/* ========================================
   51cg.com吃西瓜 · 设计系统
   风格：西瓜夏日乐园 / Watermelon Dream
   ======================================== */

/* 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: #FFF9F0;
  color: #2D3436;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

::selection {
  background: #FF6B6B;
  color: #fff;
}

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

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

.section:nth-child(even) {
  background: linear-gradient(180deg, #F0FBF4, #E8F8EF);
}

/* 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(18px);
  -webkit-backdrop-filter: blur(18px);
  border-bottom: none;
  box-shadow: 0 1px 0 rgba(255, 107, 107, 0.08), 0 8px 32px rgba(255, 107, 107, 0.04);
}

.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: 800;
  font-size: 1.25rem;
  text-decoration: none;
  color: #2D3436;
  letter-spacing: -0.5px;
}

.logo-icon {
  width: 42px;
  height: 42px;
  border-radius: 50%;
  background: radial-gradient(circle at 50% 68%, #FF6B6B 0%, #FF6B6B 52%, #2ED573 53%, #2ED573 72%, #1FBF6E 73%);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1rem;
  color: #fff;
  box-shadow: 0 4px 14px rgba(255, 107, 107, 0.35), inset 0 -2px 4px rgba(0,0,0,0.08);
  font-weight: 700;
}

.main-nav {
  display: flex;
  align-items: center;
  gap: 30px;
  list-style: none;
}

.main-nav a {
  text-decoration: none;
  font-size: 0.9rem;
  font-weight: 500;
  color: #4A5568;
  padding: 4px 0;
  position: relative;
  transition: color 0.3s;
}

.main-nav a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  border-radius: 2px;
  background: linear-gradient(90deg, #FF6B6B, #2ED573);
  transition: width 0.3s ease;
}

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

.main-nav a:hover {
  color: #FF6B6B;
}

.nav-cta {
  padding: 8px 24px !important;
  border-radius: 50px;
  color: #fff !important;
  font-weight: 600;
  background: linear-gradient(135deg, #FF6B6B, #FF4D4D);
  box-shadow: 0 4px 14px rgba(255, 107, 107, 0.35);
  transition: all 0.3s ease;
}

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

.nav-cta:hover {
  background: linear-gradient(135deg, #2ED573, #1FBF6E);
  box-shadow: 0 4px 14px rgba(46, 213, 115, 0.35);
  color: #fff !important;
  transform: translateY(-1px);
}

.menu-toggle {
  display: none;
  width: 44px;
  height: 44px;
  border: none;
  border-radius: 12px;
  background: #fff;
  color: #FF6B6B;
  font-size: 1.4rem;
  cursor: pointer;
  align-items: center;
  justify-content: center;
  box-shadow: 0 2px 10px rgba(255, 107, 107, 0.15);
}

/* Hero */
.hero {
  min-height: 75vh;
  display: flex;
  align-items: center;
  position: relative;
  overflow: hidden;
  background:
    radial-gradient(circle at 82% 18%, rgba(255, 107, 107, 0.12) 0%, transparent 34%),
    radial-gradient(circle at 68% 55%, rgba(46, 213, 115, 0.1) 0%, transparent 28%),
    radial-gradient(circle at 92% 75%, rgba(255, 217, 61, 0.12) 0%, transparent 24%),
    linear-gradient(145deg, #FFF9F0 0%, #FFF1E8 100%);
}

.hero::before {
  content: '';
  position: absolute;
  width: 480px;
  height: 480px;
  border-radius: 50%;
  background: rgba(255, 107, 107, 0.06);
  right: 10%;
  top: -120px;
  z-index: 0;
  pointer-events: none;
}

.hero .container {
  display: flex;
  align-items: center;
  gap: 56px;
  flex-wrap: wrap;
  position: relative;
  z-index: 1;
}

.hero-content {
  max-width: 680px;
  flex: 1 1 480px;
  animation: heroFadeIn 0.8s ease forwards;
}

.hero-eyebrow {
  display: inline-block;
  font-size: 0.8rem;
  font-weight: 700;
  padding: 6px 18px;
  border-radius: 50px;
  margin-bottom: 20px;
  background: linear-gradient(135deg, #fff5f5, #ffe0e0);
  color: #FF4D4D;
  border: 1px solid rgba(255, 107, 107, 0.15);
  box-shadow: 0 2px 8px rgba(255, 107, 107, 0.1);
  letter-spacing: 0.5px;
}

