/* ═══════════════════════════════════════════════════════
   SmartCalc v2.0 · styles.css
   Diseño: Cyberpunk Minimalista + Glassmorphism
   Autor: D&Q Labs
   Arquitectura: CSS Variables + BEM + Mobile-first
═══════════════════════════════════════════════════════ */

/* ─────────────────────────────────────────────
   1. DESIGN TOKENS / CSS VARIABLES
───────────────────────────────────────────── */
:root {
  /* Paleta base */
  --bg-deep:    #050508;
  --bg-base:    #080810;
  --bg-surface: #0d0d1a;
  --bg-raised:  #121228;
  --bg-glass:   rgba(255,255,255,0.04);
  --bg-glass-hover: rgba(255,255,255,0.07);

  /* Bordes */
  --border-dim:    rgba(255,255,255,0.06);
  --border-subtle: rgba(255,255,255,0.10);
  --border-bright: rgba(255,255,255,0.20);

  /* Colores de acento */
  --c-green:   #7dff6a;
  --c-cyan:    #6ae0ff;
  --c-amber:   #ffca6a;
  --c-red:     #ff6a6a;
  --c-purple:  #c06aff;
  --c-pink:    #ff6ab4;

  /* Glow por calculadora */
  --glow-cientifica: rgba(125,255,106,0.20);
  --glow-imc:        rgba(106,224,255,0.20);
  --glow-iva:        rgba(255,106,106,0.20);
  --glow-regla3:     rgba(255,202,106,0.20);
  --glow-calorias:   rgba(192,106,255,0.20);
  --glow-porcentaje: rgba(125,255,106,0.20);
  --glow-interes:    rgba(106,224,255,0.20);
  --glow-ohm:        rgba(255,202,106,0.20);

  /* Texto */
  --text-primary:   #e8e8f8;
  --text-secondary: #8888aa;
  --text-dim:       #44445a;

  /* Tipografía */
  --font-display: 'Syne', sans-serif;
  --font-mono:    'JetBrains Mono', monospace;
  --font-body:    'Inter', sans-serif;

  /* Espaciado */
  --space-xs:  4px;
  --space-sm:  8px;
  --space-md:  16px;
  --space-lg:  24px;
  --space-xl:  40px;
  --space-2xl: 64px;

  /* Radios */
  --r-sm: 8px;
  --r-md: 12px;
  --r-lg: 18px;
  --r-xl: 24px;

  /* Transiciones */
  --ease-out:  cubic-bezier(0.16, 1, 0.3, 1);
  --ease-back: cubic-bezier(0.34, 1.56, 0.64, 1);
  --t-fast: 150ms;
  --t-mid:  250ms;
  --t-slow: 400ms;

  /* Layout */
  --container-max: 1200px;
  --container-pad: clamp(16px, 5vw, 48px);
}

/* ─────────────────────────────────────────────
   2. RESET + BASE
───────────────────────────────────────────── */
*, *::before, *::after { margin:0; padding:0; box-sizing:border-box; }

html {
  scroll-behavior: smooth;
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
}

body {
  background: var(--bg-deep);
  color: var(--text-primary);
  font-family: var(--font-body);
  font-weight: 400;
  line-height: 1.6;
  min-height: 100vh;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* ─────────────────────────────────────────────
   3. FONDO ANIMADO
───────────────────────────────────────────── */
.bg-grid {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
  background-image:
    linear-gradient(rgba(125,255,106,0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(125,255,106,0.03) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: radial-gradient(ellipse 80% 60% at 50% 0%, black 40%, transparent 100%);
}

.bg-glow {
  position: fixed;
  pointer-events: none;
  z-index: 0;
  border-radius: 50%;
  filter: blur(120px);
  opacity: 0.35;
  animation: glow-drift 12s ease-in-out infinite alternate;
}
.bg-glow--1 {
  width: 600px; height: 600px;
  background: radial-gradient(circle, rgba(125,255,106,0.15) 0%, transparent 70%);
  top: -200px; left: -100px;
}
.bg-glow--2 {
  width: 500px; height: 500px;
  background: radial-gradient(circle, rgba(106,224,255,0.12) 0%, transparent 70%);
  bottom: -150px; right: -100px;
  animation-delay: -6s;
}
@keyframes glow-drift {
  from { transform: translate(0, 0) scale(1); }
  to   { transform: translate(30px, 20px) scale(1.08); }
}

