/* =============================================
   开云app — 暖砂纸风格设计系统
   Awwwards-inspired unique design language
   ============================================= */

:root {
  --bg-warm: #faf7f2;
  --bg-warm-alt: #f3ede4;
  --bg-sand: #ede4d8;
  --terracotta: #c47f5a;
  --terracotta-dark: #b06d4a;
  --terracotta-light: #f0d9cb;
  --sage: #7a9b7e;
  --sage-dark: #5f7d63;
  --sage-light: #e4efe5;
  --amber: #d4a853;
  --amber-light: #fdf3dc;
  --brown-deep: #3d322b;
  --brown-mid: #6b5d53;
  --brown-light: #9a8c82;
  --linen: #e8e0d5;
  --linen-light: #f0ebe3;
  --white-soft: #fffdf9;
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --radius-xl: 28px;
  --shadow-card: 0 1px 3px rgba(61, 50, 43, 0.06), 0 4px 12px rgba(61, 50, 43, 0.04);
  --shadow-card-hover: 0 2px 6px rgba(61, 50, 43, 0.08), 0 8px 24px rgba(61, 50, 43, 0.07);
  --shadow-lg: 0 4px 20px rgba(61, 50, 43, 0.08), 0 12px 40px rgba(61, 50, 43, 0.05);
  --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-smooth: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
  font-family: system-ui, 'PingFang SC', 'Microsoft YaHei', 'Noto Sans SC', sans-serif;
  overflow-x: hidden;
  background: var(--bg-warm);
  color: var(--brown-deep);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body::before {
  content: '';
  position: fixed;
  top: -40%;
  right: -20%;
  width: 70vw;
  height: 70vw;
  background: radial-gradient(ellipse at center, rgba(122, 155, 126, 0.04) 0%, transparent 70%);
  pointer-events: none;
  z-index: 0;
  border-radius: 50%;
}

body::after {
  content: '';
  position: fixed;
  bottom: -30%;
  left: -15%;
  width: 60vw;
  height: 60vw;
  background: radial-gradient(ellipse at center, rgba(196, 127, 90, 0.03) 0%, transparent 70%);
  pointer-events: none;
  z-index: 0;
  border-radius: 50%;
}

/* 核心布局 */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
  position: relative;
  z-index: 1;
}

.section {
  padding: 80px 0;
  position: relative;
}

.section:nth-child(even) {
  background: var(--bg-warm-alt);
  position: relative;
}

.section:nth-child(even)::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: 
    radial-gradient(circle at 15% 50%, rgba(122, 155, 126, 0.03) 0%, transparent 50%),
    radial-gradient(circle at 85% 30%, rgba(212, 168, 83, 0.03) 0%, transparent 50%);
  pointer-events: none;
}

/* 导航 */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1000;
  background: rgba(250, 247, 242, 0.92);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--linen);
  transition: var(--transition-smooth);
}

.site-header.scrolled {
  box-shadow: 0 1px 8px rgba(61, 50, 43, 0.06);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 68px;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 1.2rem;
  text-decoration: none;
  color: var(--brown-deep);
  letter-spacing: -0.01em;
  transition: var(--transition-fast);
}

.logo:hover {
  color: var(--terracotta);
}

.logo-icon {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1rem;
  background: linear-gradient(135deg, var(--terracotta) 0%, #d4956f 100%);
  color: #fff;
  font-weight: 800;
  box-shadow: 0 2px 8px rgba(196, 127, 90, 0.25);
}

.main-nav {
  display: flex;
  align-items: center;
  gap: 32px;
  list-style: none;
}

.main-nav a {
  text-decoration: none;
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--brown-mid);
  transition: var(--transition-fast);
  position: relative;
  padding: 4px 0;
}

.main-nav a::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--terracotta);
  border-radius: 2px;
  transition: width var(--transition-smooth);
}

