:root {
  --primary: #2b2d42;
  --accent: #ef233c;
  --accent-2: #d90429;
  --light: #edf2f4;
  --mid: #8d99ae;
  --bg: #ffffff;
  --text: #1a1a2e;
  --card-bg: #f8f9fa;
  --border: #e0e0e0;
  --glass: rgba(255, 255, 255, 0.7);
  --glass-border: rgba(255, 255, 255, 0.35);
  --shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 12px 40px rgba(0, 0, 0, 0.12);
  --radius: 16px;
  --radius-sm: 10px;
  --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

[data-theme="dark"] {
  --primary: #edf2f4;
  --accent: #ef233c;
  --accent-2: #ff4d6d;
  --light: #1a1a2e;
  --mid: #8d99ae;
  --bg: #0f0f1a;
  --text: #edf2f4;
  --card-bg: #1a1a2e;
  --border: #2b2d42;
  --glass: rgba(26, 26, 46, 0.7);
  --glass-border: rgba(255, 255, 255, 0.08);
  --shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
  --shadow-lg: 0 12px 40px rgba(0, 0, 0, 0.5);
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: 80px;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.8;
  transition: background var(--transition), color var(--transition);
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

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

a:hover {
  color: var(--accent-2);
}

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

ul, ol {
  list-style: none;
}

button {
  font-family: inherit;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

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

/* ========== Header 毛玻璃 ========== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: var(--glass);
  border-bottom: 1px solid var(--glass-border);
  -webkit-backdrop-filter: blur(16px) saturate(180%);
  backdrop-filter: blur(16px) saturate(180%);
  transition: box-shadow var(--transition), background var(--transition);
}

.site-header.scrolled {
  box-shadow: var(--shadow);
  background: var(--glass);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
  gap: 16px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 800;
  font-size: 1.2rem;
  color: var(--text);
  letter-spacing: -0.02em;
}

.logo svg {
  width: 36px;
  height: 36px;
  flex-shrink: 0;
  transition: transform var(--transition);
}

.logo:hover svg {
  transform: rotate(-6deg) scale(1.05);
}

.main-nav {
  display: flex;
  gap: 2px;
}

.main-nav a {
  padding: 8px 14px;
  border-radius: 8px;
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text);
  white-space: nowrap;
  transition: background var(--transition), color var(--transition);
}

.main-nav a:hover {
  background: var(--card-bg);
  color: var(--accent);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 8px;
}

.search-box {
  position: relative;
  display: flex;
  align-items: center;
}

.search-box input {
  width: 180px;
  padding: 8px 12px 8px 34px;
  border: 1px solid var(--border);
  border-radius: 20px;
  background: var(--card-bg);
  color: var(--text);
  font-size: 0.85rem;
  outline: none;
  transition: width var(--transition), border-color var(--transition), box-shadow var(--transition);
}

.search-box input:focus {
  width: 220px;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(239, 35, 60, 0.12);
}

.search-box svg {
  position: absolute;
  left: 10px;
  width: 16px;
  height: 16px;
  fill: var(--mid);
  pointer-events: none;
}

.theme-toggle,
.menu-toggle {
  background: none;
  border: 1px solid var(--border);
  border-radius: 8px;
  width: 38px;
  height: 38px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  color: var(--text);
  transition: background var(--transition), border-color var(--transition), transform var(--transition);
}

.theme-toggle:hover,
.menu-toggle:hover {
  background: var(--card-bg);
  border-color: var(--accent);
  transform: translateY(-1px);
}

.theme-toggle svg,
.menu-toggle svg {
  width: 20px;
  height: 20px;
  fill: currentColor;
}

.menu-toggle {
  display: none;
}

.mobile-nav {
  display: none;
  flex-direction: column;
  padding: 12px 20px 20px;
  border-top: 1px solid var(--border);
  background: var(--bg);
  animation: slideDown 0.3s ease;
}

.mobile-nav.open {
  display: flex;
}

.mobile-nav a {
  padding: 10px 0;
  border-bottom: 1px solid var(--border);
  color: var(--text);
  font-size: 0.95rem;
}

.mobile-nav a:last-child {
  border-bottom: none;
}

@keyframes slideDown {
  from { opacity: 0; transform: translateY(-8px); }
  to { opacity: 1; transform: translateY(0); }
}

/* ========== Breadcrumb ========== */
.breadcrumb {
  padding: 16px 0;
  font-size: 0.85rem;
  color: var(--mid);
}

