/* ================================================
   lutube娜娜 | 企业视觉设计系统
   风格定义：暖调现代主义 / Warm Modernist Editorial
   色彩体系：奶油纸白 · 珊瑚陶土 · 芥末黄 · 鼠尾草绿
   ================================================ */

:root {
  --bg-primary: #FBF6EF;
  --bg-soft: #F5EFE6;
  --bg-card: #FFFDF9;
  --bg-footer: #EDE3D6;
  --text-ink: #2D2A27;
  --text-medium: #6B6560;
  --text-light: #8A8378;
  --accent-coral: #FF6B4A;
  --accent-terracotta: #E85D3D;
  --accent-sage: #8AB17D;
  --accent-mustard: #F2C14E;
  --shadow-sm: 0 2px 8px rgba(45, 42, 39, 0.05);
  --shadow-md: 0 6px 20px rgba(45, 42, 39, 0.08);
  --shadow-lg: 0 16px 48px rgba(45, 42, 39, 0.1);
  --radius-sm: 10px;
  --radius-md: 18px;
  --radius-lg: 24px;
  --radius-pill: 50px;
}

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

body {
  font-family: system-ui, 'PingFang SC', 'Microsoft YaHei', sans-serif;
  overflow-x: hidden;
  background: var(--bg-primary);
  color: var(--text-ink);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

::selection {
  background: var(--accent-mustard);
  color: var(--text-ink);
}

::-webkit-scrollbar {
  width: 10px;
}
::-webkit-scrollbar-track {
  background: var(--bg-soft);
}
::-webkit-scrollbar-thumb {
  background: var(--accent-terracotta);
  border-radius: 5px;
}

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

a {
  color: inherit;
}

/* ================================================
   核心布局
   ================================================ */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

.section {
  padding: 100px 0;
  position: relative;
}

.section:nth-child(even) {
  background: var(--bg-soft);
}

/* ================================================
   导航 — 固定顶部
   ================================================ */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1000;
  background: rgba(251, 246, 239, 0.82);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: none;
  box-shadow: 0 1px 0 rgba(45, 42, 39, 0.05), 0 4px 24px rgba(45, 42, 39, 0.04);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 900;
  font-size: 1.25rem;
  text-decoration: none;
  color: var(--text-ink);
  letter-spacing: -0.02em;
}

.logo-icon {
  width: 40px;
  height: 40px;
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  background: linear-gradient(135deg, var(--accent-coral), var(--accent-terracotta));
  color: #fff;
  box-shadow: 0 4px 12px rgba(232, 93, 61, 0.35);
}

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

.main-nav a {
  text-decoration: none;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-ink);
  position: relative;
  padding: 4px 0;
  transition: color 0.25s;
  letter-spacing: 0.02em;
}

.main-nav a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2.5px;
  border-radius: 2px;
  background: linear-gradient(90deg, var(--accent-coral), var(--accent-mustard));
  transition: width 0.3s cubic-bezier(0.65, 0, 0.35, 1);
}

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

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

.nav-cta {
  padding: 10px 24px !important;
  border-radius: var(--radius-pill) !important;
  color: #FFFDF9 !important;
  font-weight: 700 !important;
  background: linear-gradient(135deg, var(--accent-coral), var(--accent-terracotta));
  box-shadow: 0 4px 12px rgba(232, 93, 61, 0.3);
  transition: transform 0.25s, box-shadow 0.25s !important;
}

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

.nav-cta:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(232, 93, 61, 0.4);
}

.menu-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 5px;
  width: 44px;
  height: 44px;
  background: var(--bg-soft);
  border: 1.5px solid #E0D8CC;
  border-radius: 12px;
  cursor: pointer;
  padding: 0;
}

.menu-toggle span {
  width: 18px;
  height: 2px;
  background: var(--text-ink);
  border-radius: 2px;
  transition: transform 0.25s;
}