/* ─────────────────────────────────────────────
   4. LAYOUT HELPERS
───────────────────────────────────────────── */
.container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding-inline: var(--container-pad);
  position: relative;
  z-index: 1;
}

/* ─────────────────────────────────────────────
   5. HEADER
───────────────────────────────────────────── */
.site-header {
  padding-block: 28px;
  border-bottom: 1px solid var(--border-dim);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(5,5,8,0.80);
}

.header-inner {
  display: flex;
  align-items: center;
  gap: var(--space-md);
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: inherit;
}
.logo-icon {
  font-size: 1.4rem;
  filter: drop-shadow(0 0 8px var(--c-green));
  animation: pulse-icon 3s ease-in-out infinite;
}
@keyframes pulse-icon {
  0%,100% { filter: drop-shadow(0 0 6px var(--c-green)); }
  50%      { filter: drop-shadow(0 0 18px var(--c-green)) brightness(1.2); }
}
.logo-text {
  font-family: var(--font-display);
  font-size: 1.6rem;
  font-weight: 800;
  letter-spacing: -0.5px;
  color: var(--text-primary);
}
.logo-text em {
  font-style: normal;
  color: var(--c-green);
}
.logo-badge {
  font-family: var(--font-mono);
  font-size: 0.6rem;
  color: var(--c-green);
  border: 1px solid rgba(125,255,106,0.3);
  border-radius: 4px;
  padding: 1px 5px;
  letter-spacing: 0.08em;
  align-self: flex-start;
  margin-top: 4px;
}

.header-meta {
  margin-left: auto;
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: 2px;
}
.header-tag {
  font-family: var(--font-mono);
  font-size: 0.65rem;
  color: var(--text-dim);
  letter-spacing: 0.1em;
}
.header-brand {
  font-family: var(--font-display);
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--text-secondary);
  letter-spacing: 0.15em;
  text-transform: uppercase;
}

/* ─────────────────────────────────────────────
   6. HERO
───────────────────────────────────────────── */
.hero {
  padding-block: clamp(40px, 7vw, 80px);
  text-align: center;
}
.hero-eyebrow {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--c-green);
  letter-spacing: 0.2em;
  text-transform: uppercase;
  margin-bottom: var(--space-md);
  animation: fade-up 0.6s var(--ease-out) both;
}
.hero-title {
  font-family: var(--font-display);
  font-size: clamp(2.4rem, 6vw, 5rem);
  font-weight: 800;
  line-height: 1.05;
  letter-spacing: -2px;
  color: var(--text-primary);
  margin-bottom: var(--space-md);
  animation: fade-up 0.6s var(--ease-out) 0.1s both;
}
.hero-accent {
  background: linear-gradient(135deg, var(--c-green) 0%, var(--c-cyan) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.hero-desc {
  font-size: 1.05rem;
  color: var(--text-secondary);
  max-width: 560px;
  margin: 0 auto;
  animation: fade-up 0.6s var(--ease-out) 0.2s both;
}
@keyframes fade-up {
  from { opacity:0; transform: translateY(20px); }
  to   { opacity:1; transform: translateY(0); }
}

/* ─────────────────────────────────────────────
   7. NAVEGACIÓN — TARJETAS ÍCONO
───────────────────────────────────────────── */
.calc-nav {
  padding-bottom: var(--space-xl);
}

.nav-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(110px, 1fr));
  gap: var(--space-sm);
}

