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

:root {
  --primary: #4f6ef7;
  --primary-dark: #3a56d4;
  --accent: #00b4d8;
  --text: #1a1a2e;
  --text-light: #555;
  --bg: #f8f9fc;
  --white: #ffffff;
  --border: #e8ecf1;
  --shadow: 0 4px 20px rgba(79, 110, 247, 0.12);
  --radius: 12px;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.7;
  font-size: 16px;
}

a {
  color: var(--primary);
  text-decoration: none;
  transition: color 0.2s;
}

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

.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 20px;
}

/* Header */
header {
  background: var(--white);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 2px 8px rgba(0,0,0,0.04);
}

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

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 20px;
  font-weight: 700;
  color: var(--text);
}

.logo img {
  width: 36px;
  height: 36px;
}

nav ul {
  display: flex;
  list-style: none;
  gap: 28px;
}

nav a {
  color: var(--text-light);
  font-size: 15px;
  font-weight: 500;
}

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

/* Hero */
.hero {
  background: linear-gradient(135deg, #4f6ef7 0%, #00b4d8 100%);
  color: var(--white);
  padding: 80px 0 70px;
  text-align: center;
}

.hero h1 {
  font-size: 2.4rem;
  font-weight: 700;
  margin-bottom: 16px;
  letter-spacing: -0.5px;
}

.hero p {
  font-size: 1.15rem;
  opacity: 0.92;
  max-width: 640px;
  margin: 0 auto 32px;
}

.btn {
  display: inline-block;
  padding: 14px 36px;
  border-radius: 50px;
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.25s;
  border: none;
}

.btn-primary {
  background: var(--white);
  color: var(--primary);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(0,0,0,0.15);
  color: var(--primary-dark);
}

.btn-outline {
  background: transparent;
  color: var(--white);
  border: 2px solid rgba(255,255,255,0.7);
  margin-left: 12px;
}

.btn-outline:hover {
  background: rgba(255,255,255,0.15);
  color: var(--white);
}

.btn-download {
  background: var(--primary);
  color: var(--white);
  padding: 12px 28px;
}

.btn-download:hover {
  background: var(--primary-dark);
  color: var(--white);
  transform: translateY(-1px);
}

/* Sections */
section {
  padding: 60px 0;
}

.section-title {
  text-align: center;
  font-size: 1.8rem;
  margin-bottom: 12px;
  font-weight: 700;
}

.section-desc {
  text-align: center;
  color: var(--text-light);
  margin-bottom: 40px;
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

/* Features Grid */
.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
}

.feature-card {
  background: var(--white);
  border-radius: var(--radius);
  padding: 32px 28px;
  box-shadow: var(--shadow);
  transition: transform 0.25s;
}

.feature-card:hover {
  transform: translateY(-4px);
}

.feature-icon {
  width: 52px;
  height: 52px;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 24px;
  margin-bottom: 18px;
  color: var(--white);
}

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

.feature-card p {
  color: var(--text-light);
  font-size: 0.95rem;
}

/* Download Cards */
.download-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 20px;
}

.download-card {
  background: var(--white);
  border-radius: var(--radius);
  padding: 36px 24px;
  text-align: center;
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
}

.download-card .platform-icon {
  font-size: 48px;
  margin-bottom: 16px;
}

.download-card h3 {
  margin-bottom: 8px;
}

.download-card p {
  color: var(--text-light);
  font-size: 0.9rem;
  margin-bottom: 20px;
}

/* Articles */
.articles-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 24px;
}

.article-card {
  background: var(--white);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
  transition: transform 0.25s;
}

.article-card:hover {
  transform: translateY(-3px);
}

.article-card-body {
  padding: 24px;
}

.article-card .date {
  font-size: 0.85rem;
  color: var(--text-light);
  margin-bottom: 8px;
}

.article-card h3 {
  font-size: 1.1rem;
  margin-bottom: 10px;
  line-height: 1.5;
}

.article-card p {
  color: var(--text-light);
  font-size: 0.92rem;
  margin-bottom: 14px;
}

.read-more {
  font-weight: 600;
  font-size: 0.9rem;
}

/* Article Page */
.article-header {
  background: var(--white);
  padding: 50px 0 30px;
  border-bottom: 1px solid var(--border);
}

