/* ============ 基础 ============ */
* { margin: 0; padding: 0; box-sizing: border-box; }

:root {
  --bg: #faf9f7;
  --bg-alt: #f3f2ef;
  --card: #ffffff;
  --border: #e3e1dc;
  --border-hover: #cfccc5;
  --text: #1a1a1a;
  --text-body: #3d3d3d;
  --text-dim: #8a8780;
  --accent: #2b2b2b;
  --accent-hover: #1a1a1a;
  --shadow-hover: 0 12px 32px rgba(0,0,0,0.08);
}

html { scroll-behavior: smooth; }

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  background: var(--bg);
  color: var(--text-body);
  line-height: 1.7;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
}

/* ============ 光标 ============ */
h1, h2, h3, span, div { cursor: default; user-select: none; }
p { cursor: text; user-select: text; }
a, button, .btn, .project-card, .community-card, .hero-img { cursor: pointer; }

/* ============ 入场动画 ============ */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.7s ease, transform 0.7s cubic-bezier(.2,.8,.2,1);
}
.reveal.on { opacity: 1; transform: translateY(0); }
.delay-1 { transition-delay: 0.08s; }
.delay-2 { transition-delay: 0.16s; }
.delay-3 { transition-delay: 0.24s; }
.delay-4 { transition-delay: 0.32s; }

/* ============ 导航 ============ */
.header {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  background: rgba(250, 249, 247, 0.85);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  transition: background 0.2s;
}

.nav {
  max-width: 1100px;
  margin: 0 auto;
  padding: 18px 32px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  font-size: 20px;
  font-weight: 600;
  letter-spacing: -0.3px;
  color: var(--text);
  text-decoration: none;
}

.nav-menu {
  display: flex;
  gap: 32px;
  list-style: none;
}

.nav-menu a {
  color: var(--text-dim);
  text-decoration: none;
  font-size: 15px;
  transition: color 0.2s;
}

.nav-menu a:hover { color: var(--text); }

/* ============ Hero ============ */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding: 120px 32px 80px;
}

.hero-content {
  max-width: 1100px;
  width: 100%;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
}

.hero-text { padding-bottom: 20px; }

.hero h1 {
  font-size: clamp(48px, 7vw, 80px);
  font-weight: 700;
  letter-spacing: -2.5px;
  margin-bottom: 24px;
  color: var(--text);
}

.hero p {
  font-size: 18px;
  color: var(--text-dim);
  max-width: 520px;
  margin-bottom: 48px;
}

.hero-actions {
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
  margin-top: 20px;
}

/* ============ Hero 右侧宣传图 ============ */
.hero-visual {
  display: flex;
  justify-content: center;
  align-items: center;
}

.hero-img {
  width: 100%;
  max-width: 520px;
  height: auto;
  border-radius: 12px;
  border: 1px solid var(--border);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.05);
  transition: transform 0.4s cubic-bezier(.2,.8,.2,1),
              box-shadow 0.4s ease,
              border-color 0.4s ease;
  display: block;
}

.hero-img:hover {
  transform: translateY(-8px) scale(1.03);
  box-shadow: 0 20px 48px rgba(0, 0, 0, 0.12);
  border-color: var(--border-hover);
}

/* ============ 按钮 ============ */
.btn {
  display: inline-block;
  padding: 12px 26px;
  font-size: 15px;
  font-weight: 500;
  text-decoration: none;
  border-radius: 6px;
  transition: background 0.2s, transform 0.2s, border-color 0.2s;
  border: 1px solid transparent;
}

.btn-primary { background: var(--accent); color: #faf9f7; }
.btn-primary:hover { background: var(--accent-hover); transform: translateY(-2px); }

.btn-secondary {
  background: transparent;
  color: var(--text-body);
  border-color: var(--border);
}
.btn-secondary:hover {
  border-color: var(--border-hover);
  background: rgba(0, 0, 0, 0.02);
  transform: translateY(-2px);
}