.nav-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 7px;
  padding: 16px 10px;
  background: var(--bg-glass);
  border: 1px solid var(--border-dim);
  border-radius: var(--r-lg);
  color: var(--text-secondary);
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.03em;
  cursor: pointer;
  transition:
    transform var(--t-mid) var(--ease-out),
    border-color var(--t-mid),
    background var(--t-mid),
    box-shadow var(--t-mid);
  position: relative;
  overflow: hidden;
  -webkit-tap-highlight-color: transparent;
}
.nav-card:hover {
  transform: translateY(-3px);
  background: var(--bg-glass-hover);
  border-color: var(--border-subtle);
}
.nav-card__icon {
  font-size: 1.6rem;
  line-height: 1;
  transition: filter var(--t-mid), transform var(--t-mid);
}
.nav-card:hover .nav-card__icon { transform: scale(1.12); }
.nav-card__label { line-height: 1; }
.nav-card__glow {
  position: absolute;
  inset: 0;
  border-radius: inherit;
  opacity: 0;
  transition: opacity var(--t-mid);
  pointer-events: none;
}

/* Colores activos por tab */
.nav-card[data-tab="cientifica"]  { --nc: var(--c-green);  --ng: var(--glow-cientifica); }
.nav-card[data-tab="imc"]         { --nc: var(--c-cyan);   --ng: var(--glow-imc); }
.nav-card[data-tab="iva"]         { --nc: var(--c-red);    --ng: var(--glow-iva); }
.nav-card[data-tab="regla3"]      { --nc: var(--c-amber);  --ng: var(--glow-regla3); }
.nav-card[data-tab="calorias"]    { --nc: var(--c-purple); --ng: var(--glow-calorias); }
.nav-card[data-tab="porcentaje"]  { --nc: var(--c-green);  --ng: var(--glow-porcentaje); }
.nav-card[data-tab="interes"]     { --nc: var(--c-cyan);   --ng: var(--glow-interes); }
.nav-card[data-tab="ohm"]         { --nc: var(--c-amber);  --ng: var(--glow-ohm); }

.nav-card:hover,
.nav-card.active {
  border-color: var(--nc);
  color: var(--nc);
}
.nav-card:hover .nav-card__glow,
.nav-card.active .nav-card__glow {
  opacity: 1;
  background: radial-gradient(circle at center, var(--ng) 0%, transparent 70%);
}
.nav-card.active {
  box-shadow: 0 0 0 1px var(--nc), 0 8px 32px var(--ng);
}
.nav-card.active .nav-card__icon {
  filter: drop-shadow(0 0 8px var(--nc));
}

/* ─────────────────────────────────────────────
   8. PANELES
───────────────────────────────────────────── */
.calc-main { padding-bottom: var(--space-2xl); }

.calc-panel {
  animation: panel-in 0.35s var(--ease-out) both;
}
.calc-panel[hidden] { display: none !important; }
@keyframes panel-in {
  from { opacity:0; transform:translateY(12px); }
  to   { opacity:1; transform:translateY(0); }
}

.panel-header { margin-bottom: var(--space-xl); }

.panel-title {
  font-family: var(--font-display);
  font-size: clamp(1.8rem, 4vw, 2.8rem);
  font-weight: 800;
  letter-spacing: -1px;
  line-height: 1.1;
  color: var(--text-primary);
}
.panel-title span {
  background: linear-gradient(135deg, var(--c-green), var(--c-cyan));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.panel-desc {
  font-size: 0.9rem;
  color: var(--text-secondary);
  margin-top: 8px;
  font-family: var(--font-mono);
  letter-spacing: 0.02em;
}

/* ─────────────────────────────────────────────
   9. GLASS CARD
───────────────────────────────────────────── */
.glass-card {
  background: var(--bg-glass);
  border: 1px solid var(--border-subtle);
  border-radius: var(--r-xl);
  padding: clamp(20px, 4vw, 36px);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  position: relative;
}
.glass-card::before {
  content: '';
  position: absolute;
  inset: 0;
  border-radius: inherit;
  background: linear-gradient(135deg, rgba(255,255,255,0.05) 0%, transparent 60%);
  pointer-events: none;
}

/* ─────────────────────────────────────────────
   10. FORMULARIOS
───────────────────────────────────────────── */
.form-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-lg);
  align-items: start;
}
@media (min-width: 768px) {
  .form-layout { grid-template-columns: 1fr 1fr; }
}

