:root {
  --primary: #3964fe;
  --primary-dark: #2349d6;
  --primary-light: #6a8cff;
  --primary-soft: rgba(57, 100, 254, 0.08);
  --bg: #f8f9ff;
  --bg-elevated: #ffffff;
  --text: #0f1225;
  --text-secondary: #5a6078;
  --text-muted: #8b91a8;
  --border: #e2e5f2;
  --success: #16a34a;
  --warning: #d97706;
  --danger: #dc2626;
  --shadow-sm: 0 2px 8px rgba(15, 18, 37, 0.06);
  --shadow: 0 12px 32px rgba(15, 18, 37, 0.1);
  --shadow-lg: 0 24px 64px rgba(15, 18, 37, 0.14);
  --radius: 14px;
  --radius-sm: 10px;
  --max-width: 1180px;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Microsoft YaHei", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

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

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

.container {
  width: 92%;
  max-width: var(--max-width);
  margin: 0 auto;
}

.section {
  padding: 100px 0;
}

.section-title {
  font-size: clamp(28px, 4vw, 40px);
  font-weight: 700;
  line-height: 1.25;
  margin-bottom: 16px;
  letter-spacing: -0.02em;
}

.section-subtitle {
  font-size: 17px;
  color: var(--text-secondary);
  max-width: 680px;
  margin-bottom: 56px;
}

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

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

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 14px 28px;
  border-radius: 100px;
  font-size: 15px;
  font-weight: 600;
  border: none;
  cursor: pointer;
  transition: all 0.2s ease;
}

.btn-primary {
  background: var(--primary);
  color: #fff;
  box-shadow: 0 8px 20px rgba(57, 100, 254, 0.28);
}

.btn-primary:hover {
  background: var(--primary-dark);
  transform: translateY(-2px);
  box-shadow: 0 12px 28px rgba(57, 100, 254, 0.32);
}

.btn-secondary {
  background: #fff;
  color: var(--primary);
  border: 1.5px solid var(--primary);
}

.btn-secondary:hover {
  background: var(--primary-soft);
}

.btn-large {
  padding: 16px 36px;
  font-size: 16px;
}

.badge {
  display: inline-block;
  padding: 6px 14px;
  border-radius: 100px;
  background: var(--primary-soft);
  color: var(--primary);
  font-size: 13px;
  font-weight: 600;
  margin-bottom: 16px;
}

.card {
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

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

/* Header */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: rgba(248, 249, 255, 0.86);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid rgba(226, 229, 242, 0.6);
}

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

.logo {
  font-size: 22px;
  font-weight: 800;
  color: var(--text);
  display: flex;
  align-items: center;
  gap: 10px;
}

.logo-mark {
  width: 34px;
  height: 34px;
  background: var(--primary);
  border-radius: 9px;
  display: grid;
  place-items: center;
  color: #fff;
  font-size: 16px;
  font-weight: 800;
}

.nav {
  display: flex;
  align-items: center;
  gap: 36px;
}

.nav a {
  color: var(--text-secondary);
  font-size: 15px;
  font-weight: 500;
  transition: color 0.2s;
}

.nav a:hover {
  color: var(--primary);
}

.nav a.active {
  color: var(--primary);
  position: relative;
}

.nav a.active::after {
  content: '';
  position: absolute;
  left: 0;
  right: 0;
  bottom: -4px;
  height: 2px;
  background: var(--primary);
  border-radius: 2px;
}

.nav .btn-primary:hover {
  color: #fff;
}

.nav .btn {
  padding: 10px 22px;
  font-size: 14px;
}

.nav .btn-primary {
  color: #fff;
}

.mobile-menu-btn {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 6px;
}

.mobile-menu-btn span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--text);
  margin: 5px 0;
  border-radius: 2px;
}

/* Hero */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  position: relative;
  overflow: hidden;
  padding-top: 72px;
  background: linear-gradient(135deg, #eef2ff 0%, #f8f9ff 50%, #fff 100%);
}