.breadcrumb a {
  color: var(--mid);
}

.breadcrumb a:hover {
  color: var(--accent);
}

.breadcrumb span {
  margin: 0 6px;
}

/* ========== Banner 渐变 ========== */
.banner {
  position: relative;
  overflow: hidden;
  background: linear-gradient(135deg, #2b2d42 0%, #1a1a2e 45%, #3d1a24 100%);
  color: #fff;
  min-height: 440px;
  display: flex;
  align-items: center;
}

.banner::before {
  content: "";
  position: absolute;
  top: -50%;
  right: -10%;
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(239, 35, 60, 0.35) 0%, transparent 70%);
  border-radius: 50%;
  pointer-events: none;
  animation: floatBlob 12s ease-in-out infinite;
}

.banner::after {
  content: "";
  position: absolute;
  bottom: -40%;
  left: -5%;
  width: 500px;
  height: 500px;
  background: radial-gradient(circle, rgba(141, 153, 174, 0.25) 0%, transparent 70%);
  border-radius: 50%;
  pointer-events: none;
  animation: floatBlob 15s ease-in-out infinite reverse;
}

@keyframes floatBlob {
  0%, 100% { transform: translate(0, 0) scale(1); }
  50% { transform: translate(-30px, 30px) scale(1.1); }
}

.banner .container {
  position: relative;
  z-index: 2;
}

.banner-slides {
  position: relative;
  width: 100%;
}

.banner-slide {
  display: none;
  padding: 60px 0;
  animation: fadeIn 0.6s ease;
}

.banner-slide.active {
  display: block;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

.banner-slide h1 {
  font-size: 2.4rem;
  margin-bottom: 16px;
  line-height: 1.3;
  font-weight: 800;
  letter-spacing: -0.02em;
}

.banner-slide h1 span {
  color: var(--accent);
  background: linear-gradient(90deg, #ef233c, #ff4d6d);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.banner-slide p {
  font-size: 1.1rem;
  opacity: 0.9;
  max-width: 640px;
  margin-bottom: 24px;
}

.banner-cta {
  display: inline-block;
  padding: 12px 32px;
  background: var(--accent);
  color: #fff;
  border-radius: 30px;
  font-weight: 600;
  font-size: 1rem;
  box-shadow: 0 8px 24px rgba(239, 35, 60, 0.35);
  transition: background var(--transition), transform var(--transition), box-shadow var(--transition);
}

.banner-cta:hover {
  background: var(--accent-2);
  color: #fff;
  transform: translateY(-3px);
  box-shadow: 0 12px 32px rgba(239, 35, 60, 0.5);
}

.banner-dots {
  position: absolute;
  bottom: 20px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  gap: 8px;
  z-index: 3;
}

.banner-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.4);
  border: none;
  cursor: pointer;
  transition: background var(--transition), transform var(--transition);
}

.banner-dot.active {
  background: var(--accent);
  transform: scale(1.3);
}

/* ========== Sections ========== */
.section {
  padding: 64px 0;
}

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

.section-header {
  text-align: center;
  margin-bottom: 48px;
}

.section-header h2 {
  font-size: 2rem;
  margin-bottom: 12px;
  font-weight: 800;
  letter-spacing: -0.02em;
}

.section-header p {
  color: var(--mid);
  font-size: 1rem;
  max-width: 640px;
  margin: 0 auto;
}

.section-header .accent-line {
  width: 60px;
  height: 4px;
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
  margin: 16px auto 0;
  border-radius: 2px;
}

/* ========== Grids ========== */
.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.grid-2 {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}

.grid-4 {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

/* ========== Cards 圆角 + hover ========== */
.card {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px;
  transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition);
  position: relative;
  overflow: hidden;
}

.card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--transition);
}

.card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-lg);
  border-color: var(--accent);
}

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

.card h3 {
  font-size: 1.15rem;
  margin-bottom: 10px;
  font-weight: 700;
}

.card p {
  color: var(--mid);
  font-size: 0.92rem;
  line-height: 1.7;
}

.card-icon {
  width: 48px;
  height: 48px;
  margin-bottom: 16px;
}

.card-icon svg {
  width: 100%;
  height: 100%;
}

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

.stat-item .stat-number {
  font-size: 2.4rem;
  font-weight: 800;
  color: var(--accent);
  letter-spacing: -0.02em;
}

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

/* ========== Articles ========== */
.article-list {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}

