:root {
  --primary-color: #6366f1;
  --primary-dark: #4f46e5;
  --secondary-color: #8b5cf6;
  --accent-color: #ec4899;
  --text-primary: #1f2937;
  --text-secondary: #6b7280;
  --bg-light: #f9fafb;
  --bg-white: #ffffff;
  --border-color: #e5e7eb;
  --success-color: #10b981;
  --gradient-1: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  --gradient-2: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
  --gradient-3: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
  --section-gap: 48px;
  --card-radius: 16px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
  line-height: 1.6;
  color: var(--text-primary);
  background: var(--bg-light);
  position: relative;
}

a { color: var(--primary-color); text-decoration: none; }
a:hover { text-decoration: underline; }

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 24px 16px;
}

/* ============================================
   导航栏
   ============================================ */
.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 18px 0;
  margin-bottom: var(--section-gap);
}

.brand {
  display: inline-flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 4px;
  font-weight: 800;
  letter-spacing: 0.2px;
  color: var(--primary-color);
  text-decoration: none;
}

.brand span:first-child {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.2em;
}

.brand-tagline {
  font-size: 0.75em;
  color: var(--text-secondary);
  font-weight: normal;
}

.nav {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 14px;
  font-size: 14px;
}

.nav a {
  color: var(--text-secondary);
  padding: 8px 12px;
  border: 1px solid transparent;
  border-radius: 999px;
  transition: all 0.2s ease;
}
.nav a:hover {
  color: var(--primary-color);
  border-color: var(--border-color);
  background: rgba(255, 255, 255, 0.04);
  text-decoration: none;
}

/* ============================================
   Hero区域
   ============================================ */
.hero-prototype {
  padding: 60px 24px;
  text-align: center;
  background: var(--bg-white);
  border: 1px solid var(--border-color);
  border-radius: var(--card-radius);
  margin-bottom: var(--section-gap);
  box-shadow: var(--shadow-md);
  position: relative;
  overflow: hidden;
}

.hero-content-prototype {
  position: relative;
  z-index: 1;
  max-width: 800px;
  margin: 0 auto;
}

.hero-title {
  margin: 0 0 24px 0;
  font-size: clamp(32px, 5vw, 48px);
  line-height: 1.2;
  letter-spacing: -0.5px;
  color: var(--text-primary);
  font-weight: 700;
}

.hero-subtitle {
  margin: 0 0 32px 0;
  font-size: clamp(18px, 2.5vw, 24px);
  line-height: 1.6;
  color: var(--text-secondary);
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

/* ============================================
   核心理念区域
   ============================================ */
.concepts-prototype {
  padding: 48px 24px;
  background: rgba(255, 255, 255, 0.6);
  backdrop-filter: blur(8px);
  border-radius: var(--card-radius);
  margin-bottom: var(--section-gap);
}

.concepts-container-prototype {
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
  max-width: 900px;
  margin: 0 auto;
  margin-top: 32px;
}

@media (min-width: 768px) {
  .concepts-container-prototype {
    grid-template-columns: repeat(2, 1fr);
  }
}

.concept-text-prototype {
  margin: 0;
  color: var(--text-secondary);
  font-size: 16px;
  line-height: 1.8;
  text-align: left;
}

/* ============================================
   需求层次区域 - 金字塔（左）+ 描述（右）
   ============================================ */
.needs-prototype {
  padding: 48px 24px;
  background: rgba(255, 255, 255, 0.6);
  backdrop-filter: blur(8px);
  border-radius: var(--card-radius);
  margin-bottom: var(--section-gap);
}

.needs-layout-prototype {
  display: flex;
  align-items: stretch;
  gap: 28px;
  margin-top: 32px;
  max-width: 820px;
  margin-left: auto;
  margin-right: auto;
}

.pyramid-wrapper {
  flex: 0 0 340px;
  display: flex;
  flex-direction: column;
  gap: 2px;
  aspect-ratio: 4 / 3;
  clip-path: polygon(35% 0%, 65% 0%, 100% 100%, 0% 100%);
}