.form-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-md);
}
@media (max-width: 500px) {
  .form-grid { grid-template-columns: 1fr; }
}

.field { display: flex; flex-direction: column; gap: 7px; }
.field--full { grid-column: 1 / -1; }

label {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  color: var(--text-secondary);
  letter-spacing: 0.12em;
  text-transform: uppercase;
}
label .unit {
  color: var(--text-dim);
  text-transform: none;
}

input, select {
  width: 100%;
  background: rgba(255,255,255,0.05);
  border: 1px solid var(--border-subtle);
  border-radius: var(--r-md);
  padding: 12px 16px;
  color: var(--text-primary);
  font-family: var(--font-mono);
  font-size: 0.95rem;
  outline: none;
  transition: border-color var(--t-mid), box-shadow var(--t-mid), background var(--t-mid);
  -webkit-appearance: none;
}
input:focus, select:focus {
  border-color: var(--c-green);
  box-shadow: 0 0 0 3px rgba(125,255,106,0.12);
  background: rgba(125,255,106,0.04);
}
input::placeholder { color: var(--text-dim); }
select option { background: var(--bg-raised); color: var(--text-primary); }
.input--result { color: var(--c-amber); font-weight: 500; cursor: default; }

/* ─────────────────────────────────────────────
   11. BOTONES
───────────────────────────────────────────── */
.btn-row { display: flex; gap: var(--space-sm); flex-wrap: wrap; margin-top: var(--space-lg); }

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 28px;
  border-radius: var(--r-md);
  border: 1px solid transparent;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  font-weight: 500;
  letter-spacing: 0.08em;
  cursor: pointer;
  transition:
    transform var(--t-fast) var(--ease-back),
    filter var(--t-fast),
    box-shadow var(--t-mid);
  -webkit-tap-highlight-color: transparent;
}
.btn:active { transform: scale(0.97); }

.btn--primary {
  background: var(--c-green);
  color: #080810;
  border-color: var(--c-green);
  box-shadow: 0 0 0 0 rgba(125,255,106,0);
}
.btn--primary:hover {
  filter: brightness(1.1);
  box-shadow: 0 4px 24px rgba(125,255,106,0.35);
  transform: translateY(-2px);
}

.btn--ghost {
  background: transparent;
  color: var(--text-secondary);
  border-color: var(--border-subtle);
}
.btn--ghost:hover {
  color: var(--text-primary);
  border-color: var(--border-bright);
  background: var(--bg-glass);
}

/* Toggle group */
.toggle-group {
  display: flex;
  gap: 6px;
  background: rgba(255,255,255,0.04);
  border: 1px solid var(--border-subtle);
  border-radius: var(--r-md);
  padding: 4px;
  width: fit-content;
}
.toggle-btn {
  padding: 9px 22px;
  border-radius: calc(var(--r-md) - 2px);
  border: none;
  background: transparent;
  color: var(--text-secondary);
  font-family: var(--font-mono);
  font-size: 0.78rem;
  cursor: pointer;
  transition: all var(--t-mid);
}
.toggle-btn.active {
  background: var(--c-purple);
  color: white;
  box-shadow: 0 2px 12px rgba(192,106,255,0.4);
}

/* ─────────────────────────────────────────────
   12. RESULT PANEL
───────────────────────────────────────────── */
.result-panel {
  background: var(--bg-glass);
  border: 1px solid var(--border-subtle);
  border-radius: var(--r-xl);
  padding: clamp(20px, 4vw, 32px);
  animation: fade-up 0.3s var(--ease-out) both;
}
.result-panel--inline {
  margin-top: var(--space-lg);
  border-radius: var(--r-lg);
  padding: var(--space-lg);
}

