/* ========================================
   style.css - MK体育 (cat-mksports.com)
   风格：科技金黑 · 渐变 · 毛玻璃 · 圆角卡片
   暗色模式 · 响应式 · 滚动动画 · hover动效
   ======================================== */

/* ===== 基础重置与变量 ===== */
:root {
  --bg: #f4f6fc;
  --surface: #ffffff;
  --text: #1a1a2e;
  --text2: #4a4a6a;
  --primary: #1a1a2e;
  --accent: #f0c040;
  --accent2: #e6a800;
  --border: #e0e4f0;
  --shadow: 0 8px 30px rgba(0, 0, 0, 0.07);
  --radius: 20px;
  --transition: 0.35s cubic-bezier(0.4, 0, 0.2, 1);
  --glass-bg: rgba(255, 255, 255, 0.6);
  --glass-border: rgba(255, 255, 255, 0.25);
  --hero-start: #0d0d2b;
  --hero-mid: #1a1a4e;
  --hero-end: #2a1a5e;
  --font: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
}

.dark {
  --bg: #0b0b1a;
  --surface: #151528;
  --text: #e8e8f5;
  --text2: #9a9abf;
  --border: #2a2a4a;
  --shadow: 0 8px 30px rgba(0, 0, 0, 0.6);
  --glass-bg: rgba(21, 21, 40, 0.7);
  --glass-border: rgba(255, 255, 255, 0.08);
  --hero-start: #050512;
  --hero-mid: #0f0f2a;
  --hero-end: #1a0f3a;
}

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

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
}

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  transition: background var(--transition), color var(--transition);
  overflow-x: hidden;
}

a {
  color: var(--accent2);
  text-decoration: none;
  transition: color var(--transition);
}

a:hover {
  text-decoration: underline;
  color: var(--accent);
}

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

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  border: 0;
}

/* ===== 滚动动画（通用） ===== */
.fade-up {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}

.fade-up.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ===== 顶部导航 ===== */
header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--glass-bg);
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  border-bottom: 1px solid var(--glass-border);
  transition: background var(--transition), border-color var(--transition);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 68px;
}

.logo {
  font-size: 1.6rem;
  font-weight: 800;
  color: var(--accent);
  letter-spacing: -0.5px;
  background: linear-gradient(135deg, var(--accent), #ffd966);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.logo span {
  color: var(--text);
  -webkit-text-fill-color: var(--text);
}

nav {
  display: flex;
  gap: 28px;
  align-items: center;
}

nav a {
  color: var(--text2);
  font-weight: 500;
  font-size: 0.95rem;
  transition: color var(--transition), transform 0.2s;
  position: relative;
}

nav a::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--accent);
  transition: width var(--transition);
}

nav a:hover {
  color: var(--accent);
  transform: translateY(-1px);
  text-decoration: none;
}

nav a:hover::after {
  width: 100%;
}

.menu-toggle {
  display: none;
  background: none;
  border: none;
  font-size: 1.5rem;
  color: var(--text);
  cursor: pointer;
  padding: 4px;
  transition: color var(--transition);
}

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

/* 暗色模式切换按钮 */
.dark-toggle {
  background: none;
  border: 1px solid var(--border);
  border-radius: 50%;
  width: 38px;
  height: 38px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  color: var(--text);
  font-size: 1.15rem;
  transition: background var(--transition), color var(--transition), border-color var(--transition), transform 0.2s;
}

.dark-toggle:hover {
  background: var(--accent);
  color: var(--primary);
  border-color: var(--accent);
  transform: scale(1.1);
}