/* ================================================
   首页Hero
   ================================================ */
.hero {
  position: relative;
  min-height: 85vh;
  display: flex;
  align-items: center;
  background: linear-gradient(175deg, var(--bg-primary) 0%, var(--bg-soft) 100%);
  overflow: hidden;
  padding: 140px 0 80px;
}

.hero::before {
  content: '';
  position: absolute;
  right: 4%;
  top: 18%;
  width: 340px;
  height: 340px;
  border-radius: 30% 70% 70% 30% / 30% 30% 70% 70%;
  background: linear-gradient(135deg, rgba(255, 107, 74, 0.18), rgba(242, 193, 78, 0.2));
  z-index: 0;
  animation: heroFloat 12s ease-in-out infinite;
}

.hero::after {
  content: '';
  position: absolute;
  right: 18%;
  bottom: 14%;
  width: 170px;
  height: 170px;
  border-radius: 70% 30% 50% 50% / 60% 40% 60% 40%;
  background: rgba(138, 177, 125, 0.2);
  z-index: 0;
  animation: heroFloat 15s ease-in-out infinite reverse;
}

@keyframes heroFloat {
  0%, 100% { transform: translateY(0) rotate(0deg); }
  50% { transform: translateY(-18px) rotate(3deg); }
}

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

.hero-eyebrow {
  display: inline-block;
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  padding: 7px 20px;
  border-radius: var(--radius-pill);
  margin-bottom: 20px;
  background: var(--accent-mustard);
  color: var(--text-ink);
  box-shadow: 0 2px 8px rgba(242, 193, 78, 0.35);
}

.hero h1 {
  font-size: clamp(2.4rem, 5.2vw, 3.8rem);
  line-height: 1.15;
  margin-bottom: 22px;
  font-weight: 900;
  letter-spacing: -0.03em;
  color: var(--text-ink);
}

.hero h1 .text-accent {
  background: linear-gradient(120deg, var(--accent-coral), var(--accent-terracotta));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero p {
  font-size: 1.1rem;
  opacity: 0.75;
  max-width: 560px;
  margin-bottom: 36px;
  color: var(--text-medium);
  line-height: 1.8;
}

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

.hero-image {
  position: relative;
  z-index: 2;
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-lg);
  border: 4px solid #fff;
}

.hero-image img {
  width: 100%;
  height: auto;
  transition: transform 0.6s ease;
}

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

/* ================================================
   按钮
   ================================================ */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 30px;
  border-radius: var(--radius-pill);
  font-weight: 700;
  cursor: pointer;
  border: none;
  text-decoration: none;
  transition: transform 0.25s, box-shadow 0.25s, background 0.25s;
  font-size: 0.95rem;
  letter-spacing: 0.02em;
}

.btn-primary {
  background: linear-gradient(135deg, var(--accent-coral), var(--accent-terracotta));
  color: #ffffff;
  box-shadow: 0 6px 18px rgba(232, 93, 61, 0.35);
}

.btn-primary:hover {
  transform: translateY(-3px);
  box-shadow: 0 10px 28px rgba(232, 93, 61, 0.45);
}

.btn-outline {
  background: transparent;
  border: 2px solid var(--text-ink);
  color: var(--text-ink);
}

.btn-outline:hover {
  background: var(--text-ink);
  color: var(--bg-primary);
  transform: translateY(-3px);
  box-shadow: 0 8px 20px rgba(45, 42, 39, 0.15);
}

/* ================================================
   标签 / 标题
   ================================================ */
.section-label {
  display: inline-block;
  font-size: 0.8rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  margin-bottom: 14px;
  text-transform: uppercase;
  color: var(--accent-terracotta);
  position: relative;
  padding-left: 36px;
}

.section-label::before {
  content: '';
  position: absolute;
  left: 0;
  top: 50%;
  width: 24px;
  height: 2.5px;
  border-radius: 3px;
  background: linear-gradient(90deg, var(--accent-coral), var(--accent-mustard));
}

.section-title {
  font-size: clamp(1.9rem, 3.5vw, 2.7rem);
  font-weight: 900;
  letter-spacing: -0.03em;
  margin-bottom: 16px;
  color: var(--text-ink);
  line-height: 1.2;
  position: relative;
}