.pyramid-level {
  flex: 1;
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 8px;
  color: white;
  transition: filter 0.2s ease;
  cursor: default;
}

.pyramid-level:hover { filter: brightness(1.1); }

.pyramid-level.level-1 { background: #a855f7; }
.pyramid-level.level-2 { background: #7c3aed; }
.pyramid-level.level-3 { background: #6366f1; }
.pyramid-level.level-4 { background: #3b82f6; }
.pyramid-level.level-5 { background: #0ea5e9; }
.pyramid-level.level-6 { background: #06b6d4; }

.need-icon {
  font-size: 1.2em;
  line-height: 1;
  flex-shrink: 0;
}

.need-title {
  margin: 0;
  font-size: 0.9em;
  color: white;
  font-weight: 700;
  white-space: nowrap;
}

.desc-wrapper {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.desc-item {
  flex: 1;
  display: flex;
  align-items: center;
  padding-left: 12px;
  border-left: 3px solid transparent;
}

.desc-item .desc-text {
  font-size: 0.9em;
  color: var(--text-secondary);
  line-height: 1.4;
}

.desc-item.desc-1 { border-left-color: #a855f7; }
.desc-item.desc-2 { border-left-color: #7c3aed; }
.desc-item.desc-3 { border-left-color: #6366f1; }
.desc-item.desc-4 { border-left-color: #3b82f6; }
.desc-item.desc-5 { border-left-color: #0ea5e9; }
.desc-item.desc-6 { border-left-color: #06b6d4; }

@media (max-width: 767px) {
  .needs-layout-prototype {
    flex-direction: column;
    align-items: center;
    gap: 20px;
  }

  .pyramid-wrapper {
    flex: none;
    width: 80%;
    max-width: 300px;
  }

  .desc-wrapper {
    width: 100%;
    gap: 8px;
  }

  .desc-item {
    flex: none;
    padding: 6px 12px;
  }

  .need-icon { font-size: 1em; }
  .need-title { font-size: 0.8em; }
}

/* ============================================
   价值主张预览区域
   ============================================ */
.values-preview-prototype {
  padding: 48px 24px;
  background: rgba(255, 255, 255, 0.6);
  backdrop-filter: blur(8px);
  border-radius: var(--card-radius);
  margin-bottom: var(--section-gap);
}

.values-preview-container-prototype {
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
  margin-top: 32px;
  max-width: 1000px;
  margin-left: auto;
  margin-right: auto;
}

@media (min-width: 768px) {
  .values-preview-container-prototype {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1024px) {
  .values-preview-container-prototype {
    grid-template-columns: repeat(3, 1fr);
  }
}

.value-card-prototype {
  background: rgba(255, 255, 255, 0.8);
  border: 1px solid var(--border-color);
  border-radius: var(--card-radius);
  padding: 24px;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
  backdrop-filter: blur(8px);
}

.value-card-prototype:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-lg);
}

.value-card-title {
  margin: 0 0 12px 0;
  font-size: 1.2em;
  color: var(--primary-color);
  font-weight: 600;
  line-height: 1.4;
}

.value-card-desc {
  margin: 0;
  font-size: 0.95em;
  color: var(--text-secondary);
  line-height: 1.6;
}

.values-preview-cta {
  text-align: center;
  margin-top: 32px;
}

/* ============================================
   智能体社群招募区域
   ============================================ */
.community-preview-prototype {
  margin-bottom: var(--section-gap);
}

.community-hero-card {
  background: var(--gradient-1);
  border-radius: var(--card-radius);
  padding: 48px 40px;
  color: white;
  text-align: center;
  box-shadow: var(--shadow-lg);
  margin-bottom: 20px;
}

.community-hero-card .community-title {
  margin: 0 0 16px 0;
  font-size: clamp(24px, 3vw, 32px);
  color: white;
  font-weight: 700;
}

