@import url('https://fonts.googleapis.com/css2?family=Space+Grotesk:wght@700&display=swap');

/* ===== 变量 ===== */
:root {
  --c-blue: #3bb1ff;
  --c-red: #ff5252;
  --c-black: #000000;
  --c-white: #ffffff;
  --c-cream: #fffbe6;
  --c-bg: #f5f5f5;
  --c-card-bg: rgba(255,255,255,0.82);
  --border: 3px solid var(--c-black);
  --shadow: 5px 5px 0 var(--c-black);
  --shadow-blue: 5px 5px 0 var(--c-blue);
  --shadow-red: 5px 5px 0 var(--c-red);
  --radius: 10px;
  --font: 'Space Grotesk', 'Helvetica Neue', Arial, sans-serif;
  --max-w: 1200px;
  --prose-w: 720px;
}

/* ===== 重置 ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { font-size: 16px; scroll-behavior: smooth; }
body {
  font-family: var(--font);
  font-weight: 700;
  background: var(--c-bg);
  color: var(--c-black);
  line-height: 1.6;
  overflow-x: hidden;
}
a { color: inherit; text-decoration: none; }
a:hover { text-decoration: underline; }
img { display: block; max-width: 100%; height: auto; }
ul, ol { list-style: none; }
button { cursor: pointer; font-family: var(--font); font-weight: 700; }
input, select, textarea { font-family: var(--font); font-weight: 700; font-size: 1rem; }

/* ===== 全局包装 ===== */
.site-wrap { display: flex; flex-direction: column; min-height: 100vh; }

/* ===== 顶部 Header ===== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 200;
  background: var(--c-black);
  border-bottom: var(--border);
}
.header-brand-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 24px;
  height: 60px;
  border-bottom: 2px solid rgba(255,255,255,0.12);
}
.brand-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
}
.brand-name {
  font-size: 1.35rem;
  color: var(--c-white);
  letter-spacing: 0.04em;
  text-transform: uppercase;
}
.logo-img { width: 36px; height: 36px; border-radius: 6px; }

/* 汉堡按钮 */
.nav-burger {
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 44px;
  height: 44px;
  background: var(--c-blue);
  border: var(--border);
  border-color: var(--c-white);
  border-radius: 6px;
  padding: 8px;
  box-shadow: 3px 3px 0 var(--c-red);
}
.nav-burger span {
  display: block;
  height: 3px;
  background: var(--c-black);
  border-radius: 2px;
  transition: transform 0.2s, opacity 0.2s;
}
.nav-burger[aria-expanded="true"] span:nth-child(1) { transform: rotate(45deg) translate(5px, 5px); }
.nav-burger[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.nav-burger[aria-expanded="true"] span:nth-child(3) { transform: rotate(-45deg) translate(5px, -5px); }

/* 桌面菜单行 */
.header-menu-row {
  padding: 0 24px;
  height: 44px;
  display: flex;
  align-items: center;
  overflow-x: auto;
  scrollbar-width: none;
}
.header-menu-row::-webkit-scrollbar { display: none; }
.desktop-nav { display: flex; gap: 4px; white-space: nowrap; }
.dnav-link {
  display: inline-flex;
  align-items: center;
  height: 32px;
  padding: 0 12px;
  font-size: 0.78rem;
  color: rgba(255,255,255,0.8);
  border: 2px solid transparent;
  border-radius: 6px;
  transition: background 0.15s, color 0.15s, border-color 0.15s;
  text-decoration: none;
}
.dnav-link:hover, .dnav-link.active {
  background: var(--c-blue);
  color: var(--c-black);
  border-color: var(--c-white);
  text-decoration: none;
}

