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

/* =========================================================
   CSS 自定义属性
   ========================================================= */
:root {
  --blue: #3bb1ff;
  --red: #ff5252;
  --black: #000000;
  --white: #ffffff;
  --yellow: #ffe14d;
  --bg: #f5f5f5;
  --border: 3px solid #000;
  --shadow: 5px 5px 0 #000;
  --shadow-sm: 3px 3px 0 #000;
  --shadow-lg: 8px 8px 0 #000;
  --radius-card: 28px;
  --radius-btn: 0px;
  --font-head: 'Outfit', 'Rubik', system-ui, sans-serif;
  --font-body: 'Rubik', 'Outfit', system-ui, sans-serif;
  --header-h: 64px;
  --max-w: 1120px;
  --gap: 24px;
}

/* =========================================================
   Reset
   ========================================================= */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { font-size: 16px; scroll-behavior: smooth; }
body {
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.7;
  background: var(--bg);
  color: var(--black);
  overflow-x: hidden;
}
img { max-width: 100%; height: auto; display: block; }
a { color: inherit; text-decoration: none; }
ul, ol { list-style: none; }
button { cursor: pointer; font-family: inherit; }

/* =========================================================
   全屏侧边 / 遮罩导航
   ========================================================= */
.site-aside {
  position: fixed;
  inset: 0;
  z-index: 200;
  background: var(--blue);
  border-right: var(--border);
  transform: translateX(-100%);
  transition: transform 0.3s cubic-bezier(0.22, 1, 0.36, 1);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 2rem;
}
.site-aside.is-open { transform: translateX(0); }

.aside-overlay {
  display: none;
  position: fixed;
  inset: 0;
  z-index: 190;
  background: rgba(0,0,0,0.5);
}
.aside-overlay.is-visible { display: block; }

.site-nav { width: 100%; max-width: 480px; }
.nav-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}
.nav-list li { width: 100%; }
.nav-link {
  display: block;
  padding: 14px 20px;
  font-family: var(--font-head);
  font-size: 1.05rem;
  font-weight: 700;
  border: var(--border);
  background: var(--white);
  box-shadow: var(--shadow-sm);
  transition: transform 0.15s ease, box-shadow 0.15s ease;
  line-height: 1.3;
  min-height: 44px;
}
.nav-link:hover {
  background: var(--yellow);
  transform: translate(-2px, -2px);
  box-shadow: 7px 7px 0 #000;
}
.nav-link.is-current {
  background: var(--red);
  color: var(--white);
}

/* =========================================================
   Header
   ========================================================= */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--white);
  border-bottom: var(--border);
  height: var(--header-h);
}
.header-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 20px;
  gap: 16px;
}

.brand-link {
  flex: 0 0 auto;
}
.brand-text {
  font-family: var(--font-head);
  font-size: 1.6rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--black);
}
.brand-logo { height: 40px; width: auto; }

.nav-toggle {
  display: flex;
  flex-direction: column;
  gap: 5px;
  justify-content: center;
  align-items: center;
  width: 44px;
  height: 44px;
  border: var(--border);
  background: var(--yellow);
  box-shadow: var(--shadow-sm);
  transition: transform 0.15s ease, box-shadow 0.15s ease;
  flex-shrink: 0;
}
.nav-toggle:hover {
  transform: translate(-2px, -2px);
  box-shadow: 7px 7px 0 #000;
}
.hamburger-line {
  display: block;
  width: 20px;
  height: 3px;
  background: var(--black);
  border-radius: 0;
}

/* =========================================================
   共用 Wrap / Main
   ========================================================= */
.site-main { min-height: calc(100vh - var(--header-h) - 120px); }
.wrap {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 20px;
}

/* =========================================================
   按钮
   ========================================================= */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 24px;
  font-family: var(--font-head);
  font-size: 1rem;
  font-weight: 700;
  border: var(--border);
  min-height: 44px;
  transition: transform 0.15s ease, box-shadow 0.15s ease;
  cursor: pointer;
  text-align: center;
  line-height: 1.3;
}
.btn:hover {
  transform: translate(-3px, -3px);
  box-shadow: 8px 8px 0 #000;
}
.btn--primary {
  background: var(--blue);
  color: var(--white);
  box-shadow: var(--shadow);
}
.btn--outline {
  background: var(--white);
  color: var(--black);
  box-shadow: var(--shadow-sm);
}
.btn--red {
  background: var(--red);
  color: var(--white);
  box-shadow: var(--shadow);
}