.hero-bg {
  position: absolute;
  inset: 0;
  pointer-events: none;
}

.hero-orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(80px);
  opacity: 0.45;
}

.hero-orb-1 {
  width: 560px;
  height: 560px;
  background: var(--primary);
  top: -120px;
  right: -80px;
}

.hero-orb-2 {
  width: 420px;
  height: 420px;
  background: #7c3aed;
  bottom: -80px;
  left: -100px;
  opacity: 0.22;
}

.hero-content {
  position: relative;
  z-index: 2;
  max-width: 560px;
}

/* Hero illustration */
.hero > .container {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
}

.hero-illustration {
  position: relative;
  z-index: 2;
  display: flex;
  justify-content: flex-end;
}

.hero-mockup {
  width: 100%;
  max-width: 440px;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-lg);
  overflow: hidden;
}

.mockup-bar {
  background: #f4f6ff;
  padding: 10px 16px;
  display: flex;
  gap: 6px;
  align-items: center;
  border-bottom: 1px solid var(--border);
}

.mockup-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--border);
  display: inline-block;
}

.mockup-body {
  padding: 20px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.mockup-prompt {
  display: flex;
  align-items: center;
  gap: 8px;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 100px;
  padding: 9px 14px;
  font-size: 13px;
  color: var(--text-secondary);
}

.mockup-answer {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 14px;
}

.mockup-ai-badge {
  display: inline-block;
  background: var(--primary-soft);
  color: var(--primary);
  font-size: 11px;
  font-weight: 700;
  padding: 3px 10px;
  border-radius: 100px;
  margin-bottom: 8px;
}

.mockup-answer p {
  font-size: 13px;
  color: var(--text);
  line-height: 1.6;
  margin-bottom: 10px;
}

.mockup-brand {
  color: var(--primary);
  font-weight: 700;
  background: rgba(57,100,254,0.08);
  padding: 0 4px;
  border-radius: 4px;
}

.mockup-cite {
  display: flex;
  gap: 8px;
}

.mockup-cite span {
  font-size: 11px;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 3px 8px;
  color: var(--text-muted);
}

.mockup-metrics {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.mockup-metric {
  display: flex;
  align-items: center;
  gap: 10px;
}

.metric-label {
  font-size: 12px;
  color: var(--text-secondary);
  width: 56px;
  flex-shrink: 0;
}

.metric-bar {
  flex: 1;
  height: 6px;
  background: var(--border);
  border-radius: 100px;
  overflow: hidden;
}

.metric-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--primary), var(--primary-light));
  border-radius: 100px;
}

.metric-val {
  font-size: 12px;
  font-weight: 700;
  color: var(--primary);
  width: 32px;
  text-align: right;
  flex-shrink: 0;
}

.hero h1 {
  font-size: clamp(36px, 5.5vw, 64px);
  font-weight: 800;
  line-height: 1.12;
  margin-bottom: 24px;
  letter-spacing: -0.03em;
}

.hero h1 span {
  color: var(--primary);
}

.hero-desc {
  font-size: 18px;
  color: var(--text-secondary);
  max-width: 560px;
  margin-bottom: 36px;
}

.hero-actions {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  margin-bottom: 48px;
}

.hero-stats {
  display: flex;
  gap: 48px;
  flex-wrap: wrap;
}

.hero-stat strong {
  display: block;
  font-size: 32px;
  font-weight: 800;
  color: var(--primary);
  line-height: 1;
}

.hero-stat span {
  font-size: 14px;
  color: var(--text-secondary);
}

/* Marquee banner */
.marquee-wrap {
  position: absolute;
  bottom: 80px;
  left: 0;
  right: 0;
  overflow: hidden;
  opacity: 0.8;
}

.marquee-track {
  display: flex;
  gap: 24px;
  width: max-content;
  animation: marquee 32s linear infinite;
}

.marquee-item {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 12px 22px;
  background: rgba(255, 255, 255, 0.78);
  border: 1px solid var(--border);
  border-radius: 100px;
  font-size: 14px;
  font-weight: 500;
  color: var(--text-secondary);
  white-space: nowrap;
  backdrop-filter: blur(8px);
}

