@import url('https://fonts.googleapis.com/css2?family=Lexend:wght@300;400;500;600;700&family=Source+Sans+3:wght@300;400;500;600;700&display=swap');

/* ===== 设计令牌 ===== */
:root {
  --clr-primary: #c8e0f4;
  --clr-secondary: #f5e0e8;
  --clr-dark: #171f26;
  --clr-dark-2: #1e2a35;
  --clr-dark-3: #243040;
  --clr-dark-4: #2d3d4e;
  --clr-primary-dim: #a8c8e8;
  --clr-secondary-dim: #e8c8d8;
  --clr-text: #c8e0f4;
  --clr-text-soft: #9ab8d0;
  --clr-text-muted: #6a90a8;
  --clr-accent: #e8c8d8;

  --shadow-neu-out:
    -5px -5px 15px rgba(200, 224, 244, 0.06),
    5px 5px 15px rgba(0, 0, 0, 0.5);
  --shadow-neu-in:
    inset -3px -3px 8px rgba(200, 224, 244, 0.05),
    inset 3px 3px 8px rgba(0, 0, 0, 0.4);
  --shadow-neu-hover:
    -7px -7px 20px rgba(200, 224, 244, 0.08),
    7px 7px 20px rgba(0, 0, 0, 0.6);

  --radius-card: 14px;
  --radius-btn: 10px;
  --radius-sm: 8px;

  --font-main: 'Lexend', 'Source Sans 3', system-ui, -apple-system, sans-serif;
  --font-body: 'Source Sans 3', 'Lexend', system-ui, -apple-system, sans-serif;

  --nav-h: 110px;
  --transition-std: 200ms ease;
}

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

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

body {
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.7;
  color: var(--clr-text);
  background-color: var(--clr-dark);
  min-height: 100vh;
  overflow-x: hidden;
}

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

a {
  color: var(--clr-primary);
  text-decoration: none;
  transition: color var(--transition-std), opacity var(--transition-std);
}

a:hover {
  color: var(--clr-secondary);
  opacity: 0.9;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-main);
  line-height: 1.3;
  font-weight: 600;
  color: var(--clr-primary);
}

p {
  margin-bottom: 1rem;
}

article {
  scroll-margin-top: calc(var(--nav-h) + 12px);
}

/* ===== 顶部导航 ===== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--clr-dark);
  border-bottom: 1px solid rgba(200, 224, 244, 0.1);
  box-shadow: 0 2px 16px rgba(0, 0, 0, 0.5);
}

.brand-row {
  background: linear-gradient(145deg, var(--clr-dark-2), var(--clr-dark-3));
  border-bottom: 1px solid rgba(200, 224, 244, 0.07);
  padding: 0.75rem 1.5rem;
}

.brand-inner {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  gap: 1rem;
}

.brand-link {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  text-decoration: none;
}

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

.brand-mark {
  width: 36px;
  height: 36px;
  border-radius: 8px;
}

.brand-name {
  font-family: var(--font-main);
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--clr-primary);
  letter-spacing: 0.03em;
}

.brand-tagline {
  font-size: 0.8rem;
  color: var(--clr-text-muted);
  margin: 0;
  display: none;
}

@media (min-width: 640px) {
  .brand-tagline {
    display: block;
  }
}

.main-nav {
  background: linear-gradient(145deg, var(--clr-dark-3), var(--clr-dark-2));
  padding: 0 1.5rem;
}

.main-nav > p {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  flex-wrap: wrap;
  gap: 0.25rem;
  align-items: center;
  min-height: 48px;
}

.main-nav > p > a {
  display: inline-flex;
  align-items: center;
  padding: 0.55rem 0.9rem;
  font-family: var(--font-main);
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--clr-text-soft);
  border-radius: var(--radius-sm);
  transition: background var(--transition-std), color var(--transition-std), box-shadow var(--transition-std);
  min-height: 40px;
  white-space: nowrap;
}

.main-nav > p > a:hover {
  color: var(--clr-primary);
  background: rgba(200, 224, 244, 0.08);
  box-shadow: var(--shadow-neu-out);
}

