@import url('https://fonts.googleapis.com/css2?family=Barlow+Condensed:wght@400;500;600;700&family=Barlow:wght@300;400;500;600;700&display=swap');

/* ===== 基础重置 ===== */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --color-black: #000000;
  --color-white: #ffffff;
  --color-gray-100: #f5f5f5;
  --color-gray-200: #e8e8e8;
  --color-gray-400: #999999;
  --color-gray-600: #555555;
  --color-gray-800: #222222;
  --color-accent: #d0d0d0;
  --nav-width: 220px;
  --font-condensed: 'Barlow Condensed', 'Arial Narrow', sans-serif;
  --font-body: 'Barlow', system-ui, -apple-system, sans-serif;
  --transition: 0.2s ease;
  --radius: 10px;
  --shadow: 0 4px 20px rgba(0,0,0,0.10);
  --shadow-hover: 0 8px 32px rgba(0,0,0,0.18);
}

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

body {
  font-family: var(--font-body);
  font-weight: 400;
  line-height: 1.65;
  color: var(--color-black);
  background: var(--color-white);
  min-height: 100vh;
  overflow-x: hidden;
}

a {
  color: var(--color-black);
  text-decoration: underline;
  text-underline-offset: 3px;
  transition: opacity var(--transition);
}
a:hover { opacity: 0.65; }

img { display: block; max-width: 100%; height: auto; }
ul, menu { list-style: none; }

/* ===== 布局骨架 ===== */
.site-wrap {
  display: flex;
  min-height: 100vh;
}

.page-body {
  flex: 1;
  margin-left: var(--nav-width);
  display: flex;
  flex-direction: column;
  min-width: 0;
}

/* ===== 左侧固定竖排导航 ===== */
.sidenav {
  position: fixed;
  top: 0;
  left: 0;
  width: var(--nav-width);
  height: 100vh;
  background: var(--color-black);
  color: var(--color-white);
  display: flex;
  flex-direction: column;
  padding: 24px 0 24px;
  z-index: 100;
  overflow-y: auto;
  border-right: 2px solid var(--color-black);
}

.sidenav-brand {
  padding: 0 20px 20px;
  border-bottom: 1px solid rgba(255,255,255,0.15);
  margin-bottom: 16px;
}

.brand-mark {
  display: inline-block;
  width: 40px;
  height: 40px;
  background: var(--color-white);
  color: var(--color-black);
  font-family: var(--font-condensed);
  font-size: 26px;
  font-weight: 700;
  line-height: 40px;
  text-align: center;
  border-radius: 4px;
}

/* details > summary + menu > li > a 结构 */
.nav-group {
  flex: 1;
  padding: 0 0 16px;
}

.nav-group-label {
  display: block;
  padding: 8px 20px;
  font-family: var(--font-condensed);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-gray-400);
  cursor: pointer;
  user-select: none;
  list-style: none;
}

.nav-group-label::-webkit-details-marker { display: none; }
.nav-group-label::marker { display: none; }

.nav-group menu {
  margin-top: 4px;
}

.nav-group menu li a {
  display: block;
  padding: 10px 20px;
  font-family: var(--font-condensed);
  font-size: 15px;
  font-weight: 500;
  color: var(--color-white);
  text-decoration: none;
  border-left: 3px solid transparent;
  transition: background var(--transition), border-color var(--transition);
  min-height: 40px;
  line-height: 20px;
}

.nav-group menu li a:hover,
.nav-group menu li a[aria-current="page"] {
  background: rgba(255,255,255,0.08);
  border-left-color: var(--color-white);
  opacity: 1;
}

.sidenav-cta {
  display: block;
  margin: 12px 16px 0;
  padding: 12px 16px;
  background: var(--color-white);
  color: var(--color-black);
  font-family: var(--font-condensed);
  font-size: 15px;
  font-weight: 700;
  text-align: center;
  text-decoration: none;
  border-radius: var(--radius);
  letter-spacing: 0.04em;
  min-height: 44px;
  line-height: 20px;
  transition: background var(--transition), color var(--transition);
}
.sidenav-cta:hover {
  background: var(--color-gray-200);
  color: var(--color-black);
  opacity: 1;
}

/* ===== 主内容区 ===== */
main {
  flex: 1;
  padding: 0;
}

/* ===== Hero 区（首页） ===== */
.hero-section {
  min-height: 70vh;
  display: grid;
  grid-template-columns: 80px 1fr;
  grid-template-areas: "aside figure";
  border-bottom: 2px solid var(--color-black);
  position: relative;
  overflow: hidden;
}