/* 移动端导航 */
@media (max-width: 768px) {
  nav {
    display: none;
    flex-direction: column;
    position: absolute;
    top: 68px;
    left: 0;
    right: 0;
    background: var(--glass-bg);
    backdrop-filter: blur(20px) saturate(180%);
    -webkit-backdrop-filter: blur(20px) saturate(180%);
    padding: 24px 20px;
    border-bottom: 1px solid var(--glass-border);
    gap: 18px;
    box-shadow: var(--shadow);
    animation: slideDown 0.35s ease;
  }

  nav.open {
    display: flex;
  }

  .menu-toggle {
    display: block;
  }
}

@keyframes slideDown {
  from {
    opacity: 0;
    transform: translateY(-12px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ===== Hero 区域 ===== */
.hero {
  background: linear-gradient(135deg, var(--hero-start), var(--hero-mid), var(--hero-end));
  color: #fff;
  padding: 100px 0 120px;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: radial-gradient(circle at 30% 50%, rgba(240, 192, 64, 0.08) 0%, transparent 60%),
              radial-gradient(circle at 70% 30%, rgba(255, 215, 0, 0.06) 0%, transparent 50%);
  animation: heroGlow 12s ease-in-out infinite alternate;
  pointer-events: none;
}

@keyframes heroGlow {
  0% { transform: translate(0, 0) rotate(0deg); }
  100% { transform: translate(2%, 2%) rotate(3deg); }
}

.hero::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 80px;
  background: var(--bg);
  border-radius: 50% 50% 0 0 / 100% 100% 0 0;
  transition: background var(--transition);
}

.hero h1 {
  font-size: clamp(2rem, 5vw, 3.6rem);
  font-weight: 800;
  margin-bottom: 18px;
  line-height: 1.2;
  letter-spacing: -0.02em;
  position: relative;
  z-index: 1;
  background: linear-gradient(to right, #fff, #f0c040, #ffd966);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero p {
  font-size: 1.2rem;
  max-width: 680px;
  margin: 0 auto 36px;
  color: rgba(255, 255, 255, 0.8);
  position: relative;
  z-index: 1;
}

.hero .btn {
  display: inline-block;
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  color: var(--primary);
  padding: 16px 48px;
  border-radius: 50px;
  font-weight: 700;
  font-size: 1.05rem;
  transition: transform var(--transition), box-shadow var(--transition);
  border: none;
  cursor: pointer;
  position: relative;
  z-index: 1;
  box-shadow: 0 4px 20px rgba(240, 192, 64, 0.35);
}

.hero .btn:hover {
  transform: translateY(-3px) scale(1.02);
  box-shadow: 0 8px 30px rgba(240, 192, 64, 0.5);
  text-decoration: none;
}

/* ===== 通用 Section ===== */
section {
  padding: 70px 0;
  transition: background var(--transition);
}

.section-title {
  font-size: clamp(1.6rem, 3vw, 2.3rem);
  font-weight: 700;
  margin-bottom: 12px;
  text-align: center;
  letter-spacing: -0.01em;
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.section-sub {
  text-align: center;
  color: var(--text2);
  max-width: 600px;
  margin: 0 auto 44px;
  font-size: 1.05rem;
}

/* ===== 卡片网格 ===== */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 28px;
}

.card {
  background: var(--surface);
  border-radius: var(--radius);
  padding: 32px 28px;
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
  transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition);
  backdrop-filter: blur(4px);
}

.card:hover {
  transform: translateY(-6px);
  box-shadow: 0 16px 40px rgba(0, 0, 0, 0.1);
  border-color: var(--accent);
}

.card h3 {
  font-size: 1.2rem;
  margin-bottom: 10px;
  color: var(--accent);
}

.card p {
  color: var(--text2);
  font-size: 0.95rem;
  line-height: 1.6;
}

/* ===== 关于我们 ===== */
.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: center;
}

@media (max-width: 768px) {
  .about-grid {
    grid-template-columns: 1fr;
    gap: 32px;
  }
}

.about-text h2 {
  font-size: 1.8rem;
  margin-bottom: 16px;
}

.about-text p {
  color: var(--text2);
  margin-bottom: 14px;
}

.about-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  text-align: center;
}

.stat-value {
  font-size: 2.2rem;
  font-weight: 800;
  color: var(--accent);
  line-height: 1.2;
}