/* =========================================================
   首页 Hero
   ========================================================= */
.hero-section {
  position: relative;
  min-height: 70vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 80px 0 60px;
  overflow: hidden;
  border-bottom: var(--border);
  background: var(--white);
  margin-bottom: 48px;
}
.hero-bg-text {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  font-family: var(--font-head);
  font-size: clamp(100px, 20vw, 280px);
  font-weight: 700;
  color: rgba(59,177,255,0.08);
  white-space: nowrap;
  pointer-events: none;
  user-select: none;
  letter-spacing: -0.05em;
  z-index: 0;
}
.hero-content {
  position: relative;
  z-index: 1;
  text-align: center;
  max-width: 720px;
  padding: 0 16px;
}
.hero-eyebrow {
  display: inline-block;
  background: var(--red);
  color: var(--white);
  font-family: var(--font-head);
  font-size: 0.85rem;
  font-weight: 700;
  padding: 4px 14px;
  border: var(--border);
  box-shadow: var(--shadow-sm);
  margin-bottom: 20px;
  letter-spacing: 0.05em;
}
.hero-h1 {
  font-family: var(--font-head);
  font-size: clamp(2rem, 5vw, 3.2rem);
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.02em;
  margin-bottom: 20px;
  color: var(--black);
}
.hero-desc {
  font-size: 1.1rem;
  line-height: 1.7;
  color: #333;
  margin-bottom: 32px;
  max-width: 560px;
  margin-left: auto;
  margin-right: auto;
}
.hero-cta-row {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
}

/* =========================================================
   首页功能卡片网格
   ========================================================= */
.features-section { margin-bottom: 48px; }
.section-title {
  font-family: var(--font-head);
  font-size: 1.8rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 24px;
  padding-bottom: 12px;
  border-bottom: var(--border);
}
.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: var(--gap);
}
.feature-card {
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 24px;
  background: var(--white);
  border: var(--border);
  box-shadow: var(--shadow);
  border-radius: var(--radius-card);
  transition: transform 0.15s ease, box-shadow 0.15s ease;
  position: relative;
  overflow: hidden;
}
.feature-card:hover {
  transform: translate(-3px, -3px);
  box-shadow: 9px 9px 0 #000;
}
.feature-card__num {
  font-family: var(--font-head);
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--blue);
  line-height: 1;
  opacity: 0.6;
}
.feature-card__title {
  font-family: var(--font-head);
  font-size: 1.05rem;
  font-weight: 700;
  line-height: 1.4;
  color: var(--black);
}
.feature-card__desc {
  font-size: 0.9rem;
  color: #555;
  line-height: 1.6;
}

/* =========================================================
   子页链接卡片列表（children-list）
   ========================================================= */
.children-section { margin-bottom: 48px; }
.children-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}
.child-card {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 16px 20px;
  background: var(--white);
  border: var(--border);
  box-shadow: var(--shadow-sm);
  transition: transform 0.15s ease, box-shadow 0.15s ease, background 0.15s ease;
}
.child-card:hover {
  background: var(--yellow);
  transform: translate(-2px, -2px);
  box-shadow: 7px 7px 0 #000;
}
.child-card__title {
  font-family: var(--font-head);
  font-size: 1rem;
  font-weight: 700;
  flex: 1;
  line-height: 1.4;
}
.child-card__desc {
  font-size: 0.88rem;
  color: #555;
  flex: 2;
  line-height: 1.5;
}
.child-card__arrow {
  font-size: 1.2rem;
  font-weight: 700;
  flex-shrink: 0;
}

