:root{color-scheme:light;--bg:#f8fafc;--card:#fff;--text:#0f172a;--muted:#64748b;--brand:#0ea5e9;--brand-dark:#2563eb;--brand-soft:#e0f2fe;--border:#e2e8f0;--radius:16px;--shadow:0 1px 2px rgba(15,23,42,.06);--max:480px}*{box-sizing:border-box}body{margin:0;font-family:"IBM Plex Sans Thai",ui-sans-serif,system-ui,sans-serif;background:var(--bg);color:var(--text);line-height:1.6;-webkit-font-smoothing:antialiased}a{color:inherit}.page{max-width:var(--max);margin:0 auto;padding:20px 16px 48px}.site-header{display:flex;align-items:center;gap:10px;margin-bottom:24px}.site-logo{display:flex;width:36px;height:36px;align-items:center;justify-content:center;border-radius:12px;background:linear-gradient(to bottom right,#0ea5e9,#2563eb);color:#fff;font-size:18px;box-shadow:var(--shadow)}.site-title{min-width:0}.site-title strong{display:block;font-size:16px;line-height:1.25}.site-title span{display:block;font-size:12px;font-weight:500;color:var(--muted)}.hero{margin-bottom:20px}.hero h1{margin:0 0 8px;font-size:26px;line-height:1.25}.hero p{margin:0;color:var(--muted);font-size:15px}.card{background:var(--card);border:1px solid var(--border);border-radius:var(--radius);padding:20px 18px;margin-bottom:16px;box-shadow:var(--shadow)}.menu{display:grid;gap:12px}.menu-btn{display:flex;min-height:56px;align-items:center;justify-content:center;padding:14px 18px;border-radius:14px;color:#fff;font:inherit;font-size:16px;font-weight:600;text-align:center;text-decoration:none;box-shadow:var(--shadow)}.menu-btn.primary{background:linear-gradient(to bottom right,#0ea5e9,#2563eb)}.menu-btn.tutor{background:linear-gradient(to bottom right,#f59e0b,#d97706)}.back-link{display:inline-flex;align-items:center;gap:6px;margin-bottom:16px;color:var(--brand);font-size:14px;font-weight:500;text-decoration:none}.step{margin-bottom:28px}.step:last-child{margin-bottom:0}.step-badge{display:inline-block;margin-bottom:8px;padding:4px 10px;border-radius:999px;background:var(--brand-soft);color:#0369a1;font-size:12px;font-weight:600}.step h2{margin:0 0 8px;font-size:18px;line-height:1.35}.step p{margin:0 0 12px;font-size:15px;color:var(--muted)}.figure{margin:0;border:1px solid var(--border);border-radius:12px;overflow:hidden;background:#fff}.figure img{display:block;width:100%;height:auto}.figure figcaption{padding:10px 12px;font-size:13px;color:var(--muted);border-top:1px solid var(--border);background:#fff}.section-title{margin:0 0 16px;padding-bottom:12px;border-bottom:1px solid var(--border);font-size:17px;font-weight:600}.section-note{margin:0 0 16px;font-size:14px;color:var(--muted)}footer{margin-top:24px;text-align:center;color:var(--muted);font-size:13px}@media(min-width:768px){.page{padding-top:32px}.hero h1{font-size:30px}}