.stat-label {
  font-size: 0.9rem;
  color: var(--text2);
  margin-top: 4px;
}

/* ===== 产品图标 ===== */
.product-icon {
  width: 52px;
  height: 52px;
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.6rem;
  margin-bottom: 14px;
  color: var(--primary);
  font-weight: 700;
  box-shadow: 0 4px 12px rgba(240, 192, 64, 0.2);
}

/* ===== 用户评价 ===== */
.testimonial {
  background: var(--surface);
  border-radius: var(--radius);
  padding: 32px 28px;
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
  transition: transform var(--transition), box-shadow var(--transition);
}

.testimonial:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 36px rgba(0, 0, 0, 0.08);
}

.testimonial p {
  font-style: italic;
  color: var(--text2);
  margin-bottom: 14px;
  font-size: 1rem;
}

.testimonial .author {
  font-weight: 600;
  color: var(--text);
}

/* ===== FAQ 手风琴 ===== */
.faq-item {
  border-bottom: 1px solid var(--border);
  padding: 18px 0;
  transition: border-color var(--transition);
}

.faq-question {
  display: flex;
  justify-content: space-between;
  align-items: center;
  cursor: pointer;
  font-weight: 600;
  font-size: 1.05rem;
  background: none;
  border: none;
  color: var(--text);
  width: 100%;
  text-align: left;
  padding: 6px 0;
  transition: color var(--transition);
}

.faq-question:hover {
  color: var(--accent);
}

.faq-question::after {
  content: '+';
  font-size: 1.4rem;
  transition: transform var(--transition), color var(--transition);
  color: var(--accent);
}

.faq-item.open .faq-question::after {
  content: '−';
  transform: rotate(180deg);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.45s ease, padding 0.3s ease;
  color: var(--text2);
  padding-top: 0;
}

.faq-item.open .faq-answer {
  max-height: 300px;
  padding-top: 14px;
}

/* ===== 指南步骤 ===== */
.howto-step {
  display: flex;
  gap: 18px;
  margin-bottom: 28px;
  align-items: flex-start;
}

.howto-num {
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  color: var(--primary);
  width: 40px;
  height: 40px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  flex-shrink: 0;
  font-size: 1.1rem;
  box-shadow: 0 4px 12px rgba(240, 192, 64, 0.25);
}

.howto-content h4 {
  font-weight: 600;
  margin-bottom: 4px;
}

.howto-content p {
  color: var(--text2);
  font-size: 0.95rem;
}

/* ===== 资讯卡片 ===== */
.blog-card .date {
  font-size: 0.85rem;
  color: var(--text2);
  margin-bottom: 6px;
}

.blog-card h3 {
  font-size: 1.1rem;
  margin-bottom: 6px;
}

.blog-card p {
  color: var(--text2);
  font-size: 0.9rem;
  margin-bottom: 12px;
}

.blog-card .read-more {
  font-weight: 600;
  color: var(--accent2);
  transition: color var(--transition), gap 0.2s;
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

.blog-card .read-more:hover {
  color: var(--accent);
  gap: 8px;
  text-decoration: none;
}

/* ===== 联系 ===== */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
}

@media (max-width: 768px) {
  .contact-grid {
    grid-template-columns: 1fr;
  }
}

.contact-info p {
  margin-bottom: 10px;
  color: var(--text2);
}

.contact-info strong {
  color: var(--text);
}

/* ===== 搜索框 ===== */
.search-box {
  display: flex;
  gap: 10px;
  max-width: 420px;
  margin: 0 auto 40px;
}

.search-box input {
  flex: 1;
  padding: 14px 20px;
  border: 1px solid var(--border);
  border-radius: 50px;
  background: var(--surface);
  color: var(--text);
  font-size: 0.95rem;
  outline: none;
  transition: border-color var(--transition), box-shadow var(--transition);
}

.search-box input:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(240, 192, 64, 0.15);
}

.search-box button {
  padding: 14px 24px;
  border-radius: 50px;
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  color: var(--primary);
  font-weight: 600;
  border: none;
  cursor: pointer;
  transition: transform var(--transition), box-shadow var(--transition);
}

