:root {
  --color-bg: #ffffff;
  --color-text: #1f2937;
  --color-muted: #6b7280;
  --color-primary: #2563eb;
  --color-primary-dark: #1d4ed8;
  --color-surface: #f8fafc;
  --color-border: #e5e7eb;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.6;
}

.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 24px;
}

/* Header */
.site-header {
  border-bottom: 1px solid var(--color-border);
  position: sticky;
  top: 0;
  background: var(--color-bg);
  z-index: 10;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 18px 24px;
}

.logo {
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--color-primary);
}

.site-header nav a {
  margin-left: 24px;
  text-decoration: none;
  color: var(--color-text);
  font-weight: 500;
}

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

/* Hero */
.hero {
  padding: 120px 0;
  background: linear-gradient(180deg, rgba(15, 23, 42, 0.65), rgba(15, 23, 42, 0.65)), url("banner.jpg") center/cover no-repeat;
  text-align: center;
  color: #fff;
}

.hero h1 {
  font-size: 2.5rem;
  margin: 0 0 16px;
  color: #fff;
}

.hero p {
  max-width: 640px;
  margin: 0 auto 32px;
  color: #e5e7eb;
  font-size: 1.1rem;
}

.cta {
  display: inline-block;
  padding: 12px 28px;
  background: var(--color-primary);
  color: #fff;
  text-decoration: none;
  border-radius: 6px;
  font-weight: 600;
}

.cta:hover {
  background: var(--color-primary-dark);
}

/* Features */
.features {
  padding: 72px 0;
}

.features h2,
.platforms h2 {
  text-align: center;
  font-size: 2rem;
  margin-bottom: 8px;
}

.section-intro {
  text-align: center;
  color: var(--color-muted);
  margin-bottom: 48px;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 24px;
}

.feature-card {
  border: 1px solid var(--color-border);
  border-radius: 10px;
  padding: 24px;
  background: var(--color-surface);
}

.feature-card h3 {
  margin: 0 0 8px;
  font-size: 1.05rem;
  color: var(--color-primary-dark);
}

.feature-card p {
  margin: 0;
  color: var(--color-muted);
  font-size: 0.95rem;
}

/* Platforms */
.platforms {
  padding: 72px 0;
  background: var(--color-surface);
}

.platform-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 24px;
  max-width: 640px;
  margin: 0 auto;
}

.platform-card {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: 10px;
  padding: 24px;
  text-align: center;
}

.platform-card h3 {
  margin: 0 0 8px;
  color: var(--color-primary-dark);
}

.platform-card p {
  margin: 0;
  color: var(--color-muted);
  font-size: 0.95rem;
}

/* Footer */
.site-footer {
  padding: 32px 0;
  text-align: center;
  color: var(--color-muted);
  border-top: 1px solid var(--color-border);
  font-size: 0.9rem;
}