/* ============================================
   51吃瓜官网 - 全局样式
   主题：吃瓜 / 八卦娱乐 · 橙红热情风
   ============================================ */

:root {
  --primary: #ff6b35;
  --primary-dark: #e5531f;
  --secondary: #ffd166;
  --accent: #ff3d5a;
  --dark-bg: #14141f;
  --dark-bg-2: #1d1d2e;
  --card-bg: #232336;
  --text-main: #f5f5fa;
  --text-muted: #a9a9c0;
  --border-color: rgba(255, 255, 255, 0.08);
  --shadow: 0 12px 32px rgba(0, 0, 0, 0.35);
  --radius: 16px;
  --gradient-main: linear-gradient(135deg, #ff6b35 0%, #ff3d5a 100%);
  --max-width: 1200px;
  --font-main: 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', sans-serif;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-main);
  background: var(--dark-bg);
  color: var(--text-main);
  line-height: 1.7;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

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

a {
  text-decoration: none;
  color: inherit;
}

ul {
  list-style: none;
}

.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

/* ---------- 渐入动画 ---------- */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes fadeIn {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}

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

@keyframes pulse {
  0%, 100% {
    box-shadow: 0 0 0 0 rgba(255, 107, 53, 0.5);
  }
  50% {
    box-shadow: 0 0 0 14px rgba(255, 107, 53, 0);
  }
}

.fade-in-up {
  opacity: 0;
  animation: fadeInUp 0.8s ease forwards;
}

.delay-1 { animation-delay: 0.15s; }
.delay-2 { animation-delay: 0.3s; }
.delay-3 { animation-delay: 0.45s; }
.delay-4 { animation-delay: 0.6s; }

/* ---------- 头部导航 ---------- */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1000;
  background: rgba(20, 20, 31, 0.92);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--border-color);
  transition: box-shadow 0.3s ease, background 0.3s ease;
}

.site-header.scrolled {
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.45);
  background: rgba(16, 16, 26, 0.98);
}

.navbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.45rem;
  font-weight: 800;
  letter-spacing: 1px;
}

.brand-icon {
  width: 42px;
  height: 42px;
  border-radius: 12px;
  background: var(--gradient-main);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.3rem;
  color: #fff;
  box-shadow: 0 4px 16px rgba(255, 107, 53, 0.4);
}

.brand-text {
  background: var(--gradient-main);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 8px;
}

.nav-link {
  padding: 9px 18px;
  border-radius: 999px;
  font-size: 0.95rem;
  color: var(--text-muted);
  transition: color 0.3s ease, background 0.3s ease;
  position: relative;
}

.nav-link:hover,
.nav-link.active {
  color: #fff;
  background: rgba(255, 107, 53, 0.15);
}

.nav-link.active::after {
  content: '';
  position: absolute;
  bottom: 2px;
  left: 50%;
  transform: translateX(-50%);
  width: 20px;
  height: 3px;
  border-radius: 3px;
  background: var(--gradient-main);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
}

.nav-toggle span {
  width: 24px;
  height: 2px;
  background: #fff;
  border-radius: 2px;
  transition: transform 0.3s ease, opacity 0.3s ease;
}

.nav-toggle.open span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.nav-toggle.open span:nth-child(2) {
  opacity: 0;
}

.nav-toggle.open span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* ---------- Hero 主视觉 ---------- */
.hero {
  position: relative;
  padding: 160px 0 100px;
  background:
    radial-gradient(circle at 20% 20%, rgba(255, 107, 53, 0.18) 0%, transparent 45%),
    radial-gradient(circle at 80% 30%, rgba(255, 61, 90, 0.14) 0%, transparent 40%),
    linear-gradient(160deg, #1a1a2e 0%, #14141f 70%);
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -120px;
  right: -120px;
  width: 420px;
  height: 420px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(255, 107, 53, 0.12), transparent 70%);
  animation: float 6s ease-in-out infinite;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 48px;
  align-items: center;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 18px;
  border-radius: 999px;
  background: rgba(255, 107, 53, 0.15);
  border: 1px solid rgba(255, 107, 53, 0.35);
  color: var(--secondary);
  font-size: 0.85rem;
  font-weight: 600;
  margin-bottom: 22px;
}

