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

/* ===== 设计令牌 ===== */
:root {
  --clr-blue: #c8e0f4;
  --clr-pink: #f5e0e8;
  --clr-dark: #171f26;
  --clr-blue-light: #ddeefa;
  --clr-blue-dark: #a9caec;
  --clr-pink-light: #faeef3;
  --clr-pink-dark: #e8c8d8;
  --clr-surface: #dce8f2;
  --clr-text: #1e2d3a;
  --clr-text-muted: #5a6e80;
  --clr-white: #ffffff;

  --shadow-raise:
    -5px -5px 15px rgba(255,255,255,0.85),
     5px  5px 15px rgba(166,196,226,0.55);
  --shadow-press:
    inset -3px -3px 8px rgba(255,255,255,0.75),
    inset  3px  3px 10px rgba(166,196,226,0.55);
  --shadow-card:
    -4px -4px 12px rgba(255,255,255,0.8),
     4px  4px 12px rgba(166,196,226,0.5);
  --shadow-inset:
    inset 2px 2px 6px rgba(166,196,226,0.4),
    inset -2px -2px 6px rgba(255,255,255,0.7);

  --radius-sm: 12px;
  --radius-md: 16px;
  --radius-lg: 24px;

  --ff-serif: 'Playfair Display', Georgia, serif;
  --ff-sans: 'Inter', system-ui, -apple-system, sans-serif;

  --nav-h: 72px;
  --transition: 150ms ease;
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: var(--nav-h);
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
}

body.neu-body {
  font-family: var(--ff-sans);
  background: var(--clr-blue);
  color: var(--clr-text);
  line-height: 1.7;
  min-height: 100vh;
  overflow-x: hidden;
}

img { display: block; max-width: 100%; height: auto; }
a { color: inherit; text-decoration: none; }
ul, menu { list-style: none; }
button { cursor: pointer; border: none; background: none; font: inherit; }

/* ===== 页面包装 ===== */
.page-wrapper {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

/* ===== 导航 ===== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--clr-blue);
  box-shadow: 0 2px 12px rgba(166,196,226,0.4);
  height: var(--nav-h);
}

.site-nav {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0;
  max-width: 1200px;
  margin: 0 auto;
  height: var(--nav-h);
  padding: 0 1.5rem;
}

.nav-left,
.nav-right {
  display: flex;
  align-items: center;
  gap: 0.25rem;
  flex: 1;
}

.nav-right { justify-content: flex-end; }

.nav-brand {
  flex-shrink: 0;
  padding: 0 1.5rem;
}

.brand-link,
.footer-logo-link {
  display: flex;
  align-items: center;
}

.brand-logo { height: 40px; width: auto; }

.brand-text {
  font-family: var(--ff-serif);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--clr-dark);
  letter-spacing: 0.02em;
  white-space: nowrap;
}

.nav-link {
  display: inline-flex;
  align-items: center;
  padding: 0.5rem 0.85rem;
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--clr-text);
  transition: box-shadow var(--transition), background var(--transition), transform var(--transition);
  white-space: nowrap;
  min-height: 40px;
}

.nav-link:hover {
  background: var(--clr-blue-light);
  box-shadow: var(--shadow-raise);
}

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

/* details/summary 手机菜单 */
.nav-details {
  display: none;
  position: relative;
}

.nav-summary {
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  box-shadow: var(--shadow-raise);
  background: var(--clr-blue);
  transition: box-shadow var(--transition);
}

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

.nav-summary:active { box-shadow: var(--shadow-press); }

.hamburger {
  display: flex;
  flex-direction: column;
  gap: 5px;
}

.hamburger span {
  display: block;
  width: 20px;
  height: 2px;
  background: var(--clr-dark);
  border-radius: 2px;
  transition: transform var(--transition);
}