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

.article-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: var(--accent);
}

.article-card .article-meta {
  font-size: 0.8rem;
  color: var(--mid);
  margin-bottom: 8px;
  display: flex;
  gap: 16px;
}

.article-card h3 {
  font-size: 1.05rem;
  margin-bottom: 8px;
}

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

.article-card .read-more {
  font-size: 0.88rem;
  font-weight: 600;
  display: inline-block;
  transition: transform var(--transition);
}

.article-card:hover .read-more {
  transform: translateX(4px);
}

/* ========== FAQ ========== */
.faq-list {
  max-width: 860px;
  margin: 0 auto;
}

.faq-item {
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  margin-bottom: 12px;
  overflow: hidden;
  background: var(--bg);
  transition: border-color var(--transition), box-shadow var(--transition);
}

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

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

.faq-question {
  width: 100%;
  padding: 18px 24px;
  background: none;
  border: none;
  text-align: left;
  font-size: 1rem;
  font-weight: 600;
  color: var(--text);
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  transition: background var(--transition);
}

.faq-question:hover {
  background: var(--card-bg);
}

.faq-question .faq-icon {
  transition: transform var(--transition);
  flex-shrink: 0;
}

.faq-question .faq-icon svg {
  width: 20px;
  height: 20px;
  fill: var(--mid);
}

.faq-item.open .faq-question .faq-icon {
  transform: rotate(180deg);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.35s ease, padding 0.35s ease;
  padding: 0 24px;
  color: var(--mid);
  font-size: 0.92rem;
  line-height: 1.8;
}

.faq-item.open .faq-answer {
  max-height: 500px;
  padding: 0 24px 20px;
}

/* ========== HowTo ========== */
.howto-steps {
  counter-reset: step;
  max-width: 860px;
  margin: 0 auto;
}

.howto-step {
  position: relative;
  padding: 24px 24px 24px 72px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  margin-bottom: 16px;
  background: var(--bg);
  transition: border-color var(--transition), transform var(--transition), box-shadow var(--transition);
}

.howto-step:hover {
  border-color: var(--accent);
  transform: translateX(4px);
  box-shadow: var(--shadow);
}

.howto-step::before {
  counter-increment: step;
  content: counter(step);
  position: absolute;
  left: 20px;
  top: 24px;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 0.95rem;
  box-shadow: 0 4px 12px rgba(239, 35, 60, 0.3);
}

.howto-step h3 {
  font-size: 1.05rem;
  margin-bottom: 6px;
}

.howto-step p {
  font-size: 0.9rem;
  color: var(--mid);
}

/* ========== Testimonials ========== */
.testimonial-card {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px;
  position: relative;
  transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition);
}

.testimonial-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: var(--accent);
}

.testimonial-card::before {
  content: '"';
  font-size: 4rem;
  color: var(--accent);
  opacity: 0.15;
  position: absolute;
  top: 8px;
  left: 20px;
  font-family: Georgia, serif;
  line-height: 1;
}

.testimonial-card p {
  font-size: 0.95rem;
  color: var(--mid);
  margin-bottom: 16px;
  position: relative;
  z-index: 1;
}

.testimonial-author {
  display: flex;
  align-items: center;
  gap: 12px;
}

.testimonial-avatar {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  overflow: hidden;
  flex-shrink: 0;
}

.testimonial-avatar svg {
  width: 100%;
  height: 100%;
}

.testimonial-name {
  font-weight: 600;
  font-size: 0.9rem;
}

.testimonial-role {
  font-size: 0.8rem;
  color: var(--mid);
}

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

.contact-info h3 {
  font-size: 1.3rem;
  margin-bottom: 16px;
}

.contact-item {
  display: flex;
  gap: 12px;
  margin-bottom: 16px;
  align-items: flex-start;
}

.contact-item svg {
  width: 22px;
  height: 22px;
  fill: var(--accent);
  flex-shrink: 0;
  margin-top: 3px;
}

.contact-item strong {
  display: block;
  font-size: 0.9rem;
  margin-bottom: 2px;
}

.contact-item span {
  font-size: 0.88rem;
  color: var(--mid);
}

.contact-form {
  display: flex;
  flex-direction: column;
  gap: 14px;
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px;
}

.contact-form input,
.contact-form textarea {
  padding: 12px 16px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--bg);
  color: var(--text);
  font-size: 0.92rem;
  font-family: inherit;
  outline: none;
  transition: border-color var(--transition), box-shadow var(--transition);
}