/* ===== 全屏遮罩菜单 ===== */
.fullscreen-nav {
  position: fixed;
  inset: 0;
  z-index: 300;
  background: var(--c-black);
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  justify-content: center;
  padding: 60px 48px;
  transform: translateX(-100%);
  transition: transform 0.35s cubic-bezier(0.77,0,0.18,1);
}
.fullscreen-nav.is-open {
  transform: translateX(0);
}
.nav-close {
  position: absolute;
  top: 20px;
  right: 24px;
  background: var(--c-red);
  color: var(--c-white);
  border: var(--border);
  border-color: var(--c-white);
  width: 48px;
  height: 48px;
  font-size: 1.2rem;
  border-radius: 8px;
  box-shadow: var(--shadow-blue);
  display: flex;
  align-items: center;
  justify-content: center;
}
.fnav-links { display: flex; flex-direction: column; gap: 16px; width: 100%; }
.fnav-item {
  font-size: clamp(1.1rem, 3vw, 1.8rem);
  color: var(--c-white);
  border-left: 5px solid var(--c-blue);
  padding: 10px 20px;
  border-radius: 0 8px 8px 0;
  text-decoration: none;
  background: rgba(59,177,255,0.06);
  transition: background 0.15s, color 0.15s, border-color 0.15s;
  opacity: 0;
  transform: translateX(-24px);
}
.fullscreen-nav.is-open .fnav-item {
  opacity: 1;
  transform: translateX(0);
  transition: opacity 0.3s calc(var(--i) * 0.06s + 0.1s), transform 0.3s calc(var(--i) * 0.06s + 0.1s), background 0.15s;
}
.fnav-item:hover {
  background: var(--c-blue);
  color: var(--c-black);
  border-color: var(--c-red);
  text-decoration: none;
}

/* ===== Hero（首页）===== */
.hero {
  position: relative;
  min-height: 70vh;
  display: flex;
  align-items: center;
  overflow: hidden;
  background: var(--c-black);
  border-bottom: var(--border);
}
.hero-bg-img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0.35;
  z-index: 0;
}
.hero-mask {
  position: absolute;
  inset: 0;
  background: linear-gradient(120deg, rgba(0,0,0,0.7) 0%, rgba(0,0,0,0.3) 100%);
  z-index: 1;
}

/* 网格底纹 */
.hero-grid-bg {
  position: absolute;
  inset: 0;
  z-index: 0;
  background-image:
    linear-gradient(rgba(59,177,255,0.15) 1px, transparent 1px),
    linear-gradient(90deg, rgba(59,177,255,0.15) 1px, transparent 1px);
  background-size: 40px 40px;
  pointer-events: none;
}

.hero-content {
  position: relative;
  z-index: 2;
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 80px 24px 80px;
  width: 100%;
}
.hero-eyebrow {
  display: inline-block;
  background: var(--c-blue);
  color: var(--c-black);
  font-size: 0.8rem;
  padding: 4px 14px;
  border: var(--border);
  border-radius: 4px;
  margin-bottom: 20px;
  box-shadow: 3px 3px 0 var(--c-red);
  letter-spacing: 0.08em;
}
.hero-title {
  font-size: clamp(2rem, 6vw, 3.8rem);
  color: var(--c-white);
  line-height: 1.15;
  max-width: 800px;
  margin-bottom: 20px;
  text-shadow: 4px 4px 0 rgba(0,0,0,0.5);
}
.hero-sub {
  font-size: 1.1rem;
  color: rgba(255,255,255,0.85);
  max-width: 560px;
  margin-bottom: 36px;
  line-height: 1.7;
}
.hero-actions { display: flex; gap: 16px; flex-wrap: wrap; }

/* ===== 按钮 ===== */
.btn-primary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 0 28px;
  background: var(--c-blue);
  color: var(--c-black);
  font-size: 1rem;
  font-weight: 700;
  border: var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  text-decoration: none;
  transition: box-shadow 0.15s, transform 0.15s;
}
.btn-primary:hover {
  box-shadow: 2px 2px 0 var(--c-black);
  transform: translate(3px, 3px);
  text-decoration: none;
}
.btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 0 28px;
  background: var(--c-red);
  color: var(--c-white);
  font-size: 1rem;
  font-weight: 700;
  border: var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  text-decoration: none;
  transition: box-shadow 0.15s, transform 0.15s;
}
.btn-secondary:hover {
  box-shadow: 2px 2px 0 var(--c-black);
  transform: translate(3px, 3px);
  text-decoration: none;
}
.btn-sm { min-height: 40px; padding: 0 20px; font-size: 0.9rem; }