/* ===== Hero ===== */
.hero-section {
  position: relative;
  min-height: 70vh;
  display: flex;
  align-items: center;
  overflow: hidden;
  background: linear-gradient(135deg, var(--clr-dark) 0%, var(--clr-dark-2) 50%, var(--clr-dark-3) 100%);
}

.hero-grid-bg {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(200, 224, 244, 0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(200, 224, 244, 0.04) 1px, transparent 1px);
  background-size: 40px 40px;
  pointer-events: none;
}

.hero-grid-bg::after {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse 60% 50% at 30% 50%, rgba(200, 224, 244, 0.06) 0%, transparent 70%);
}

.hero-inner {
  position: relative;
  z-index: 1;
  max-width: 1200px;
  margin: 0 auto;
  padding: 4rem 1.5rem;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
  align-items: center;
  width: 100%;
}

.hero-text {
  display: flex;
  flex-direction: column;
  gap: 1.2rem;
}

.hero-text h1 {
  font-size: clamp(1.8rem, 4vw, 3rem);
  font-weight: 700;
  color: var(--clr-primary);
  line-height: 1.2;
  letter-spacing: -0.01em;
}

.hero-desc {
  font-size: 1rem;
  color: var(--clr-text-soft);
  line-height: 1.7;
  margin: 0;
  max-width: 42ch;
}

.hero-cta {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.75rem 2rem;
  background: linear-gradient(145deg, var(--clr-dark-3), var(--clr-dark-4));
  color: var(--clr-primary);
  font-family: var(--font-main);
  font-size: 0.95rem;
  font-weight: 600;
  border-radius: var(--radius-btn);
  box-shadow: var(--shadow-neu-out);
  transition: box-shadow var(--transition-std), transform var(--transition-std), color var(--transition-std);
  align-self: flex-start;
  min-height: 44px;
}

.hero-cta:hover {
  box-shadow: var(--shadow-neu-hover);
  color: var(--clr-secondary);
  transform: translateY(-1px);
}

.hero-cta:active {
  box-shadow: var(--shadow-neu-in);
  transform: scale(0.98);
}

.hero-visual {
  display: flex;
  justify-content: center;
  align-items: center;
}

.hero-visual .hero-img {
  border-radius: var(--radius-card);
  box-shadow: var(--shadow-neu-out);
  max-height: 420px;
  object-fit: cover;
  width: 100%;
}

.hero-visual--placeholder {
  min-height: 320px;
}

.hero-placeholder-card {
  width: 220px;
  height: 280px;
  background: linear-gradient(145deg, var(--clr-dark-3), var(--clr-dark-4));
  border-radius: var(--radius-card);
  box-shadow: var(--shadow-neu-out);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 1rem;
}

.hero-placeholder-icon {
  font-family: var(--font-main);
  font-size: 4rem;
  font-weight: 700;
  color: var(--clr-primary);
  opacity: 0.6;
}

.hero-placeholder-label {
  font-family: var(--font-main);
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--clr-text-muted);
  letter-spacing: 0.1em;
}

@media (max-width: 768px) {
  .hero-inner {
    grid-template-columns: 1fr;
    gap: 2rem;
    padding: 3rem 1.25rem;
    text-align: left;
  }
  .hero-visual {
    display: none;
  }
  .hero-section {
    min-height: auto;
  }
}

/* ===== 主体内容 ===== */
.site-main {
  max-width: 1200px;
  margin: 0 auto;
  padding: 3rem 1.5rem;
}

.content-article {
  width: 100%;
}

.content-with-aside {
  display: grid;
  grid-template-columns: 1fr 280px;
  gap: 2.5rem;
  align-items: flex-start;
}

@media (max-width: 960px) {
  .content-with-aside {
    grid-template-columns: 1fr;
  }
  .content-aside {
    order: -1;
  }
}

/* ===== 正文内容（page.content） ===== */
.content-section.page-content {
  width: 100%;
}

.page-content article {
  margin-bottom: 3rem;
  padding: 2rem;
  background: linear-gradient(145deg, var(--clr-dark-2), var(--clr-dark-3));
  border-radius: var(--radius-card);
  box-shadow: var(--shadow-neu-out);
  transition: box-shadow var(--transition-std);
}