.hero-badge .dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--accent);
  animation: pulse 1.8s infinite;
}

.hero h1 {
  font-size: clamp(2.2rem, 5vw, 3.6rem);
  font-weight: 900;
  line-height: 1.25;
  margin-bottom: 20px;
}

.hero h1 .highlight {
  background: var(--gradient-main);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-desc {
  font-size: 1.08rem;
  color: var(--text-muted);
  max-width: 560px;
  margin-bottom: 32px;
}

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

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 13px 30px;
  border-radius: 999px;
  font-size: 0.98rem;
  font-weight: 600;
  border: none;
  cursor: pointer;
  transition: transform 0.3s ease, box-shadow 0.3s ease, background 0.3s ease;
}

.btn-primary {
  background: var(--gradient-main);
  color: #fff;
  box-shadow: 0 6px 20px rgba(255, 107, 53, 0.4);
}

.btn-primary:hover {
  transform: translateY(-3px);
  box-shadow: 0 10px 28px rgba(255, 107, 53, 0.55);
}

.btn-outline {
  background: transparent;
  color: #fff;
  border: 1.5px solid rgba(255, 255, 255, 0.25);
}

.btn-outline:hover {
  border-color: var(--primary);
  color: var(--primary);
  transform: translateY(-3px);
}

.btn-light {
  background: #fff;
  color: var(--primary-dark);
}

.btn-light:hover {
  transform: translateY(-3px);
  box-shadow: 0 10px 26px rgba(255, 255, 255, 0.25);
}

.hero-stats {
  display: flex;
  gap: 34px;
  margin-top: 34px;
}

.hero-stats .stat-item {
  text-align: left;
}

.hero-stats .stat-num {
  font-size: 1.9rem;
  font-weight: 800;
  color: var(--secondary);
}

.hero-stats .stat-label {
  font-size: 0.85rem;
  color: var(--text-muted);
}

.hero-visual {
  position: relative;
}

.hero-card {
  background: var(--card-bg);
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  padding: 20px;
  box-shadow: var(--shadow);
  animation: float 5s ease-in-out infinite;
}

.hero-card .card-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 14px;
}

.hero-card .card-title {
  font-weight: 700;
  font-size: 0.95rem;
}

.hero-card .live-tag {
  background: var(--accent);
  color: #fff;
  font-size: 0.72rem;
  padding: 4px 10px;
  border-radius: 999px;
  animation: pulse 1.6s infinite;
}

.hero-card .hot-item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 0;
  border-bottom: 1px dashed var(--border-color);
}

.hero-card .hot-item:last-child {
  border-bottom: none;
}

.hot-rank {
  width: 28px;
  height: 28px;
  border-radius: 8px;
  background: rgba(255, 107, 53, 0.18);
  color: var(--primary);
  font-size: 0.82rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.hot-rank.top {
  background: var(--gradient-main);
  color: #fff;
}

.hot-text {
  flex: 1;
  font-size: 0.88rem;
  color: var(--text-muted);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.hot-heat {
  font-size: 0.75rem;
  color: var(--secondary);
  flex-shrink: 0;
}

/* ---------- 通用 Section ---------- */
.section {
  padding: 96px 0;
}

.section-head {
  text-align: center;
  max-width: 720px;
  margin: 0 auto 56px;
}

.section-tag {
  display: inline-block;
  padding: 6px 16px;
  border-radius: 999px;
  background: rgba(255, 107, 53, 0.12);
  color: var(--primary);
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 1px;
  margin-bottom: 16px;
  text-transform: uppercase;
}

.section h2 {
  font-size: clamp(1.7rem, 3.5vw, 2.5rem);
  font-weight: 800;
  margin-bottom: 14px;
}

.section-sub {
  color: var(--text-muted);
  font-size: 1rem;
}

.section-alt {
  background: var(--dark-bg-2);
}

/* ---------- 特性区 ---------- */
.features-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

