:root {
  --bg-main: #fcfcfc;
  --bg-card: #ffffff;
  --text-main: #1e293b;
  --text-light: #64748b;
  --accent-1: #6366f1;
  --accent-2: #8b5cf6;
  --border: #e2e8f0;
  --shadow-sm: 0 4px 6px -1px rgb(0 0 0 / 0.1);
  --shadow-lg: 0 20px 25px -5px rgb(0 0 0 / 0.1);
  --radius: 16px;
}

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

body {
  font-family: system-ui, -apple-system, sans-serif;
  background-color: var(--bg-main);
  color: var(--text-main);
  line-height: 1.6;
}

/* Nav */
.nav {
  position: sticky; top: 0; z-index: 100;
  background: rgba(252, 252, 252, 0.8);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  padding: 1rem 0;
}
.nav-wrap {
  max-width: 1200px; margin: 0 auto; padding: 0 2rem;
  display: flex; justify-content: space-between; align-items: center;
}
.logo { font-size: 1.5rem; font-weight: 800; color: var(--text-main); text-decoration: none; display: flex; align-items: center; gap: 8px;}
.logo span { background: linear-gradient(135deg, var(--accent-1), var(--accent-2)); -webkit-background-clip: text; color: transparent; background-clip: text;}
.links { display: flex; gap: 2rem; }
.links a { color: var(--text-light); text-decoration: none; font-weight: 500; transition: color 0.2s; }
.links a:hover, .links a.active { color: var(--accent-1); }

/* Buttons */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  padding: 0.875rem 1.75rem; border-radius: 99px; font-weight: 600; text-decoration: none;
  cursor: pointer; transition: transform 0.2s, box-shadow 0.2s; border: none; font-size: 1rem;
}
.btn-primary { background: linear-gradient(135deg, var(--accent-1), var(--accent-2)); color: white; }
.btn-primary:hover { transform: translateY(-2px); box-shadow: var(--shadow-sm); }
.btn-outline { background: transparent; border: 2px solid var(--border); color: var(--text-main); }
.btn-outline:hover { border-color: var(--accent-1); color: var(--accent-1); }

/* Hero */
.hero { padding: 6rem 2rem; text-align: center; max-width: 1000px; margin: 0 auto; }
.hero-tag { display: inline-block; padding: 6px 16px; background: #e0e7ff; color: var(--accent-1); border-radius: 99px; font-size: 0.875rem; font-weight: 600; margin-bottom: 2rem; }
.hero h1 { font-size: 4rem; line-height: 1.1; margin-bottom: 1.5rem; letter-spacing: -0.02em; }
.hero p { font-size: 1.25rem; color: var(--text-light); margin-bottom: 2.5rem; max-width: 700px; margin-inline: auto; }
.hero-btns { display: flex; justify-content: center; gap: 1rem; }

/* Section Grid */
.grid-section { max-width: 1200px; margin: 0 auto; padding: 4rem 2rem; }
.grid-title { font-size: 2.5rem; text-align: center; margin-bottom: 3rem; }
.cards { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 2rem; }
.card { background: var(--bg-card); padding: 2.5rem; border-radius: var(--radius); border: 1px solid var(--border); box-shadow: var(--shadow-sm); transition: transform 0.3s; }
.card:hover { transform: translateY(-5px); border-color: var(--accent-1); }
.card-icon { width: 48px; height: 48px; color: var(--accent-1); margin-bottom: 1.5rem; }
.card h3 { font-size: 1.5rem; margin-bottom: 1rem; }
.card p { color: var(--text-light); }

/* Plat Grid */
.plat-section { background: #f8fafc; padding: 5rem 0; margin: 4rem 0; border-top: 1px solid var(--border); border-bottom: 1px solid var(--border);}
.plat-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 2rem; max-width: 1200px; margin: 0 auto; padding: 0 2rem;}
.plat-card { text-align: center; padding: 2rem; background: white; border-radius: 12px; border: 1px solid var(--border); }
.plat-icon { width: 64px; height: 64px; margin: 0 auto 1.5rem; color: var(--text-main); }
.plat-name { font-size: 1.25rem; font-weight: 600; margin-bottom: 1rem; }

/* FAQ */
.faq { max-width: 800px; margin: 0 auto; padding: 4rem 2rem; }
.faq-item { border: 1px solid var(--border); border-radius: 12px; margin-bottom: 1rem; background: var(--bg-card); overflow: hidden; }
.faq-q { padding: 1.5rem; font-weight: 600; cursor: pointer; display: flex; justify-content: space-between; align-items: center; transition: color 0.2s; }
.faq-a { padding: 0 1.5rem; height: 0; opacity: 0; color: var(--text-light); transition: all 0.3s ease; }
.faq-item.active .faq-a { padding: 0 1.5rem 1.5rem; height: auto; opacity: 1; }
.faq-item.active .faq-q { color: var(--accent-1); }

/* Article */
.article-wrap { display: grid; grid-template-columns: 1fr 300px; gap: 3rem; max-width: 1200px; margin: 4rem auto; padding: 0 2rem;}
.article-content { background: var(--bg-card); padding: 3rem; border-radius: var(--radius); border: 1px solid var(--border);}
.article-content h2 { margin: 2rem 0 1rem; font-size: 1.8rem; color: var(--accent-1); }
.article-content p { margin-bottom: 1.5rem; font-size: 1.1rem; }
.sidebar { position: sticky; top: 100px; }
.sidebar-box { background: var(--bg-card); padding: 1.5rem; border-radius: 12px; border: 1px solid var(--border); margin-bottom: 1.5rem; }

/* Footer */
.footer { border-top: 1px solid var(--border); padding: 3rem 2rem; text-align: center; color: var(--text-light); margin-top: 4rem; background: white;}
.security { display: inline-flex; align-items: center; gap: 8px; background: #f0fdf4; color: #166534; padding: 8px 16px; border-radius: 8px; margin-bottom: 1.5rem; font-size: 0.875rem; border: 1px solid #bbf7d0;}

@media (max-width: 768px) {
  .hero h1 { font-size: 2.5rem; }
  .hero-btns { flex-direction: column; }
  .article-wrap { grid-template-columns: 1fr; }
  .nav-wrap { flex-direction: column; gap: 1rem; }
}