/* ========================================
   51吃瓜在线 · 夏日瓜田设计系统
   独创「瓜果渐层 × 玻璃通透 × 杂志网格」
   ======================================== */

:root {
  --primary: #2EC4B6;
  --primary-dark: #1A8C80;
  --accent: #FF6B6B;
  --accent-dark: #E85454;
  --yellow: #FFD93D;
  --text: #1E3D3F;
  --text-light: #6B989C;
  --bg: #FFF9F0;
  --bg-alt: #F5FCFA;
  --white: #FFFFFF;
  --border: #E8F0EE;
  --shadow-sm: 0 2px 12px rgba(46, 196, 182, 0.08);
  --shadow-md: 0 10px 30px rgba(46, 196, 182, 0.14);
  --shadow-lg: 0 20px 48px rgba(255, 107, 107, 0.16);
  --radius: 20px;
  --radius-lg: 28px;
}

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

html { scroll-behavior: smooth; }

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

::selection {
  background: var(--accent);
  color: #fff;
}

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

.section {
  padding: 96px 0;
  position: relative;
}

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

/* ========================================
   导航
   ======================================== */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1000;
  background: rgba(255, 249, 240, 0.92);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid rgba(46, 196, 182, 0.15);
  box-shadow: 0 1px 20px rgba(46, 196, 182, 0.06);
}

.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: 800;
  font-size: 1.25rem;
  text-decoration: none;
  color: var(--text);
  letter-spacing: -0.02em;
  transition: opacity 0.2s;
}

.logo:hover { opacity: 0.8; }

.logo-icon {
  width: 38px;
  height: 38px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  background: linear-gradient(135deg, var(--primary) 0%, #48D8C8 60%, var(--yellow) 100%);
  color: #fff;
  box-shadow: 0 4px 12px rgba(46, 196, 182, 0.35);
  position: relative;
}

.logo-icon::after {
  content: '';
  position: absolute;
  bottom: 3px;
  right: 3px;
  width: 10px;
  height: 10px;
  background: var(--accent);
  border-radius: 50%;
  border: 2px solid #fff;
}

.main-nav {
  display: flex;
  align-items: center;
  gap: 4px;
  list-style: none;
}

.main-nav a {
  text-decoration: none;
  font-size: 0.92rem;
  font-weight: 500;
  color: var(--text);
  padding: 8px 16px;
  border-radius: 100px;
  transition: all 0.25s;
  position: relative;
}

.main-nav a:not(.nav-cta):hover {
  background: rgba(46, 196, 182, 0.1);
  color: var(--primary-dark);
}

.main-nav a:not(.nav-cta)::after {
  content: '';
  position: absolute;
  bottom: 2px;
  left: 50%;
  transform: translateX(-50%);
  width: 0;
  height: 2px;
  background: var(--accent);
  border-radius: 2px;
  transition: width 0.3s cubic-bezier(0.65, 0, 0.35, 1);
}

.main-nav a:not(.nav-cta):hover::after {
  width: 18px;
}

.nav-cta {
  padding: 10px 24px;
  border-radius: 100px;
  color: #fff !important;
  font-weight: 700;
  background: linear-gradient(135deg, var(--primary), var(--primary-dark));
  box-shadow: 0 4px 14px rgba(46, 196, 182, 0.3);
  margin-left: 8px;
}

.nav-cta:hover {
  transform: translateY(-1px);
  box-shadow: 0 8px 20px rgba(46, 196, 182, 0.4);
}

.menu-toggle {
  display: none;
  width: 42px;
  height: 42px;
  border: none;
  background: transparent;
  cursor: pointer;
  position: relative;
  border-top: 2px solid var(--text);
  border-bottom: 2px solid var(--text);
  border-radius: 8px;
  transition: all 0.2s;
}

.menu-toggle::before {
  content: '';
  position: absolute;
  top: 50%;
  left: 8px;
  right: 8px;
  border-top: 2px solid var(--text);
  transform: translateY(-50%);
}

.menu-toggle:hover {
  border-color: var(--primary);
}

.menu-toggle:hover::before {
  border-color: var(--primary);
}

/* ========================================
   Hero
   ======================================== */
.hero {
  min-height: 80vh;
  display: flex;
  align-items: center;
  position: relative;
  overflow: hidden;
  padding: 120px 0 80px;
  background:
    radial-gradient(circle at 85% 20%, rgba(255, 217, 61, 0.2) 0%, transparent 50%),
    radial-gradient(circle at 15% 80%, rgba(46, 196, 182, 0.15) 0%, transparent 45%),
    linear-gradient(160deg, #FFFDF7 0%, #F0FAF7 100%);
}