/* ===== 页内Hero条 ===== */
.page-hero-bar {
  position: relative;
  background: var(--c-black);
  border-bottom: var(--border);
  overflow: hidden;
  min-height: 200px;
  display: flex;
  align-items: center;
}
.page-hero-bar--about { background: var(--c-blue); }
.page-hero-bar--contact { background: var(--c-red); }
.page-hero-bar--privacy { background: #1a1a1a; }
.page-hero-content {
  position: relative;
  z-index: 2;
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 40px 24px;
  width: 100%;
}
.page-eyebrow {
  display: inline-block;
  background: var(--c-blue);
  color: var(--c-black);
  font-size: 0.75rem;
  padding: 3px 12px;
  border: 2px solid var(--c-black);
  border-radius: 4px;
  margin-bottom: 12px;
  box-shadow: 3px 3px 0 var(--c-red);
  letter-spacing: 0.06em;
}
.page-hero-bar--about .page-eyebrow { background: var(--c-black); color: var(--c-blue); }
.page-hero-bar--contact .page-eyebrow { background: var(--c-black); color: var(--c-red); }
.page-hero-title {
  font-size: clamp(1.6rem, 4vw, 2.8rem);
  color: var(--c-white);
  line-height: 1.2;
  max-width: 800px;
}
.page-hero-bar--about .page-hero-title { color: var(--c-black); }
.page-dates {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  margin-top: 12px;
}
.article-date {
  font-size: 0.82rem;
  color: rgba(255,255,255,0.65);
  border: 1px solid rgba(255,255,255,0.25);
  padding: 2px 8px;
  border-radius: 4px;
}

/* ===== Main + 布局 ===== */
.main-content {
  flex: 1;
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 40px 24px 60px;
  width: 100%;
}
.content-article { width: 100%; }
.prose-section { width: 100%; }

/* 内容+侧边栏布局 */
.content-with-aside {
  display: grid;
  grid-template-columns: 260px 1fr;
  gap: 32px;
  align-items: start;
}

/* ===== aside ===== */
.content-aside {
  display: flex;
  flex-direction: column;
  gap: 20px;
  position: sticky;
  top: 120px;
}
.aside-box {
  background: var(--c-card-bg);
  border: var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 20px;
  backdrop-filter: blur(8px);
}
.aside-box--accent {
  background: var(--c-blue);
  box-shadow: var(--shadow-red);
}
.aside-title {
  font-size: 0.9rem;
  margin-bottom: 14px;
  border-bottom: 2px solid var(--c-black);
  padding-bottom: 8px;
  text-transform: uppercase;
  letter-spacing: 0.06em;
}
.aside-nav { display: flex; flex-direction: column; gap: 0; }
.aside-nav dt, .aside-nav dd {
  padding: 6px 0;
  font-size: 0.88rem;
  border-bottom: 1px solid rgba(0,0,0,0.1);
}
.aside-nav dt:last-child, .aside-nav dd:last-child { border-bottom: none; }
.aside-nav a {
  display: block;
  padding: 4px 0;
  color: var(--c-black);
  text-decoration: none;
  transition: color 0.15s;
}
.aside-nav a:hover { color: var(--c-red); text-decoration: underline; }
.aside-box--accent .aside-nav a { color: var(--c-black); }

/* ===== 正文排版 ===== */
.prose-body {
  min-width: 0;
  font-size: 1rem;
  line-height: 1.75;
}
.prose-body h2, .prose-body h3 {
  margin: 2rem 0 0.75rem;
  line-height: 1.3;
}
.prose-body h2 { font-size: 1.5rem; }
.prose-body h3 { font-size: 1.2rem; }
.prose-body p { margin-bottom: 1.1rem; }
.prose-body ul, .prose-body ol {
  margin: 1rem 0;
  padding-left: 1.6rem;
  list-style: disc;
}
.prose-body ol { list-style: decimal; }
.prose-body li { margin-bottom: 0.4rem; }
.prose-body strong { font-weight: 700; }
.prose-body a { color: var(--c-red); text-decoration: underline; }
.prose-body a:hover { color: var(--c-blue); }

/* ===== Section 标题 ===== */
.section-heading {
  font-size: 1.6rem;
  margin: 40px 0 24px;
  display: flex;
  align-items: center;
  gap: 12px;
}
.section-heading span {
  display: inline-block;
  border-bottom: 4px solid var(--c-blue);
  padding-bottom: 4px;
}
.section-heading::before {
  content: '';
  display: inline-block;
  width: 18px;
  height: 18px;
  background: var(--c-red);
  border: var(--border);
  flex-shrink: 0;
  transform: rotate(45deg);
}

/* ===== FAQ卡片区（首页）===== */
.faq-cards-section { margin-top: 48px; }
.cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 24px;
}