.nav-menu-mobile {
  position: absolute;
  top: calc(100% + 8px);
  left: 0;
  min-width: 200px;
  background: var(--clr-blue);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-raise);
  padding: 0.75rem;
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
  z-index: 200;
}

.nav-menu-mobile li a {
  display: flex;
  align-items: center;
  padding: 0.6rem 1rem;
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--clr-text);
  transition: background var(--transition), box-shadow var(--transition);
  min-height: 44px;
}

.nav-menu-mobile li a:hover {
  background: var(--clr-blue-light);
  box-shadow: var(--shadow-card);
}

/* ===== Hero ===== */
.hero-section {
  position: relative;
  min-height: 45vh;
  display: flex;
  align-items: center;
  justify-content: flex-end;
  overflow: hidden;
  background: linear-gradient(135deg, var(--clr-blue) 0%, var(--clr-blue-dark) 50%, var(--clr-pink-dark) 100%);
}

.hero-media {
  position: absolute;
  inset: 0;
  z-index: 0;
}

.hero-img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0.35;
}

.hero-placeholder {
  background: linear-gradient(145deg, var(--clr-blue-dark), var(--clr-pink-dark));
}

.hero-content {
  position: relative;
  z-index: 2;
  max-width: 560px;
  text-align: right;
  padding: 3rem 3rem 4rem;
}

.hero-h1 {
  font-family: var(--ff-serif);
  font-size: clamp(1.75rem, 4vw, 3rem);
  font-weight: 700;
  color: var(--clr-dark);
  line-height: 1.25;
  margin-bottom: 1rem;
  text-shadow: 1px 1px 0 rgba(255,255,255,0.6);
}

.hero-lead {
  font-size: 1rem;
  color: var(--clr-text-muted);
  margin-bottom: 1.75rem;
  line-height: 1.7;
}

.neu-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.75rem 2rem;
  border-radius: var(--radius-sm);
  font-family: var(--ff-sans);
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--clr-dark);
  background: linear-gradient(145deg, var(--clr-blue-light), var(--clr-blue));
  box-shadow: var(--shadow-raise);
  transition: box-shadow var(--transition), transform var(--transition);
  min-height: 44px;
}

.neu-btn:hover {
  box-shadow:
    -7px -7px 20px rgba(255,255,255,0.9),
     7px  7px 20px rgba(166,196,226,0.65);
}

.neu-btn:active {
  box-shadow: var(--shadow-press);
  transform: scale(0.97);
}

.hero-arc {
  position: absolute;
  bottom: -2px;
  left: 0;
  right: 0;
  height: 60px;
  background: var(--clr-blue);
  clip-path: ellipse(55% 100% at 50% 100%);
  z-index: 3;
}

/* ===== 主内容 ===== */
.site-main {
  flex: 1;
  max-width: 1200px;
  margin: 0 auto;
  width: 100%;
  padding: 3rem 1.5rem;
}

.content-section {
  display: grid;
  grid-template-columns: 1fr 260px;
  grid-template-rows: auto 1fr;
  gap: 2rem;
  align-items: start;
}

.content-figure {
  grid-column: 1;
  grid-row: 1;
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: var(--shadow-card);
  background: linear-gradient(145deg, var(--clr-pink-light), var(--clr-blue-light));
  min-height: 6px;
}

.figure-deco {
  height: 6px;
  background: linear-gradient(90deg, var(--clr-blue-dark), var(--clr-pink-dark), var(--clr-blue-dark));
  border-radius: var(--radius-md);
}

.content-aside {
  grid-column: 2;
  grid-row: 1 / 3;
  position: sticky;
  top: calc(var(--nav-h) + 1.5rem);
  border-radius: var(--radius-md);
  background: linear-gradient(145deg, var(--clr-blue-light), var(--clr-blue));
  box-shadow: var(--shadow-raise);
  padding: 1.5rem;
}

.aside-title {
  font-family: var(--ff-serif);
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--clr-dark);
  margin-bottom: 0.35rem;
}