.main-nav a:hover {
  color: var(--terracotta);
}

.main-nav a:hover::after {
  width: 100%;
}

.nav-cta {
  padding: 8px 22px !important;
  border-radius: 24px !important;
  color: #fff !important;
  font-weight: 600 !important;
  background: linear-gradient(135deg, var(--terracotta) 0%, #d48a65 100%);
  box-shadow: 0 2px 10px rgba(196, 127, 90, 0.3);
  transition: var(--transition-smooth) !important;
}

.nav-cta:hover {
  background: linear-gradient(135deg, var(--terracotta-dark) 0%, #c47f5a 100%) !important;
  box-shadow: 0 4px 16px rgba(196, 127, 90, 0.4) !important;
  transform: translateY(-1px);
}

.nav-cta::after {
  display: none !important;
}

.menu-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
  color: var(--brown-deep);
  font-size: 1.5rem;
  line-height: 1;
}

/* 首页Hero */
.hero {
  min-height: 70vh;
  display: flex;
  align-items: center;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -120px;
  right: -80px;
  width: 500px;
  height: 500px;
  background: radial-gradient(circle, rgba(122, 155, 126, 0.06) 0%, transparent 70%);
  border-radius: 50%;
  pointer-events: none;
}

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

.hero-eyebrow {
  display: inline-block;
  font-size: 0.85rem;
  font-weight: 600;
  padding: 5px 16px;
  border-radius: 20px;
  margin-bottom: 18px;
  background: var(--sage-light);
  color: var(--sage-dark);
  letter-spacing: 0.04em;
}

.hero h1 {
  font-size: 3.2rem;
  line-height: 1.15;
  margin-bottom: 22px;
  font-weight: 800;
  letter-spacing: -0.03em;
  color: var(--brown-deep);
}

.hero h1 .highlight {
  color: var(--terracotta);
  position: relative;
  display: inline-block;
}

.hero h1 .highlight::after {
  content: '';
  position: absolute;
  bottom: 4px;
  left: 0;
  width: 100%;
  height: 8px;
  background: var(--terracotta-light);
  border-radius: 4px;
  z-index: -1;
  opacity: 0.6;
}

.hero p {
  font-size: 1.15rem;
  opacity: 0.75;
  max-width: 560px;
  margin-bottom: 36px;
  color: var(--brown-mid);
  line-height: 1.7;
}

.hero-buttons {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

.hero-image {
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-lg);
  position: relative;
}

.hero-image::after {
  content: '';
  position: absolute;
  inset: 0;
  border-radius: var(--radius-lg);
  border: 1px solid rgba(232, 224, 213, 0.5);
  pointer-events: none;
}

.hero-image img {
  width: 100%;
  height: auto;
  display: block;
}

/* 按钮 */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 28px;
  border-radius: 24px;
  font-weight: 600;
  cursor: pointer;
  border: none;
  text-decoration: none;
  transition: var(--transition-smooth);
  font-size: 0.95rem;
  letter-spacing: 0.01em;
  position: relative;
  overflow: hidden;
}

.btn::before {
  content: '';
  position: absolute;
  inset: 0;
  opacity: 0;
  transition: opacity var(--transition-fast);
  border-radius: 24px;
}

.btn:hover::before {
  opacity: 1;
}

.btn-primary {
  color: #fff;
  background: linear-gradient(135deg, var(--terracotta) 0%, #d48a65 100%);
  box-shadow: 0 3px 14px rgba(196, 127, 90, 0.3);
}

.btn-primary:hover {
  box-shadow: 0 6px 22px rgba(196, 127, 90, 0.4);
  transform: translateY(-2px);
}

.btn-outline {
  background: transparent;
  border: 1.5px solid var(--terracotta);
  color: var(--terracotta);
}

.btn-outline:hover {
  background: var(--terracotta);
  color: #fff;
  border-color: var(--terracotta);
  transform: translateY(-2px);
  box-shadow: 0 4px 16px rgba(196, 127, 90, 0.25);
}

/* 标签/标题 */
.section-label {
  display: inline-block;
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 2.5px;
  margin-bottom: 12px;
  text-transform: uppercase;
  color: var(--terracotta);
}