.result-hero { text-align: center; margin-bottom: var(--space-lg); }
.result-label {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  color: var(--text-dim);
  letter-spacing: 0.2em;
  text-transform: uppercase;
  margin-bottom: 6px;
}
.result-value {
  font-family: var(--font-display);
  font-size: clamp(2rem, 5vw, 3.2rem);
  font-weight: 800;
  letter-spacing: -2px;
  color: var(--c-green);
  line-height: 1;
  margin-bottom: 10px;
}
.result-badge {
  display: inline-block;
  background: rgba(125,255,106,0.1);
  color: var(--c-green);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  padding: 4px 14px;
  border-radius: 100px;
  border: 1px solid rgba(125,255,106,0.2);
}

/* ─────────────────────────────────────────────
   13. CIENTÍFICA
───────────────────────────────────────────── */
.sci-layout {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: var(--space-lg);
  align-items: start;
}
@media (max-width: 900px) {
  .sci-layout { grid-template-columns: 1fr; }
}

/* Pantalla */
.sci-calc { max-width: 460px; }
.sci-screen {
  background: #0a1a0a;
  border: 1px solid rgba(125,255,106,0.2);
  border-radius: var(--r-lg) var(--r-lg) 0 0;
  padding: 20px 20px 14px;
  min-height: 110px;
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  align-items: flex-end;
  box-shadow: inset 0 2px 12px rgba(0,0,0,0.5), 0 0 40px rgba(125,255,106,0.05);
  position: relative;
}
.sci-screen__memory {
  position: absolute;
  top: 12px;
  left: 14px;
  font-family: var(--font-mono);
  font-size: 0.6rem;
  color: rgba(125,255,106,0.4);
  letter-spacing: 0.08em;
}
.sci-screen__expr {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  color: rgba(125,255,106,0.5);
  min-height: 20px;
  word-break: break-all;
  text-align: right;
  width: 100%;
}
.sci-screen__num {
  font-family: var(--font-mono);
  font-size: clamp(1.8rem, 4vw, 2.6rem);
  font-weight: 700;
  color: var(--c-green);
  text-shadow: 0 0 20px rgba(125,255,106,0.5);
  word-break: break-all;
  text-align: right;
  width: 100%;
  letter-spacing: 1px;
  line-height: 1.2;
  transition: color var(--t-fast);
}

/* Grid botones */
.sci-buttons {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 5px;
  background: #111118;
  border: 1px solid var(--border-subtle);
  border-top: none;
  border-radius: 0 0 var(--r-lg) var(--r-lg);
  padding: 12px;
}

.sb {
  border: none;
  border-radius: var(--r-sm);
  padding: 11px 4px;
  font-family: var(--font-mono);
  font-size: 0.76rem;
  cursor: pointer;
  transition: transform var(--t-fast) var(--ease-back), filter var(--t-fast);
  border-bottom: 2px solid rgba(0,0,0,0.4);
  text-align: center;
  -webkit-tap-highlight-color: transparent;
  user-select: none;
}
.sb:active { transform: scale(0.91); filter: brightness(0.8); }

.sb--mem  { background: #1e1e2e; color: #7070aa; }
.sb--mem:hover  { background: #28283e; color: #9090cc; }
.sb--fn   { background: #1e2030; color: #8888bb; }
.sb--fn:hover   { background: #282840; color: #aaaadd; }
.sb--num  { background: #282828; color: #cccccc; }
.sb--num:hover  { background: #323232; color: #eeeeee; }
.sb--op   { background: #1a2a1a; color: var(--c-green); font-weight: 500; }
.sb--op:hover   { background: #223222; }
.sb--ac   { background: #2a1a1a; color: var(--c-red); font-weight: 600; }
.sb--ac:hover   { background: #381e1e; }
.sb--del  { background: #2a1e00; color: var(--c-amber); }
.sb--del:hover  { background: #362600; }
.sb--eq   {
  background: var(--c-green);
  color: #080810;
  font-weight: 700;
  font-size: 1.1rem;
  box-shadow: 0 4px 16px rgba(125,255,106,0.3);
}
.sb--eq:hover { filter: brightness(1.1); }
.sb--zero { grid-column: span 4; }