.hero::before {
  content: '';
  position: absolute;
  top: -100px;
  right: -80px;
  width: 480px;
  height: 480px;
  background:
    radial-gradient(circle at 30% 30%, rgba(46, 196, 182, 0.25) 0%, transparent 55%),
    radial-gradient(circle at 70% 70%, rgba(255, 107, 107, 0.18) 0%, transparent 45%);
  border-radius: 50%;
  z-index: 0;
  animation: float 12s ease-in-out infinite;
}

.hero::after {
  content: '🍉';
  position: absolute;
  bottom: 10%;
  left: 5%;
  font-size: 5rem;
  opacity: 0.15;
  transform: rotate(-15deg);
  animation: bounce 6s ease-in-out infinite;
}

@keyframes float {
  0%, 100% { transform: translate(0, 0); }
  50% { transform: translate(-20px, 20px); }
}

@keyframes bounce {
  0%, 100% { transform: rotate(-15deg) translateY(0); }
  50% { transform: rotate(-15deg) translateY(-18px); }
}

.hero-content {
  max-width: 720px;
  position: relative;
  z-index: 1;
}

.hero-eyebrow {
  display: inline-block;
  font-size: 0.82rem;
  font-weight: 700;
  padding: 6px 18px;
  border-radius: 100px;
  margin-bottom: 20px;
  background: linear-gradient(135deg, rgba(255, 107, 107, 0.15), rgba(255, 217, 61, 0.2));
  color: var(--accent-dark);
  letter-spacing: 0.04em;
  text-transform: uppercase;
  box-shadow: 0 2px 8px rgba(255, 107, 107, 0.1);
}

.hero h1 {
  font-size: clamp(2.4rem, 5vw, 3.6rem);
  line-height: 1.15;
  margin-bottom: 22px;
  font-weight: 900;
  letter-spacing: -0.03em;
  background: linear-gradient(120deg, var(--text) 30%, var(--primary-dark) 70%, var(--accent) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero p {
  font-size: 1.12rem;
  opacity: 0.72;
  max-width: 560px;
  margin-bottom: 36px;
  line-height: 1.8;
}

.hero-buttons {
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
}

.hero-image {
  border-radius: var(--radius-lg);
  overflow: hidden;
  position: absolute;
  right: 3%;
  width: 38%;
  box-shadow: var(--shadow-lg);
  transform: rotate(2deg);
}

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

.hero-image:hover img {
  transform: scale(1.04) rotate(-1deg);
}

/* ========================================
   按钮
   ======================================== */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 14px 30px;
  border-radius: 100px;
  font-weight: 700;
  font-size: 0.95rem;
  cursor: pointer;
  border: none;
  text-decoration: none;
  transition: all 0.3s cubic-bezier(0.65, 0, 0.35, 1);
  letter-spacing: 0.01em;
}

.btn-primary {
  color: #fff;
  background: linear-gradient(135deg, var(--accent), var(--accent-dark));
  box-shadow: 0 6px 20px rgba(255, 107, 107, 0.35);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 10px 28px rgba(255, 107, 107, 0.45);
}

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

.btn-outline:hover {
  background: rgba(46, 196, 182, 0.08);
  border-color: var(--primary-dark);
  transform: translateY(-2px);
}

/* ========================================
   标签 / 标题
   ======================================== */
.section-label {
  display: inline-block;
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  margin-bottom: 14px;
  color: var(--accent-dark);
  background: rgba(255, 107, 107, 0.1);
  padding: 4px 14px;
  border-radius: 100px;
}

.section-title {
  font-size: clamp(1.8rem, 3vw, 2.4rem);
  margin-bottom: 16px;
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.25;
  color: var(--text);
}

.section-desc {
  max-width: 600px;
  opacity: 0.7;
  margin-bottom: 48px;
  font-size: 1.02rem;
  line-height: 1.75;
}

/* ========================================
   卡片网格
   ======================================== */
.cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 28px;
}

.category-card {
  border-radius: var(--radius);
  padding: 32px 28px;
  border: 1px solid var(--border);
  background: var(--white);
  transition: all 0.35s cubic-bezier(0.65, 0, 0.35, 1);
  position: relative;
  overflow: hidden;
}

.category-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--primary), var(--yellow), var(--accent));
  border-radius: 0 0 4px 4px;
  opacity: 0;
  transition: opacity 0.3s;
}

.category-card:nth-child(2n)::before {
  background: linear-gradient(90deg, var(--accent), var(--yellow), var(--primary));
}