.marquee-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--primary);
}

@keyframes marquee {
  0% { transform: translateX(0); }
  100% { transform: translateX(-50%); }
}

/* Definition */
.definition-grid {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 48px;
  align-items: start;
}

.definition-text h2 {
  text-align: left;
}

.definition-text p {
  color: var(--text-secondary);
  margin-bottom: 24px;
}

.definition-list {
  list-style: none;
}

.definition-list li {
  display: flex;
  gap: 14px;
  margin-bottom: 18px;
  color: var(--text);
}

.definition-list .icon {
  width: 28px;
  height: 28px;
  border-radius: 50%;
  background: var(--primary-soft);
  color: var(--primary);
  display: grid;
  place-items: center;
  font-size: 13px;
  font-weight: 700;
  flex-shrink: 0;
}

.comparison-table {
  width: 100%;
  border-collapse: separate;
  border-spacing: 0;
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--border);
  background: var(--bg-elevated);
}

.comparison-table th,
.comparison-table td {
  padding: 18px 20px;
  text-align: left;
  border-bottom: 1px solid var(--border);
  font-size: 15px;
}

.comparison-table th {
  background: #f4f6ff;
  color: var(--text);
  font-weight: 600;
}

.comparison-table td:first-child {
  color: var(--text-secondary);
  width: 120px;
}

.comparison-table tr:last-child td {
  border-bottom: none;
}

.comparison-table .highlight {
  color: var(--primary);
  font-weight: 600;
}

/* CTA section with video background */
.cta-section {
  color: #fff;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.cta-video-bg {
  position: absolute;
  top: 50%;
  left: 50%;
  min-width: 100%;
  min-height: 100%;
  width: auto;
  height: auto;
  transform: translate(-50%, -50%);
  object-fit: cover;
  z-index: 0;
}

.cta-section::before {
  content: "";
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.35);
  z-index: 1;
}

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

.cta-section .section-title,
.cta-section .section-subtitle {
  color: #fff;
  margin-left: auto;
  margin-right: auto;
}

.cta-section .section-subtitle {
  opacity: 0.85;
}

.cta-section .btn-secondary {
  background: #fff;
  border-color: #fff;
  color: var(--primary);
}

.cta-section .btn-secondary:hover {
  background: rgba(255, 255, 255, 0.92);
}

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

.pricing-card {
  padding: 36px 28px;
  text-align: center;
  position: relative;
}

.pricing-card.featured {
  border: 2px solid var(--primary);
  box-shadow: var(--shadow);
}

.pricing-card.featured::before {
  content: "推荐";
  position: absolute;
  top: -1px;
  right: 24px;
  background: var(--primary);
  color: #fff;
  font-size: 12px;
  font-weight: 700;
  padding: 6px 14px;
  border-radius: 0 0 8px 8px;
}

.pricing-card h3 {
  font-size: 20px;
  margin-bottom: 8px;
}

.pricing-card .price {
  font-size: 42px;
  font-weight: 800;
  color: var(--primary);
  line-height: 1;
  margin: 24px 0 8px;
}

.pricing-card .price span {
  font-size: 15px;
  color: var(--text-secondary);
  font-weight: 500;
}

.pricing-card .price-note {
  font-size: 13px;
  color: var(--text-muted);
  margin-bottom: 24px;
}

.pricing-card ul {
  list-style: none;
  text-align: left;
  margin-bottom: 28px;
}

.pricing-card li {
  padding: 10px 0;
  border-bottom: 1px solid var(--border);
  font-size: 14px;
  color: var(--text-secondary);
  display: flex;
  gap: 10px;
}

.pricing-card li::before {
  content: "";
  width: 18px;
  height: 18px;
  background: var(--primary-soft);
  border-radius: 50%;
  flex-shrink: 0;
  margin-top: 2px;
}

/* Screenshots / Comparison */
.comparison-section {
  background: var(--bg-elevated);
}

.comparison-grid {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 48px;
  align-items: center;
}