.hero-aside {
  grid-area: aside;
  background: var(--color-black);
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 40px 8px;
  gap: 16px;
}

.hero-figure {
  grid-area: figure;
  padding: 60px 56px 60px 48px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  background: var(--color-white);
}

.hero-overline {
  font-family: var(--font-condensed);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--color-gray-600);
  margin-bottom: 20px;
}

.hero-title {
  font-family: var(--font-condensed);
  font-size: clamp(48px, 7vw, 96px);
  font-weight: 700;
  line-height: 0.95;
  letter-spacing: -0.02em;
  color: var(--color-black);
  margin-bottom: 28px;
  text-transform: uppercase;
}

.hero-lead {
  font-size: 18px;
  font-weight: 300;
  line-height: 1.7;
  color: var(--color-gray-800);
  max-width: 560px;
  margin-bottom: 40px;
}

.hero-actions {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

/* ===== 徽章 ===== */
.badge {
  display: inline-block;
  padding: 6px 10px;
  background: var(--color-white);
  color: var(--color-black);
  font-family: var(--font-condensed);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  border: 1.5px solid var(--color-white);
  border-radius: 4px;
  writing-mode: vertical-rl;
  text-orientation: mixed;
}

.badge-alt {
  background: var(--color-black);
  color: var(--color-white);
  border-color: rgba(255,255,255,0.4);
}

.article-tag {
  display: inline-block;
  padding: 4px 10px;
  background: var(--color-black);
  color: var(--color-white);
  font-family: var(--font-condensed);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  border-radius: 3px;
}

/* ===== 按钮 ===== */
.btn {
  display: inline-block;
  padding: 14px 28px;
  font-family: var(--font-condensed);
  font-size: 16px;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  text-decoration: none;
  border-radius: var(--radius);
  min-height: 48px;
  line-height: 20px;
  transition: background var(--transition), color var(--transition), transform var(--transition);
}
.btn:hover { transform: translateY(-2px); opacity: 1; }

.btn-primary {
  background: var(--color-black);
  color: var(--color-white);
  border: 2px solid var(--color-black);
}
.btn-primary:hover { background: var(--color-gray-800); }

.btn-outline {
  background: transparent;
  color: var(--color-black);
  border: 2px solid var(--color-black);
}
.btn-outline:hover { background: var(--color-black); color: var(--color-white); }

/* ===== 内容区块（首页） ===== */
.content-section {
  display: grid;
  grid-template-columns: 200px 1fr;
  gap: 0;
  border-bottom: 2px solid var(--color-black);
}

.content-aside {
  padding: 40px 24px;
  border-right: 1.5px solid var(--color-black);
  background: var(--color-gray-100);
}

.content-main {
  padding: 48px 56px;
}

/* ===== aside 样式 ===== */
.aside-label {
  font-family: var(--font-condensed);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--color-gray-600);
  margin-bottom: 16px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--color-gray-200);
}

.aside-links {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.aside-links li a {
  display: block;
  padding: 8px 0;
  font-size: 14px;
  font-weight: 500;
  color: var(--color-black);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  min-height: 40px;
  line-height: 24px;
  transition: border-color var(--transition);
}
.aside-links li a:hover {
  border-bottom-color: var(--color-black);
  opacity: 1;
}

.aside-note {
  font-size: 13px;
  line-height: 1.6;
  color: var(--color-gray-600);
}

.aside-divider {
  height: 1px;
  background: var(--color-gray-200);
  margin: 20px 0;
}

/* ===== 指南卡片区 ===== */
.guides-section {
  padding: 56px 56px 56px 56px;
  border-bottom: 2px solid var(--color-black);
  display: grid;
  grid-template-columns: 1fr;
  gap: 0;
}

.guides-section h2.section-heading {
  margin-bottom: 8px;
}

.guides-section > hr {
  margin-bottom: 36px;
}

.card {
  padding: 28px 32px;
  border: 1.5px solid var(--color-gray-200);
  border-radius: var(--radius);
  background: var(--color-white);
  box-shadow: var(--shadow);
  margin-bottom: 20px;
  transition: box-shadow var(--transition), transform var(--transition);
  display: grid;
  grid-template-columns: auto 1fr auto;
  grid-template-rows: auto auto;
  gap: 8px 20px;
  align-items: start;
}

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

.card-eyebrow {
  grid-column: 1;
  grid-row: 1;
  font-family: var(--font-condensed);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-gray-400);
}