.article-header h1 {
  font-size: 2rem;
  margin-bottom: 12px;
  line-height: 1.4;
}

.article-meta {
  color: var(--text-light);
  font-size: 0.9rem;
}

.article-content {
  background: var(--white);
  padding: 40px 0 60px;
}

.article-content .container {
  max-width: 780px;
}

.article-content h2 {
  font-size: 1.4rem;
  margin: 32px 0 14px;
  color: var(--text);
}

.article-content h3 {
  font-size: 1.15rem;
  margin: 24px 0 10px;
}

.article-content p {
  margin-bottom: 16px;
  color: var(--text);
}

.article-content ul,
.article-content ol {
  margin: 12px 0 16px 24px;
  color: var(--text);
}

.article-content li {
  margin-bottom: 8px;
}

.article-content blockquote {
  border-left: 4px solid var(--primary);
  padding: 12px 20px;
  margin: 20px 0;
  background: #f0f3ff;
  color: var(--text-light);
  border-radius: 0 8px 8px 0;
}

/* Steps */
.steps {
  counter-reset: step;
  list-style: none;
  margin: 20px 0;
  padding: 0;
}

.steps li {
  counter-increment: step;
  padding: 16px 16px 16px 56px;
  position: relative;
  background: var(--bg);
  border-radius: 8px;
  margin-bottom: 12px;
}

.steps li::before {
  content: counter(step);
  position: absolute;
  left: 16px;
  top: 50%;
  transform: translateY(-50%);
  width: 28px;
  height: 28px;
  background: var(--primary);
  color: var(--white);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 14px;
  font-weight: 700;
}

/* FAQ */
.faq-list {
  max-width: 780px;
  margin: 0 auto;
}

.faq-item {
  background: var(--white);
  border-radius: var(--radius);
  margin-bottom: 12px;
  box-shadow: var(--shadow);
  overflow: hidden;
}

.faq-item summary {
  padding: 18px 24px;
  font-weight: 600;
  cursor: pointer;
  list-style: none;
}

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

.faq-item p {
  padding: 0 24px 18px;
  color: var(--text-light);
}

/* Daily Update Section */
.daily-update {
  background: var(--white);
  border-radius: var(--radius);
  padding: 32px;
  box-shadow: var(--shadow);
  margin-top: 20px;
}

.daily-update h3 {
  font-size: 1.2rem;
  margin-bottom: 16px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.daily-update .update-badge {
  background: #e8f5e9;
  color: #2e7d32;
  font-size: 0.75rem;
  padding: 3px 10px;
  border-radius: 20px;
  font-weight: 600;
}

.daily-update-item {
  padding: 16px 0;
  border-bottom: 1px solid var(--border);
}

.daily-update-item:last-child {
  border-bottom: none;
}

.daily-update-item h4 {
  font-size: 1rem;
  margin-bottom: 6px;
}

.daily-update-item p {
  color: var(--text-light);
  font-size: 0.9rem;
}

/* Footer */
footer {
  background: #1a1a2e;
  color: rgba(255,255,255,0.7);
  padding: 40px 0 24px;
  margin-top: 40px;
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 30px;
  margin-bottom: 30px;
}

.footer-col h4 {
  color: var(--white);
  margin-bottom: 14px;
  font-size: 1rem;
}

.footer-col ul {
  list-style: none;
}

.footer-col li {
  margin-bottom: 8px;
}

.footer-col a {
  color: rgba(255,255,255,0.65);
  font-size: 0.9rem;
}

.footer-col a:hover {
  color: var(--white);
}

.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.1);
  padding-top: 20px;
  text-align: center;
  font-size: 0.85rem;
}

/* Breadcrumb */
.breadcrumb {
  padding: 16px 0;
  font-size: 0.9rem;
  color: var(--text-light);
}

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

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

/* Responsive */
@media (max-width: 768px) {
  .hero h1 {
    font-size: 1.8rem;
  }

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

  .btn-outline {
    margin-left: 0;
    margin-top: 12px;
  }

  nav ul {
    gap: 16px;
  }

  .header-inner {
    flex-direction: column;
    height: auto;
    padding: 12px 0;
    gap: 10px;
  }

  .footer-inner {
    flex-direction: column;
  }
}