/* Historial */
.sci-history {
  min-height: 300px;
  background: var(--bg-glass);
  border: 1px solid var(--border-dim);
  border-radius: var(--r-lg);
  overflow: hidden;
  display: flex;
  flex-direction: column;
}
.history-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 18px;
  border-bottom: 1px solid var(--border-dim);
}
.history-title {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--text-secondary);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  font-weight: 400;
}
.history-clear {
  font-family: var(--font-mono);
  font-size: 0.65rem;
  color: var(--text-dim);
  background: none;
  border: none;
  cursor: pointer;
  letter-spacing: 0.08em;
  transition: color var(--t-fast);
}
.history-clear:hover { color: var(--c-red); }

.history-list {
  flex: 1;
  overflow-y: auto;
  padding: 8px;
  list-style: none;
  display: flex;
  flex-direction: column-reverse;
  gap: 4px;
}
.history-list::-webkit-scrollbar { width: 4px; }
.history-list::-webkit-scrollbar-track { background: transparent; }
.history-list::-webkit-scrollbar-thumb { background: var(--border-subtle); border-radius: 2px; }

.history-item {
  padding: 10px 12px;
  border-radius: var(--r-sm);
  background: rgba(255,255,255,0.03);
  cursor: pointer;
  transition: background var(--t-fast);
}
.history-item:hover { background: rgba(125,255,106,0.06); }
.history-item__expr {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  color: var(--text-dim);
}
.history-item__result {
  font-family: var(--font-mono);
  font-size: 0.9rem;
  color: var(--c-green);
  font-weight: 500;
}
.history-empty {
  text-align: center;
  padding: 40px 20px;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--text-dim);
  letter-spacing: 0.08em;
  list-style: none;
}

/* Hint teclado */
.keyboard-hint {
  margin-top: 14px;
  font-family: var(--font-mono);
  font-size: 0.65rem;
  color: var(--text-dim);
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}
kbd {
  background: rgba(255,255,255,0.08);
  border: 1px solid var(--border-subtle);
  border-bottom-width: 2px;
  border-radius: 4px;
  padding: 1px 6px;
  font-size: inherit;
  color: var(--text-secondary);
}

/* ─────────────────────────────────────────────
   14. IMC
───────────────────────────────────────────── */
.imc-scale { margin: var(--space-lg) 0 var(--space-md); }
.imc-bar-track {
  height: 10px;
  background: var(--bg-raised);
  border-radius: 100px;
  position: relative;
  overflow: visible;
}
.imc-bar-fill {
  height: 100%;
  border-radius: 100px;
  background: linear-gradient(90deg, var(--c-cyan) 0%, var(--c-green) 35%, var(--c-amber) 65%, var(--c-red) 100%);
}
.imc-marker {
  position: absolute;
  top: -5px;
  width: 20px;
  height: 20px;
  background: white;
  border-radius: 50%;
  border: 3px solid var(--bg-deep);
  box-shadow: 0 0 0 2px var(--c-cyan), 0 4px 12px rgba(0,0,0,0.4);
  transform: translateX(-50%);
  transition: left 0.5s var(--ease-back);
}
.imc-labels {
  display: flex;
  justify-content: space-between;
  margin-top: 6px;
  font-family: var(--font-mono);
  font-size: 0.62rem;
  color: var(--text-dim);
}
.imc-legend {
  display: flex;
  gap: var(--space-md);
  flex-wrap: wrap;
}
.legend-item {
  display: flex;
  align-items: center;
  gap: 6px;
  font-family: var(--font-mono);
  font-size: 0.68rem;
  color: var(--text-secondary);
}
.dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  flex-shrink: 0;
}
.dot--cyan  { background: var(--c-cyan); }
.dot--green { background: var(--c-green); }
.dot--amber { background: var(--c-amber); }
.dot--red   { background: var(--c-red); }