/* =========================================================
   通用正文内容
   ========================================================= */
.content-section { margin-bottom: 48px; }
.prose-content {
  max-width: 800px;
  margin: 0 auto;
  font-size: 1rem;
  line-height: 1.8;
  color: #1a1a1a;
}
.prose-content h2 {
  font-family: var(--font-head);
  font-size: 1.5rem;
  font-weight: 700;
  margin: 2em 0 0.8em;
  padding-left: 16px;
  border-left: 5px solid var(--blue);
  line-height: 1.3;
}
.prose-content h3 {
  font-family: var(--font-head);
  font-size: 1.2rem;
  font-weight: 700;
  margin: 1.6em 0 0.6em;
  color: var(--black);
}
.prose-content p { margin-bottom: 1.2em; }
.prose-content ul, .prose-content ol {
  padding-left: 1.5em;
  margin-bottom: 1.2em;
  list-style: disc;
}
.prose-content ol { list-style: decimal; }
.prose-content li { margin-bottom: 0.5em; line-height: 1.7; }
.prose-content a {
  color: var(--black);
  font-weight: 600;
  text-decoration: underline;
  text-underline-offset: 3px;
  transition: color 0.1s;
}
.prose-content a:hover { color: var(--red); }
.prose-content strong { font-weight: 700; }
.prose-content em { font-style: italic; }
.prose-content code {
  background: #eee;
  border: 1px solid #ccc;
  padding: 2px 6px;
  font-size: 0.9em;
  font-family: monospace;
}
.prose-content pre {
  background: var(--black);
  color: var(--white);
  padding: 20px;
  overflow-x: auto;
  border: var(--border);
  margin-bottom: 1.2em;
}
.prose-content blockquote {
  border-left: 5px solid var(--red);
  padding: 12px 20px;
  background: #fff8f8;
  margin-bottom: 1.2em;
  font-style: italic;
}
.prose-content table {
  width: 100%;
  border-collapse: collapse;
  margin-bottom: 1.2em;
  border: var(--border);
}
.prose-content th, .prose-content td {
  border: 2px solid #000;
  padding: 10px 14px;
  text-align: left;
}
.prose-content th {
  background: var(--black);
  color: var(--white);
  font-family: var(--font-head);
  font-weight: 700;
}

/* =========================================================
   日期标记
   ========================================================= */
.article-date {
  display: inline-block;
  background: var(--yellow);
  color: var(--black);
  font-size: 0.85rem;
  font-weight: 600;
  padding: 3px 10px;
  border: 2px solid #000;
  box-shadow: 2px 2px 0 #000;
  margin-right: 8px;
}
.article-date-mod {
  display: inline-block;
  background: var(--white);
  color: #555;
  font-size: 0.82rem;
  padding: 3px 10px;
  border: 2px solid #999;
}

/* =========================================================
   指南页布局
   ========================================================= */
.site-main--guide .wrap { padding-top: 0; }
.guide-layout {
  display: grid;
  grid-template-columns: 260px 1fr;
  gap: 40px;
  padding-top: 40px;
}
.guide-toc {
  position: sticky;
  top: calc(var(--header-h) + 20px);
  align-self: start;
  background: var(--white);
  border: var(--border);
  box-shadow: var(--shadow);
  padding: 20px;
  height: fit-content;
}
.toc-header {
  font-family: var(--font-head);
  font-size: 0.85rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  padding-bottom: 12px;
  border-bottom: var(--border);
  margin-bottom: 12px;
  color: var(--black);
}
.toc-list { display: flex; flex-direction: column; gap: 4px; }
.toc-item a.toc-link {
  display: block;
  padding: 8px 12px;
  font-size: 0.9rem;
  font-weight: 500;
  border: 2px solid transparent;
  transition: background 0.15s, border-color 0.15s;
  line-height: 1.4;
  min-height: 40px;
  display: flex;
  align-items: center;
}
.toc-item a.toc-link:hover {
  background: var(--yellow);
  border-color: var(--black);
}
.toc-item--active a.toc-link {
  background: var(--blue);
  color: var(--white);
  border-color: var(--black);
  font-weight: 700;
}
.toc-home-link {
  display: block;
  margin-top: 16px;
  padding: 8px 12px;
  font-size: 0.85rem;
  font-weight: 600;
  border-top: var(--border);
  padding-top: 16px;
  transition: color 0.15s;
}
.toc-home-link:hover { color: var(--red); }

.guide-body { min-width: 0; }
.guide-hero {
  padding: 40px 0 32px;
  border-bottom: var(--border);
  margin-bottom: 40px;
}
.guide-eyebrow {
  display: inline-block;
  background: var(--blue);
  color: var(--white);
  font-family: var(--font-head);
  font-size: 0.8rem;
  font-weight: 700;
  padding: 4px 12px;
  border: var(--border);
  box-shadow: var(--shadow-sm);
  margin-bottom: 16px;
  letter-spacing: 0.05em;
}
.guide-h1 {
  font-family: var(--font-head);
  font-size: clamp(1.6rem, 4vw, 2.4rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.2;
  margin-bottom: 16px;
}
.guide-meta { display: flex; gap: 8px; flex-wrap: wrap; align-items: center; }
.guide-nav-row {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  padding-top: 32px;
  border-top: var(--border);
  margin-top: 40px;
}