/* 玻璃拟态卡片 */
.card {
  background: var(--c-card-bg);
  border: var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  backdrop-filter: blur(10px);
  transition: box-shadow 0.15s, transform 0.15s;
}
.card:hover {
  box-shadow: 2px 2px 0 var(--c-black);
  transform: translate(3px, 3px);
}
.card-inner { padding: 24px; display: flex; flex-direction: column; gap: 10px; }
.card-tag {
  display: inline-block;
  font-size: 0.72rem;
  background: var(--c-blue);
  color: var(--c-black);
  padding: 2px 10px;
  border: 2px solid var(--c-black);
  border-radius: 4px;
  width: fit-content;
  letter-spacing: 0.04em;
}
.card-title { font-size: 1rem; line-height: 1.4; }
.card-title span { display: inline; }
.card-desc { font-size: 0.88rem; color: #333; line-height: 1.6; flex: 1; }
.card-link {
  display: inline-flex;
  align-items: center;
  height: 36px;
  padding: 0 14px;
  font-size: 0.85rem;
  background: var(--c-black);
  color: var(--c-white);
  border: 2px solid var(--c-black);
  border-radius: 6px;
  text-decoration: none;
  width: fit-content;
  margin-top: 4px;
  transition: background 0.15s, color 0.15s;
}
.card-link:hover { background: var(--c-red); border-color: var(--c-red); color: var(--c-white); text-decoration: none; }

/* ===== FAQ行式卡片 ===== */
.related-faqs-section, .about-links-section, .contact-links-section, .privacy-links-section { margin-top: 48px; }
.faq-row-card {
  background: var(--c-card-bg);
  border: var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-blue);
  backdrop-filter: blur(8px);
  margin-bottom: 16px;
  transition: box-shadow 0.15s, transform 0.15s;
}
.faq-row-card:hover {
  box-shadow: 2px 2px 0 var(--c-blue);
  transform: translate(3px, 3px);
}
.faq-row-inner { padding: 20px 24px; }
.faq-row-title { font-size: 1.05rem; margin-bottom: 8px; }
.faq-row-title span { display: inline; }
.faq-row-desc { font-size: 0.9rem; color: #333; margin-bottom: 12px; line-height: 1.65; }
.faq-row-link {
  display: inline-flex;
  align-items: center;
  height: 36px;
  padding: 0 14px;
  font-size: 0.85rem;
  background: var(--c-blue);
  color: var(--c-black);
  border: 2px solid var(--c-black);
  border-radius: 6px;
  text-decoration: none;
  transition: background 0.15s;
}
.faq-row-link:hover { background: var(--c-red); color: var(--c-white); text-decoration: none; }

/* ===== About 统计块 ===== */
.about-stats-row {
  display: flex;
  gap: 16px;
  margin-bottom: 32px;
  flex-wrap: wrap;
}
.stat-block {
  flex: 1;
  min-width: 100px;
  background: var(--c-blue);
  border: var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-red);
  padding: 20px;
  text-align: center;
}
.stat-num { font-size: 2rem; color: var(--c-black); line-height: 1; }
.stat-label { font-size: 0.82rem; color: var(--c-black); margin-top: 6px; }

/* ===== Contact 表单 ===== */
.contact-form-wrap {
  margin-top: 36px;
  background: var(--c-card-bg);
  border: var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-blue);
  padding: 28px;
}
.form-title { font-size: 1.2rem; margin-bottom: 20px; }
.form-title span { display: inline; }
.contact-form { display: flex; flex-direction: column; gap: 18px; }
.form-group { display: flex; flex-direction: column; gap: 6px; }
.form-group label { font-size: 0.9rem; }
.req { color: var(--c-red); }
.form-group input, .form-group select, .form-group textarea {
  padding: 10px 14px;
  border: var(--border);
  border-radius: 8px;
  background: var(--c-white);
  font-size: 1rem;
  box-shadow: 3px 3px 0 var(--c-black);
  outline: none;
  transition: box-shadow 0.15s;
  color: var(--c-black);
}
.form-group input:focus, .form-group select:focus, .form-group textarea:focus {
  box-shadow: 3px 3px 0 var(--c-blue);
}
.form-group textarea { resize: vertical; min-height: 120px; }

