@import url('https://fonts.googleapis.com/css2?family=JetBrains+Mono:ital,wght@0,400;0,500;1,400&display=swap');

/* ====================================================
   CSS 自定义属性
   ==================================================== */
:root {
  --mint: #b4fde1;
  --ice: #add8e6;
  --ink: #172620;
  --ink-2: #1e3028;
  --ink-3: #243b30;
  --ink-light: #2e4a3c;
  --mint-dim: rgba(180, 253, 225, 0.15);
  --mint-glow: rgba(180, 253, 225, 0.35);
  --ice-dim: rgba(173, 216, 230, 0.15);
  --ice-glow: rgba(173, 216, 230, 0.30);
  --text-primary: #d8f8ec;
  --text-secondary: #8fbfaa;
  --text-muted: #5a7a6a;
  --border-mint: #b4fde1;
  --border-ice: #add8e6;
  --radius-sm: 12px;
  --radius-md: 16px;
  --radius-lg: 20px;
  --radius-xl: 24px;
  --border-w: 3px;
  --border-w-thick: 4px;
  --shadow-clay-out: 4px 4px 10px rgba(0,0,0,0.5), 2px 2px 4px rgba(0,0,0,0.4);
  --shadow-clay-in: inset -2px -2px 8px rgba(180,253,225,0.12), inset 2px 2px 8px rgba(0,0,0,0.35);
  --shadow-card: 4px 4px 12px rgba(0,0,0,0.55), inset -1px -1px 6px rgba(180,253,225,0.08);
  --nav-h: 68px;
  --font-mono: 'JetBrains Mono', 'Courier New', monospace;
  --transition-soft: 200ms cubic-bezier(0.34, 1.56);
  --transition-std: 250ms ease-out;
}

/* ====================================================
   Reset & Base
   ==================================================== */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

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

body {
  font-family: var(--font-mono);
  background-color: var(--ink);
  color: var(--text-primary);
  line-height: 1.7;
  min-height: 100vh;
  overflow-x: hidden;
}

section[id] {
  scroll-margin-bottom: calc(var(--nav-h) + 20px);
}

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

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

a:focus-visible {
  outline: 2px solid var(--mint);
  outline-offset: 3px;
  border-radius: 4px;
}

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

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-mono);
  line-height: 1.3;
  font-weight: 500;
}

p { line-height: 1.75; }

hr {
  border: none;
  border-top: 2px solid var(--mint-dim);
  margin: 1rem 0;
}

/* ====================================================
   Page Wrap
   ==================================================== */
.page-wrap {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  padding-bottom: var(--nav-h);
}

/* ====================================================
   底部固定导航
   契约: header > nav > p > a
   ==================================================== */
.bottom-nav {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: linear-gradient(180deg, var(--ink-2) 0%, var(--ink) 100%);
  border-top: var(--border-w) solid var(--mint);
  box-shadow: 0 -4px 20px rgba(0,0,0,0.6), 0 -1px 0 rgba(180,253,225,0.2);
  height: var(--nav-h);
}

.bottom-nav-inner {
  display: flex;
  align-items: stretch;
  justify-content: space-between;
  height: 100%;
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 8px;
  gap: 4px;
}

.nav-group {
  display: flex;
  align-items: center;
  flex: 1;
  gap: 0;
  margin: 0;
}

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

.nav-link {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  min-width: 44px;
  padding: 8px 8px;
  border-radius: var(--radius-sm);
  color: var(--text-secondary);
  font-size: 10px;
  font-family: var(--font-mono);
  text-align: center;
  transition: color var(--transition-soft), background var(--transition-soft), transform var(--transition-soft);
  white-space: nowrap;
}

.nav-link:hover,
.nav-link:focus-visible {
  color: var(--mint);
  background: var(--mint-dim);
  transform: translateY(-2px);
}

.nav-icon {
  display: block;
  font-size: 14px;
  line-height: 1;
  margin-bottom: 2px;
}