/* ─────────────────────────────────────────────
   15. BREAKDOWN LIST (IVA / Interés)
───────────────────────────────────────────── */
.breakdown-list { display: flex; flex-direction: column; gap: 2px; }
.breakdown-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 12px 4px;
  border-bottom: 1px solid var(--border-dim);
}
.breakdown-row:last-child { border-bottom: none; }
.breakdown-row--total {
  margin-top: 8px;
  padding-top: 16px;
  border-top: 1px solid var(--border-subtle);
}
.breakdown-label {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-secondary);
}
.breakdown-value {
  font-family: var(--font-mono);
  font-size: 0.9rem;
  color: var(--text-primary);
  font-weight: 500;
}
.breakdown-value--accent { color: var(--c-amber); }
.breakdown-value--hero {
  font-family: var(--font-display);
  font-size: 1.8rem;
  font-weight: 800;
  color: var(--c-green);
  letter-spacing: -1px;
}

/* ─────────────────────────────────────────────
   16. REGLA DE 3
───────────────────────────────────────────── */
.r3-grid {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: end;
  gap: var(--space-md);
  margin-bottom: var(--space-md);
}
.r3-arrow {
  font-size: 1.4rem;
  color: var(--text-dim);
  padding-bottom: 12px;
  text-align: center;
}
.r3-arrow--accent { color: var(--c-amber); }

.formula-display {
  margin-top: var(--space-md);
  padding: 12px 16px;
  background: rgba(255,202,106,0.06);
  border: 1px solid rgba(255,202,106,0.15);
  border-radius: var(--r-md);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--c-amber);
  letter-spacing: 0.03em;
}

/* ─────────────────────────────────────────────
   17. CALORÍAS — MACRO GRID
───────────────────────────────────────────── */
.macro-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-sm);
  margin-top: var(--space-lg);
}
.macro-card {
  background: rgba(255,255,255,0.03);
  border: 1px solid var(--border-dim);
  border-radius: var(--r-md);
  padding: 16px 12px;
  text-align: center;
  transition: border-color var(--t-mid);
}
.macro-card--amber { border-color: rgba(255,202,106,0.2); }
.macro-card--cyan  { border-color: rgba(106,224,255,0.2); }
.macro-card--red   { border-color: rgba(255,106,106,0.2); }
.macro-val {
  font-family: var(--font-display);
  font-size: 1.4rem;
  font-weight: 700;
}
.macro-card--amber .macro-val { color: var(--c-amber); }
.macro-card--cyan  .macro-val { color: var(--c-cyan); }
.macro-card--red   .macro-val { color: var(--c-red); }
.macro-label {
  font-family: var(--font-mono);
  font-size: 0.62rem;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-top: 4px;
}
.macro-pct {
  font-family: var(--font-mono);
  font-size: 0.6rem;
  color: var(--text-dim);
  margin-top: 2px;
}

/* ─────────────────────────────────────────────
   18. LEY DE OHM
───────────────────────────────────────────── */
.ohm-diagram {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  margin-bottom: var(--space-xl);
  padding: var(--space-lg);
  background: rgba(255,255,255,0.02);
  border-radius: var(--r-lg);
}
.ohm-circle {
  width: 52px;
  height: 52px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-display);
  font-size: 1.1rem;
  font-weight: 800;
  border: 2px solid;
}
.ohm-circle--v { border-color: var(--c-amber); color: var(--c-amber); box-shadow: 0 0 16px rgba(255,202,106,0.2); }
.ohm-circle--i { border-color: var(--c-cyan);  color: var(--c-cyan);  box-shadow: 0 0 16px rgba(106,224,255,0.2); }
.ohm-circle--r { border-color: var(--c-red);   color: var(--c-red);   box-shadow: 0 0 16px rgba(255,106,106,0.2); }
.ohm-equals, .ohm-times {
  font-family: var(--font-display);
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--text-dim);
}

.ohm-results {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: var(--space-sm);
}
.ohm-result-card {
  background: rgba(255,255,255,0.03);
  border: 1px solid var(--border-dim);
  border-radius: var(--r-md);
  padding: 14px;
  text-align: center;
}
.ohm-result-sym {
  font-family: var(--font-display);
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: 4px;
}
.ohm-result-val {
  font-family: var(--font-mono);
  font-size: 1.1rem;
  color: var(--text-primary);
}
.ohm-result-unit {
  font-family: var(--font-mono);
  font-size: 0.62rem;
  color: var(--text-dim);
  margin-top: 2px;
}