/* =========================================================
   FAQ 页
   ========================================================= */
.faq-hero {
  position: relative;
  padding: 60px 0 48px;
  overflow: hidden;
  border-bottom: var(--border);
  margin-bottom: 48px;
  background: var(--white);
}
.faq-bg-text {
  position: absolute;
  right: -20px;
  top: 50%;
  transform: translateY(-50%);
  font-family: var(--font-head);
  font-size: clamp(80px, 15vw, 200px);
  font-weight: 700;
  color: rgba(255,82,82,0.07);
  pointer-events: none;
  user-select: none;
  letter-spacing: -0.05em;
}
.faq-hero-content { position: relative; z-index: 1; }
.faq-eyebrow {
  display: inline-block;
  background: var(--red);
  color: var(--white);
  font-family: var(--font-head);
  font-size: 0.85rem;
  font-weight: 700;
  padding: 4px 14px;
  border: var(--border);
  box-shadow: var(--shadow-sm);
  margin-bottom: 16px;
}
.faq-h1 {
  font-family: var(--font-head);
  font-size: clamp(1.8rem, 4vw, 2.8rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.2;
  margin-bottom: 16px;
}
.faq-prose h2 {
  background: var(--yellow);
  border: var(--border);
  box-shadow: var(--shadow-sm);
  padding: 12px 18px;
  font-size: 1.15rem;
  margin: 2.5em 0 0.8em;
  border-left: 6px solid var(--black);
}
.faq-bottom-nav {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  padding-top: 32px;
  border-top: var(--border);
  margin-top: 40px;
  margin-bottom: 48px;
}

/* =========================================================
   更新日志页
   ========================================================= */
.changelog-header {
  padding: 48px 0 36px;
  border-bottom: var(--border);
  margin-bottom: 48px;
}
.changelog-badge {
  display: inline-block;
  background: var(--black);
  color: var(--yellow);
  font-family: var(--font-head);
  font-size: 0.8rem;
  font-weight: 700;
  padding: 4px 14px;
  border: var(--border);
  margin-bottom: 16px;
  letter-spacing: 0.1em;
}
.changelog-h1 {
  font-family: var(--font-head);
  font-size: clamp(1.8rem, 4vw, 2.8rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.2;
  margin-bottom: 12px;
}
.changelog-dates { display: flex; gap: 12px; flex-wrap: wrap; }
.changelog-prose h2 {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 1.25rem;
  margin: 2.5em 0 0.8em;
}
.changelog-prose h2::before {
  content: '';
  display: inline-block;
  width: 16px;
  height: 16px;
  background: var(--blue);
  border: 2px solid #000;
  flex-shrink: 0;
}
.changelog-footer-nav {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  padding-top: 32px;
  border-top: var(--border);
  margin-top: 40px;
  margin-bottom: 48px;
}

/* =========================================================
   关于页
   ========================================================= */
.about-hero {
  position: relative;
  min-height: 50vh;
  display: flex;
  align-items: center;
  overflow: hidden;
  background: var(--blue);
  border-bottom: var(--border);
  margin-bottom: 48px;
  padding: 60px 0;
}
.about-num {
  position: absolute;
  right: -20px;
  bottom: -40px;
  font-family: var(--font-head);
  font-size: clamp(120px, 20vw, 300px);
  font-weight: 700;
  color: rgba(0,0,0,0.08);
  line-height: 1;
  pointer-events: none;
  user-select: none;
}
.about-hero-content { position: relative; z-index: 1; }
.about-eyebrow {
  display: inline-block;
  background: var(--white);
  color: var(--black);
  font-family: var(--font-head);
  font-size: 0.85rem;
  font-weight: 700;
  padding: 4px 14px;
  border: var(--border);
  box-shadow: var(--shadow-sm);
  margin-bottom: 16px;
}
.about-h1 {
  font-family: var(--font-head);
  font-size: clamp(1.8rem, 4vw, 2.8rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.2;
  margin-bottom: 16px;
  color: var(--white);
}
.about-intro {
  font-size: 1.05rem;
  color: rgba(255,255,255,0.9);
  max-width: 600px;
  line-height: 1.7;
}
.about-links-row {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  padding-top: 32px;
  border-top: var(--border);
  margin-top: 40px;
  margin-bottom: 48px;
}