.nav-text {
  display: block;
  font-size: 9px;
  letter-spacing: 0.02em;
}

.nav-brand {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  min-width: 80px;
  padding: 8px 12px;
  flex-shrink: 0;
  border-radius: var(--radius-md);
  border: var(--border-w) solid var(--mint);
  background: linear-gradient(135deg, var(--ink-3) 0%, var(--ink-2) 100%);
  box-shadow: var(--shadow-clay-out), var(--shadow-clay-in);
  color: var(--mint);
  font-size: 11px;
  font-weight: 500;
  text-align: center;
  transition: transform var(--transition-soft), box-shadow var(--transition-soft);
  position: relative;
  top: -8px;
}

.nav-brand:hover {
  transform: translateY(-4px) scale(1.04);
  box-shadow: 6px 6px 16px rgba(0,0,0,0.6), inset -2px -2px 8px rgba(180,253,225,0.18);
  color: var(--mint);
}

.nav-brand-text {
  font-family: var(--font-mono);
  font-size: 10px;
  font-weight: 500;
  letter-spacing: 0.05em;
}

.site-logo {
  width: auto;
  height: 32px;
  object-fit: contain;
}

/* ====================================================
   Hero Section
   ==================================================== */
.hero-section {
  position: relative;
  min-height: 70vh;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  background: var(--ink);
}

.hero-grid-bg {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(180,253,225,0.06) 1px, transparent 1px),
    linear-gradient(90deg, rgba(180,253,225,0.06) 1px, transparent 1px);
  background-size: 40px 40px;
  pointer-events: none;
}

.hero-grid-bg::after {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse 70% 60% at 50% 50%, transparent 30%, var(--ink) 100%);
}

.hero-content {
  position: relative;
  z-index: 1;
  text-align: center;
  max-width: 860px;
  padding: 2rem 1.5rem;
}

.hero-eyebrow {
  display: inline-block;
  margin-bottom: 1.2rem;
  font-size: 12px;
  letter-spacing: 0.15em;
  font-family: var(--font-mono);
  font-weight: 400;
}

.clay-bubble {
  background: linear-gradient(135deg, var(--ink-3), var(--ink-2));
  border: var(--border-w) solid var(--mint);
  border-radius: var(--radius-xl);
  padding: 6px 18px;
  color: var(--mint);
  box-shadow: var(--shadow-clay-out), var(--shadow-clay-in);
  font-size: 11px;
  letter-spacing: 0.12em;
}

.hero-title {
  font-size: clamp(2.2rem, 8vw, 5rem);
  font-weight: 500;
  color: var(--mint);
  letter-spacing: -0.01em;
  margin-bottom: 1rem;
  text-shadow: 0 0 40px rgba(180,253,225,0.3), 0 2px 4px rgba(0,0,0,0.5);
  line-height: 1.2;
}

.hero-desc {
  font-size: clamp(0.9rem, 2.5vw, 1.1rem);
  color: var(--text-secondary);
  max-width: 580px;
  margin: 0 auto 2rem;
  line-height: 1.8;
}

.clay-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 12px 28px;
  border-radius: var(--radius-lg);
  border: var(--border-w) solid var(--mint);
  background: linear-gradient(135deg, var(--ink-3) 0%, var(--ink-2) 100%);
  color: var(--mint);
  font-family: var(--font-mono);
  font-size: 14px;
  font-weight: 500;
  letter-spacing: 0.06em;
  box-shadow: var(--shadow-clay-out), var(--shadow-clay-in);
  cursor: pointer;
  transition: transform var(--transition-soft), box-shadow var(--transition-soft), background var(--transition-soft);
}

.clay-btn:hover {
  transform: translateY(-3px) scale(1.03);
  box-shadow: 6px 6px 18px rgba(0,0,0,0.6), inset -2px -2px 8px rgba(180,253,225,0.2);
  background: linear-gradient(135deg, var(--ink-light) 0%, var(--ink-3) 100%);
  color: var(--mint);
}