.section-title {
  font-size: 2.2rem;
  margin-bottom: 16px;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--brown-deep);
  line-height: 1.25;
}

.section-desc {
  max-width: 600px;
  opacity: 0.7;
  margin-bottom: 44px;
  color: var(--brown-mid);
  font-size: 1.05rem;
  line-height: 1.7;
}

/* 卡片网格 */
.cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 24px;
}

.category-card {
  border-radius: var(--radius-md);
  padding: 30px 28px;
  border: 1px solid var(--linen);
  transition: var(--transition-smooth);
  background: var(--white-soft);
  position: relative;
  overflow: hidden;
}

.category-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 3px;
  background: linear-gradient(90deg, var(--terracotta), var(--amber));
  opacity: 0;
  transition: opacity var(--transition-smooth);
  border-radius: 0 0 3px 3px;
}

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

.category-card:hover::before {
  opacity: 1;
}

.card-icon {
  width: 48px;
  height: 48px;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 18px;
  font-size: 1.4rem;
  background: var(--sage-light);
  color: var(--sage-dark);
  transition: var(--transition-smooth);
}

.category-card:hover .card-icon {
  background: var(--sage);
  color: #fff;
  transform: scale(1.05);
}

.category-card h3 {
  font-size: 1.1rem;
  margin-bottom: 8px;
  color: var(--brown-deep);
  font-weight: 600;
}

.category-card p {
  font-size: 0.9rem;
  color: var(--brown-mid);
  opacity: 0.8;
  line-height: 1.6;
  margin-bottom: 14px;
}

.card-link {
  font-weight: 600;
  font-size: 0.85rem;
  text-decoration: none;
  color: var(--terracotta);
  display: inline-flex;
  align-items: center;
  gap: 4px;
  transition: var(--transition-fast);
}

.card-link:hover {
  gap: 8px;
  color: var(--terracotta-dark);
}

/* 特性块 */
.feature-block {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 56px;
  align-items: center;
}

.feature-image {
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-lg);
  position: relative;
}

.feature-image::after {
  content: '';
  position: absolute;
  inset: 0;
  border-radius: var(--radius-lg);
  border: 1px solid rgba(232, 224, 213, 0.4);
  pointer-events: none;
}

.feature-image img {
  width: 100%;
  height: auto;
  display: block;
  transition: transform 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

.feature-image:hover img {
  transform: scale(1.03);
}

.feature-text h3 {
  font-size: 1.5rem;
  margin-bottom: 12px;
  color: var(--brown-deep);
  font-weight: 700;
}

.feature-text p {
  color: var(--brown-mid);
  opacity: 0.8;
  line-height: 1.7;
  margin-bottom: 18px;
}

.feature-list {
  list-style: none;
}

.feature-list li {
  padding: 8px 0;
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--brown-mid);
  font-size: 0.95rem;
}

.feature-list li::before {
  content: '✓';
  font-weight: 700;
  color: var(--sage);
  font-size: 0.9rem;
  width: 24px;
  height: 24px;
  border-radius: 50%;
  background: var(--sage-light);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

/* 数据条 */
.stats-bar {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  text-align: center;
}

.stat-item {
  padding: 28px 20px;
  border-radius: var(--radius-md);
  border: 1px solid var(--linen);
  background: var(--white-soft);
  transition: var(--transition-smooth);
  position: relative;
}

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

.stat-number {
  font-size: 2.4rem;
  font-weight: 800;
  color: var(--terracotta);
  letter-spacing: -0.03em;
  line-height: 1;
}

.stat-label {
  font-size: 0.9rem;
  opacity: 0.65;
  margin-top: 8px;
  color: var(--brown-mid);
  font-weight: 500;
}

/* 内容墙 */
.content-wall {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 24px;
}

.content-wall-item {
  border-radius: var(--radius-md);
  overflow: hidden;
  border: 1px solid var(--linen);
  transition: var(--transition-smooth);
  background: var(--white-soft);
  cursor: pointer;
}