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

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

.card-icon {
  width: 54px;
  height: 54px;
  border-radius: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
  font-size: 1.5rem;
  background: linear-gradient(135deg, var(--primary), #48D8C8);
  color: #fff;
  box-shadow: 0 6px 16px rgba(46, 196, 182, 0.25);
}

.category-card:nth-child(2n) .card-icon {
  background: linear-gradient(135deg, var(--accent), #FF9A8B);
  box-shadow: 0 6px 16px rgba(255, 107, 107, 0.25);
}

.category-card:nth-child(3n) .card-icon {
  background: linear-gradient(135deg, #FFD93D, #FFB627);
  box-shadow: 0 6px 16px rgba(255, 217, 61, 0.3);
}

.card-link {
  font-weight: 600;
  font-size: 0.85rem;
  text-decoration: none;
  color: var(--primary-dark);
  display: inline-flex;
  align-items: center;
  gap: 6px;
  margin-top: 14px;
  transition: gap 0.2s;
}

.card-link:hover {
  gap: 10px;
  color: var(--accent-dark);
}

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

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

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

.feature-image:hover img {
  transform: scale(1.05);
}

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

.feature-text p {
  opacity: 0.7;
  margin-bottom: 20px;
}

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

.feature-list li {
  padding: 8px 0;
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 500;
  color: var(--text);
}

.feature-list li::before {
  content: '✓';
  font-weight: 900;
  color: var(--primary);
  background: rgba(46, 196, 182, 0.12);
  width: 24px;
  height: 24px;
  border-radius: 50%;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 0.75rem;
}

/* ========================================
   数据条
   ======================================== */
.stats-bar {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 28px;
  text-align: center;
}

.stat-item {
  padding: 32px 20px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--white);
  transition: all 0.35s;
  position: relative;
  overflow: hidden;
}

.stat-item::after {
  content: '';
  position: absolute;
  bottom: -30px;
  left: 50%;
  transform: translateX(-50%);
  width: 80px;
  height: 80px;
  background: radial-gradient(circle, rgba(46, 196, 182, 0.12), transparent 70%);
  border-radius: 50%;
}

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

.stat-number {
  font-size: 2.6rem;
  font-weight: 900;
  line-height: 1.2;
  background: linear-gradient(135deg, var(--primary), var(--primary-dark));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.stat-item:nth-child(2n) .stat-number {
  background: linear-gradient(135deg, var(--accent), var(--accent-dark));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.stat-label {
  font-size: 0.9rem;
  opacity: 0.6;
  margin-top: 6px;
  letter-spacing: 0.06em;
}

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

.content-wall-item {
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--border);
  background: var(--white);
  transition: all 0.4s cubic-bezier(0.65, 0, 0.35, 1);
  position: relative;
}

.content-wall-item:hover {
  transform: translateY(-6px) rotate(-0.5deg);
  box-shadow: var(--shadow-lg);
}

.content-wall-item:nth-child(3n):hover {
  transform: translateY(-6px) rotate(0.5deg);
}

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

.content-wall-item:hover img {
  transform: scale(1.06);
}

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

.content-wall-body h4 {
  font-size: 1.05rem;
  margin-bottom: 6px;
  font-weight: 700;
}

.content-wall-body p {
  font-size: 0.88rem;
  opacity: 0.65;
  line-height: 1.6;
}

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

.faq-item {
  border: 1px solid var(--border);
  border-radius: 16px;
  margin-bottom: 12px;
  overflow: hidden;
  cursor: pointer;
  background: var(--white);
  transition: all 0.3s;
}

.faq-item:hover {
  border-color: var(--primary);
  box-shadow: var(--shadow-sm);
}

.faq-item.open {
  border-color: var(--primary);
}

.faq-item .faq-question {
  padding: 18px 22px;
  font-weight: 700;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 1.02rem;
  color: var(--text);
}

.faq-item .faq-question::after {
  content: '+';
  font-size: 1.4rem;
  font-weight: 400;
  color: var(--primary);
  transition: transform 0.3s;
}

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

.faq-item .faq-answer {
  padding: 0 22px 20px;
  display: none;
  opacity: 0.75;
  line-height: 1.7;
  font-size: 0.95rem;
}

.faq-item.open .faq-answer {
  display: block;
  animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(-6px); }
  to { opacity: 0.75; transform: translateY(0); }
}

/* ========================================
   CTA 横幅
   ======================================== */
.cta-banner {
  padding: 64px 48px;
  text-align: center;
  border-radius: var(--radius-lg);
  background: linear-gradient(135deg, var(--primary) 0%, #2EC4B6 35%, var(--accent) 100%);
  color: #fff;
  position: relative;
  overflow: hidden;
  box-shadow: 0 20px 40px rgba(46, 196, 182, 0.35);
}

