:root {
  --bg-primary: #0a0a0f;
  --bg-secondary: #14141f;
  --bg-tertiary: #1e1e2e;
  --text-primary: #ffffff;
  --text-secondary: #a0a0b0;
  --text-muted: #606070;
  --accent: #00d4ff;
  --accent-secondary: #00ff88;
  --danger: #ff4466;
  --warn: #ffaa33;
  --focus-ring: #00d4ff;
  --focus-glow: rgba(0, 212, 255, 0.4);
  --radius-md: 12px;
  --radius-lg: 18px;
}

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

html, body {
  width: 600px;
  height: 600px;
  overflow: hidden;
  background: #000;
  color: var(--text-primary);
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  -webkit-font-smoothing: antialiased;
}

#app { width: 100%; height: 100%; position: relative; }

.screen {
  width: 100%;
  height: 100%;
  position: absolute;
  top: 0; left: 0;
  display: flex;
  flex-direction: column;
  padding: 24px;
  gap: 16px;
}

.screen.hidden { display: none; }

.hidden { display: none !important; }

.focusable {
  transition: all 0.15s ease;
  border: 2px solid transparent;
  cursor: pointer;
  outline: none;
  background: var(--bg-secondary);
  color: var(--text-primary);
  font-family: inherit;
}

.focusable:focus {
  border-color: var(--focus-ring);
  box-shadow: 0 0 20px var(--focus-glow);
  background: var(--bg-tertiary);
}

/* ---------- HEADER ---------- */
.header {
  background: var(--bg-primary);
  border-radius: var(--radius-md);
  padding: 16px 20px;
  border-left: 4px solid var(--accent);
}

.header-title {
  font-size: 26px;
  font-weight: 700;
  letter-spacing: 0.5px;
  color: var(--text-primary);
}

.header-sub {
  margin-top: 4px;
  font-size: 14px;
  color: var(--text-secondary);
}

/* ---------- HOME ---------- */
.home-body {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 20px;
  justify-content: center;
  align-items: center;
}

.last-card {
  width: 100%;
  background: var(--bg-primary);
  border-radius: var(--radius-lg);
  padding: 28px;
  text-align: center;
  border: 1px solid var(--bg-tertiary);
}

.last-label {
  font-size: 14px;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 2px;
}

.last-bmi {
  font-size: 80px;
  font-weight: 200;
  margin: 8px 0;
  color: var(--accent);
  line-height: 1;
}

.last-cat {
  font-size: 18px;
  color: var(--text-secondary);
  font-weight: 500;
}

.hint {
  font-size: 13px;
  color: var(--text-muted);
  text-align: center;
}

.home-nav {
  display: flex;
  gap: 12px;
}

/* ---------- BUTTONS ---------- */
.btn {
  flex: 1;
  min-height: 88px;
  border-radius: var(--radius-md);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 4px;
  padding: 12px;
}

.btn-wide {
  width: 100%;
  min-height: 72px;
}

.btn-primary {
  background: var(--bg-primary);
  border: 2px solid var(--accent);
}

.btn-primary:focus {
  background: var(--accent);
  color: #000;
  border-color: var(--accent);
}

.btn-secondary {
  background: var(--bg-primary);
  border: 2px solid var(--bg-tertiary);
}

.btn-secondary:focus {
  border-color: var(--focus-ring);
}

.btn-label {
  font-size: 20px;
  font-weight: 700;
  letter-spacing: 1.5px;
}

.btn-sub {
  font-size: 12px;
  color: var(--text-muted);
  font-weight: 400;
}

.btn-primary:focus .btn-sub {
  color: rgba(0,0,0,0.7);
}

.btn-text {
  background: transparent;
  border: 2px solid transparent;
  padding: 12px;
  font-size: 16px;
  color: var(--text-secondary);
  border-radius: var(--radius-md);
  min-height: 44px;
}

/* ---------- INPUT ---------- */
.input-body {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.row {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.row-label {
  font-size: 13px;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 2px;
  padding-left: 4px;
}

.spinner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: var(--bg-primary);
  border-radius: var(--radius-md);
  padding: 14px 24px;
  min-height: 68px;
}

.spin-arrow {
  font-size: 26px;
  color: var(--text-muted);
  font-weight: 700;
  transition: color 0.15s;
}

.spinner:focus .spin-arrow {
  color: var(--accent);
}

.spin-value {
  font-size: 32px;
  font-weight: 600;
  letter-spacing: 1px;
  color: var(--text-primary);
}

.spin-unit {
  font-size: 18px;
  color: var(--text-secondary);
  margin-left: 6px;
  font-weight: 400;
}

/* ---------- RESULT ---------- */
.result-body {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 14px;
}

.bmi-display {
  display: flex;
  align-items: baseline;
  gap: 8px;
  margin-top: 4px;
}

.bmi-number {
  font-size: 84px;
  font-weight: 200;
  color: var(--accent);
  line-height: 1;
  letter-spacing: -2px;
}

.bmi-unit {
  font-size: 16px;
  color: var(--text-muted);
}

.cat-badge {
  padding: 10px 28px;
  border-radius: 999px;
  font-size: 18px;
  font-weight: 700;
  letter-spacing: 1.5px;
  background: var(--bg-tertiary);
  border: 2px solid var(--bg-tertiary);
}

.cat-badge.cat-under {
  background: rgba(0, 212, 255, 0.15);
  border-color: var(--accent);
  color: var(--accent);
}
.cat-badge.cat-normal {
  background: rgba(0, 255, 136, 0.15);
  border-color: var(--accent-secondary);
  color: var(--accent-secondary);
}
.cat-badge.cat-over {
  background: rgba(255, 170, 51, 0.15);
  border-color: var(--warn);
  color: var(--warn);
}
.cat-badge.cat-obese {
  background: rgba(255, 68, 102, 0.15);
  border-color: var(--danger);
  color: var(--danger);
}

.gauge {
  width: 100%;
  margin-top: 4px;
}

.gauge-track {
  position: relative;
  height: 14px;
  border-radius: 7px;
  overflow: hidden;
  display: flex;
}

.gauge-seg {
  height: 100%;
}

.seg-under   { background: var(--accent); width: 17%; }
.seg-normal  { background: var(--accent-secondary); width: 27%; }
.seg-over    { background: var(--warn); width: 21%; }
.seg-obese   { background: var(--danger); width: 35%; }

.gauge-marker {
  position: absolute;
  top: -4px;
  width: 4px;
  height: 22px;
  background: #fff;
  border-radius: 2px;
  box-shadow: 0 0 10px rgba(255,255,255,0.8);
  transform: translateX(-2px);
  transition: left 0.3s ease;
  left: 0;
}

.gauge-labels {
  display: flex;
  justify-content: space-between;
  margin-top: 6px;
  font-size: 11px;
  color: var(--text-muted);
}

.advice {
  text-align: center;
  font-size: 15px;
  color: var(--text-secondary);
  line-height: 1.5;
  padding: 0 8px;
  margin-top: 4px;
}

.result-nav {
  display: flex;
  gap: 12px;
}