.aside-title + .subtitle {
  font-size: 0.82rem;
  color: var(--clr-text-muted);
  margin-bottom: 1.25rem;
}

.aside-nav-list {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.aside-link {
  display: flex;
  align-items: center;
  padding: 0.55rem 0.9rem;
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--clr-text);
  background: var(--clr-blue);
  box-shadow: var(--shadow-card);
  transition: box-shadow var(--transition), background var(--transition), transform var(--transition);
  min-height: 40px;
}

.aside-link:hover {
  background: var(--clr-blue-light);
  box-shadow:
    -4px -4px 12px rgba(255,255,255,0.9),
     4px  4px 12px rgba(166,196,226,0.6);
}

.aside-link:active {
  box-shadow: var(--shadow-press);
  transform: scale(0.97);
}

.page-content {
  grid-column: 1;
  grid-row: 2;
}

/* ===== 正文内容样式 ===== */
.page-content h2,
.page-content h3,
.page-content h4 {
  font-family: var(--ff-serif);
  color: var(--clr-dark);
  margin-top: 2.5rem;
  margin-bottom: 0.75rem;
  line-height: 1.3;
}

.page-content h2 { font-size: clamp(1.35rem, 2.5vw, 1.75rem); font-weight: 700; }
.page-content h3 { font-size: 1.2rem; font-weight: 600; }
.page-content h4 { font-size: 1rem; font-weight: 600; }

.page-content p {
  margin-bottom: 1.1rem;
  font-size: 1rem;
  line-height: 1.8;
  color: var(--clr-text);
}

.page-content ul,
.page-content ol {
  margin: 0.75rem 0 1.25rem 1.25rem;
}

.page-content li {
  margin-bottom: 0.5rem;
  font-size: 1rem;
  line-height: 1.7;
}

.page-content a {
  color: #3a78b5;
  text-decoration: underline;
  text-underline-offset: 2px;
}

.page-content a:hover { color: var(--clr-dark); }

.page-content section {
  margin-bottom: 3rem;
  padding: 2rem;
  border-radius: var(--radius-md);
  background: linear-gradient(145deg, var(--clr-blue-light), var(--clr-blue));
  box-shadow: var(--shadow-raise);
  scroll-margin-top: calc(var(--nav-h) + 1rem);
}

.page-content section:nth-child(even) {
  background: linear-gradient(145deg, var(--clr-pink-light), var(--clr-blue-light));
}

.page-content section h2:first-child,
.page-content section h3:first-child {
  margin-top: 0;
}

.page-content blockquote {
  border-left: 4px solid var(--clr-blue-dark);
  padding: 0.75rem 1.25rem;
  margin: 1.5rem 0;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  background: var(--clr-blue-light);
  box-shadow: var(--shadow-inset);
  font-style: italic;
  color: var(--clr-text-muted);
}

.page-content table {
  width: 100%;
  border-collapse: separate;
  border-spacing: 0 6px;
  margin: 1.5rem 0;
}

.page-content th,
.page-content td {
  padding: 0.75rem 1rem;
  text-align: left;
  font-size: 0.9rem;
}

.page-content th {
  font-weight: 600;
  color: var(--clr-dark);
  background: var(--clr-blue-dark);
  border-radius: var(--radius-sm) var(--radius-sm) 0 0;
}

.page-content td {
  background: var(--clr-blue-light);
}

/* h2 + subtitle 结构 */
.page-content h2 + .subtitle,
.page-content h2 + p.subtitle,
.page-content h2 + p.subhead,
.page-content h2 + p.desc,
.page-content h2 + p.lead {
  font-size: 0.95rem;
  color: var(--clr-text-muted);
  margin-top: -0.25rem;
  margin-bottom: 1.25rem;
}

/* ===== 页脚 ===== */
.site-footer {
  background: var(--clr-dark);
  color: rgba(255,255,255,0.75);
  padding: 1.75rem 1.5rem;
  margin-top: 2rem;
}