.community-hero-card .community-subtitle {
  margin: 0 0 32px 0;
  font-size: 1.05em;
  color: rgba(255, 255, 255, 0.9);
  max-width: 620px;
  margin-left: auto;
  margin-right: auto;
  line-height: 1.7;
}

.community-steps {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
}

@media (min-width: 768px) {
  .community-steps {
    grid-template-columns: repeat(3, 1fr);
  }
}

.community-step {
  background: var(--bg-white);
  border: 1px solid var(--border-color);
  border-radius: var(--card-radius);
  padding: 28px 24px;
  text-align: center;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.community-step:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

.step-number {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: var(--gradient-1);
  color: white;
  font-weight: 700;
  font-size: 0.95em;
  margin-bottom: 14px;
}

.step-title {
  margin: 0 0 8px 0;
  font-size: 1.1em;
  font-weight: 700;
  color: var(--text-primary);
}

.step-desc {
  margin: 0;
  font-size: 0.9em;
  color: var(--text-secondary);
  line-height: 1.6;
}

@media (max-width: 767px) {
  .community-hero-card {
    padding: 36px 24px;
  }
}

/* ============================================
   Section标题样式
   ============================================ */
.section-title {
  margin: 0 0 32px 0;
  font-size: clamp(24px, 3vw, 32px);
  position: relative;
  display: inline-block;
  color: var(--primary-color);
  font-weight: 700;
}

.section-title::after {
  content: '';
  position: absolute;
  bottom: -8px;
  left: 0;
  width: 50px;
  height: 3px;
  background: var(--gradient-1);
  border-radius: 2px;
}

/* ============================================
   按钮样式
   ============================================ */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 12px 24px;
  border-radius: 12px;
  border: 1px solid var(--border-color);
  color: var(--text-primary);
  font-weight: 650;
  text-decoration: none;
  transition: all 0.2s ease;
  cursor: pointer;
}
.btn:hover {
  background: var(--bg-light);
  text-decoration: none;
}

.btn.primary {
  border-color: var(--primary-color);
  background: var(--gradient-1);
  color: white;
}
.btn.primary:hover {
  background: linear-gradient(135deg, #764ba2 0%, #667eea 100%);
}

.hero-cta {
  font-size: 18px;
  padding: 14px 36px;
}

.community-cta {
  font-size: 18px;
  padding: 14px 36px;
  background: white;
  color: var(--primary-color);
  border-color: white;
}

.community-cta:hover {
  background: rgba(255, 255, 255, 0.9);
  color: var(--primary-dark);
}

/* ============================================
   页脚
   ============================================ */
.footer {
  margin-top: var(--section-gap);
  padding-top: var(--section-gap);
  border-top: 1px solid var(--border-color);
  color: var(--text-secondary);
  font-size: 0.9em;
  background: rgba(255, 255, 255, 0.6);
  border-radius: var(--card-radius);
  backdrop-filter: blur(8px);
  padding: 24px;
}

.footer-content {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 32px;
  margin-bottom: 32px;
}

.footer-section h4 {
  margin: 0 0 16px 0;
  color: var(--text-primary);
  font-size: 1.1em;
}

.footer-section ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

.footer-section ul li {
  margin-bottom: 8px;
}

.footer-section ul li a {
  color: var(--text-secondary);
  text-decoration: none;
}

.footer-section ul li a:hover {
  color: var(--primary-color);
}

.footer-bottom {
  padding-top: 16px;
  border-top: 1px solid var(--border-color);
  text-align: center;
}

/* ============================================
   响应式调整
   ============================================ */
@media (max-width: 767px) {
  .hero-prototype {
    padding: 40px 20px;
  }

  .concepts-prototype,
  .needs-prototype,
  .values-preview-prototype {
    padding: 32px 20px;
  }

  .topbar {
    flex-direction: column;
    align-items: flex-start;
    gap: 20px;
  }

  .nav {
    width: 100%;
    justify-content: center;
  }
}