.hero h1 {
  font-size: 3.4rem;
  line-height: 1.12;
  font-weight: 800;
  letter-spacing: -2px;
  margin-bottom: 22px;
  background: linear-gradient(135deg, #2D3436 0%, #FF4D4D 55%, #FF6B6B 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero p {
  font-size: 1.12rem;
  opacity: 0.7;
  color: #5D6D7E;
  max-width: 560px;
  margin-bottom: 36px;
  line-height: 1.7;
}

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

.hero-image {
  flex: 0 1 440px;
  min-width: 300px;
  border-radius: 50% 50% 24px 24px;
  background: linear-gradient(145deg, #FF9A9A, #FF6B6B 60%, #E85A5A);
  padding: 18px;
  transform: rotate(3deg);
  box-shadow: 0 20px 60px rgba(255, 107, 107, 0.25);
  animation: float 5s ease-in-out infinite;
  position: relative;
}

.hero-image::after {
  content: '🍉';
  position: absolute;
  top: -12px;
  right: -12px;
  font-size: 2.4rem;
  background: #fff;
  width: 54px;
  height: 54px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 4px 16px rgba(0,0,0,0.12);
}

.hero-image img {
  width: 100%;
  height: auto;
  border-radius: 50% 50% 18px 18px;
  object-fit: cover;
  display: block;
}

/* 按钮 */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 13px 30px;
  border-radius: 50px;
  font-weight: 700;
  font-size: 0.9rem;
  cursor: pointer;
  border: none;
  text-decoration: none;
  transition: all 0.3s ease;
  position: relative;
  overflow: hidden;
}

.btn-primary {
  background: linear-gradient(135deg, #FF6B6B, #FF4D4D);
  color: #fff;
  box-shadow: 0 4px 18px rgba(255, 107, 107, 0.35);
}

.btn-primary::after {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.25), transparent);
  transition: left 0.5s ease;
}

.btn-primary:hover::after {
  left: 100%;
}

.btn-primary:hover {
  background: linear-gradient(135deg, #2ED573, #1FBF6E);
  box-shadow: 0 6px 24px rgba(46, 213, 115, 0.35);
  transform: translateY(-2px);
}

.btn-outline {
  background: transparent;
  border: 2px solid #2ED573;
  color: #2ED573;
}

.btn-outline:hover {
  background: rgba(46, 213, 115, 0.1);
  border-color: #1FBF6E;
  color: #1FBF6E;
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(46, 213, 115, 0.2);
}

/* 标签/标题 */
.section-label {
  display: inline-block;
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 2px;
  margin-bottom: 14px;
  padding: 6px 16px;
  border-radius: 50px;
  background: #E8F8EF;
  color: #2ED573;
  text-transform: uppercase;
}

.section-title {
  font-size: 2.3rem;
  font-weight: 800;
  color: #2D3436;
  margin-bottom: 20px;
  letter-spacing: -1px;
  position: relative;
  padding-bottom: 18px;
}

.section-title::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 90px;
  height: 3px;
  border-radius: 4px;
  background: linear-gradient(90deg, #FF6B6B 65%, #2ED573 65%);
}

.section-desc {
  max-width: 620px;
  opacity: 0.66;
  color: #5D6D7E;
  font-size: 1.02rem;
  margin-bottom: 44px;
  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 {
  border-radius: 22px;
  padding: 30px 28px;
  background: linear-gradient(145deg, #FFFFFF 55%, #FFF5F3 100%);
  border: 1px solid rgba(255, 107, 107, 0.06);
  transition: all 0.35s cubic-bezier(0.4, 0, 0.2, 1);
  position: relative;
  overflow: hidden;
}

.category-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, #FF6B6B, #FF9A5A, #2ED573);
  opacity: 0;
  transition: opacity 0.35s ease;
}

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

.category-card:hover {
  transform: translateY(-6px);
  box-shadow: inset 0 0 0 2px rgba(46, 213, 115, 0.15), 0 16px 40px rgba(255, 107, 107, 0.14);
  border-color: transparent;
}

.card-icon {
  width: 52px;
  height: 52px;
  border-radius: 18px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 18px;
  font-size: 1.4rem;
  background: linear-gradient(135deg, #FFF3E9, #FFE0E0);
  color: #FF6B6B;
  box-shadow: 0 2px 8px rgba(255, 107, 107, 0.12);
  transition: transform 0.3s ease;
}

.category-card:hover .card-icon {
  transform: scale(1.08) rotate(-6deg);
  background: linear-gradient(135deg, #E8F8EF, #D0F5E0);
  color: #2ED573;
}

.card-link {
  font-weight: 700;
  font-size: 0.85rem;
  text-decoration: none;
  color: #FF6B6B;
  transition: 0.2s;
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.card-link:hover {
  color: #2ED573;
  gap: 10px;
}

