:root{--bg: #f8f9fb;--text: #111827;--muted: #6b7280;--primary: #2563eb;--border: #e5e7eb;--surface: #ffffff;--font-base: 18px;--font-heading: 24px;--font-subheading: 20px}*{box-sizing:border-box}html,body,#root{height:100%}body{margin:0;font-family:ui-sans-serif,system-ui,-apple-system,Segoe UI,Roboto,Helvetica,Arial,"Apple Color Emoji","Segoe UI Emoji";background:var(--bg);color:var(--text);font-size:var(--font-base);line-height:1.6}h2{font-size:var(--font-heading);margin:0 0 8px}h3{font-size:var(--font-subheading);margin:0 0 8px}.container{max-width:960px;margin:0 auto;padding:20px}.nav{display:flex;justify-content:space-between;margin-bottom:20px;align-items:center;background:var(--surface);border:1px solid var(--border);border-radius:12px;padding:12px 16px;box-shadow:0 2px 8px #1118270f}.nav a{color:var(--primary);text-decoration:none;font-size:16px}.nav-left{display:flex;gap:14px;align-items:center}.nav-right{display:flex;gap:12px;align-items:center}.user{color:var(--muted)}.brand{font-weight:700;color:var(--text);margin-right:12px}.link{padding:8px 12px;border-radius:999px;border:1px solid transparent}.link:hover{background:#f3f4f6}.link.active{background:#2563eb1f;color:var(--primary);border-color:#2563eb33}.btn{padding:10px 16px;border:1px solid var(--border);border-radius:10px;background:var(--surface);cursor:pointer;font-size:16px}.btn:hover{background:#f3f4f6}.btn.primary{background:var(--primary);color:#fff;border-color:var(--primary)}.btn.danger{background:#ef4444;color:#fff;border-color:#ef4444}.form{display:grid;gap:10px;max-width:540px}.input,.textarea{padding:12px 14px;border:1px solid var(--border);border-radius:10px;background:var(--surface);font-size:16px}.textarea{min-height:100px}.table{width:100%;border-collapse:collapse;background:var(--surface);border:1px solid var(--border);border-radius:8px;overflow:hidden;font-size:16px}.table th,.table td{padding:12px 16px;border-bottom:1px solid var(--border);text-align:left}.table thead th{background:#f9fafb;font-weight:600}.table tbody tr:hover{background:#f9fafb}.section{background:var(--surface);padding:16px;border:1px solid var(--border);border-radius:10px}.center-screen{height:100vh;display:flex;align-items:center;justify-content:center}