.cta-banner::before,
.cta-banner::after {
  content: '';
  position: absolute;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.12);
}

.cta-banner::before {
  width: 180px;
  height: 180px;
  top: -80px;
  right: -40px;
}

.cta-banner::after {
  width: 280px;
  height: 280px;
  bottom: -140px;
  left: -80px;
  background: rgba(255, 217, 61, 0.15);
}

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

.cta-banner p {
  color: rgba(255, 255, 255, 0.85);
  margin-bottom: 24px;
  position: relative;
  z-index: 1;
}

.cta-banner .btn-primary {
  background: #fff;
  color: var(--primary-dark);
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.15);
  position: relative;
  z-index: 1;
}

.cta-banner .btn-primary:hover {
  transform: translateY(-2px) scale(1.02);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.2);
}

/* ========================================
   页脚
   ======================================== */
.site-footer {
  padding: 72px 0 28px;
  background: var(--bg-alt);
  border-top: 1px solid var(--border);
  position: relative;
}

.site-footer::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--primary), var(--yellow), var(--accent), var(--primary));
  background-size: 300% 100%;
  animation: flow 12s linear infinite;
}

@keyframes flow {
  0% { background-position: 0% 0; }
  100% { background-position: 300% 0; }
}

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

.footer-brand {
  padding-right: 40px;
}

.footer-brand p {
  color: var(--text-light);
  font-size: 0.92rem;
  margin-top: 16px;
  line-height: 1.7;
}

.footer-col h5 {
  color: var(--text);
  font-size: 1rem;
  margin-bottom: 16px;
  font-weight: 700;
  letter-spacing: 0.02em;
}

.footer-col a {
  display: block;
  padding: 5px 0;
  color: var(--text-light);
  text-decoration: none;
  font-size: 0.9rem;
  transition: all 0.25s;
}

.footer-col a:hover {
  color: var(--primary);
  transform: translateX(4px);
}

.footer-bottom {
  border-top: 1px solid rgba(46, 196, 182, 0.15);
  margin-top: 48px;
  padding-top: 24px;
  text-align: center;
  font-size: 0.85rem;
  color: var(--text-light);
}

/* ========================================
   工具类
   ======================================== */
.text-accent {
  color: var(--accent);
  font-weight: 600;
}

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

.seo-description {
  max-width: 600px;
  margin: 0 auto 48px;
  opacity: 0.7;
  text-align: center;
  line-height: 1.8;
}

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

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

/* ========================================
   滚动条美化
   ======================================== */
::-webkit-scrollbar {
  width: 10px;
}

::-webkit-scrollbar-track {
  background: var(--bg);
}

::-webkit-scrollbar-thumb {
  background: linear-gradient(180deg, var(--primary), var(--accent));
  border-radius: 10px;
  border: 2px solid var(--bg);
}

::-webkit-scrollbar-thumb:hover {
  background: linear-gradient(180deg, var(--primary-dark), var(--accent-dark));
}

/* ========================================
   响应式
   ======================================== */
@media (max-width: 1024px) {
  .hero-image {
    display: none;
  }

  .hero {
    min-height: 70vh;
  }
}

@media (max-width: 768px) {
  .feature-block {
    grid-template-columns: 1fr;
    gap: 40px;
  }

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

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

  .footer-brand {
    grid-column: 1 / -1;
    padding-right: 0;
  }

  .main-nav {
    display: none;
  }

  .menu-toggle {
    display: block;
  }

  .main-nav.open {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: 72px;
    left: 0;
    width: 100%;
    background: var(--bg);
    padding: 24px;
    padding-bottom: 32px;
    box-shadow: 0 12px 30px rgba(0, 0, 0, 0.08);
    border-radius: 0 0 20px 20px;
    gap: 8px;
  }

  .main-nav.open a {
    width: 100%;
    text-align: center;
    padding: 12px;
  }

  .main-nav.open .nav-cta {
    margin: 12px auto 0;
    max-width: 200px;
  }

  .section {
    padding: 72px 0;
  }

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

  .cta-banner {
    padding: 48px 28px;
    border-radius: 20px;
  }
}

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

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

  .header-inner {
    padding: 0 18px;
    height: 64px;
  }

  .main-nav.open {
    top: 64px;
  }

  .hero-buttons {
    flex-direction: column;
    width: 100%;
  }

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

  .hero {
    padding: 100px 0 60px;
    min-height: auto;
  }

  .hero p {
    font-size: 1rem;
  }

  .section-title {
    font-size: 1.7rem;
  }

  .stat-number {
    font-size: 2rem;
  }

  .content-wall-item img {
    height: 180px;
  }
}