/* ─────────────────────────────────────────────
   19. TOAST NOTIFICATIONS
───────────────────────────────────────────── */
.toast-container {
  position: fixed;
  bottom: 24px;
  right: 24px;
  z-index: 999;
  display: flex;
  flex-direction: column;
  gap: 8px;
  pointer-events: none;
}
.toast {
  background: var(--bg-raised);
  border: 1px solid var(--border-subtle);
  border-radius: var(--r-md);
  padding: 12px 18px;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-primary);
  box-shadow: 0 8px 32px rgba(0,0,0,0.4);
  animation: toast-in 0.3s var(--ease-out) both;
  pointer-events: auto;
}
.toast--error  { border-color: rgba(255,106,106,0.4); color: var(--c-red); }
.toast--success { border-color: rgba(125,255,106,0.4); color: var(--c-green); }
@keyframes toast-in {
  from { opacity:0; transform: translateX(20px); }
  to   { opacity:1; transform: translateX(0); }
}

/* ─────────────────────────────────────────────
   20. FOOTER
───────────────────────────────────────────── */
.site-footer {
  border-top: 1px solid var(--border-dim);
  padding-block: var(--space-xl);
  margin-top: var(--space-2xl);
}
.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: var(--space-lg);
}
.footer-logo {
  font-family: var(--font-display);
  font-size: 1.2rem;
  font-weight: 800;
  color: var(--text-primary);
}
.footer-logo em { font-style: normal; color: var(--c-green); }
.footer-tagline {
  font-family: var(--font-mono);
  font-size: 0.65rem;
  color: var(--text-dim);
  margin-top: 4px;
  letter-spacing: 0.08em;
}
.footer-dev {
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: 3px;
}
.footer-dev__by {
  font-family: var(--font-mono);
  font-size: 0.6rem;
  color: var(--text-dim);
  letter-spacing: 0.15em;
  text-transform: uppercase;
}
.footer-dev__name {
  font-family: var(--font-display);
  font-size: 1rem;
  font-weight: 800;
  letter-spacing: 3px;
  background: linear-gradient(135deg, var(--c-green), var(--c-cyan));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  text-transform: uppercase;
}
.footer-dev__copy {
  font-family: var(--font-mono);
  font-size: 0.6rem;
  color: var(--text-dim);
}

/* ─────────────────────────────────────────────
   21. RESPONSIVE
───────────────────────────────────────────── */
@media (max-width: 600px) {
  .nav-grid { grid-template-columns: repeat(4, 1fr); }
  .nav-card { padding: 12px 6px; min-width: 0; }
  .nav-card__icon { font-size: 1.3rem; }
  .nav-card__label { font-size: 0.62rem; }
  .header-tag { display: none; }
  .sci-calc { max-width: 100%; }
  .macro-grid { grid-template-columns: repeat(3,1fr); }
  .r3-grid { grid-template-columns: 1fr; }
  .r3-arrow { padding-bottom: 0; transform: rotate(90deg); }
  .ohm-diagram { gap: 8px; }
  .ohm-circle { width: 42px; height: 42px; font-size: 0.9rem; }
}

@media (max-width: 400px) {
  .nav-grid { grid-template-columns: repeat(4, 1fr); gap: 4px; }
  .sci-buttons { gap: 4px; padding: 8px; }
  .sb { font-size: 0.68rem; padding: 9px 2px; }
}

/* ─────────────────────────────────────────────
   22. ACCESIBILIDAD
───────────────────────────────────────────── */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
}

:focus-visible {
  outline: 2px solid var(--c-green);
  outline-offset: 3px;
  border-radius: 4px;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  white-space: nowrap;
  border: 0;
}

/* ─────────────────────────────────────────────
   23. PRINT
───────────────────────────────────────────── */
@media print {
  .bg-grid, .bg-glow, .site-header, .calc-nav { display: none; }
  body { background: white; color: black; }
}