.section-title::after {
  content: '';
  display: block;
  width: 56px;
  height: 4px;
  border-radius: 4px;
  background: linear-gradient(90deg, var(--accent-coral), var(--accent-mustard));
  margin-top: 16px;
}

.section-desc {
  max-width: 600px;
  opacity: 0.75;
  margin-bottom: 48px;
  color: var(--text-medium);
  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: 28px;
}

.category-card {
  background: var(--bg-card);
  border-radius: var(--radius-md);
  padding: 32px 28px;
  border: none;
  box-shadow: var(--shadow-sm);
  position: relative;
  overflow: hidden;
  transition: transform 0.3s, box-shadow 0.3s;
}

.category-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 4px;
  background: linear-gradient(90deg, var(--accent-coral), var(--accent-mustard));
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.4s cubic-bezier(0.65, 0, 0.35, 1);
}

.category-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-md);
}

.category-card:hover::before {
  transform: scaleX(1);
}

.card-icon {
  width: 52px;
  height: 52px;
  border-radius: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 18px;
  font-size: 1.4rem;
  background: linear-gradient(135deg, rgba(255, 107, 74, 0.12), rgba(242, 193, 78, 0.12));
  transition: transform 0.3s;
}

.category-card:hover .card-icon {
  transform: rotate(-6deg) scale(1.08);
}

.category-card h3 {
  font-size: 1.1rem;
  font-weight: 800;
  margin-bottom: 8px;
  color: var(--text-ink);
}

.category-card p {
  font-size: 0.9rem;
  color: var(--text-medium);
  margin-bottom: 16px;
  line-height: 1.6;
}

.card-link {
  font-weight: 700;
  font-size: 0.85rem;
  text-decoration: none;
  color: var(--accent-terracotta);
  display: inline-flex;
  align-items: center;
  gap: 6px;
  transition: gap 0.25s;
}

.card-link::after {
  content: '→';
  font-size: 1rem;
}

.category-card:hover .card-link {
  gap: 10px;
}

/* ================================================
   特性块
   ================================================ */
.feature-block {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: center;
}

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

.feature-image::after {
  content: '';
  position: absolute;
  inset: 0;
  border-radius: inherit;
  border: 3px solid rgba(255, 255, 255, 0.4);
}

.feature-image img {
  width: 100%;
  height: auto;
  transition: transform 0.6s ease;
}

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

.feature-text {
  position: relative;
}

.feature-text h3 {
  font-size: 1.7rem;
  font-weight: 900;
  color: var(--text-ink);
  margin-bottom: 16px;
  letter-spacing: -0.02em;
  line-height: 1.3;
}

.feature-text p {
  color: var(--text-medium);
  font-size: 1.05rem;
  line-height: 1.8;
  margin-bottom: 20px;
}

.feature-list {
  list-style: none;
  margin-top: 8px;
}

.feature-list li {
  padding: 8px 0;
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 0.98rem;
  color: var(--text-ink);
  font-weight: 500;
}

.feature-list li::before {
  content: '✓';
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 22px;
  height: 22px;
  min-width: 22px;
  background: var(--accent-sage);
  color: #FFFDF9;
  border-radius: 50%;
  font-size: 0.7rem;
  font-weight: 800;
  box-shadow: 0 2px 6px rgba(138, 177, 125, 0.3);
}

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

.stat-item {
  background: var(--bg-card);
  padding: 36px 20px;
  border-radius: var(--radius-lg);
  border: none;
  box-shadow: var(--shadow-sm);
  transition: transform 0.3s, box-shadow 0.3s;
  position: relative;
  overflow: hidden;
}

.stat-item::before {
  content: '';
  position: absolute;
  top: -40px;
  right: -40px;
  width: 100px;
  height: 100px;
  border-radius: 50%;
  background: rgba(138, 177, 125, 0.15);
}