.clay-btn:active {
  transform: translateY(1px) scale(0.98);
  box-shadow: 2px 2px 6px rgba(0,0,0,0.5), inset -1px -1px 4px rgba(180,253,225,0.08);
  transition-duration: 100ms;
}

/* ====================================================
   主内容区
   契约: main > section > figure/aside 交错
   ==================================================== */
.main-content {
  flex: 1;
  width: 100%;
}

.content-shell {
  display: grid;
  grid-template-columns: 240px 1fr;
  gap: 2rem;
  max-width: 1280px;
  margin: 0 auto;
  padding: 2.5rem 1.5rem 3rem;
  align-items: start;
}

/* ====================================================
   Aside (内容左侧)
   ==================================================== */
.content-aside {
  position: sticky;
  top: 20px;
  display: flex;
  flex-direction: column;
  gap: 1.2rem;
}

.clay-card {
  background: linear-gradient(145deg, var(--ink-3) 0%, var(--ink-2) 100%);
  border: var(--border-w) solid var(--mint);
  border-radius: var(--radius-lg);
  padding: 1.2rem;
  box-shadow: var(--shadow-card);
}

.aside-title {
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--mint);
  font-weight: 500;
  margin-bottom: 0.5rem;
  text-transform: uppercase;
}

.aside-link {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 10px;
  border-radius: var(--radius-sm);
  color: var(--text-secondary);
  font-size: 11px;
  line-height: 1.4;
  transition: color var(--transition-soft), background var(--transition-soft), transform var(--transition-soft);
  border: 1px solid transparent;
  min-height: 40px;
}

.aside-link:hover {
  color: var(--mint);
  background: var(--mint-dim);
  border-color: var(--mint-dim);
  transform: translateX(4px);
}

.aside-brand-card {
  border-color: var(--ice);
}

.aside-figure {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.8rem;
}

.aside-logo img,
.aside-logo {
  width: 56px;
  height: 56px;
  object-fit: contain;
  border-radius: var(--radius-md);
}

.aside-logo-text {
  width: 56px;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--mint-dim);
  border-radius: var(--radius-md);
  border: var(--border-w) solid var(--mint);
  font-size: 10px;
  color: var(--mint);
  font-weight: 500;
  text-align: center;
  letter-spacing: 0.05em;
}

.aside-figcaption {
  font-size: 11px;
  color: var(--text-muted);
  text-align: center;
  line-height: 1.5;
}

/* ====================================================
   正文内容体
   ==================================================== */
.content-body {
  min-width: 0;
}

.content-body section {
  margin-bottom: 3rem;
  padding: 2rem;
  background: linear-gradient(145deg, var(--ink-2) 0%, var(--ink-3) 100%);
  border: var(--border-w) solid var(--mint-dim);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-card);
  position: relative;
  overflow: hidden;
}

.content-body section::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--mint), var(--ice), transparent);
  opacity: 0.6;
}

.content-body h2 {
  font-size: clamp(1.3rem, 3vw, 1.7rem);
  color: var(--mint);
  margin-bottom: 0.4rem;
  letter-spacing: -0.01em;
}

.content-body h2 + hr {
  border-top-color: var(--mint-dim);
  margin-bottom: 1rem;
}

.content-body h3 {
  font-size: 1.1rem;
  color: var(--ice);
  margin: 1.5rem 0 0.6rem;
}

.content-body h3 + hr {
  border-top-color: var(--ice-dim);
  margin-bottom: 0.8rem;
}

.content-body p {
  color: var(--text-primary);
  font-size: 15px;
  line-height: 1.8;
  margin-bottom: 1rem;
}

.content-body ul,
.content-body ol {
  padding-left: 1.4rem;
  margin-bottom: 1rem;
  color: var(--text-primary);
  font-size: 15px;
  line-height: 1.8;
}

.content-body li { margin-bottom: 0.3rem; }

.content-body strong { color: var(--mint); font-weight: 500; }
.content-body em { color: var(--ice); font-style: italic; }

