/* === CSS Custom Properties === */
:root {
  --color-paper: #FAF6EE;
  --color-vermillion: #B84C3B;
  --color-vermillion-dark: #9A3F30;
  --color-copper: #C4A66A;
  --color-copper-light: #D4C49A;
  --color-bark: #4A3728;
  --color-stone: #8B7355;
  --color-stone-light: #B0A090;

  --font-heading: 'Noto Serif SC', 'SimSun', 'STSong', serif;
  --font-body: 'Microsoft YaHei', 'PingFang SC', -apple-system, sans-serif;

  --max-width: 1200px;
  --nav-height: 64px;
}

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

@media (prefers-reduced-motion: no-preference) {
  html {
    scroll-behavior: smooth;
  }
}
html {
  font-size: 16px;
}

body {
  font-family: var(--font-body);
  background-color: var(--color-paper);
  color: var(--color-stone);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--color-vermillion); text-decoration: none; }
a:hover { color: var(--color-vermillion-dark); }

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

h1, h2, h3, h4 {
  font-family: var(--font-heading);
  color: var(--color-bark);
  line-height: 1.4;
}

/* === 导航栏 === */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  height: var(--nav-height);
  background: rgba(250, 246, 238, 0.92);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--color-copper);
}

.nav-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-heading);
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--color-bark);
  text-decoration: none;
}
.nav-brand:hover { color: var(--color-vermillion); }

.nav-icon { font-size: 1.3rem; }

.nav-menu {
  display: flex;
  align-items: center;
  gap: 8px;
}

.nav-link {
  display: inline-block;
  padding: 8px 16px;
  font-size: 0.9rem;
  color: var(--color-stone);
  border-radius: 4px;
  transition: color 0.2s, background 0.2s;
}
.nav-link:hover { color: var(--color-bark); background: rgba(196, 166, 106, 0.12); }
.nav-link.active { color: var(--color-vermillion); }

.nav-cta {
  background: var(--color-vermillion);
  color: #fff !important;
  margin-left: 8px;
  padding: 8px 20px;
  border-radius: 4px;
  font-weight: 500;
  transition: background 0.2s;
}
.nav-cta:hover { background: var(--color-vermillion-dark); }

/* 移动端汉堡按钮 */
.nav-toggle { display: none; }

/* === Hero 段落 === */
.hero {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: calc(var(--nav-height) + 40px) 24px 60px;
  position: relative;
  /* 封面图片背景 */
  background: url('../img/hero-cover.jpg') center center / cover no-repeat;
  background-attachment: fixed;
  isolation: isolate;
}

/* 暗色遮罩 — 保证文字可读，同时保留图片质感 */
.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  z-index: 0;
  background: linear-gradient(160deg,
    rgba(30, 20, 15, 0.55) 0%,
    rgba(30, 20, 15, 0.35) 30%,
    rgba(20, 12, 8, 0.45) 60%,
    rgba(30, 20, 15, 0.55) 100%
  );
}

/* 宣纸纹理覆盖层 — 叠加在图片上方增加东方质感 */
.hero::after {
  content: '';
  position: absolute;
  inset: 0;
  z-index: 0;
  opacity: 0.06;
  background-image: url("data:image/svg+xml,%3Csvg width='60' height='60' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence baseFrequency='0.8' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='1'/%3E%3C/svg%3E");
  pointer-events: none;
}

.hero-content {
  position: relative;
  z-index: 2;
  max-width: 720px;
}

.hero-subtitle-en {
  font-size: 0.75rem;
  letter-spacing: 5px;
  color: var(--color-copper);
  margin-bottom: 12px;
  text-transform: uppercase;
  text-shadow: 0 1px 3px rgba(0,0,0,0.3);
}

.hero-title {
  font-size: clamp(2rem, 5vw, 3.2rem);
  font-weight: 700;
  color: #fff;
  margin-bottom: 16px;
  letter-spacing: 4px;
  text-shadow: 0 2px 12px rgba(0,0,0,0.4);
}

.hero-desc {
  font-size: 1.05rem;
  color: rgba(255,255,255,0.9);
  margin-bottom: 36px;
  line-height: 1.8;
  text-shadow: 0 1px 4px rgba(0,0,0,0.3);
}

.hero-actions {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
}

/* 向下滚动指示器适配深色背景 */
.hero-scroll-hint {
  color: var(--color-copper);
  z-index: 2;
}
.hero-scroll-hint span {
  color: rgba(255,255,255,0.7);
}
.hero-scroll-hint svg {
  stroke: rgba(255,255,255,0.6);
}

/* === 按钮 === */
.btn {
  display: inline-block;
  padding: 13px 32px;
  font-size: 1rem;
  font-weight: 500;
  border-radius: 6px;
  cursor: pointer;
  transition: all 0.25s;
  font-family: var(--font-body);
  text-decoration: none;
  border: none;
}

