:root {
  --bg: #f5f7fa;
  --card: #ffffff;
  --primary: #0f766e;
  --primary-dark: #115e59;
  --text: #0f172a;
  --muted: #64748b;
  --border: #e2e8f0;
}

* { box-sizing: border-box; }
body { margin: 0; font-family: system-ui, -apple-system, "Segoe UI", sans-serif; background: var(--bg); color: var(--text); }

.topnav {
  background: var(--primary-dark);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 24px;
  position: sticky; top: 0; z-index: 10;
}
.brand { font-weight: 700; font-size: 1.15rem; }
.navlinks a { color: #d1fae5; text-decoration: none; margin-left: 18px; font-size: 0.95rem; }
.navlinks a:hover { color: #fff; }

main { max-width: 860px; margin: 20px auto; padding: 0 16px 60px; display: grid; gap: 16px; }

.card { background: var(--card); border: 1px solid var(--border); border-radius: 12px; padding: 20px 24px; box-shadow: 0 1px 3px rgba(15,23,42,0.05); }
.card h2 { margin: 0 0 14px; font-size: 1.2rem; color: var(--primary-dark); }
.card h3 { margin: 18px 0 8px; font-size: 1rem; }

.grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(180px, 1fr)); gap: 12px; margin-bottom: 12px; }
label { display: flex; flex-direction: column; gap: 4px; font-size: 0.88rem; color: var(--muted); }
label.full { grid-column: 1 / -1; }
input, select {
  border: 1px solid var(--border); border-radius: 8px; padding: 9px 11px; font-size: 0.95rem; background: #fbfcfe;
}
input:focus, select:focus { outline: 2px solid var(--primary); border-color: transparent; }

.btn {
  background: var(--primary); color: #fff; border: none; border-radius: 8px;
  padding: 10px 18px; font-size: 0.95rem; cursor: pointer;
}
.btn:hover { background: var(--primary-dark); }
.btn.secondary { background: #fff; color: var(--text); border: 1px solid var(--border); }
.btn:disabled { opacity: 0.5; cursor: not-allowed; }

.hidden { display: none; }
.error { color: #dc2626; }
.muted { color: var(--muted); }

.bmi-value { display: flex; align-items: center; gap: 12px; margin-top: 8px; }
#bmi-number { font-size: 2rem; font-weight: 700; }
.badge { padding: 4px 14px; border-radius: 999px; color: #fff; font-size: 0.85rem; font-weight: 600; }
.badge.underweight { background: #2563eb; }
.badge.normal { background: #16a34a; }
.badge.overweight { background: #ea580c; }
.badge.obese { background: #dc2626; }

.calorie-big #calories { font-size: 2.2rem; font-weight: 700; color: var(--primary-dark); }
.macro { margin: 8px 0; }
.macro .bar { height: 10px; background: var(--border); border-radius: 999px; overflow: hidden; }
.macro .fill { height: 100%; border-radius: 999px; background: var(--primary); }
.macro .row { display: flex; justify-content: space-between; font-size: 0.85rem; color: var(--muted); margin-bottom: 3px; }

.meal-card {
  border: 1px solid var(--border); border-radius: 10px; padding: 14px 16px; margin: 10px 0;
}
.meal-card .type { font-size: 0.75rem; text-transform: uppercase; letter-spacing: 0.08em; color: var(--primary); font-weight: 700; }
.meal-card h4 { margin: 4px 0 6px; }
.meal-card .macros { font-size: 0.83rem; color: var(--muted); margin: 4px 0; }
.meal-card details summary { cursor: pointer; font-size: 0.88rem; color: var(--primary-dark); }

.banner { background: #fef3c7; border: 1px solid #f59e0b; color: #92400e; border-radius: 8px; padding: 10px 14px; margin: 10px 0; font-size: 0.9rem; }

#plan-total { margin-top: 10px; font-weight: 600; }

#modify-form { display: flex; gap: 8px; }
#modify-input { flex: 1; }
#modification-history { padding-left: 18px; color: var(--muted); font-size: 0.9rem; }

.row { display: flex; gap: 10px; align-items: center; flex-wrap: wrap; }
pre { background: #f1f5f9; border-radius: 8px; padding: 12px; overflow-x: auto; font-size: 0.82rem; }

@media (max-width: 600px) {
  main { padding: 0 8px 40px; }
  .card { padding: 14px; }
  .topnav { padding: 10px 14px; }
  .navlinks a { margin-left: 10px; font-size: 0.85rem; }
}