.feature-card {
  background: var(--card-bg);
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  padding: 30px 24px;
  transition: transform 0.35s ease, border-color 0.35s ease, box-shadow 0.35s ease;
}

.feature-card:hover {
  transform: translateY(-8px);
  border-color: rgba(255, 107, 53, 0.5);
  box-shadow: 0 16px 40px rgba(0, 0, 0, 0.4);
}

.feature-icon {
  width: 60px;
  height: 60px;
  border-radius: 16px;
  background: var(--gradient-main);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.6rem;
  margin-bottom: 18px;
  box-shadow: 0 6px 18px rgba(255, 107, 53, 0.3);
}

.feature-card h3 {
  font-size: 1.1rem;
  margin-bottom: 10px;
}

.feature-card p {
  font-size: 0.9rem;
  color: var(--text-muted);
}

/* ---------- 服务介绍 ---------- */
.services-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.service-card {
  background: var(--card-bg);
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  overflow: hidden;
  transition: transform 0.35s ease, box-shadow 0.35s ease;
}

.service-card:hover {
  transform: translateY(-6px);
  box-shadow: 0 16px 40px rgba(0, 0, 0, 0.45);
}

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

.service-card:hover .service-img {
  transform: scale(1.05);
}

.service-body {
  padding: 24px;
}

.service-body h3 {
  font-size: 1.1rem;
  margin-bottom: 10px;
}

.service-body p {
  font-size: 0.9rem;
  color: var(--text-muted);
  margin-bottom: 14px;
}

.service-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.8rem;
  color: var(--text-muted);
}

.service-meta .hot-badge {
  color: var(--accent);
  font-weight: 700;
}

/* ---------- 新闻列表 ---------- */
.news-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.news-card {
  background: var(--card-bg);
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  overflow: hidden;
  transition: transform 0.35s ease, box-shadow 0.35s ease;
}

.news-card:hover {
  transform: translateY(-6px);
  box-shadow: 0 16px 40px rgba(0, 0, 0, 0.45);
}

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

.news-card:hover .news-img {
  transform: scale(1.04);
}

.news-body {
  padding: 22px;
}

.news-cat {
  display: inline-block;
  font-size: 0.72rem;
  color: var(--primary);
  background: rgba(255, 107, 53, 0.12);
  padding: 3px 10px;
  border-radius: 999px;
  margin-bottom: 10px;
  font-weight: 600;
}

.news-body h3 {
  font-size: 1.02rem;
  line-height: 1.5;
  margin-bottom: 10px;
}

.news-body h3 a {
  transition: color 0.3s ease;
}

.news-body h3 a:hover {
  color: var(--primary);
}

.news-body p {
  font-size: 0.86rem;
  color: var(--text-muted);
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
  margin-bottom: 14px;
}

.news-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.78rem;
  color: var(--text-muted);
  border-top: 1px solid var(--border-color);
  padding-top: 12px;
}

/* ---------- 热门榜单 ---------- */
.hot-list {
  background: var(--card-bg);
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  padding: 30px;
}

.hot-list-item {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 16px 0;
  border-bottom: 1px dashed var(--border-color);
  transition: padding-left 0.3s ease;
}

.hot-list-item:hover {
  padding-left: 8px;
}

.hot-list-item:last-child {
  border-bottom: none;
}

.hot-rank-lg {
  width: 44px;
  height: 44px;
  border-radius: 12px;
  background: rgba(255, 255, 255, 0.06);
  color: var(--text-muted);
  font-size: 1.1rem;
  font-weight: 800;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.hot-rank-lg.top-1 { background: var(--gradient-main); color: #fff; }
.hot-rank-lg.top-2 { background: linear-gradient(135deg, #c0c0d0, #7a7a92); color: #fff; }
.hot-rank-lg.top-3 { background: linear-gradient(135deg, #d9a05b, #8c5a22); color: #fff; }

