:root {
     --bg: #0f172a;
     --panel: #0b1221;
     --card: #111a2e;
     --accent: #38bdf8;
     --muted: #cbd5e1;
     --text: #e2e8f0;
     --border: rgba(255, 255, 255, 0.08);
 }

 * {
     box-sizing: border-box;
 }

 body {
     margin: 0;
     font-family: 'Plus Jakarta Sans', 'Segoe UI', sans-serif;
     background: radial-gradient(110% 140% at 15% 20%, #122341 0%, #0b1220 40%, #0a101d 100%);
     color: var(--text);
     min-height: 100vh;
 }

 header {
     padding: 2.5rem 1.5rem 1.25rem;
     max-width: 1100px;
     margin: 0 auto;
 }

 .top-bar {
     display: flex;
     align-items: center;
     justify-content: space-between;
     gap: 1rem;
     flex-wrap: wrap;
     margin-bottom: 1.5rem;
 }

 .back-link {
     color: var(--muted);
     text-decoration: none;
     display: inline-flex;
     align-items: center;
     gap: 0.5rem;
     padding: 0.5rem 0.75rem;
     border-radius: 999px;
     background: rgba(255, 255, 255, 0.04);
     border: 1px solid var(--border);
     transition: 0.2s ease;
 }

 .back-link:hover {
     color: #fff;
     border-color: rgba(56, 189, 248, 0.5);
 }

 h1 {
     font-size: 2rem;
     margin: 0 0 0.35rem;
     letter-spacing: -0.02em;
 }

 p.lead {
     margin: 0;
     color: var(--muted);
     max-width: 760px;
 }

 main {
     max-width: 1200px;
     margin: 0 auto;
     padding: 0 1.5rem 2rem;
     display: grid;
     grid-template-columns: repeat(4, minmax(240px, 1fr));
     gap: 1rem;
 }

 .card {
     background: linear-gradient(145deg, var(--card), var(--panel));
     border: 1px solid var(--border);
     border-radius: 1rem;
     padding: 1.25rem 1.25rem 1.1rem;
     box-shadow: 0 12px 40px rgba(0, 0, 0, 0.35);
 }

 .card h2 {
     font-size: 1.1rem;
     margin: 0 0 0.6rem;
     display: inline-flex;
     align-items: center;
     gap: 0.5rem;
 }

 .card h2 i {
     color: var(--accent);
 }

 ul,
 ol {
     margin: 0;
     padding-left: 1.1rem;
     color: var(--muted);
 }

 li {
     margin-bottom: 0.35rem;
     line-height: 1.45;
 }

 code {
     background: rgba(255, 255, 255, 0.08);
     border-radius: 0.35rem;
     padding: 0.15rem 0.35rem;
     color: #f8fafc;
     font-size: 0.95em;
 }

 .tag {
     display: inline-flex;
     align-items: center;
     gap: 0.35rem;
     padding: 0.25rem 0.55rem;
     border-radius: 999px;
     background: rgba(56, 189, 248, 0.15);
     color: #bae6fd;
     font-weight: 600;
     font-size: 0.85rem;
     margin-right: 0.4rem;
 }

 .tip {
     margin-top: 0.75rem;
     padding: 0.75rem 0.9rem;
     border-radius: 0.85rem;
     border: 1px dashed var(--border);
     color: var(--muted);
     background: rgba(255, 255, 255, 0.03);
 }

 @media (max-width: 1100px) {
     main {
         grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
     }
 }

 @media (max-width: 720px) {
     header {
         padding-top: 1.8rem;
     }

     h1 {
         font-size: 1.6rem;
     }
 }