.card-title {
  grid-column: 2;
  grid-row: 1;
  font-family: var(--font-condensed);
  font-size: 22px;
  font-weight: 700;
  line-height: 1.2;
}
.card-title a { text-decoration: none; }
.card-title a:hover { text-decoration: underline; opacity: 1; }

.card-desc {
  grid-column: 2;
  grid-row: 2;
  font-size: 15px;
  color: var(--color-gray-600);
  line-height: 1.6;
}

.card-link {
  grid-column: 3;
  grid-row: 1 / 3;
  align-self: center;
  display: inline-block;
  padding: 10px 18px;
  background: var(--color-black);
  color: var(--color-white);
  font-family: var(--font-condensed);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  text-decoration: none;
  border-radius: 6px;
  min-height: 40px;
  line-height: 20px;
  transition: background var(--transition);
  white-space: nowrap;
}
.card-link:hover { background: var(--color-gray-800); opacity: 1; }

/* ===== 引用区（首页） ===== */
.pullquote-section {
  display: grid;
  grid-template-columns: 1fr 200px;
  gap: 0;
  border-bottom: 2px solid var(--color-black);
}

.pull-quote {
  padding: 56px 48px;
  border-right: 1.5px solid var(--color-black);
}

.pull-quote blockquote {
  position: relative;
  padding-left: 28px;
  border-left: 4px solid var(--color-black);
}

.pull-quote blockquote p {
  font-family: var(--font-condensed);
  font-size: clamp(22px, 2.5vw, 32px);
  font-weight: 600;
  line-height: 1.35;
  color: var(--color-black);
}

.pull-quote figcaption {
  margin-top: 16px;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-gray-600);
  padding-left: 28px;
}

.stat-aside {
  padding: 40px 24px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 32px;
  background: var(--color-black);
}

.stat-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
}

.stat-num {
  font-family: var(--font-condensed);
  font-size: 40px;
  font-weight: 700;
  color: var(--color-white);
  line-height: 1;
}

.stat-label {
  font-family: var(--font-condensed);
  font-size: 12px;
  font-weight: 500;
  color: var(--color-gray-400);
  letter-spacing: 0.08em;
  margin-top: 6px;
  text-transform: uppercase;
}

/* ===== 文章布局（guide 等内页） ===== */
.article-layout {}

.article-section {
  display: grid;
  grid-template-columns: 80px 1fr;
  grid-template-areas: "aside figure";
  border-bottom: 2px solid var(--color-black);
  min-height: 28vh;
}

.article-aside {
  grid-area: aside;
  background: var(--color-black);
  padding: 40px 8px;
}

.article-figure {
  grid-area: figure;
  padding: 48px 56px 40px 48px;
  background: var(--color-white);
}

.article-meta {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 20px;
  flex-wrap: wrap;
}

.article-date {
  font-family: var(--font-condensed);
  font-size: 13px;
  color: var(--color-gray-600);
  font-weight: 500;
}

.article-mod {
  font-family: var(--font-condensed);
  font-size: 12px;
  color: var(--color-gray-400);
}

.article-title {
  font-family: var(--font-condensed);
  font-size: clamp(36px, 5vw, 64px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.01em;
  text-transform: uppercase;
  color: var(--color-black);
  margin-bottom: 20px;
}

.article-lead {
  font-size: 17px;
  font-weight: 300;
  line-height: 1.7;
  color: var(--color-gray-800);
  max-width: 640px;
}

/* ===== 正文区（guide prose 区） ===== */
.prose-section {
  display: grid;
  grid-template-columns: 200px 1fr;
  gap: 0;
  border-bottom: 2px solid var(--color-black);
}

.toc-aside {
  padding: 40px 24px;
  border-right: 1.5px solid var(--color-black);
  background: var(--color-gray-100);
}

.prose-body {
  padding: 48px 56px;
}

/* ===== 通用页面 header div ===== */
.page-header-section {
  display: grid;
  grid-template-columns: 80px 1fr;
  grid-template-areas: "aside figure";
  border-bottom: 2px solid var(--color-black);
  min-height: 20vh;
}

.header-aside {
  grid-area: aside;
  background: var(--color-black);
  padding: 32px 8px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
}

.header-figure {
  grid-area: figure;
  padding: 40px 56px 36px 48px;
}

/* ===== 通用正文容器 ===== */
.faq-body-section,
.about-body-section,
.privacy-body-section,
.changelog-body-section,
.default-body-section {
  display: grid;
  grid-template-columns: 200px 1fr;
  gap: 0;
  border-bottom: 2px solid var(--color-black);
}

