/* ===== RESET & BASE ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --army-dark:    #0d1117;
  --army-green:   #1a3a1a;
  --army-olive:   #4a5c2a;
  --army-khaki:   #8a9a5b;
  --army-tan:     #c9b89a;
  --army-gold:    #d4a017;
  --army-red:     #b22222;
  --army-light:   #f0ede8;
  --card-bg:      #161c14;
  --card-border:  #2a3a2a;
  --text-primary: #e8e4dc;
  --text-muted:   #8a9a7a;
  --input-bg:     #0f1a0f;
  --input-border: #2e4a2e;
  --accent:       #d4a017;

  --pass:  #4caf50;
  --fail:  #e53935;
  --warn:  #ff9800;

  --radius: 6px;
  --shadow: 0 4px 24px rgba(0,0,0,0.5);
}

body {
  background: var(--army-dark);
  color: var(--text-primary);
  font-family: 'DM Sans', sans-serif;
  font-size: 15px;
  min-height: 100vh;
  background-image:
    repeating-linear-gradient(
      45deg,
      transparent,
      transparent 40px,
      rgba(26,58,26,0.04) 40px,
      rgba(26,58,26,0.04) 80px
    );
}

/* ===== HEADER ===== */
header {
  background: linear-gradient(135deg, #0d1a0d 0%, #1a3a1a 60%, #0d1a0d 100%);
  border-bottom: 3px solid var(--army-gold);
  padding: 28px 24px 20px;
  text-align: center;
  position: relative;
  overflow: hidden;
}
header::before {
  content: '';
  position: absolute;
  inset: 0;
  background: repeating-linear-gradient(
    90deg,
    transparent,
    transparent 60px,
    rgba(212,160,23,0.04) 60px,
    rgba(212,160,23,0.04) 61px
  );
}
.header-inner { position: relative; z-index: 1; }
.logo {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  margin-bottom: 6px;
}
.star {
  color: var(--army-gold);
  font-size: 22px;
  animation: spin 8s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }
.logo-text {
  font-family: 'Bebas Neue', sans-serif;
  font-size: 42px;
  letter-spacing: 4px;
  color: #fff;
  text-shadow: 0 0 20px rgba(212,160,23,0.4);
}
.logo-text .accent { color: var(--army-gold); }
.tagline {
  font-size: 11px;
  letter-spacing: 3px;
  text-transform: uppercase;
  color: var(--army-khaki);
}
.header-stripe {
  height: 3px;
  background: repeating-linear-gradient(
    90deg,
    var(--army-gold) 0px,
    var(--army-gold) 20px,
    transparent 20px,
    transparent 26px
  );
  margin-top: 20px;
}

/* ===== TAB NAV ===== */
.tab-nav {
  display: flex;
  background: #0a120a;
  border-bottom: 2px solid var(--card-border);
  padding: 0 24px;
}
.tab-btn {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 14px 24px;
  background: none;
  border: none;
  border-bottom: 3px solid transparent;
  color: var(--text-muted);
  font-family: 'Bebas Neue', sans-serif;
  font-size: 18px;
  letter-spacing: 2px;
  cursor: pointer;
  transition: all 0.2s;
  margin-bottom: -2px;
}
.tab-btn:hover { color: var(--army-tan); }
.tab-btn.active {
  color: var(--army-gold);
  border-bottom-color: var(--army-gold);
}
.tab-icon { font-size: 14px; }

/* ===== MAIN ===== */
main {
  max-width: 760px;
  margin: 0 auto;
  padding: 28px 20px 40px;
}

/* ===== SECTIONS ===== */
.tab-section { display: none; animation: fadeIn 0.3s ease; }
.tab-section.active { display: block; }
@keyframes fadeIn { from { opacity: 0; transform: translateY(6px); } to { opacity: 1; transform: none; } }

/* ===== CARDS ===== */
.card {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: var(--radius);
  padding: 28px;
  margin-bottom: 20px;
  box-shadow: var(--shadow);
  position: relative;
  overflow: hidden;
}
.card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--army-olive), var(--army-gold), var(--army-olive));
}
.card-header { margin-bottom: 26px; }
.card-header h2 {
  font-family: 'Bebas Neue', sans-serif;
  font-size: 28px;
  letter-spacing: 2px;
  color: #fff;
  margin-bottom: 4px;
}
.card-header p { color: var(--text-muted); font-size: 13px; }