.btn-primary {
  background: var(--color-vermillion);
  color: #fff;
}
.btn-primary:hover {
  background: var(--color-vermillion-dark);
  transform: translateY(-1px);
  box-shadow: 0 4px 14px rgba(184, 76, 59, 0.3);
}

.btn-secondary {
  background: transparent;
  color: var(--color-bark);
  border: 1.5px solid var(--color-copper);
}
.btn-secondary:hover {
  background: rgba(196, 166, 106, 0.12);
  border-color: var(--color-bark);
}

/* 在 hero 区域中按钮适配深色背景 */
.hero .btn-secondary {
  color: #fff;
  border-color: rgba(255,255,255,0.5);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
}
.hero .btn-secondary:hover {
  background: rgba(255,255,255,0.12);
  border-color: #fff;
}
.hero .btn-primary {
  box-shadow: 0 4px 20px rgba(184, 76, 59, 0.4);
}

/* === Hero 入场动画 === */
@keyframes heroFadeIn {
  from {
    opacity: 0;
    transform: translateY(24px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes heroBgZoom {
  from {
    transform: scale(1.08);
  }
  to {
    transform: scale(1);
  }
}

.hero-content > * {
  animation: heroFadeIn 0.9s ease-out backwards;
}
.hero-subtitle-en  { animation-delay: 0.15s; }
.hero-title        { animation-delay: 0.30s; }
.hero-desc         { animation-delay: 0.45s; }
.hero-actions      { animation-delay: 0.60s; }

/* 滚动提示 */
.hero-scroll-hint {
  position: absolute;
  bottom: 30px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  font-size: 0.75rem;
  color: var(--color-copper);
  animation: bounce 2s infinite;
}
@keyframes bounce {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(6px); }
}

/* === 通用段落 === */
.section {
  padding: 80px 24px;
}

.section-inner {
  max-width: var(--max-width);
  margin: 0 auto;
}

.section-header {
  text-align: center;
  margin-bottom: 48px;
}

.section-title {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 10px;
  position: relative;
  display: inline-block;
}

/* 标题下方铜金装饰线 */
.section-title::after {
  content: '';
  display: block;
  width: 48px;
  height: 3px;
  background: var(--color-copper);
  margin: 12px auto 0;
  border-radius: 2px;
}

.section-subtitle {
  font-size: 1rem;
  color: var(--color-stone-light);
  margin-top: 8px;
}

/* === 功能卡片网格 === */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.feature-card {
  background: rgba(255, 255, 255, 0.5);
  border: 1px solid var(--color-copper-light);
  border-radius: 8px;
  padding: 32px 24px;
  text-align: center;
  transition: transform 0.3s, box-shadow 0.3s;
  position: relative;
}

.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 28px rgba(74, 55, 40, 0.1);
}

.feature-icon {
  font-size: 2.2rem;
  margin-bottom: 16px;
}

.feature-card h3 {
  font-size: 1.1rem;
  margin-bottom: 10px;
  color: var(--color-bark);
}

.feature-card p {
  font-size: 0.9rem;
  line-height: 1.7;
  color: var(--color-stone);
}

/* === 技术段落 === */
.section-alt {
  background: rgba(196, 166, 106, 0.06);
}

.tech-flow {
  display: flex;
  align-items: flex-start;
  justify-content: center;
  gap: 12px;
  margin-bottom: 60px;
  flex-wrap: wrap;
}

.tech-node {
  background: var(--color-bark);
  color: var(--color-paper);
  padding: 24px 18px;
  border-radius: 8px;
  text-align: center;
  min-width: 140px;
  flex: 0 0 auto;
}
.tech-node strong {
  display: block;
  margin: 8px 0 4px;
  font-size: 0.95rem;
}
.tech-node p {
  font-size: 0.78rem;
  opacity: 0.8;
  line-height: 1.5;
}
.tech-node-icon { font-size: 1.6rem; }

.tech-arrow {
  align-self: center;
  font-size: 1.5rem;
  color: var(--color-copper);
  padding: 0 4px;
  margin-top: 12px;
}

.tech-stats h3 {
  text-align: center;
  font-size: 1.3rem;
  margin-bottom: 24px;
}

.stats-table-wrapper {
  overflow-x: auto;
  max-width: 640px;
  margin: 0 auto;
}

.stats-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.9rem;
}

.stats-table th,
.stats-table td {
  padding: 12px 16px;
  text-align: center;
  border-bottom: 1px solid var(--color-copper-light);
}

.stats-table th {
  background: var(--color-bark);
  color: var(--color-paper);
  font-weight: 500;
}

.stats-table tbody tr:hover {
  background: rgba(196, 166, 106, 0.08);
}

.table-note {
  text-align: center;
  font-size: 0.8rem;
  color: var(--color-stone-light);
  margin-top: 12px;
}
.table-note code {
  background: rgba(196, 166, 106, 0.15);
  padding: 2px 6px;
  border-radius: 3px;
  font-size: 0.85em;
}