.faq-content,
.about-content,
.privacy-content,
.changelog-content,
.default-content {
  padding: 48px 56px;
}

/* ===== 标题装饰 ===== */
.section-heading {
  font-family: var(--font-condensed);
  font-size: clamp(28px, 3vw, 42px);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: -0.01em;
  line-height: 1.1;
  margin-bottom: 12px;
}

hr {
  border: none;
  border-top: 2px solid var(--color-black);
  margin-bottom: 32px;
}

/* ===== Prose 正文排版 ===== */
.prose {
  font-size: 17px;
  line-height: 1.75;
  color: var(--color-black);
  max-width: 72ch;
}

.prose h2 {
  font-family: var(--font-condensed);
  font-size: 28px;
  font-weight: 700;
  text-transform: uppercase;
  margin: 2em 0 0.5em;
  padding-bottom: 8px;
  border-bottom: 1.5px solid var(--color-gray-200);
}

.prose h3 {
  font-family: var(--font-condensed);
  font-size: 22px;
  font-weight: 600;
  margin: 1.6em 0 0.4em;
}

.prose p { margin-bottom: 1.2em; }

.prose ul, .prose ol {
  padding-left: 1.6em;
  margin-bottom: 1.2em;
}

.prose li { margin-bottom: 0.4em; }

.prose a {
  color: var(--color-black);
  font-weight: 500;
}

.prose blockquote {
  border-left: 4px solid var(--color-black);
  padding-left: 20px;
  margin: 1.5em 0;
  color: var(--color-gray-600);
  font-style: italic;
}

.prose table {
  width: 100%;
  border-collapse: collapse;
  margin-bottom: 1.5em;
  font-size: 15px;
}

.prose th, .prose td {
  padding: 10px 14px;
  border: 1px solid var(--color-gray-200);
  text-align: left;
}

.prose th {
  background: var(--color-gray-100);
  font-family: var(--font-condensed);
  font-weight: 700;
  font-size: 13px;
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.prose code {
  background: var(--color-gray-100);
  padding: 2px 6px;
  border-radius: 3px;
  font-size: 0.9em;
}

.prose pre {
  background: var(--color-black);
  color: var(--color-white);
  padding: 20px 24px;
  border-radius: var(--radius);
  overflow-x: auto;
  margin-bottom: 1.5em;
}

/* 首字下沉 */
.drop-cap .prose > p:first-of-type::first-letter,
.drop-cap > p:first-of-type::first-letter {
  float: left;
  font-family: var(--font-condensed);
  font-size: 5em;
  font-weight: 700;
  line-height: 0.75;
  margin-right: 10px;
  margin-top: 6px;
  color: var(--color-black);
}

/* ===== Pull quote block ===== */
.pull-quote-block {
  margin: 2.5em 0;
}

.pull-quote-block blockquote {
  border-left: 4px solid var(--color-black);
  padding: 16px 24px;
  background: var(--color-gray-100);
}

.pull-quote-block blockquote p {
  font-family: var(--font-condensed);
  font-size: 22px;
  font-weight: 600;
  line-height: 1.4;
  margin: 0;
}

/* ===== Changelog prose ===== */
.changelog-prose h2 {
  font-family: var(--font-condensed);
  font-size: 20px;
  font-weight: 700;
  padding: 6px 14px;
  background: var(--color-black);
  color: var(--color-white);
  display: inline-block;
  margin: 2em 0 1em;
  border-radius: 4px;
}

/* ===== 子页列表（div > section×n） ===== */
.guides-section > section {
  /* 已在 .card 定义，此处确保无多余包装 */
}

/* ===== 页脚 ===== */
.site-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 20px 56px;
  border-top: 2px solid var(--color-black);
  background: var(--color-white);
  flex-wrap: wrap;
  gap: 12px;
}

.footer-address {
  font-style: normal;
  font-family: var(--font-condensed);
  font-size: 14px;
  font-weight: 600;
  letter-spacing: 0.06em;
  color: var(--color-black);
}

.footer-links {
  display: flex;
  gap: 0;
}

.footer-links li a {
  display: block;
  padding: 10px 16px;
  font-family: var(--font-condensed);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  text-decoration: none;
  color: var(--color-black);
  min-height: 40px;
  line-height: 20px;
  border: 1px solid transparent;
  border-radius: 4px;
  transition: border-color var(--transition), background var(--transition);
}
.footer-links li a:hover {
  border-color: var(--color-black);
  opacity: 1;
}