.screenshot-stack {
  position: relative;
}

.screenshot {
  background: linear-gradient(145deg, #f4f6ff, #eef2ff);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  aspect-ratio: 16/10;
  display: grid;
  place-items: center;
  color: var(--text-muted);
  font-size: 15px;
  overflow: hidden;
}

.screenshot img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.screenshot-label {
  position: absolute;
  bottom: -16px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--text);
  color: #fff;
  padding: 8px 18px;
  border-radius: 100px;
  font-size: 13px;
  font-weight: 600;
}

.advantage-list {
  list-style: none;
}

.advantage-list li {
  display: flex;
  gap: 16px;
  padding: 22px 0;
  border-bottom: 1px solid var(--border);
}

.advantage-list li:last-child {
  border-bottom: none;
}

.advantage-list .adv-icon {
  width: 44px;
  height: 44px;
  border-radius: 12px;
  background: var(--primary-soft);
  color: var(--primary);
  display: grid;
  place-items: center;
  font-size: 18px;
  font-weight: 700;
  flex-shrink: 0;
}

.advantage-list h4 {
  font-size: 17px;
  margin-bottom: 6px;
}

.advantage-list p {
  font-size: 14px;
  color: var(--text-secondary);
}

/* FAQ */
.faq-grid {
  max-width: 840px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.faq-item {
  padding: 0;
  overflow: hidden;
}

.faq-item summary {
  padding: 22px 28px;
  font-size: 17px;
  font-weight: 600;
  cursor: pointer;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
  color: var(--text);
}

.faq-item summary::-webkit-details-marker {
  display: none;
}

.faq-item summary::after {
  content: "+";
  font-size: 24px;
  font-weight: 400;
  color: var(--primary);
  flex-shrink: 0;
  margin-left: 16px;
}

.faq-item[open] summary::after {
  content: "−";
}

.faq-answer {
  padding: 0 28px 24px;
  color: var(--text-secondary);
  font-size: 15px;
  line-height: 1.8;
}

.faq-answer p {
  margin-bottom: 0;
}

.faq-answer strong {
  color: var(--text);
}

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

.usecase-card {
  padding: 0;
  overflow: hidden;
}

.usecase-img {
  width: 100%;
  height: 180px;
  overflow: hidden;
}

.usecase-img img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.4s ease;
}

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

.usecase-body {
  padding: 24px 28px;
}

.usecase-card h3 {
  font-size: 19px;
  margin-bottom: 10px;
  color: var(--text);
}

.usecase-card p {
  font-size: 15px;
  color: var(--text-secondary);
  line-height: 1.7;
}

@media (max-width: 960px) {
  .usecase-grid {
    grid-template-columns: 1fr;
  }
}

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

.news-card {
  padding: 0;
  overflow: hidden;
}

.news-cover {
  width: 100%;
  height: 160px;
  overflow: hidden;
}

.news-cover img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.4s ease;
}

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

.news-body {
  padding: 22px 24px;
}

.news-card .date {
  font-size: 13px;
  color: var(--text-muted);
  margin-bottom: 10px;
}

.news-card h3 {
  font-size: 17px;
  margin-bottom: 10px;
  line-height: 1.4;
}

.news-card p {
  font-size: 14px;
  color: var(--text-secondary);
}

.news-card-link {
  display: block;
  text-decoration: none;
  color: inherit;
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}

.news-card-link:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow);
}

.news-card-link h3 {
  color: var(--text);
}

/* Label highlight */
.label-highlight {
  color: var(--success);
  font-weight: 600;
  margin-left: 4px;
}

/* Hero responsive */
@media (max-width: 900px) {
  .hero > .container {
    grid-template-columns: 1fr;
  }
  .hero-illustration {
    display: none;
  }
}

/* Pricing icon */
.pricing-icon {
  width: 52px;
  height: 52px;
  border-radius: var(--radius-sm);
  background: var(--primary-soft);
  display: grid;
  place-items: center;
  margin: 0 auto 16px;
}

.contact-section {
  background: linear-gradient(180deg, var(--bg) 0%, #fff 100%);
}