.page-content article:hover {
  box-shadow: var(--shadow-neu-hover);
}

.page-content h2 {
  font-size: 1.5rem;
  font-weight: 600;
  color: var(--clr-primary);
  margin-bottom: 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid rgba(200, 224, 244, 0.12);
}

.page-content h3 {
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--clr-secondary);
  margin: 1.2rem 0 0.6rem;
}

.page-content p {
  font-size: 1rem;
  color: var(--clr-text-soft);
  line-height: 1.8;
  margin-bottom: 0.9rem;
}

.page-content ul,
.page-content ol {
  padding-left: 1.5rem;
  margin-bottom: 1rem;
  color: var(--clr-text-soft);
}

.page-content li {
  margin-bottom: 0.4rem;
  line-height: 1.7;
}

.page-content a {
  color: var(--clr-primary);
  text-decoration: underline;
  text-decoration-color: rgba(200, 224, 244, 0.3);
  text-underline-offset: 3px;
  transition: color var(--transition-std), text-decoration-color var(--transition-std);
}

.page-content a:hover {
  color: var(--clr-secondary);
  text-decoration-color: rgba(245, 224, 232, 0.6);
}

.page-content strong {
  color: var(--clr-primary);
  font-weight: 600;
}

.page-content table {
  width: 100%;
  border-collapse: collapse;
  margin-bottom: 1.2rem;
  font-size: 0.95rem;
}

.page-content th,
.page-content td {
  padding: 0.6rem 0.9rem;
  border: 1px solid rgba(200, 224, 244, 0.1);
  text-align: left;
}

.page-content th {
  background: rgba(200, 224, 244, 0.06);
  color: var(--clr-primary);
  font-weight: 600;
}

.page-content td {
  color: var(--clr-text-soft);
}

/* ===== Aside ===== */
.content-aside {
  position: sticky;
  top: calc(var(--nav-h) + 16px);
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.aside-card {
  background: linear-gradient(145deg, var(--clr-dark-2), var(--clr-dark-3));
  border-radius: var(--radius-card);
  box-shadow: var(--shadow-neu-out);
  padding: 1.4rem;
  /* 玻璃拟态 + 软浮雕叠加 */
  border: 1px solid rgba(200, 224, 244, 0.08);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
}

.aside-eyebrow {
  display: block;
  font-size: 0.7rem;
  font-weight: 500;
  letter-spacing: 0.12em;
  color: var(--clr-text-muted);
  text-transform: uppercase;
  margin-bottom: 0.4rem;
}

.aside-title {
  font-size: 1rem;
  font-weight: 600;
  color: var(--clr-primary);
  margin-bottom: 1rem;
}

.aside-subtitle {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--clr-primary);
  margin-bottom: 0.6rem;
}

.aside-text {
  font-size: 0.85rem;
  color: var(--clr-text-muted);
  line-height: 1.6;
  margin: 0;
}

.aside-card nav {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
}

.aside-link {
  display: flex;
  align-items: center;
  padding: 0.45rem 0.7rem;
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--clr-text-soft);
  border-radius: var(--radius-sm);
  background: linear-gradient(145deg, var(--clr-dark-3), var(--clr-dark-4));
  box-shadow:
    -2px -2px 6px rgba(200, 224, 244, 0.04),
    2px 2px 6px rgba(0, 0, 0, 0.4);
  transition: box-shadow var(--transition-std), color var(--transition-std), transform var(--transition-std);
  min-height: 36px;
}

.aside-link:hover {
  color: var(--clr-primary);
  box-shadow:
    -3px -3px 10px rgba(200, 224, 244, 0.06),
    3px 3px 10px rgba(0, 0, 0, 0.5);
  transform: translateX(2px);
}

.aside-link:active {
  box-shadow: var(--shadow-neu-in);
  transform: scale(0.98);
}

.aside-card--info {
  background: linear-gradient(145deg, var(--clr-dark-2), rgba(245, 224, 232, 0.04));
}

/* ===== 页脚 ===== */
.site-footer {
  margin-top: 4rem;
  background: linear-gradient(145deg, var(--clr-dark-2), var(--clr-dark-3));
  border-top: 1px solid rgba(200, 224, 244, 0.08);
}

.site-footer > article {
  /* footer > article×n 结构契约 */
}

.footer-brand {
  padding: 3.5rem 1.5rem 2.5rem;
  border-bottom: 1px solid rgba(200, 224, 244, 0.07);
}