/* ===== 动效 ===== */
@media (prefers-reduced-motion: no-preference) {
  .card {
    animation: fadeUp 0.4s ease both;
  }
  .card:nth-child(2) { animation-delay: 0.05s; }
  .card:nth-child(3) { animation-delay: 0.10s; }
  .card:nth-child(4) { animation-delay: 0.15s; }
  .card:nth-child(5) { animation-delay: 0.20s; }
  .card:nth-child(6) { animation-delay: 0.25s; }

  .hero-title {
    animation: fadeUp 0.5s ease 0.1s both;
  }
  .hero-lead {
    animation: fadeUp 0.5s ease 0.2s both;
  }
  .hero-actions {
    animation: fadeUp 0.5s ease 0.3s both;
  }

  @keyframes fadeUp {
    from { opacity: 0; transform: translateY(18px); }
    to   { opacity: 1; transform: translateY(0); }
  }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation: none !important;
    transition: none !important;
  }
}

/* ===== 移动端断点 ===== */
@media (max-width: 900px) {
  :root {
    --nav-width: 0px;
  }

  .site-wrap {
    flex-direction: column;
  }

  .sidenav {
    position: relative;
    width: 100%;
    height: auto;
    flex-direction: row;
    align-items: center;
    padding: 12px 16px;
    gap: 16px;
    overflow-y: visible;
    overflow-x: auto;
  }

  .sidenav-brand {
    padding: 0;
    border-bottom: none;
    margin-bottom: 0;
    flex-shrink: 0;
  }

  .nav-group {
    flex: 1;
    padding: 0;
    min-width: 0;
  }

  .nav-group-label {
    padding: 8px 12px;
    font-size: 12px;
  }

  .nav-group menu {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--color-black);
    z-index: 200;
    padding: 8px 0;
    border-top: 1px solid rgba(255,255,255,0.15);
  }

  .nav-group:not([open]) menu {
    display: none;
  }

  .page-body {
    margin-left: 0;
  }

  .hero-section {
    grid-template-columns: 56px 1fr;
    min-height: auto;
  }

  .hero-figure {
    padding: 40px 24px;
  }

  .hero-aside {
    padding: 24px 6px;
  }

  .hero-title {
    font-size: clamp(36px, 10vw, 64px);
  }

  .content-section,
  .prose-section,
  .faq-body-section,
  .about-body-section,
  .privacy-body-section,
  .changelog-body-section,
  .default-body-section {
    grid-template-columns: 1fr;
  }

  .content-aside,
  .toc-aside {
    border-right: none;
    border-bottom: 1.5px solid var(--color-black);
  }

  .content-main,
  .prose-body,
  .faq-content,
  .about-content,
  .privacy-content,
  .changelog-content,
  .default-content {
    padding: 32px 24px;
  }

  .article-section {
    grid-template-columns: 56px 1fr;
  }

  .article-figure {
    padding: 32px 24px;
  }

  .article-aside {
    padding: 28px 6px;
  }

  .page-header-section {
    grid-template-columns: 56px 1fr;
  }

  .header-figure {
    padding: 28px 24px;
  }

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

  .pull-quote {
    border-right: none;
    border-bottom: 1.5px solid var(--color-black);
    padding: 36px 24px;
  }

  .stat-aside {
    flex-direction: row;
    justify-content: space-around;
    padding: 28px 24px;
  }

  .guides-section {
    padding: 36px 24px;
  }

  .card {
    grid-template-columns: 1fr;
    grid-template-rows: auto;
  }

  .card-eyebrow { grid-column: 1; grid-row: 1; }
  .card-title   { grid-column: 1; grid-row: 2; }
  .card-desc    { grid-column: 1; grid-row: 3; }
  .card-link    { grid-column: 1; grid-row: 4; justify-self: start; }

  .site-footer {
    padding: 16px 24px;
  }
}

@media (max-width: 480px) {
  .hero-figure {
    padding: 28px 16px;
  }

  .hero-actions {
    flex-direction: column;
    gap: 12px;
  }

  .btn { width: 100%; text-align: center; }

  .article-title {
    font-size: clamp(28px, 8vw, 48px);
  }

  .content-main,
  .prose-body,
  .faq-content,
  .about-content,
  .privacy-content,
  .changelog-content {
    padding: 24px 16px;
  }

  .guides-section {
    padding: 24px 16px;
  }

  .footer-links {
    flex-wrap: wrap;
    gap: 4px;
  }

  .stat-aside {
    gap: 16px;
  }
}