/* ===== Privacy 提示块 ===== */
.privacy-notice {
  background: var(--c-blue);
  border: var(--border);
  border-radius: var(--radius);
  padding: 16px 20px;
  margin-bottom: 28px;
  box-shadow: var(--shadow-red);
  font-size: 0.92rem;
}

/* ===== 页脚 ===== */
.site-footer {
  background: var(--c-black);
  color: var(--c-white);
  border-top: var(--border);
  border-color: var(--c-blue);
  margin-top: auto;
}
.footer-top {
  border-bottom: 2px solid rgba(59,177,255,0.3);
  padding: 36px 24px;
}
.footer-subscribe {
  max-width: var(--max-w);
  margin: 0 auto;
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  align-items: center;
}
.footer-subscribe-title {
  font-size: 1.2rem;
  color: var(--c-white);
  margin-right: 16px;
}
.footer-subscribe-title span { display: inline; border-bottom: 3px solid var(--c-blue); padding-bottom: 2px; }
.footer-subscribe-desc {
  flex: 1;
  min-width: 200px;
  font-size: 0.88rem;
  color: rgba(255,255,255,0.7);
  line-height: 1.6;
}
.footer-cols {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 36px 24px 24px;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 32px;
}
.footer-dl { }
.footer-dl-title {
  font-size: 0.8rem;
  color: var(--c-blue);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  margin-bottom: 14px;
  border-bottom: 1px solid rgba(59,177,255,0.3);
  padding-bottom: 8px;
  display: block;
}
.footer-dl dt, .footer-dl dd {
  margin-bottom: 8px;
}
.footer-dl dt { font-size: 0.85rem; color: rgba(255,255,255,0.5); }
.footer-dl dd { }
.footer-dl a {
  font-size: 0.88rem;
  color: rgba(255,255,255,0.8);
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  min-height: 28px;
  transition: color 0.15s;
}
.footer-dl a:hover { color: var(--c-blue); text-decoration: underline; }
.footer-nav-col .footer-dl dt { color: rgba(255,255,255,0.8); }

/* Footer 导航用 nav>dl>dt/dd>a 结构 */
footer nav dl dt a,
footer nav dl dd a {
  display: inline-flex;
  align-items: center;
  min-height: 40px;
  font-size: 0.88rem;
  color: rgba(255,255,255,0.8);
  text-decoration: none;
  padding: 4px 0;
}
footer nav dl dt a:hover,
footer nav dl dd a:hover { color: var(--c-blue); }

.footer-bar {
  border-top: 1px solid rgba(255,255,255,0.1);
  padding: 16px 24px;
  text-align: center;
  font-size: 0.8rem;
  color: rgba(255,255,255,0.45);
  max-width: var(--max-w);
  margin: 0 auto;
  width: 100%;
}

/* ===== 响应式 ===== */
@media (max-width: 900px) {
  .footer-cols {
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
  }
  .content-with-aside {
    grid-template-columns: 1fr;
  }
  .content-aside {
    position: static;
    flex-direction: row;
    flex-wrap: wrap;
  }
  .aside-box { flex: 1; min-width: 200px; }
}

@media (max-width: 640px) {
  .header-brand-row { padding: 0 16px; }
  .header-menu-row { padding: 0 16px; }
  .hero-content { padding: 60px 16px 60px; }
  .hero-title { font-size: clamp(1.6rem, 7vw, 2.4rem); }
  .hero-eyebrow { font-size: 0.72rem; }
  .main-content { padding: 24px 16px 40px; }
  .page-hero-content { padding: 32px 16px; }
  .footer-cols { grid-template-columns: 1fr 1fr; gap: 20px; padding: 24px 16px; }
  .footer-subscribe { flex-direction: column; align-items: flex-start; }
  .footer-top { padding: 24px 16px; }
  .cards-grid { grid-template-columns: 1fr; }
  .about-stats-row { flex-direction: column; }
  .content-aside { flex-direction: column; }
  .fullscreen-nav { padding: 60px 24px; }
  .fnav-item { font-size: 1.1rem; }
  .contact-form-wrap { padding: 20px 16px; }
}

@media (max-width: 400px) {
  .footer-cols { grid-template-columns: 1fr; }
  .hero-actions { flex-direction: column; }
  .btn-primary, .btn-secondary { width: 100%; justify-content: center; }
}

/* ===== prefers-reduced-motion ===== */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { transition: none !important; animation: none !important; }
  .fnav-item { opacity: 1 !important; transform: none !important; }
}