.hot-list-info {
  flex: 1;
}

.hot-list-info h3 {
  font-size: 0.98rem;
  margin-bottom: 4px;
}

.hot-list-info p {
  font-size: 0.8rem;
  color: var(--text-muted);
}

.hot-list-heat {
  font-size: 0.82rem;
  color: var(--secondary);
  flex-shrink: 0;
}

/* ---------- FAQ ---------- */
.faq-wrap {
  max-width: 820px;
  margin: 0 auto;
}

.faq-item {
  background: var(--card-bg);
  border: 1px solid var(--border-color);
  border-radius: 14px;
  margin-bottom: 16px;
  overflow: hidden;
  transition: border-color 0.3s ease;
}

.faq-item.open {
  border-color: rgba(255, 107, 53, 0.45);
}

.faq-question {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 20px 24px;
  background: none;
  border: none;
  color: #fff;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  text-align: left;
  font-family: var(--font-main);
}

.faq-icon {
  font-size: 1.2rem;
  color: var(--primary);
  transition: transform 0.3s ease;
  flex-shrink: 0;
}

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

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.4s ease;
}

.faq-item.open .faq-answer {
  max-height: 300px;
}

.faq-answer p {
  padding: 0 24px 22px;
  color: var(--text-muted);
  font-size: 0.92rem;
}

/* ---------- CTA ---------- */
.cta {
  padding: 90px 0;
  background:
    radial-gradient(circle at 50% 120%, rgba(255, 107, 53, 0.28) 0%, transparent 60%),
    linear-gradient(135deg, #2a1830 0%, #1d1d2e 60%, #14141f 100%);
  text-align: center;
}

.cta h2 {
  font-size: clamp(1.8rem, 4vw, 2.6rem);
  font-weight: 800;
  margin-bottom: 16px;
}

.cta p {
  color: var(--text-muted);
  max-width: 620px;
  margin: 0 auto 34px;
  font-size: 1.02rem;
}

/* ---------- 内容区（详细页） ---------- */
.page-hero {
  padding: 150px 0 60px;
  text-align: center;
  background:
    radial-gradient(circle at 20% 20%, rgba(255, 107, 53, 0.15) 0%, transparent 45%),
    var(--dark-bg);
}

.page-hero h1 {
  font-size: clamp(1.9rem, 4vw, 2.8rem);
  font-weight: 800;
  margin-bottom: 12px;
}

.page-hero .breadcrumb {
  color: var(--text-muted);
  font-size: 0.9rem;
}

.page-hero .breadcrumb a {
  color: var(--primary);
}

.content-section {
  padding: 70px 0;
}

.content-grid {
  display: grid;
  grid-template-columns: 2fr 1fr;
  gap: 40px;
  align-items: start;
}

.content-block {
  background: var(--card-bg);
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  padding: 30px;
  margin-bottom: 28px;
}

.content-block h2 {
  font-size: 1.5rem;
  margin-bottom: 16px;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--border-color);
  position: relative;
}

.content-block h2::after {
  content: '';
  position: absolute;
  left: 0;
  bottom: -2px;
  width: 60px;
  height: 3px;
  border-radius: 3px;
  background: var(--gradient-main);
}

.content-block h3 {
  font-size: 1.15rem;
  margin: 18px 0 10px;
  color: var(--secondary);
}

.content-block p {
  color: var(--text-muted);
  margin-bottom: 14px;
  font-size: 0.95rem;
}

.content-block ul {
  margin: 12px 0 18px;
  padding-left: 6px;
}

.content-block ul li {
  position: relative;
  padding-left: 22px;
  margin-bottom: 10px;
  color: var(--text-muted);
  font-size: 0.95rem;
}

.content-block ul li::before {
  content: '◆';
  position: absolute;
  left: 0;
  color: var(--primary);
  font-size: 0.8rem;
  top: 2px;
}

.sidebar-card {
  background: var(--card-bg);
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  padding: 24px;
  margin-bottom: 24px;
}

.sidebar-card h3 {
  font-size: 1.05rem;
  margin-bottom: 16px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--border-color);
}