/* 特性块 */
.feature-block {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 56px;
  align-items: center;
}

.feature-image {
  border-radius: 30px 30px 80px 30px;
  overflow: hidden;
  box-shadow: 0 16px 48px rgba(255, 107, 107, 0.14);
  position: relative;
  transform: rotate(-2deg);
  transition: transform 0.4s ease;
}

.feature-image:hover {
  transform: rotate(0deg) scale(1.01);
}

.feature-image::before {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(145deg, transparent 60%, rgba(255, 107, 107, 0.15));
  z-index: 1;
}

.feature-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
  min-height: 320px;
}

.feature-text {
  position: relative;
}

.feature-text .section-title {
  font-size: 2rem;
}

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

.feature-list li {
  padding: 8px 0;
  display: flex;
  align-items: center;
  gap: 12px;
  color: #4A5568;
  font-size: 0.98rem;
}

.feature-list li::before {
  content: '✓';
  font-weight: 700;
  color: #2ED573;
  background: #E8F8EF;
  width: 22px;
  height: 22px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.7rem;
  flex-shrink: 0;
}

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

.stat-item {
  padding: 30px 20px;
  border-radius: 22px;
  border: none;
  background: linear-gradient(145deg, #FFFFFF, #FFF9F5);
  box-shadow: 0 4px 24px rgba(0, 0, 0, 0.05);
  position: relative;
  overflow: hidden;
  transition: transform 0.3s ease;
}

.stat-item::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 36px;
  height: 4px;
  border-radius: 4px;
  background: linear-gradient(90deg, #FF6B6B, #2ED573);
}

.stat-item:hover {
  transform: translateY(-4px);
}

.stat-number {
  font-size: 2.8rem;
  font-weight: 800;
  line-height: 1.1;
  background: linear-gradient(135deg, #FF6B6B, #FF9A5A);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.stat-label {
  font-size: 0.9rem;
  opacity: 0.6;
  color: #5D6D7E;
  margin-top: 8px;
  font-weight: 500;
}

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

.content-wall-item {
  border-radius: 22px;
  overflow: hidden;
  background: #fff;
  border: none;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.04);
  transition: all 0.35s cubic-bezier(0.4, 0, 0.2, 1);
}

.content-wall-item:hover {
  transform: translateY(-6px) rotate(0.5deg);
  box-shadow: 0 16px 40px rgba(255, 107, 107, 0.12);
}

.content-wall-item img {
  width: 100%;
  height: 210px;
  object-fit: cover;
  transition: transform 0.45s ease;
  display: block;
}

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

.content-wall-body {
  padding: 22px 24px;
  font-size: 0.95rem;
  color: #4A5568;
  line-height: 1.65;
}

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

.faq-item {
  border: 1px solid rgba(255, 107, 107, 0.1);
  border-radius: 16px;
  margin-bottom: 10px;
  overflow: hidden;
  cursor: pointer;
  background: #fff;
  transition: box-shadow 0.3s ease, border-color 0.3s ease;
}

.faq-item:hover {
  border-color: rgba(255, 107, 107, 0.25);
  box-shadow: 0 4px 16px rgba(255, 107, 107, 0.07);
}

.faq-item .faq-question {
  padding: 18px 22px;
  font-weight: 700;
  font-size: 0.98rem;
  color: #2D3436;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.faq-item .faq-question::after {
  content: '+';
  font-size: 1.3rem;
  font-weight: 400;
  color: #FF6B6B;
  transition: transform 0.3s ease;
}

.faq-item.open .faq-question::after {
  transform: rotate(45deg);
  color: #2ED573;
}

.faq-item .faq-answer {
  padding: 0 22px 18px;
  display: none;
  opacity: 0.68;
  color: #5D6D7E;
  font-size: 0.93rem;
  line-height: 1.7;
  animation: answerIn 0.3s ease forwards;
}

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

/* CTA横幅 */
.cta-banner {
  padding: 64px 36px;
  text-align: center;
  border-radius: 30px;
  color: #fff;
  background: linear-gradient(145deg, #FF6B6B, #FF4D4D, #FF8A5A);
  position: relative;
  overflow: hidden;
  box-shadow: 0 20px 60px rgba(255, 107, 107, 0.3);
}

.cta-banner::before {
  content: '';
  position: absolute;
  width: 220px;
  height: 220px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.1);
  top: -80px;
  right: -60px;
}

.cta-banner::after {
  content: '';
  position: absolute;
  width: 140px;
  height: 140px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.12);
  bottom: -50px;
  left: -40px;
}