/* =========================================================
   隐私政策页
   ========================================================= */
.privacy-header {
  padding: 48px 0 36px;
  border-bottom: var(--border);
  margin-bottom: 48px;
}
.privacy-tag {
  display: inline-block;
  background: var(--red);
  color: var(--white);
  font-family: var(--font-head);
  font-size: 0.8rem;
  font-weight: 700;
  padding: 4px 14px;
  border: var(--border);
  margin-bottom: 16px;
  letter-spacing: 0.05em;
}
.privacy-h1 {
  font-family: var(--font-head);
  font-size: clamp(1.8rem, 4vw, 2.8rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.2;
  margin-bottom: 12px;
}
.privacy-dates { display: flex; gap: 12px; flex-wrap: wrap; }
.privacy-prose h2 {
  border-bottom: 3px solid var(--black);
  padding-bottom: 8px;
  font-size: 1.2rem;
  margin: 2em 0 0.8em;
}
.privacy-footer-nav {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  padding-top: 32px;
  border-top: var(--border);
  margin-top: 40px;
  margin-bottom: 48px;
}

/* =========================================================
   简单 hero（default layout）
   ========================================================= */
.page-hero-simple {
  padding: 48px 0 32px;
  border-bottom: var(--border);
  margin-bottom: 40px;
}
.simple-h1 {
  font-family: var(--font-head);
  font-size: clamp(1.6rem, 4vw, 2.4rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.2;
  margin-bottom: 12px;
}
.default-nav-row {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  padding-top: 32px;
  border-top: var(--border);
  margin-top: 40px;
  margin-bottom: 48px;
}

/* =========================================================
   页脚
   ========================================================= */
.site-footer {
  background: var(--black);
  color: var(--white);
  border-top: var(--border);
  padding: 32px 20px 24px;
  text-align: center;
}
.footer-brand {
  font-family: var(--font-head);
  font-size: clamp(3rem, 10vw, 7rem);
  font-weight: 700;
  letter-spacing: -0.04em;
  line-height: 1;
  margin-bottom: 12px;
  color: var(--white);
  opacity: 0.15;
}
.footer-copy {
  font-size: 0.88rem;
  color: rgba(255,255,255,0.65);
  line-height: 1.6;
}
.footer-copy a {
  color: var(--blue);
  font-weight: 600;
  text-decoration: underline;
  text-underline-offset: 2px;
}
.footer-copy a:hover { color: var(--yellow); }

/* =========================================================
   Scroll Reveal
   ========================================================= */
@media (prefers-reduced-motion: no-preference) {
  .reveal {
    opacity: 0;
    transform: translateY(28px);
    transition: opacity 0.55s ease, transform 0.55s ease;
  }
  .reveal.is-visible {
    opacity: 1;
    transform: translateY(0);
  }
  .reveal-delay-1 { transition-delay: 0.1s; }
  .reveal-delay-2 { transition-delay: 0.2s; }
  .reveal-delay-3 { transition-delay: 0.3s; }
}
@media (prefers-reduced-motion: reduce) {
  .reveal { opacity: 1; transform: none; }
}

/* =========================================================
   响应式
   ========================================================= */
@media (max-width: 900px) {
  .guide-layout {
    grid-template-columns: 1fr;
    gap: 0;
  }
  .guide-toc {
    position: static;
    margin-bottom: 32px;
  }
}

@media (max-width: 640px) {
  :root {
    --shadow: 4px 4px 0 #000;
    --shadow-sm: 2px 2px 0 #000;
    --gap: 16px;
  }
  .hero-section { min-height: 70vh; padding: 60px 0 40px; }
  .hero-h1 { font-size: 1.8rem; }
  .hero-cta-row { gap: 12px; }
  .feature-grid { grid-template-columns: 1fr; }
  .child-card { flex-direction: column; align-items: flex-start; gap: 8px; }
  .child-card__desc { flex: none; }
  .brand-text { font-size: 1.3rem; }
  .btn { padding: 12px 18px; font-size: 0.95rem; }
  .about-hero { min-height: 40vh; }
  .guide-layout { padding-top: 24px; }
  .faq-bottom-nav, .changelog-footer-nav, .privacy-footer-nav,
  .about-links-row, .guide-nav-row, .default-nav-row {
    flex-direction: column;
  }
  .faq-bottom-nav .btn, .changelog-footer-nav .btn,
  .privacy-footer-nav .btn, .about-links-row .btn,
  .guide-nav-row .btn, .default-nav-row .btn,
  .hero-cta-row .btn {
    width: 100%;
  }
  .guide-hero { padding: 24px 0 20px; }
  .changelog-header, .privacy-header { padding: 32px 0 24px; }
}

@media (max-width: 375px) {
  .brand-text { font-size: 1.1rem; }
  .hero-h1 { font-size: 1.5rem; }
  .nav-link { font-size: 0.95rem; }
}