/* ============================================================
   Calculadora de Función Renal Pediátrica — Estilos
   ============================================================ */

:root {
  --primary:       #1d4ed8;
  --primary-light: #3b82f6;
  --primary-dark:  #1e3a8a;
  --accent:        #0891b2;
  --bg:            #f1f5f9;
  --surface:       #ffffff;
  --surface-2:     #f8fafc;
  --border:        #e2e8f0;
  --text:          #0f172a;
  --text-2:        #475569;
  --text-3:        #94a3b8;

  --ok:            #16a34a;
  --ok-bg:         #f0fdf4;
  --ok-border:     #bbf7d0;
  --warn:          #d97706;
  --warn-bg:       #fffbeb;
  --warn-border:   #fde68a;
  --danger:        #dc2626;
  --danger-bg:     #fef2f2;
  --danger-border: #fecaca;
  --info:          #0891b2;
  --info-bg:       #ecfeff;
  --info-border:   #a5f3fc;

  --sidebar-w:     280px;
  --radius:        10px;
  --shadow:        0 1px 3px rgba(0,0,0,.08), 0 1px 2px rgba(0,0,0,.04);
  --shadow-md:     0 4px 6px -1px rgba(0,0,0,.1), 0 2px 4px -2px rgba(0,0,0,.06);
}

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

html { font-size: 15px; }

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
  display: flex;
  min-height: 100vh;
}

/* ── Sidebar ──────────────────────────────────────────────── */
.sidebar {
  width: var(--sidebar-w);
  min-width: var(--sidebar-w);
  background: var(--primary-dark);
  color: #fff;
  display: flex;
  flex-direction: column;
  position: fixed;
  top: 0; left: 0;
  height: 100vh;
  overflow-y: auto;
  z-index: 100;
}

.sidebar-header {
  padding: 24px 20px 20px;
  border-bottom: 1px solid rgba(255,255,255,.12);
}

.sidebar-header .logo {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 4px;
}

.sidebar-header .logo svg {
  flex-shrink: 0;
}

.sidebar-header h1 {
  font-size: 1.1rem;
  font-weight: 700;
  line-height: 1.2;
}

.sidebar-header p {
  font-size: .78rem;
  color: rgba(255,255,255,.55);
  margin-top: 4px;
}

.sidebar-nav { padding: 12px 0 24px; flex: 1; }

.nav-group { margin-bottom: 4px; }

.nav-group-label {
  font-size: .67rem;
  font-weight: 700;
  letter-spacing: .08em;
  text-transform: uppercase;
  color: rgba(255,255,255,.4);
  padding: 12px 20px 4px;
}

.nav-item {
  display: flex;
  align-items: center;
  gap: 8px;
  width: 100%;
  background: none;
  border: none;
  color: rgba(255,255,255,.75);
  font-size: .88rem;
  padding: 8px 20px;
  cursor: pointer;
  text-align: left;
  border-radius: 0;
  transition: background .15s, color .15s;
}

.nav-item:hover {
  background: rgba(255,255,255,.08);
  color: #fff;
}

.nav-item.active {
  background: var(--primary-light);
  color: #fff;
  font-weight: 600;
}

.nav-item .nav-icon {
  font-size: 1rem;
  width: 20px;
  text-align: center;
  flex-shrink: 0;
}

/* ── Main ─────────────────────────────────────────────────── */
.main-content {
  margin-left: var(--sidebar-w);
  flex: 1;
  padding: 32px;
  max-width: 860px;
}

/* ── Calculator card ──────────────────────────────────────── */
.calc-card {
  background: var(--surface);
  border-radius: var(--radius);
  box-shadow: var(--shadow-md);
  overflow: hidden;
}

.calc-header {
  background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
  color: #fff;
  padding: 24px 28px;
}

.calc-header .category-badge {
  font-size: .72rem;
  font-weight: 700;
  letter-spacing: .08em;
  text-transform: uppercase;
  background: rgba(255,255,255,.2);
  padding: 3px 10px;
  border-radius: 999px;
  display: inline-block;
  margin-bottom: 8px;
}

.calc-header h2 {
  font-size: 1.4rem;
  font-weight: 700;
  margin-bottom: 6px;
}

.calc-header p.subtitle {
  font-size: .88rem;
  opacity: .85;
  line-height: 1.5;
}

.calc-body { padding: 28px; }

/* Formula box */
.formula-box {
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-left: 4px solid var(--primary-light);
  border-radius: 6px;
  padding: 14px 18px;
  margin-bottom: 24px;
}

.formula-box .formula-label {
  font-size: .72rem;
  font-weight: 700;
  letter-spacing: .06em;
  text-transform: uppercase;
  color: var(--text-3);
  margin-bottom: 6px;
}

.formula-box .formula-text {
  font-family: 'Courier New', monospace;
  font-size: .92rem;
  color: var(--primary-dark);
  line-height: 1.6;
}

/* Input grid */
.input-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 16px;
  margin-bottom: 24px;
}

.field {
  display: flex;
  flex-direction: column;
  gap: 5px;
}

.field label {
  font-size: .82rem;
  font-weight: 600;
  color: var(--text-2);
}

.field .input-wrapper {
  display: flex;
  align-items: center;
  border: 1.5px solid var(--border);
  border-radius: 6px;
  background: var(--surface);
  transition: border-color .15s;
}