.sidebar-card ul li {
  padding: 10px 0;
  border-bottom: 1px dashed var(--border-color);
}

.sidebar-card ul li:last-child {
  border-bottom: none;
}

.sidebar-card ul li a {
  font-size: 0.88rem;
  color: var(--text-muted);
  transition: color 0.3s ease, padding-left 0.3s ease;
  display: inline-block;
}

.sidebar-card ul li a:hover {
  color: var(--primary);
  padding-left: 6px;
}

/* ---------- 详情文章 ---------- */
.article-hero-img {
  width: 100%;
  max-height: 460px;
  object-fit: cover;
  border-radius: var(--radius);
  margin-bottom: 28px;
}

.article-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 18px;
  color: var(--text-muted);
  font-size: 0.85rem;
  margin-bottom: 24px;
  padding-bottom: 20px;
  border-bottom: 1px solid var(--border-color);
}

.article-body h3 {
  color: var(--secondary);
  margin: 24px 0 12px;
}

/* ---------- 产品页 ---------- */
.products-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.product-card {
  background: var(--card-bg);
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  overflow: hidden;
  transition: transform 0.35s ease, box-shadow 0.35s ease;
  display: flex;
  flex-direction: column;
}

.product-card:hover {
  transform: translateY(-8px);
  box-shadow: 0 18px 44px rgba(0, 0, 0, 0.5);
}

.product-img {
  width: 100%;
  height: 210px;
  object-fit: cover;
}

.product-body {
  padding: 24px;
  flex: 1;
  display: flex;
  flex-direction: column;
}

.product-body h3 {
  font-size: 1.1rem;
  margin-bottom: 8px;
}

.product-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 12px;
}

.product-tags span {
  font-size: 0.72rem;
  color: var(--primary);
  background: rgba(255, 107, 53, 0.1);
  padding: 3px 10px;
  border-radius: 999px;
}

.product-body p {
  font-size: 0.88rem;
  color: var(--text-muted);
  flex: 1;
  margin-bottom: 16px;
}

.product-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-top: 1px solid var(--border-color);
  padding-top: 14px;
}

.product-price {
  font-size: 1.1rem;
  font-weight: 800;
  color: var(--secondary);
}

.product-link {
  font-size: 0.85rem;
  color: var(--primary);
  font-weight: 600;
  transition: letter-spacing 0.3s ease;
}

.product-link:hover {
  letter-spacing: 1px;
}

/* ---------- 联系页 ---------- */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 40px;
  align-items: start;
}

.contact-info-item {
  display: flex;
  gap: 16px;
  padding: 18px 0;
  border-bottom: 1px dashed var(--border-color);
  align-items: flex-start;
}

.contact-info-item .ci-icon {
  width: 48px;
  height: 48px;
  border-radius: 14px;
  background: rgba(255, 107, 53, 0.12);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.3rem;
  flex-shrink: 0;
}

.contact-info-item h3 {
  font-size: 1rem;
  margin-bottom: 4px;
}

.contact-info-item p {
  font-size: 0.9rem;
  color: var(--text-muted);
}

.contact-form {
  background: var(--card-bg);
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  padding: 30px;
}

.form-group {
  margin-bottom: 20px;
}

.form-group label {
  display: block;
  font-size: 0.88rem;
  margin-bottom: 8px;
  color: var(--text-muted);
}

.form-group input,
.form-group textarea,
.form-group select {
  width: 100%;
  padding: 13px 16px;
  border-radius: 10px;
  border: 1px solid var(--border-color);
  background: rgba(255, 255, 255, 0.05);
  color: #fff;
  font-family: var(--font-main);
  font-size: 0.92rem;
  transition: border-color 0.3s ease, box-shadow 0.3s ease;
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(255, 107, 53, 0.15);
}

.form-group textarea {
  min-height: 140px;
  resize: vertical;
}

.form-tip {
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-top: 6px;
}

/* ---------- 页脚 ---------- */
.site-footer {
  background: #101018;
  border-top: 1px solid var(--border-color);
  padding: 64px 0 0;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1.4fr;
  gap: 40px;
  padding-bottom: 44px;
}