.cta-banner h2 {
  color: #fff;
  font-size: 2rem;
  font-weight: 800;
  letter-spacing: -1px;
  margin-bottom: 12px;
  position: relative;
  z-index: 1;
}

.cta-banner p {
  color: rgba(255, 255, 255, 0.9);
  margin-bottom: 28px;
  font-size: 1.05rem;
  position: relative;
  z-index: 1;
}

.cta-banner .btn-primary {
  background: #fff;
  color: #FF6B6B;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
  position: relative;
  z-index: 1;
}

.cta-banner .btn-primary:hover {
  background: #FFE0E0;
  color: #FF4D4D;
  transform: translateY(-2px);
}

/* 页脚 */
.site-footer {
  padding: 60px 0 28px;
  background: linear-gradient(180deg, #E8F8EF, #DBF5E8);
  color: #2D3436;
}

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

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 44px;
}

.footer-brand .logo {
  margin-bottom: 12px;
}

.footer-brand p {
  color: #5D6D7E;
  font-size: 0.9rem;
  line-height: 1.7;
  margin-top: 12px;
  opacity: 0.8;
}

.footer-col h4 {
  font-size: 0.82rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-bottom: 18px;
  color: #2D3436;
}

.footer-col a {
  display: block;
  color: #6B7A8D;
  font-size: 0.88rem;
  text-decoration: none;
  padding: 3px 0;
  transition: all 0.2s ease;
}

.footer-col a:hover {
  color: #FF6B6B;
  padding-left: 6px;
}

.footer-bottom {
  border-top: 1px solid rgba(0, 0, 0, 0.07);
  margin-top: 44px;
  padding-top: 22px;
  text-align: center;
  font-size: 0.82rem;
  color: #6B7A8D;
}

.footer-bottom .text-accent {
  color: #FF6B6B;
  font-weight: 700;
}

/* 工具类 */
.text-accent {
  color: #FF6B6B;
  font-weight: 700;
}

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

.text-center .section-title::after {
  left: 50%;
  transform: translateX(-50%);
}

.text-center .section-desc {
  margin-left: auto;
  margin-right: auto;
}

.seo-description {
  max-width: 600px;
  margin: 0 auto 48px;
  opacity: 0.66;
  color: #5D6D7E;
  line-height: 1.75;
}

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

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

/* 动画 */
@keyframes heroFadeIn {
  from {
    opacity: 0;
    transform: translateY(28px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes float {
  0%, 100% {
    transform: translateY(0) rotate(3deg);
  }
  50% {
    transform: translateY(-12px) rotate(2deg);
  }
}

@keyframes answerIn {
  from {
    opacity: 0;
    transform: translateY(-6px);
  }
  to {
    opacity: 0.68;
    transform: translateY(0);
  }
}

/* ⚠️ 响应式 */
@media (max-width: 992px) {
  .hero h1 {
    font-size: 3rem;
  }

  .feature-block {
    grid-template-columns: 1fr;
    gap: 40px;
  }

  .feature-image {
    max-width: 560px;
  }

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

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

@media (max-width: 768px) {
  .section {
    padding: 64px 0;
  }

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

  .hero .container {
    flex-direction: column-reverse;
    gap: 40px;
    padding-top: 40px;
  }

  .hero-content {
    text-align: center;
    max-width: 100%;
  }

  .hero p {
    margin-left: auto;
    margin-right: auto;
  }

  .hero-buttons {
    justify-content: center;
  }

  .hero-image {
    max-width: 380px;
    margin: 0 auto;
  }

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

  .feature-block .feature-text {
    text-align: left;
  }

  .stats-bar {
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
  }

  .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: 68px;
    left: 0;
    width: 100%;
    background: #FFF9F0;
    padding: 24px;
    gap: 18px;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.08);
    border-radius: 0 0 24px 24px;
  }

  .main-nav.open a {
    font-size: 1rem;
    padding: 8px 0;
  }

  .main-nav.open .nav-cta {
    text-align: center;
  }

  .section-title {
    font-size: 1.9rem;
  }

  .cta-banner {
    padding: 48px 24px;
  }

  .cta-banner h2 {
    font-size: 1.7rem;
  }
}

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

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 28px;
  }

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

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

  .hero h1 {
    font-size: 2.1rem;
    letter-spacing: -1px;
  }

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

  .hero-image {
    min-width: 0;
    width: 100%;
    max-width: 300px;
  }

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

  .section {
    padding: 52px 0;
  }

  .stat-item {
    padding: 22px 16px;
  }

  .stat-number {
    font-size: 2.2rem;
  }

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

  .cta-banner {
    padding: 40px 18px;
    border-radius: 24px;
  }
}