.footer-brand-inner {
  max-width: 1200px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
  align-items: center;
}

@media (max-width: 640px) {
  .footer-brand-inner {
    grid-template-columns: 1fr;
  }
}

.footer-big-name {
  font-family: var(--font-main);
  font-size: clamp(2.5rem, 8vw, 5rem);
  font-weight: 700;
  color: var(--clr-primary);
  opacity: 0.15;
  letter-spacing: -0.02em;
  line-height: 1;
  display: block;
  user-select: none;
}

.footer-brand-desc {
  font-size: 0.9rem;
  color: var(--clr-text-muted);
  line-height: 1.7;
  margin: 0;
  max-width: 38ch;
}

.footer-links {
  padding: 2.5rem 1.5rem;
  border-bottom: 1px solid rgba(200, 224, 244, 0.07);
}

.footer-links-inner {
  max-width: 1200px;
  margin: 0 auto;
}

.footer-eyebrow {
  display: block;
  font-size: 0.7rem;
  font-weight: 500;
  letter-spacing: 0.12em;
  color: var(--clr-text-muted);
  text-transform: uppercase;
  margin-bottom: 0.4rem;
}

.footer-links-title {
  font-size: 1rem;
  font-weight: 600;
  color: var(--clr-primary);
  margin-bottom: 1.2rem;
}

.footer-links nav {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.footer-nav-link {
  display: inline-flex;
  align-items: center;
  padding: 0.5rem 1rem;
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--clr-text-soft);
  background: linear-gradient(145deg, var(--clr-dark-3), var(--clr-dark-4));
  border-radius: var(--radius-sm);
  box-shadow:
    -2px -2px 6px rgba(200, 224, 244, 0.04),
    2px 2px 6px rgba(0, 0, 0, 0.4);
  transition: box-shadow var(--transition-std), color var(--transition-std);
  min-height: 40px;
}

.footer-nav-link:hover {
  color: var(--clr-primary);
  box-shadow:
    -3px -3px 10px rgba(200, 224, 244, 0.07),
    3px 3px 10px rgba(0, 0, 0, 0.5);
}

.footer-nav-link:active {
  box-shadow: var(--shadow-neu-in);
  transform: scale(0.97);
}

.footer-bottom {
  padding: 1.2rem 1.5rem;
  background: var(--clr-dark);
}

.footer-copy {
  max-width: 1200px;
  margin: 0 auto;
  font-size: 0.8rem;
  color: var(--clr-text-muted);
  text-align: center;
  line-height: 1.5;
}

/* ===== 小标题眉题（small 前置 h2/h3） ===== */
small.aside-eyebrow + h2,
small.aside-eyebrow + h3,
small.footer-eyebrow + h2 {
  margin-top: 0;
}

/* ===== 滚动进入动效 ===== */
@media (prefers-reduced-motion: no-preference) {
  .page-content article {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.5s ease, transform 0.5s ease, box-shadow var(--transition-std);
  }
  .page-content article.in-view {
    opacity: 1;
    transform: translateY(0);
  }
  .aside-card {
    opacity: 0;
    transform: translateX(12px);
    transition: opacity 0.5s ease 0.15s, transform 0.5s ease 0.15s, box-shadow var(--transition-std);
  }
  .aside-card.in-view {
    opacity: 1;
    transform: translateX(0);
  }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
  html {
    scroll-behavior: auto;
  }
}

/* ===== 响应式微调 ===== */
@media (max-width: 480px) {
  .main-nav > p {
    gap: 0.15rem;
  }
  .main-nav > p > a {
    font-size: 0.78rem;
    padding: 0.5rem 0.6rem;
  }
  .site-main {
    padding: 2rem 1rem;
  }
  .page-content article {
    padding: 1.4rem 1.1rem;
  }
  .footer-brand {
    padding: 2rem 1rem 1.5rem;
  }
  .footer-links {
    padding: 1.5rem 1rem;
  }
}

@media (max-width: 375px) {
  body {
    font-size: 1rem;
  }
  .main-nav > p > a {
    font-size: 0.75rem;
    padding: 0.45rem 0.5rem;
    min-height: 40px;
  }
}