.search-box button:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 16px rgba(240, 192, 64, 0.3);
}

/* ===== 轮播 ===== */
.carousel {
  position: relative;
  overflow: hidden;
  border-radius: var(--radius);
  margin-bottom: 48px;
  background: var(--surface);
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
}

.carousel-inner {
  display: flex;
  transition: transform 0.5s cubic-bezier(0.4, 0, 0.2, 1);
}

.carousel-item {
  min-width: 100%;
  padding: 48px 36px;
  text-align: center;
}

.carousel-item h3 {
  font-size: 1.5rem;
  margin-bottom: 10px;
  color: var(--accent);
}

.carousel-item p {
  color: var(--text2);
  max-width: 500px;
  margin: 0 auto;
}

.carousel-controls {
  display: flex;
  justify-content: center;
  gap: 14px;
  padding: 16px 0;
}

.carousel-btn {
  background: var(--border);
  border: none;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  cursor: pointer;
  font-size: 1.1rem;
  color: var(--text);
  transition: background var(--transition), color var(--transition), transform 0.2s;
}

.carousel-btn:hover {
  background: var(--accent);
  color: var(--primary);
  transform: scale(1.1);
}

/* ===== 页脚 ===== */
footer {
  background: var(--primary);
  color: rgba(255, 255, 255, 0.7);
  padding: 48px 0 24px;
  transition: background var(--transition);
}

.footer-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 36px;
  margin-bottom: 36px;
}

.footer-grid h4 {
  color: #fff;
  margin-bottom: 14px;
  font-size: 1rem;
  letter-spacing: 0.5px;
}

.footer-grid a {
  display: block;
  color: rgba(255, 255, 255, 0.6);
  font-size: 0.9rem;
  margin-bottom: 8px;
  transition: color var(--transition), padding-left 0.2s;
}

.footer-grid a:hover {
  color: var(--accent);
  padding-left: 4px;
  text-decoration: none;
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding-top: 24px;
  text-align: center;
  font-size: 0.85rem;
}

.footer-bottom a {
  color: var(--accent);
  margin: 0 8px;
  transition: color var(--transition);
}

.footer-bottom a:hover {
  color: #fff;
  text-decoration: none;
}

/* ===== 返回顶部 ===== */
.back-top {
  position: fixed;
  bottom: 32px;
  right: 32px;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  color: var(--primary);
  border: none;
  font-size: 1.4rem;
  cursor: pointer;
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.25);
  transition: opacity var(--transition), visibility var(--transition), transform var(--transition);
  opacity: 0;
  visibility: hidden;
  z-index: 99;
}

.back-top.visible {
  opacity: 1;
  visibility: visible;
}

.back-top:hover {
  transform: translateY(-4px) scale(1.05);
  box-shadow: 0 8px 28px rgba(240, 192, 64, 0.4);
}

/* ===== 暗色模式额外覆盖 ===== */
.dark .hero {
  background: linear-gradient(135deg, var(--hero-start), var(--hero-mid), var(--hero-end));
}

.dark .card,
.dark .testimonial,
.dark .carousel {
  background: var(--surface);
}

.dark .card:hover {
  border-color: var(--accent);
}

/* ===== 响应式微调 ===== */
@media (max-width: 480px) {
  .container {
    padding: 0 16px;
  }

  .hero {
    padding: 70px 0 90px;
  }

  .hero .btn {
    padding: 14px 36px;
    font-size: 0.95rem;
  }

  .card {
    padding: 24px 20px;
  }

  .about-stats {
    gap: 12px;
  }

  .stat-value {
    font-size: 1.8rem;
  }

  .carousel-item {
    padding: 32px 20px;
  }

  .footer-grid {
    gap: 24px;
  }
}

/* ===== 辅助工具类 ===== */
.text-center {
  text-align: center;
}

.mt-20 {
  margin-top: 20px;
}

.mb-20 {
  margin-bottom: 20px;
}

.gap-12 {
  gap: 12px;
}

.flex-center {
  display: flex;
  justify-content: center;
  align-items: center;
}