.content-body a {
  color: var(--mint);
  border-bottom: 1px solid var(--mint-dim);
  padding-bottom: 1px;
}

.content-body a:hover {
  color: var(--ice);
  border-bottom-color: var(--ice);
}

.content-body figure {
  margin: 1.5rem 0;
  border-radius: var(--radius-md);
  overflow: hidden;
  border: var(--border-w) solid var(--mint-dim);
  box-shadow: var(--shadow-clay-out);
}

.content-body figcaption {
  padding: 0.5rem 0.8rem;
  background: var(--ink-3);
  font-size: 12px;
  color: var(--text-muted);
  letter-spacing: 0.04em;
}

.content-body aside {
  margin: 1.5rem 0;
  padding: 1rem 1.2rem;
  background: var(--ice-dim);
  border-left: var(--border-w-thick) solid var(--ice);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.7;
}

.content-body table {
  width: 100%;
  border-collapse: collapse;
  margin-bottom: 1.2rem;
  font-size: 13px;
}

.content-body th {
  background: var(--mint-dim);
  color: var(--mint);
  padding: 8px 12px;
  text-align: left;
  border: 1px solid var(--mint-dim);
  font-weight: 500;
  letter-spacing: 0.05em;
}

.content-body td {
  padding: 7px 12px;
  border: 1px solid rgba(255,255,255,0.06);
  color: var(--text-primary);
}

.content-body tr:nth-child(even) td {
  background: rgba(255,255,255,0.02);
}

.content-body code {
  background: var(--ink-3);
  border: 1px solid var(--mint-dim);
  border-radius: 6px;
  padding: 1px 6px;
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--mint);
}

.content-body pre {
  background: var(--ink-3);
  border: var(--border-w) solid var(--mint-dim);
  border-radius: var(--radius-md);
  padding: 1rem;
  overflow-x: auto;
  margin-bottom: 1.2rem;
}

.content-body pre code {
  background: none;
  border: none;
  padding: 0;
  font-size: 13px;
}

/* ====================================================
   Clay Card 通用
   ==================================================== */
.clay-card-section {
  border-radius: var(--radius-xl);
  border: var(--border-w) solid var(--ice);
  background: linear-gradient(145deg, var(--ink-2), var(--ink-3));
  box-shadow: var(--shadow-card);
  padding: 1.5rem;
  transition: transform var(--transition-soft), box-shadow var(--transition-soft);
}

.clay-card-section:hover {
  transform: translateY(-3px);
  box-shadow: 6px 8px 20px rgba(0,0,0,0.6), inset -2px -2px 8px rgba(173,216,230,0.12);
}

/* ====================================================
   页脚
   契约: footer 三列 dl (≥3 个 dl)
   ==================================================== */
.site-footer {
  background: linear-gradient(180deg, var(--ink-2) 0%, var(--ink) 100%);
  border-top: var(--border-w) solid var(--mint-dim);
  padding: 2.5rem 1.5rem 1.5rem;
  margin-top: 2rem;
}

.footer-inner {
  max-width: 1280px;
  margin: 0 auto 1.5rem;
  display: grid;
  grid-template-columns: 1.8fr 1fr 1fr;
  gap: 2rem;
}

.footer-col dt {
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--mint);
  font-weight: 500;
  text-transform: uppercase;
  margin-bottom: 0.8rem;
  font-family: var(--font-mono);
}

.footer-col dd {
  font-size: 13px;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 0.4rem;
  margin-left: 0;
}

.footer-brand-name {
  font-size: 16px !important;
  letter-spacing: 0.08em !important;
  text-transform: none !important;
  color: var(--mint) !important;
}

.footer-brand-desc {
  font-size: 13px;
  color: var(--text-muted);
  line-height: 1.7;
}

.footer-palette {
  display: flex;
  gap: 6px;
  align-items: center;
  margin-top: 0.5rem;
}