.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1.2fr;
  gap: 56px;
  align-items: start;
}

.contact-info h2 {
  text-align: left;
}

.contact-info p {
  color: var(--text-secondary);
  margin-bottom: 28px;
}

.contact-info-item {
  display: flex;
  gap: 16px;
  margin-bottom: 22px;
}

.contact-info-item .icon {
  width: 42px;
  height: 42px;
  border-radius: 12px;
  background: var(--primary-soft);
  color: var(--primary);
  display: grid;
  place-items: center;
  font-size: 16px;
  font-weight: 700;
  flex-shrink: 0;
}

.contact-info-item h4 {
  font-size: 15px;
  margin-bottom: 2px;
}

.contact-info-item span {
  font-size: 14px;
  color: var(--text-secondary);
}

.contact-form {
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 40px;
  box-shadow: var(--shadow);
}

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

.form-group label {
  display: block;
  font-size: 14px;
  font-weight: 600;
  margin-bottom: 8px;
}

.form-group input,
.form-group select,
.form-group textarea {
  width: 100%;
  padding: 13px 16px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: 15px;
  font-family: inherit;
  color: var(--text);
  background: #fff;
  transition: border-color 0.2s, box-shadow 0.2s;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(57, 100, 254, 0.12);
}

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

.sms-group {
  display: flex;
  gap: 12px;
}

.sms-group input {
  flex: 1;
}

.sms-group .btn {
  white-space: nowrap;
  padding: 13px 18px;
  font-size: 14px;
}

.sms-group .btn:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

.form-status {
  margin-top: 20px;
  padding: 16px;
  border-radius: var(--radius-sm);
  display: none;
}

.form-status.show {
  display: block;
}

.form-status.success {
  background: #f0fdf4;
  color: var(--success);
  border: 1px solid #bbf7d0;
}

.form-status.processing {
  background: #eff6ff;
  color: var(--primary);
  border: 1px solid #bfdbfe;
}

.form-status.error {
  background: #fef2f2;
  color: var(--danger);
  border: 1px solid #fecaca;
}

.progress-list {
  list-style: none;
  margin-top: 14px;
}

.progress-list li {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 14px;
  padding: 6px 0;
  color: var(--text-secondary);
}

.progress-list li.done {
  color: var(--success);
}

.progress-list li.active {
  color: var(--primary);
  font-weight: 600;
}

.progress-dot {
  width: 18px;
  height: 18px;
  border-radius: 50%;
  border: 2px solid var(--border);
  display: grid;
  place-items: center;
  font-size: 10px;
  font-weight: 700;
}

.progress-list li.done .progress-dot {
  background: var(--success);
  border-color: var(--success);
  color: #fff;
}

.progress-list li.active .progress-dot {
  border-color: var(--primary);
  color: var(--primary);
}

/* Footer */
.footer {
  background: var(--text);
  color: #a9aebf;
  padding: 48px 0 28px;
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 20px;
  margin-bottom: 28px;
}

.footer .logo {
  color: #fff;
}

.footer-links {
  display: flex;
  gap: 28px;
}

.footer-links a {
  color: #a9aebf;
  font-size: 14px;
}

.footer-links a:hover {
  color: #fff;
}

.copyright {
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  padding-top: 24px;
  font-size: 13px;
  text-align: center;
}

/* Responsive */
@media (max-width: 960px) {
  .nav {
    display: none;
  }

  .mobile-menu-btn {
    display: block;
  }

  .definition-grid,
  .comparison-grid,
  .contact-grid {
    grid-template-columns: 1fr;
  }

  .pricing-grid,
  .news-grid {
    grid-template-columns: 1fr;
  }

  .hero-stats {
    gap: 28px;
  }

  .marquee-wrap {
    display: none;
  }
}

@media (max-width: 640px) {
  .section {
    padding: 72px 0;
  }

  .form-row {
    grid-template-columns: 1fr;
  }

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

  .hero-actions .btn {
    width: 100%;
  }

  .contact-form {
    padding: 28px;
  }
}