/* === 软件截图 === */
.screenshots-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.screenshot-card {
  background: #fff;
  border: 1px solid var(--color-copper-light);
  border-radius: 8px;
  overflow: hidden;
  transition: transform 0.3s, box-shadow 0.3s;
}

.screenshot-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 28px rgba(74, 55, 40, 0.12);
}

.screenshot-card img {
  width: 100%;
  aspect-ratio: 16 / 10;
  object-fit: cover;
  display: block;
}

.screenshot-card figcaption {
  padding: 14px 16px;
  font-size: 0.85rem;
  color: var(--color-stone);
  text-align: center;
  line-height: 1.6;
}

/* === 下载段落 === */
.download-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
  align-items: stretch;
}

.download-box {
  background: #fff;
  border: 2px solid var(--color-copper);
  border-radius: 12px;
  padding: 40px 36px;
  text-align: center;
}

.download-version {
  margin-bottom: 20px;
}

.version-tag {
  display: inline-block;
  background: var(--color-bark);
  color: var(--color-paper);
  padding: 4px 14px;
  border-radius: 20px;
  font-size: 0.85rem;
  font-weight: 600;
  margin-right: 8px;
}

.download-specs {
  list-style: none;
  text-align: left;
  margin-bottom: 28px;
  display: inline-block;
}

.download-specs li {
  padding: 6px 0;
  font-size: 0.9rem;
  color: var(--color-stone);
}

.btn-large {
  padding: 16px 40px;
  font-size: 1.1rem;
}

.download-note {
  margin-top: 14px;
  font-size: 0.82rem;
  color: var(--color-stone-light);
}

.mirror-link {
  color: var(--color-stone);
  text-decoration: underline;
}

/* === 页脚 === */
.site-footer {
  text-align: center;
  padding: 32px 24px;
  border-top: 1px solid var(--color-copper-light);
  font-size: 0.82rem;
  color: var(--color-stone-light);
}

/* === 滚动入场动画 === */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

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

/* 延迟动画（卡片逐个浮现） */
.feature-card:nth-child(1) { transition-delay: 0s; }
.feature-card:nth-child(2) { transition-delay: 0.08s; }
.feature-card:nth-child(3) { transition-delay: 0.16s; }
.feature-card:nth-child(4) { transition-delay: 0.08s; }
.feature-card:nth-child(5) { transition-delay: 0.16s; }
.feature-card:nth-child(6) { transition-delay: 0.24s; }

/* === 响应式 — 平板端 === */
@media (max-width: 1024px) {
  .features-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 18px;
  }

  .screenshots-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 18px;
  }

  .tech-flow {
    gap: 8px;
  }

  .tech-node {
    min-width: 120px;
    padding: 16px 12px;
  }
  .tech-node strong { font-size: 0.85rem; }
  .tech-node p { font-size: 0.72rem; }

  .section { padding: 60px 20px; }
}

/* === 响应式 — 手机端 === */
@media (max-width: 768px) {
  :root {
    --nav-height: 56px;
  }

  html { font-size: 15px; }

  .features-grid,
  .screenshots-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .hero {
    min-height: 90vh;
    padding: calc(var(--nav-height) + 20px) 16px 40px;
    background-attachment: scroll; /* iOS 不支持 fixed */
  }

  .hero-title { font-size: 1.7rem; letter-spacing: 1px; }
  .hero-desc { font-size: 0.9rem; }
  .hero-actions { flex-direction: column; align-items: center; }

  .section { padding: 48px 16px; }
  .section-title { font-size: 1.5rem; }

  /* 导航栏移动端适配 */
  .nav-toggle {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    background: none;
    border: 1px solid var(--color-copper);
    border-radius: 4px;
    cursor: pointer;
    padding: 0;
  }

  .hamburger {
    display: block;
    width: 20px;
    height: 2px;
    background: var(--color-bark);
    position: relative;
    transition: background 0.2s;
  }
  .hamburger::before,
  .hamburger::after {
    content: '';
    position: absolute;
    left: 0;
    width: 20px;
    height: 2px;
    background: var(--color-bark);
    transition: transform 0.2s;
  }
  .hamburger::before { top: -6px; }
  .hamburger::after { top: 6px; }

  .nav-menu {
    display: none;
    position: absolute;
    top: var(--nav-height);
    left: 0;
    right: 0;
    flex-direction: column;
    background: rgba(250, 246, 238, 0.98);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--color-copper);
    padding: 12px 20px;
    gap: 4px;
  }

  .nav-menu.nav-open {
    display: flex;
  }

  .nav-link { width: 100%; padding: 12px 16px; }
  .nav-cta { margin-left: 0; text-align: center; }

  /* 技术流程改为纵向 */
  .tech-flow {
    flex-direction: column;
    align-items: center;
  }

  .tech-arrow {
    transform: rotate(90deg);
    margin: 0;
  }

  .download-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .download-box {
    padding: 28px 20px;
    border-radius: 8px;
  }
}