.stat-item:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}

.stat-number {
  font-size: clamp(2rem, 3vw, 2.6rem);
  font-weight: 900;
  letter-spacing: -0.03em;
  background: linear-gradient(135deg, var(--accent-coral), var(--accent-terracotta));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  display: inline-block;
}

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

/* ================================================
   内容墙
   ================================================ */
.content-wall {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 28px;
}

.content-wall-item {
  background: var(--bg-card);
  border-radius: var(--radius-md);
  overflow: hidden;
  border: none;
  box-shadow: var(--shadow-sm);
  transition: transform 0.3s, box-shadow 0.3s;
  cursor: pointer;
}

.content-wall-item:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-md);
}

.content-wall-item img {
  width: 100%;
  height: 220px;
  object-fit: cover;
  transition: transform 0.5s ease;
}

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

.content-wall-body {
  padding: 24px;
}

.content-tag {
  display: inline-block;
  background: var(--accent-mustard);
  color: var(--text-ink);
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  padding: 4px 14px;
  border-radius: var(--radius-pill);
  margin-bottom: 12px;
}

.content-wall-body h3 {
  font-size: 1.1rem;
  font-weight: 800;
  color: var(--text-ink);
  margin-bottom: 8px;
  line-height: 1.4;
}

.content-wall-body p {
  font-size: 0.9rem;
  color: var(--text-medium);
  line-height: 1.6;
}

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

.faq-item {
  background: var(--bg-card);
  border: none;
  border-radius: var(--radius-md);
  margin-bottom: 12px;
  overflow: hidden;
  cursor: pointer;
  box-shadow: var(--shadow-sm);
  transition: box-shadow 0.3s;
}

.faq-item:hover {
  box-shadow: var(--shadow-md);
}

.faq-item .faq-question {
  padding: 20px 24px;
  font-weight: 700;
  font-size: 1rem;
  color: var(--text-ink);
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
}

.faq-item .faq-question::after {
  content: '+';
  font-size: 1.5rem;
  font-weight: 400;
  color: var(--accent-terracotta);
  transition: transform 0.3s;
  line-height: 1;
}

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

.faq-item .faq-answer {
  padding: 0 24px 20px;
  display: none;
  opacity: 0.75;
  font-size: 0.95rem;
  color: var(--text-medium);
  line-height: 1.7;
}

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

/* ================================================
   CTA横幅
   ================================================ */
.cta-banner {
  padding: 72px 48px;
  text-align: center;
  border-radius: var(--radius-lg);
  color: #fff;
  background: linear-gradient(120deg, var(--accent-terracotta) 0%, var(--accent-coral) 60%, #F2A14E 100%);
  position: relative;
  overflow: hidden;
}

.cta-banner::before {
  content: '';
  position: absolute;
  right: -60px;
  top: -60px;
  width: 200px;
  height: 200px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.1);
}

.cta-banner::after {
  content: '';
  position: absolute;
  left: 8%;
  bottom: -50px;
  width: 140px;
  height: 140px;
  border-radius: 48% 52% 60% 40% / 55% 45% 55% 45%;
  background: rgba(255, 255, 255, 0.08);
}

.cta-banner h2 {
  color: #ffffff;
  font-size: clamp(1.7rem, 3vw, 2.3rem);
  font-weight: 900;
  margin-bottom: 14px;
  letter-spacing: -0.02em;
  position: relative;
  z-index: 2;
}

.cta-banner p {
  position: relative;
  z-index: 2;
  opacity: 0.85;
  margin-bottom: 24px;
  font-size: 1.05rem;
  max-width: 540px;
  margin-left: auto;
  margin-right: auto;
  color: #fff;
}

.cta-banner .btn-primary {
  background: var(--bg-card);
  color: var(--accent-terracotta);
  box-shadow: 0 8px 24px rgba(45, 42, 39, 0.2);
  position: relative;
  z-index: 2;
}

.cta-banner .btn-primary:hover {
  transform: translateY(-3px) scale(1.02);
  box-shadow: 0 12px 30px rgba(45, 42, 39, 0.25);
}