.contact-form input:focus,
.contact-form textarea:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(239, 35, 60, 0.12);
}

.contact-form textarea {
  min-height: 120px;
  resize: vertical;
}

.contact-form button {
  padding: 12px 24px;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  color: #fff;
  border: none;
  border-radius: 8px;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: transform var(--transition), box-shadow var(--transition), filter var(--transition);
  box-shadow: 0 6px 20px rgba(239, 35, 60, 0.3);
}

.contact-form button:hover {
  transform: translateY(-2px);
  box-shadow: 0 10px 28px rgba(239, 35, 60, 0.45);
  filter: brightness(1.05);
}

/* ========== Footer ========== */
.site-footer {
  background: var(--primary);
  color: #edf2f4;
  padding: 56px 0 0;
}

[data-theme="dark"] .site-footer {
  background: #0a0a14;
}

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

.footer-col h4 {
  font-size: 1rem;
  margin-bottom: 16px;
  font-weight: 700;
  color: #fff;
}

.footer-col p,
.footer-col a {
  font-size: 0.88rem;
  color: #8d99ae;
  line-height: 2;
}

.footer-col a {
  display: block;
  transition: color var(--transition), transform var(--transition);
}

.footer-col a:hover {
  color: var(--accent);
  transform: translateX(3px);
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding: 20px 0;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
  font-size: 0.82rem;
  color: #8d99ae;
}

.footer-bottom a {
  color: #8d99ae;
}

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

/* ========== Back to top ========== */
.back-to-top {
  position: fixed;
  bottom: 32px;
  right: 32px;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  color: #fff;
  border: none;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: opacity var(--transition), visibility var(--transition), transform var(--transition), box-shadow var(--transition);
  z-index: 999;
  box-shadow: 0 4px 16px rgba(239, 35, 60, 0.4);
}

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

.back-to-top:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 24px rgba(239, 35, 60, 0.6);
}

.back-to-top svg {
  width: 22px;
  height: 22px;
  fill: #fff;
}

/* ========== Scroll animations ========== */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.reveal.revealed {
  opacity: 1;
  transform: translateY(0);
}

/* ========== Responsive ========== */
@media (max-width: 1024px) {
  .grid-3 {
    grid-template-columns: repeat(2, 1fr);
  }
  .grid-4 {
    grid-template-columns: repeat(2, 1fr);
  }
  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 768px) {
  .main-nav {
    display: none;
  }
  .menu-toggle {
    display: flex;
  }
  .search-box input {
    width: 120px;
  }
  .search-box input:focus {
    width: 160px;
  }
  .banner-slide h1 {
    font-size: 1.6rem;
  }
  .banner {
    min-height: 360px;
  }
  .grid-3,
  .grid-2,
  .grid-4,
  .article-list {
    grid-template-columns: 1fr;
  }
  .stats-row {
    grid-template-columns: repeat(2, 1fr);
  }
  .contact-grid {
    grid-template-columns: 1fr;
  }
  .footer-grid {
    grid-template-columns: 1fr;
  }
  .section {
    padding: 40px 0;
  }
  .section-header h2 {
    font-size: 1.5rem;
  }
  .howto-step {
    padding: 20px 20px 20px 64px;
  }
  .howto-step::before {
    left: 16px;
    top: 20px;
    width: 32px;
    height: 32px;
  }
}

@media (max-width: 480px) {
  .header-inner {
    gap: 8px;
  }
  .search-box {
    display: none;
  }
  .banner-slide h1 {
    font-size: 1.35rem;
  }
  .banner-slide p {
    font-size: 0.95rem;
  }
  .stat-item .stat-number {
    font-size: 1.8rem;
  }
  .contact-form {
    padding: 20px;
  }
  .back-to-top {
    bottom: 20px;
    right: 20px;
    width: 44px;
    height: 44px;
  }
}

/* ========== Reduced motion ========== */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
  .reveal {
    opacity: 1;
    transform: none;
  }
}

/* ========== Selection & Scrollbar ========== */
::selection {
  background: var(--accent);
  color: #fff;
}

::-webkit-scrollbar {
  width: 10px;
  height: 10px;
}

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

::-webkit-scrollbar-thumb {
  background: var(--mid);
  border-radius: 5px;
  border: 2px solid var(--card-bg);
}

::-webkit-scrollbar-thumb:hover {
  background: var(--accent);
}