.content-wall-item:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-card-hover);
  border-color: transparent;
}

.content-wall-item img {
  width: 100%;
  height: 200px;
  object-fit: cover;
  transition: transform 0.5s ease;
}

.content-wall-item:hover img {
  transform: scale(1.05);
}

.content-wall-body {
  padding: 22px 20px;
}

.content-wall-body h3 {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--brown-deep);
  margin-bottom: 6px;
}

.content-wall-body p {
  font-size: 0.88rem;
  color: var(--brown-mid);
  opacity: 0.75;
  line-height: 1.5;
}

/* FAQ */
.faq-list {
  max-width: 800px;
  margin: 0 auto;
}

.faq-item {
  border: 1px solid var(--linen);
  border-radius: 10px;
  margin-bottom: 10px;
  overflow: hidden;
  cursor: pointer;
  background: var(--white-soft);
  transition: var(--transition-fast);
}

.faq-item:hover {
  border-color: var(--terracotta-light);
}

.faq-item .faq-question {
  padding: 18px 22px;
  font-weight: 600;
  display: flex;
  justify-content: space-between;
  align-items: center;
  color: var(--brown-deep);
  font-size: 1rem;
}

.faq-item .faq-question::after {
  content: '+';
  font-size: 1.3rem;
  font-weight: 400;
  color: var(--terracotta);
  transition: transform var(--transition-smooth);
  flex-shrink: 0;
  margin-left: 12px;
}

.faq-item.open .faq-question::after {
  transform: rotate(45deg);
}

.faq-item .faq-answer {
  padding: 0 22px 18px;
  display: none;
  opacity: 0.7;
  color: var(--brown-mid);
  line-height: 1.7;
  font-size: 0.95rem;
}

.faq-item.open {
  border-color: var(--terracotta-light);
  background: #fefcfa;
}

.faq-item.open .faq-answer {
  display: block;
}

/* CTA横幅 */
.cta-banner {
  padding: 60px 24px;
  text-align: center;
  border-radius: var(--radius-xl);
  color: #fff;
  background: linear-gradient(135deg, #6a8b6e 0%, var(--sage) 30%, #8aab8e 70%, #6d9071 100%);
  position: relative;
  overflow: hidden;
}

.cta-banner::before {
  content: '';
  position: absolute;
  top: -60px;
  right: -40px;
  width: 200px;
  height: 200px;
  background: rgba(255, 255, 255, 0.06);
  border-radius: 50%;
  pointer-events: none;
}

.cta-banner::after {
  content: '';
  position: absolute;
  bottom: -40px;
  left: -30px;
  width: 160px;
  height: 160px;
  background: rgba(255, 255, 255, 0.04);
  border-radius: 50%;
  pointer-events: none;
}

.cta-banner h2 {
  color: #fff;
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 12px;
  position: relative;
  z-index: 1;
}

.cta-banner p {
  color: rgba(255, 255, 255, 0.85);
  margin-bottom: 28px;
  position: relative;
  z-index: 1;
  font-size: 1.05rem;
}

.cta-banner .btn-primary {
  background: #fff;
  color: var(--sage-dark);
  box-shadow: 0 4px 18px rgba(0, 0, 0, 0.12);
  position: relative;
  z-index: 1;
  font-weight: 700;
}

.cta-banner .btn-primary:hover {
  background: #fefdfa;
  box-shadow: 0 6px 24px rgba(0, 0, 0, 0.18);
  transform: translateY(-2px);
  color: var(--sage-dark);
}

/* 页脚 */
.site-footer {
  padding: 60px 0 28px;
  background: var(--bg-warm-alt);
  border-top: 1px solid var(--linen);
  position: relative;
}

.site-footer .container {
  position: relative;
  z-index: 1;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
}

.footer-brand .logo {
  margin-bottom: 12px;
  font-size: 1.15rem;
}

.footer-brand p {
  color: var(--brown-mid);
  opacity: 0.7;
  font-size: 0.9rem;
  line-height: 1.6;
}