/* ===== FORM ===== */
.form-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 18px;
  margin-bottom: 24px;
}
.field { display: flex; flex-direction: column; gap: 8px; }
.field.full { grid-column: 1 / -1; }

label {
  font-size: 11px;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: var(--army-khaki);
  font-weight: 600;
}
.unit-hint {
  font-size: 10px;
  color: var(--text-muted);
  text-transform: none;
  letter-spacing: 0;
  font-weight: 400;
}

input[type="number"] {
  background: var(--input-bg);
  border: 1px solid var(--input-border);
  border-radius: var(--radius);
  color: var(--text-primary);
  padding: 11px 14px;
  font-size: 15px;
  font-family: 'DM Sans', sans-serif;
  width: 100%;
  transition: border-color 0.2s, box-shadow 0.2s;
  appearance: none;
  -moz-appearance: textfield;
}
input[type="number"]::-webkit-inner-spin-button,
input[type="number"]::-webkit-outer-spin-button { -webkit-appearance: none; }
input[type="number"]:focus {
  outline: none;
  border-color: var(--army-gold);
  box-shadow: 0 0 0 3px rgba(212,160,23,0.15);
}
input.small { width: calc(50% - 4px); }

.height-inputs { display: flex; gap: 8px; }

.input-unit {
  display: flex;
  align-items: stretch;
  gap: 0;
}
.input-unit input {
  border-radius: var(--radius) 0 0 var(--radius);
  border-right: none;
  flex: 1;
}
.unit-switch {
  display: flex;
  flex-direction: column;
  border: 1px solid var(--input-border);
  border-radius: 0 var(--radius) var(--radius) 0;
  overflow: hidden;
}
.unit-btn {
  flex: 1;
  padding: 0 12px;
  background: #0f1a0f;
  border: none;
  color: var(--text-muted);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 1px;
  cursor: pointer;
  transition: background 0.15s, color 0.15s;
  white-space: nowrap;
}
.unit-btn:not(:last-child) { border-bottom: 1px solid var(--input-border); }
.unit-btn.active { background: var(--army-olive); color: #fff; }
.unit-btn:hover:not(.active) { background: #1a2a1a; color: var(--army-tan); }

/* Toggle gender */
.toggle-group { display: flex; gap: 10px; }
.toggle-btn {
  flex: 1;
  padding: 11px;
  background: var(--input-bg);
  border: 1px solid var(--input-border);
  border-radius: var(--radius);
  color: var(--text-muted);
  font-family: 'DM Sans', sans-serif;
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
}
.toggle-btn.active {
  background: var(--army-olive);
  border-color: var(--army-khaki);
  color: #fff;
}
.toggle-btn:hover:not(.active) { border-color: var(--army-khaki); color: var(--army-tan); }

.field-note {
  font-size: 11px;
  color: var(--text-muted);
  font-style: italic;
}

/* ===== CALC BUTTON ===== */
.calc-btn {
  display: block;
  width: 100%;
  padding: 15px;
  background: linear-gradient(135deg, var(--army-olive) 0%, var(--army-gold) 100%);
  border: none;
  border-radius: var(--radius);
  color: #fff;
  font-family: 'Bebas Neue', sans-serif;
  font-size: 22px;
  letter-spacing: 3px;
  cursor: pointer;
  transition: all 0.2s;
  box-shadow: 0 4px 16px rgba(212,160,23,0.2);
}
.calc-btn:hover {
  transform: translateY(-1px);
  box-shadow: 0 6px 24px rgba(212,160,23,0.4);
}
.calc-btn:active { transform: translateY(0); }