/* ============ 区块 ============ */
.section { padding: 100px 32px; }
.section-alt { background: var(--bg-alt); }
.container { max-width: 1100px; margin: 0 auto; }

.section h2 {
  font-size: 30px;
  font-weight: 600;
  margin-bottom: 12px;
  letter-spacing: -0.5px;
  color: var(--text);
}

.section-desc {
  color: var(--text-dim);
  max-width: 600px;
  margin-bottom: 48px;
}

/* ============ 项目卡片（极简） ============ */
.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 20px;
}

.project-card {
  padding: 32px 28px;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 10px;
  transition: border-color 0.25s, transform 0.25s, box-shadow 0.25s;
  display: flex;
  flex-direction: column;
}

.project-card:hover {
  border-color: var(--border-hover);
  transform: translateY(-4px);
  box-shadow: var(--shadow-hover);
}

.project-card h3 {
  font-size: 20px;
  font-weight: 600;
  margin-bottom: 12px;
  color: var(--text);
}

.project-card p {
  color: var(--text-dim);
  font-size: 14px;
  margin-bottom: 24px;
  flex-grow: 1;
}

.project-footer {
  padding-top: 18px;
  border-top: 1px solid var(--border);
}

.project-card a {
  color: var(--text-body);
  text-decoration: none;
  font-size: 14px;
  font-weight: 500;
  transition: color 0.2s;
}

.project-card a:hover { color: var(--text); }

/* ============ 社区卡片 ============ */
.community-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 16px;
}

.community-card {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 20px 24px;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 10px;
  text-decoration: none;
  color: inherit;
  transition: border-color 0.25s, transform 0.25s, box-shadow 0.25s;
}

.community-card:hover {
  border-color: var(--border-hover);
  transform: translateY(-3px);
  box-shadow: var(--shadow-hover);
}

.community-icon {
  width: 42px;
  height: 42px;
  border-radius: 10px;
  background: var(--bg-alt);
  border: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 16px;
  color: var(--text);
  flex-shrink: 0;
}

.community-body { flex-grow: 1; min-width: 0; }
.community-body h3 {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 2px;
  color: var(--text);
}
.community-body p {
  font-size: 13px;
  color: var(--text-dim);
  margin: 0;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.copy-qq {
  cursor: pointer;
  transition: color 0.2s;
  user-select: none;
}
.copy-qq:hover { color: var(--text); }

.community-card .arrow {
  color: var(--text-dim);
  font-size: 16px;
  transition: transform 0.25s, color 0.25s;
}

.community-card:hover .arrow {
  transform: translateX(4px);
  color: var(--text);
}

.community-card.sponsor .community-icon {
  background: #fdecec;
  color: #c0392b;
  border-color: #f5d2d2;
}

/* ============ 复制提示 ============ */
.toast {
  position: fixed;
  left: 50%;
  bottom: 40px;
  transform: translateX(-50%) translateY(20px);
  background: var(--text);
  color: #faf9f7;
  padding: 10px 22px;
  font-size: 14px;
  border-radius: 6px;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.25s, transform 0.25s;
  z-index: 999;
}
.toast.show {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

/* ============ 页脚 ============ */
.footer {
  padding: 40px 32px;
  border-top: 1px solid var(--border);
  text-align: center;
  color: var(--text-dim);
  font-size: 14px;
}

/* ============ 响应式 ============ */
@media (max-width: 900px) {
  .hero-content {
    grid-template-columns: 1fr;
    gap: 40px;
  }
  .hero-visual { order: -1; }
  .hero-img { max-width: 100%; }
}

@media (max-width: 640px) {
  .nav { padding: 16px 20px; }
  .nav-menu { gap: 18px; }
  .nav-menu a { font-size: 13px; }
  .hero { padding: 100px 20px 60px; }
  .hero h1 { letter-spacing: -1.5px; }
  .hero-actions { margin-top: 20px; }
  .section { padding: 70px 20px; }
}