/* ================================================
   页脚
   ================================================ */
.site-footer {
  background: var(--bg-footer);
  padding: 72px 0 32px;
  position: relative;
}

.site-footer .container {
  position: relative;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 48px;
}

.footer-brand {
  max-width: 280px;
}

.footer-brand .logo {
  margin-bottom: 14px;
}

.footer-brand p {
  font-size: 0.9rem;
  color: var(--text-medium);
  line-height: 1.7;
}

.footer-col h4 {
  font-size: 0.95rem;
  font-weight: 800;
  color: var(--text-ink);
  margin-bottom: 16px;
  letter-spacing: 0.03em;
}

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

.footer-col ul li {
  margin-bottom: 10px;
}

.footer-col ul a {
  color: var(--text-medium);
  text-decoration: none;
  font-size: 0.9rem;
  transition: color 0.2s, padding-left 0.2s;
}

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

.footer-bottom {
  border-top: 1px solid rgba(74, 69, 64, 0.12);
  margin-top: 48px;
  padding-top: 24px;
  text-align: center;
  font-size: 0.85rem;
  color: var(--text-light);
}

/* ================================================
   辅助组件样式
   ================================================ */
.hero-image, .feature-image, .content-wall-item img {
  background: var(--bg-soft);
}

.feature-block + .feature-block {
  margin-top: 80px;
}

/* ================================================
   工具类
   ================================================ */
.text-accent {
  background: linear-gradient(120deg, var(--accent-coral), var(--accent-mustard));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

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

.seo-description {
  max-width: 600px;
  margin: 0 auto 52px;
  opacity: 0.75;
  color: var(--text-medium);
  font-size: 1.05rem;
  line-height: 1.7;
}

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

/* ================================================
   响应式
   ================================================ */
@media (max-width: 768px) {
  .section {
    padding: 72px 0;
  }

  .hero {
    padding-top: 120px;
    min-height: auto;
  }

  .hero::before {
    width: 220px;
    height: 220px;
    right: -40px;
    top: 10%;
  }

  .hero::after {
    width: 120px;
    height: 120px;
    right: 30%;
    bottom: 5%;
  }

  .feature-block {
    grid-template-columns: 1fr;
    gap: 36px;
  }

  .stats-bar {
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
  }

  .footer-grid {
    grid-template-columns: 1fr 1fr;
    gap: 32px;
  }

  .main-nav {
    display: none;
  }

  .menu-toggle {
    display: flex;
  }

  .main-nav.open {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: 72px;
    left: 12px;
    right: 12px;
    width: auto;
    background: var(--bg-card);
    padding: 24px;
    border-radius: 20px;
    box-shadow: var(--shadow-lg);
    gap: 20px;
    align-items: stretch;
    text-align: center;
    border: none;
  }

  .main-nav.open a {
    font-size: 1rem;
    padding: 10px 12px;
    border-radius: 12px;
    background: var(--bg-soft);
  }

  .main-nav.open a::after {
    display: none;
  }

  .main-nav.open .nav-cta {
    background: linear-gradient(135deg, var(--accent-coral), var(--accent-terracotta));
    color: #fff !important;
  }

  .cta-banner {
    padding: 56px 24px;
  }

  .hero-buttons {
    flex-wrap: wrap;
  }
}

@media (max-width: 480px) {
  .cards-grid,
  .content-wall,
  .stats-bar {
    grid-template-columns: 1fr;
  }

  .footer-grid {
    grid-template-columns: 1fr;
  }

  .hero h1 {
    font-size: 2.2rem;
  }

  .hero-buttons {
    flex-direction: column;
  }

  .hero-buttons .btn {
    width: 100%;
    justify-content: center;
  }

  .section-title::after {
    margin-top: 12px;
  }

  .cta-banner {
    padding: 48px 20px;
    border-radius: var(--radius-md);
  }

  .stats-bar {
    gap: 12px;
  }

  .stat-item {
    padding: 24px 12px;
  }
}