/* ===== RESULTS ===== */
.result-box {
  margin-top: 24px;
  padding: 22px;
  background: rgba(0,0,0,0.3);
  border: 1px solid var(--card-border);
  border-radius: var(--radius);
  animation: fadeIn 0.4s ease;
}
.result-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 14px;
  margin-bottom: 20px;
}
.result-grid.four { grid-template-columns: repeat(2, 1fr); }
.result-item {
  display: flex;
  flex-direction: column;
  gap: 5px;
  padding: 14px;
  background: rgba(26,58,26,0.3);
  border-radius: var(--radius);
  border: 1px solid var(--card-border);
}
.result-label {
  font-size: 10px;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: var(--text-muted);
}
.result-value {
  font-family: 'Bebas Neue', sans-serif;
  font-size: 26px;
  color: var(--army-gold);
  letter-spacing: 1px;
}
.status-badge {
  font-family: 'Bebas Neue', sans-serif;
  font-size: 18px;
  padding: 4px 10px;
  border-radius: 4px;
  display: inline-block;
  letter-spacing: 1px;
  width: fit-content;
}
.status-pass { background: rgba(76,175,80,0.2); color: var(--pass); border: 1px solid var(--pass); }
.status-fail { background: rgba(229,57,53,0.2); color: var(--fail); border: 1px solid var(--fail); }
.status-warn { background: rgba(255,152,0,0.2); color: var(--warn); border: 1px solid var(--warn); }

/* Gauge */
.gauge-wrap {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
}
.gauge-label {
  font-size: 13px;
  color: var(--army-tan);
  text-align: center;
}
canvas { display: block; }

/* BMI Bar */
.bmi-bar-wrap {
  position: relative;
  padding-bottom: 28px;
}
.bmi-bar {
  display: flex;
  height: 38px;
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--card-border);
}
.bmi-segment {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  font-size: 9.5px;
  font-weight: 600;
  text-align: center;
  line-height: 1.3;
  padding: 2px;
  color: rgba(255,255,255,0.85);
}
.underweight { background: #1565c0; }
.normal      { background: #2e7d32; }
.overweight  { background: #e65100; }
.obese       { background: #b71c1c; }

.bmi-marker {
  position: absolute;
  bottom: 4px;
  font-size: 16px;
  color: var(--army-gold);
  transform: translateX(-50%);
  transition: left 0.5s cubic-bezier(0.34,1.56,0.64,1);
  pointer-events: none;
}

/* ===== REFERENCE CARD ===== */
.ref-card { padding: 22px 28px; }
.ref-card h3 {
  font-family: 'Bebas Neue', sans-serif;
  font-size: 20px;
  letter-spacing: 2px;
  color: var(--army-tan);
  margin-bottom: 14px;
}
.ref-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 14px;
  margin-bottom: 14px;
}
.ref-table th, .ref-table td {
  padding: 10px 14px;
  text-align: left;
  border-bottom: 1px solid var(--card-border);
}
.ref-table th {
  background: rgba(26,58,26,0.4);
  font-size: 11px;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: var(--army-khaki);
}
.ref-table td { color: var(--text-primary); }
.ref-table tr:hover td { background: rgba(212,160,23,0.05); }
.ref-note {
  font-size: 12px;
  color: var(--text-muted);
  font-style: italic;
  line-height: 1.6;
  margin-bottom: 10px;
}

.tip-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin-top: 12px;
}
.tip-list li {
  font-size: 13px;
  color: var(--army-tan);
  padding: 8px 12px;
  background: rgba(26,58,26,0.2);
  border-left: 3px solid var(--army-olive);
  border-radius: 0 var(--radius) var(--radius) 0;
}

/* ===== FOOTER ===== */
footer {
  text-align: center;
  padding: 24px 20px;
  border-top: 1px solid var(--card-border);
  color: var(--text-muted);
  font-size: 12px;
  line-height: 1.8;
}
footer strong { color: var(--army-tan); }

/* ===== RESPONSIVE ===== */
@media (max-width: 520px) {
  .form-grid { grid-template-columns: 1fr; }
  .field.full { grid-column: 1; }
  .result-grid { grid-template-columns: 1fr 1fr; }
  .result-grid.four { grid-template-columns: 1fr 1fr; }
  .logo-text { font-size: 32px; }
  .tab-btn { padding: 12px 16px; font-size: 16px; }
}