.palette-dot {
  display: inline-block;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  border: 2px solid rgba(255,255,255,0.15);
  box-shadow: 0 1px 4px rgba(0,0,0,0.4);
}

.footer-link {
  color: var(--text-secondary);
  font-size: 13px;
  transition: color var(--transition-std);
  padding: 4px 0;
  display: inline-block;
  min-height: 40px;
  line-height: 32px;
}

.footer-link:hover { color: var(--mint); }

.footer-copy { color: var(--text-muted); font-size: 12px; }

.footer-bottom {
  max-width: 1280px;
  margin: 0 auto;
  padding-top: 1rem;
  border-top: 1px solid var(--mint-dim);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.footer-copy-small,
.footer-icp {
  font-size: 11px;
  color: var(--text-muted);
  letter-spacing: 0.04em;
}

/* ====================================================
   Scroll Reveal 动效
   ==================================================== */
.reveal-section {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 500ms ease-out, transform 500ms cubic-bezier(0.34, 1.56);
}

.reveal-section.is-visible {
  opacity: 1;
  transform: translateY(0);
}

.content-body section {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 450ms ease-out, transform 450ms cubic-bezier(0.34, 1.56);
}

.content-body section.is-visible {
  opacity: 1;
  transform: translateY(0);
}

@media (prefers-reduced-motion: reduce) {
  .reveal-section,
  .content-body section {
    opacity: 1;
    transform: none;
    transition: none;
  }
  html { scroll-behavior: auto; }
  .clay-btn:hover,
  .nav-brand:hover,
  .nav-link:hover,
  .aside-link:hover {
    transform: none;
  }
}

/* ====================================================
   响应式
   ==================================================== */
@media (max-width: 1024px) {
  .content-shell {
    grid-template-columns: 200px 1fr;
    gap: 1.5rem;
    padding: 2rem 1rem 2.5rem;
  }
  .footer-inner {
    grid-template-columns: 1.5fr 1fr 1fr;
    gap: 1.5rem;
  }
}

@media (max-width: 768px) {
  :root {
    --nav-h: 60px;
  }
  .content-shell {
    grid-template-columns: 1fr;
    padding: 1.5rem 1rem 2rem;
  }
  .content-aside {
    position: static;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
  }
  .footer-inner {
    grid-template-columns: 1fr 1fr;
    gap: 1.2rem;
  }
  .footer-brand-col {
    grid-column: 1 / -1;
  }
  .bottom-nav-inner {
    padding: 0 4px;
  }
  .nav-link {
    padding: 6px 5px;
    font-size: 9px;
    min-height: 48px;
  }
  .nav-text {
    font-size: 8px;
  }
  .hero-section {
    min-height: 70vh;
  }
  .hero-title {
    font-size: clamp(1.8rem, 10vw, 3rem);
  }
  .content-body section {
    padding: 1.5rem 1rem;
  }
}

@media (max-width: 480px) {
  .content-aside {
    grid-template-columns: 1fr;
  }
  .footer-inner {
    grid-template-columns: 1fr;
  }
  .footer-brand-col {
    grid-column: auto;
  }
  .bottom-nav-inner {
    gap: 2px;
  }
  .nav-brand {
    min-width: 60px;
    min-height: 48px;
    padding: 6px 8px;
    font-size: 10px;
  }
  .nav-link {
    padding: 6px 4px;
    min-height: 48px;
  }
  .nav-icon { font-size: 12px; }
  .nav-text { display: none; }
  .footer-bottom {
    flex-direction: column;
    align-items: flex-start;
    gap: 4px;
  }
}

/* ====================================================
   杂项工具
   ==================================================== */
.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  white-space: nowrap;
  border: 0;
}

.section-divider {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin: 2rem 0;
  color: var(--text-muted);
  font-size: 11px;
  letter-spacing: 0.1em;
}

.section-divider::before,
.section-divider::after {
  content: '';
  flex: 1;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--mint-dim), transparent);
}