.footer-col h4 {
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--brown-deep);
  margin-bottom: 16px;
  letter-spacing: 0.03em;
}

.footer-col ul {
  list-style: none;
}

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

.footer-col ul li a {
  text-decoration: none;
  color: var(--brown-mid);
  font-size: 0.88rem;
  transition: var(--transition-fast);
  opacity: 0.75;
}

.footer-col ul li a:hover {
  color: var(--terracotta);
  opacity: 1;
  padding-left: 4px;
}

.footer-bottom {
  border-top: 1px solid var(--linen);
  margin-top: 40px;
  padding-top: 20px;
  text-align: center;
  font-size: 0.85rem;
  color: var(--brown-light);
}

/* 工具类 */
.text-accent {
  color: var(--terracotta);
}

.text-center {
  text-align: center;
}

.seo-description {
  max-width: 600px;
  margin: 0 auto 48px;
  opacity: 0.7;
  color: var(--brown-mid);
  text-align: center;
  line-height: 1.7;
}

.mt-0 {
  margin-top: 0;
}

.mb-0 {
  margin-bottom: 0;
}

/* 响应式 */
@media (max-width: 1024px) {
  .hero h1 {
    font-size: 2.6rem;
  }
  
  .section-title {
    font-size: 1.8rem;
  }
  
  .footer-grid {
    grid-template-columns: 1fr 1fr;
    gap: 32px;
  }
}

@media (max-width: 768px) {
  .feature-block {
    grid-template-columns: 1fr;
    gap: 32px;
  }
  
  .stats-bar {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }
  
  .main-nav {
    display: none;
  }
  
  .menu-toggle {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    border-radius: var(--radius-sm);
    border: 1px solid var(--linen);
    background: var(--white-soft);
  }
  
  .main-nav.open {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: 68px;
    left: 0;
    width: 100%;
    background: rgba(250, 247, 242, 0.98);
    padding: 24px;
    gap: 0;
    border-bottom: 1px solid var(--linen);
    box-shadow: var(--shadow-lg);
    backdrop-filter: blur(12px);
  }
  
  .main-nav.open li {
    width: 100%;
  }
  
  .main-nav.open a {
    display: block;
    padding: 14px 8px;
    border-bottom: 1px solid var(--linen-light);
    font-size: 1rem;
  }
  
  .main-nav.open a:last-child {
    border-bottom: none;
  }
  
  .main-nav.open .nav-cta {
    margin-top: 8px;
    text-align: center;
  }
  
  .hero {
    min-height: 60vh;
    padding-top: 40px;
  }
  
  .hero h1 {
    font-size: 2.2rem;
  }
  
  .hero p {
    font-size: 1rem;
  }
  
  .section {
    padding: 56px 0;
  }
  
  .cta-banner {
    padding: 40px 20px;
  }
  
  .cta-banner h2 {
    font-size: 1.5rem;
  }
}

@media (max-width: 480px) {
  .cards-grid,
  .content-wall,
  .stats-bar {
    grid-template-columns: 1fr;
  }
  
  .footer-grid {
    grid-template-columns: 1fr;
    gap: 24px;
  }
  
  .hero-buttons {
    flex-direction: column;
    width: 100%;
  }
  
  .hero-buttons .btn {
    width: 100%;
    justify-content: center;
  }
  
  .hero h1 {
    font-size: 1.8rem;
  }
  
  .section-title {
    font-size: 1.5rem;
  }
  
  .hero-eyebrow {
    font-size: 0.75rem;
  }
  
  .stat-number {
    font-size: 1.8rem;
  }
  
  .header-inner {
    padding: 0 16px;
  }
  
  .container {
    padding: 0 16px;
  }
  
  .category-card {
    padding: 22px 18px;
  }
  
  .content-wall-body {
    padding: 16px 14px;
  }
  
  .feature-block {
    gap: 24px;
  }
}