.footer-brand .brand {
  margin-bottom: 16px;
}

.footer-brand p {
  color: var(--text-muted);
  font-size: 0.9rem;
  margin-bottom: 20px;
  max-width: 320px;
}

.footer-title {
  font-size: 1.02rem;
  font-weight: 700;
  margin-bottom: 18px;
}

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

.footer-links a {
  color: var(--text-muted);
  font-size: 0.9rem;
  transition: color 0.3s ease, padding-left 0.3s ease;
}

.footer-links a:hover {
  color: var(--primary);
  padding-left: 5px;
}

.footer-newsletter {
  color: var(--text-muted);
  font-size: 0.88rem;
  margin-bottom: 16px;
}

.newsletter-form {
  display: flex;
  gap: 10px;
}

.newsletter-form input {
  flex: 1;
  padding: 11px 14px;
  border-radius: 10px;
  border: 1px solid var(--border-color);
  background: rgba(255, 255, 255, 0.05);
  color: #fff;
  font-family: var(--font-main);
}

.newsletter-form button {
  padding: 11px 18px;
  border-radius: 10px;
  border: none;
  background: var(--gradient-main);
  color: #fff;
  font-weight: 600;
  cursor: pointer;
  font-family: var(--font-main);
  transition: transform 0.3s ease;
}

.newsletter-form button:hover {
  transform: scale(1.04);
}

.footer-bottom {
  border-top: 1px solid var(--border-color);
  padding: 22px 0;
  text-align: center;
  color: var(--text-muted);
  font-size: 0.85rem;
}

.footer-bottom .heart {
  color: var(--accent);
}

/* ---------- 返回顶部 ---------- */
.back-top {
  position: fixed;
  right: 28px;
  bottom: 28px;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: var(--gradient-main);
  color: #fff;
  border: none;
  font-size: 1.2rem;
  cursor: pointer;
  box-shadow: 0 8px 24px rgba(255, 107, 53, 0.4);
  opacity: 0;
  visibility: hidden;
  transform: translateY(20px);
  transition: opacity 0.3s ease, transform 0.3s ease, visibility 0.3s;
  z-index: 900;
}

.back-top.show {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.back-top:hover {
  transform: translateY(-4px);
}

/* ---------- 响应式 ---------- */
@media (max-width: 1024px) {
  .features-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .services-grid,
  .news-grid,
  .products-grid {
    grid-template-columns: repeat(2, 1fr);
  }

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

@media (max-width: 768px) {
  .section {
    padding: 70px 0;
  }

  .nav-toggle {
    display: flex;
  }

  .nav-menu {
    position: fixed;
    top: 72px;
    left: 0;
    width: 100%;
    flex-direction: column;
    align-items: stretch;
    gap: 4px;
    background: rgba(20, 20, 31, 0.98);
    padding: 16px 24px 24px;
    border-bottom: 1px solid var(--border-color);
    transform: translateY(-120%);
    opacity: 0;
    visibility: hidden;
    transition: transform 0.35s ease, opacity 0.35s ease, visibility 0.35s;
  }

  .nav-menu.open {
    transform: translateY(0);
    opacity: 1;
    visibility: visible;
  }

  .nav-link {
    padding: 13px 16px;
    font-size: 1rem;
    border-radius: 12px;
  }

  .hero {
    padding: 130px 0 70px;
  }

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

  .hero-visual {
    order: -1;
  }

  .hero-card {
    padding: 16px;
  }

  .hero-stats {
    gap: 20px;
  }

  .features-grid,
  .services-grid,
  .news-grid,
  .products-grid,
  .content-grid,
  .contact-grid {
    grid-template-columns: 1fr;
  }

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

  .back-top {
    right: 16px;
    bottom: 16px;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 16px;
  }

  .brand-text {
    font-size: 1.15rem;
  }

  .hero h1 {
    font-size: 1.8rem;
  }

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

  .btn {
    width: 100%;
  }

  .content-block {
    padding: 22px;
  }
}