.footer-inner {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  gap: 2rem;
  flex-wrap: wrap;
}

.footer-brand { flex-shrink: 0; }

.footer-brand .brand-text {
  color: rgba(255,255,255,0.9);
  font-size: 1.05rem;
}

.footer-brand .brand-logo { height: 32px; opacity: 0.85; }

.footer-nav { flex: 1; }

.footer-nav-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.25rem 0.5rem;
  align-items: center;
}

.footer-link {
  display: inline-flex;
  align-items: center;
  padding: 0.4rem 0.7rem;
  border-radius: 8px;
  font-size: 0.82rem;
  color: rgba(255,255,255,0.65);
  transition: color var(--transition), background var(--transition);
  min-height: 40px;
}

.footer-link:hover {
  color: rgba(255,255,255,0.95);
  background: rgba(255,255,255,0.08);
}

.footer-copy {
  flex-shrink: 0;
  font-size: 0.8rem;
  color: rgba(255,255,255,0.4);
  white-space: nowrap;
}

/* ===== 动效（Stagger + Scroll Reveal） ===== */
@media (prefers-reduced-motion: no-preference) {
  .reveal {
    opacity: 0;
    transform: translateY(24px);
    transition: opacity 0.55s ease, transform 0.55s ease;
  }
  .reveal.visible {
    opacity: 1;
    transform: translateY(0);
  }
  .stagger > * {
    opacity: 0;
    transform: translateY(18px);
    transition: opacity 0.45s ease, transform 0.45s ease;
  }
  .stagger.visible > *:nth-child(1) { transition-delay: 0.05s; }
  .stagger.visible > *:nth-child(2) { transition-delay: 0.12s; }
  .stagger.visible > *:nth-child(3) { transition-delay: 0.19s; }
  .stagger.visible > *:nth-child(4) { transition-delay: 0.26s; }
  .stagger.visible > *:nth-child(5) { transition-delay: 0.33s; }
  .stagger.visible > *:nth-child(6) { transition-delay: 0.40s; }
  .stagger.visible > *:nth-child(7) { transition-delay: 0.47s; }
  .stagger.visible > * { opacity: 1; transform: translateY(0); }

  .hero-content { animation: heroIn 0.7s ease both; }
  @keyframes heroIn {
    from { opacity: 0; transform: translateX(32px); }
    to   { opacity: 1; transform: translateX(0); }
  }
}

/* ===== 响应式 ===== */
@media (max-width: 900px) {
  .content-section {
    grid-template-columns: 1fr;
    grid-template-rows: auto auto auto;
  }
  .content-figure { grid-column: 1; grid-row: 1; }
  .content-aside  { grid-column: 1; grid-row: 2; position: static; }
  .page-content   { grid-column: 1; grid-row: 3; }
}

@media (max-width: 768px) {
  :root { --nav-h: 60px; }

  .site-nav { display: none; }
  .nav-details { display: block; }

  .site-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 1rem;
    height: var(--nav-h);
  }

  .site-header::before {
    content: attr(data-brand);
    font-family: var(--ff-serif);
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--clr-dark);
  }

  .hero-content {
    text-align: left;
    padding: 2rem 1.25rem 3rem;
    max-width: 100%;
  }

  .hero-section { justify-content: flex-start; min-height: 50vh; }

  .site-main { padding: 2rem 1rem; }

  .footer-inner {
    flex-direction: column;
    align-items: flex-start;
    gap: 1rem;
  }

  .footer-copy { white-space: normal; }

  .page-content section { padding: 1.25rem; }
}

@media (max-width: 480px) {
  .hero-h1 { font-size: 1.5rem; }
  .nav-menu-mobile { min-width: 180px; }
}

/* ===== 滚动区域的 section scroll-margin ===== */
section[id] {
  scroll-margin-top: calc(var(--nav-h) + 1rem);
}