--text);
}

.card p {
  margin: 0;
  color: var(--text-muted);
  font-size: 0.95rem;
}

/* 长文案 */
.prose {
  max-width: 52em;
  color: var(--text);
}

.prose p {
  margin: 0 0 1.1em;
}

.prose p:last-child {
  margin-bottom: 0;
}

.prose strong {
  color: var(--blue);
  font-weight: 600;
}

/* 「写给正在搜索的你」宫格已改为 Tailwind，旧 .promo-* 样式已移除 */

/* 页脚 */
.site-footer {
  background: var(--text);
  color: rgba(255, 255, 255, 0.85);
  padding: 2rem 1.25rem;
  margin-top: 2rem;
}

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

.footer-modules {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(11.5rem, 1fr));
  gap: 1.5rem 1.25rem;
  margin-bottom: 1.5rem;
  padding-bottom: 1.25rem;
}

.footer-module__title {
  margin: 0 0 0.65rem;
  font-size: 1rem;
  font-weight: 700;
  color: #fff;
}

.footer-module__list {
  list-style: none;
  margin: 0;
  padding: 0;
  font-size: 0.9rem;
  line-height: 1.55;
}

.footer-module__list li {
  margin-bottom: 0.35rem;
}

.footer-module__text {
  margin: 0;
  font-size: 0.88rem;
  line-height: 1.6;
  color: rgba(255, 255, 255, 0.78);
}

.footer-meta {
  margin-top: 1.25rem;
  padding-top: 1rem;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  text-align: center;
}

.footer-meta__line {
  margin: 0 auto 0.5rem;
  max-width: 52rem;
  font-size: 0.85rem;
  line-height: 1.65;
  color: rgba(255, 255, 255, 0.7);
  text-align: center;
  word-break: break-word;
  overflow-wrap: anywhere;
}

.footer-meta__copy {
  display: block;
  margin: 0 auto;
  max-width: 52rem;
  font-size: 0.78rem;
  line-height: 1.5;
  color: rgba(255, 255, 255, 0.5);
  text-align: center;
}

.site-footer p {
  margin: 0 0 0.75rem;
  font-size: 0.9rem;
  line-height: 1.65;
}

.site-footer small {
  font-size: 0.8rem;
  color: rgba(255, 255, 255, 0.55);
}

.site-footer a {
  color: #93c5fd;
}

.site-footer a:hover {
  color: #bfdbfe;
  text-decoration: underline;
}