.field .input-wrapper:focus-within {
  border-color: var(--primary-light);
  box-shadow: 0 0 0 3px rgba(59,130,246,.15);
}

.field input[type="number"],
.field select {
  flex: 1;
  border: none;
  outline: none;
  background: transparent;
  padding: 9px 10px;
  font-size: .92rem;
  color: var(--text);
  width: 100%;
}

.field .unit-tag {
  padding: 0 10px;
  font-size: .78rem;
  color: var(--text-3);
  border-left: 1px solid var(--border);
  white-space: nowrap;
  height: 100%;
  display: flex;
  align-items: center;
}

.field .hint {
  font-size: .72rem;
  color: var(--text-3);
}

/* Full-width field */
.field.full { grid-column: 1 / -1; }

/* Selector in input grid */
.field select {
  padding: 9px 10px;
}

/* Calculate button */
.btn-calculate {
  background: var(--primary);
  color: #fff;
  border: none;
  border-radius: 7px;
  padding: 11px 28px;
  font-size: .95rem;
  font-weight: 600;
  cursor: pointer;
  transition: background .15s, transform .1s;
  display: flex;
  align-items: center;
  gap: 8px;
}

.btn-calculate:hover { background: var(--primary-dark); }
.btn-calculate:active { transform: scale(.98); }

/* Result panel */
.result-panel {
  margin-top: 24px;
  border-radius: 8px;
  padding: 20px 22px;
  border: 1.5px solid;
  display: none;
}

.result-panel.visible { display: block; }

.result-panel.ok     { background: var(--ok-bg);     border-color: var(--ok-border);     }
.result-panel.warn   { background: var(--warn-bg);   border-color: var(--warn-border);   }
.result-panel.danger { background: var(--danger-bg); border-color: var(--danger-border); }
.result-panel.info   { background: var(--info-bg);   border-color: var(--info-border);   }

.result-main {
  display: flex;
  align-items: baseline;
  gap: 8px;
  margin-bottom: 6px;
}

.result-value {
  font-size: 2rem;
  font-weight: 800;
  line-height: 1;
}

.result-panel.ok     .result-value { color: var(--ok);     }
.result-panel.warn   .result-value { color: var(--warn);   }
.result-panel.danger .result-value { color: var(--danger); }
.result-panel.info   .result-value { color: var(--info);   }

.result-unit {
  font-size: .9rem;
  color: var(--text-2);
  font-weight: 500;
}

.result-label {
  font-size: .95rem;
  font-weight: 600;
  margin-bottom: 4px;
}

.result-panel.ok     .result-label { color: var(--ok);     }
.result-panel.warn   .result-label { color: var(--warn);   }
.result-panel.danger .result-label { color: var(--danger); }
.result-panel.info   .result-label { color: var(--info);   }

.result-detail {
  font-size: .84rem;
  color: var(--text-2);
  line-height: 1.55;
}

.result-extra {
  margin-top: 14px;
  padding-top: 14px;
  border-top: 1px solid rgba(0,0,0,.07);
}

/* Reference table */
.ref-table {
  width: 100%;
  border-collapse: collapse;
  font-size: .82rem;
  margin-top: 14px;
}

.ref-table th {
  background: var(--surface-2);
  color: var(--text-2);
  font-weight: 600;
  padding: 7px 10px;
  text-align: left;
  border-bottom: 2px solid var(--border);
}

.ref-table td {
  padding: 7px 10px;
  border-bottom: 1px solid var(--border);
  color: var(--text);
}

.ref-table tr:last-child td { border-bottom: none; }

.ref-table .highlighted { font-weight: 700; color: var(--primary); background: #eff6ff; }

/* CKD stage badge */
.ckd-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 12px;
  border-radius: 999px;
  font-size: .8rem;
  font-weight: 700;
  margin-top: 8px;
}
.ckd-G1 { background: #dcfce7; color: #166534; }
.ckd-G2 { background: #d1fae5; color: #065f46; }
.ckd-G3a { background: #fef9c3; color: #713f12; }
.ckd-G3b { background: #ffedd5; color: #7c2d12; }
.ckd-G4  { background: #fee2e2; color: #7f1d1d; }
.ckd-G5  { background: #ede9fe; color: #3b0764; }

/* Error state */
.error-msg {
  background: var(--danger-bg);
  border: 1px solid var(--danger-border);
  border-radius: 6px;
  padding: 10px 14px;
  font-size: .84rem;
  color: var(--danger);
  margin-top: 12px;
  display: none;
}
.error-msg.visible { display: block; }

/* Disclaimer */
.disclaimer {
  margin-top: 28px;
  padding: 14px 18px;
  background: #fefce8;
  border: 1px solid #fef08a;
  border-radius: 8px;
  font-size: .78rem;
  color: #713f12;
  line-height: 1.55;
}

.disclaimer strong { font-weight: 700; }

/* ── Scrollbar ────────────────────────────────────────────── */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: rgba(0,0,0,.18); border-radius: 3px; }

/* ── Responsive ───────────────────────────────────────────── */
@media (max-width: 768px) {
  .sidebar {
    width: 100%;
    height: auto;
    position: relative;
  }
  .main-content {
    margin-left: 0;
    padding: 16px;
  }
  body { flex-direction: column; }
  .input-grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 480px) {
  .input-grid { grid-template-columns: 1fr; }
  .result-value { font-size: 1.6rem; }
}