/* ═══════════════════════════════════════════════════════════
 *  HIC — Cálculos de Instrumentación Industrial
 *  Design System & Global Styles
 * ═══════════════════════════════════════════════════════════ */

/* ─── CSS Custom Properties ─── */
:root {
  /* Palette — Deep industrial blue-violet */
  --bg-primary:       #0a0e1a;
  --bg-secondary:     #111827;
  --bg-card:          #1a1f35;
  --bg-card-hover:    #222845;
  --bg-input:         #0f1425;
  --bg-sidebar:       #0d1222;

  --accent-blue:      #60a5fa;
  --accent-violet:    #a78bfa;
  --accent-cyan:      #22d3ee;
  --accent-green:     #34d399;
  --accent-red:       #f87171;
  --accent-amber:     #fbbf24;

  --text-primary:     #f1f5f9;
  --text-secondary:   #94a3b8;
  --text-muted:       #64748b;

  --border:           rgba(148, 163, 184, 0.1);
  --border-focus:     rgba(96, 165, 250, 0.5);

  --gradient-main:    linear-gradient(135deg, #60a5fa 0%, #a78bfa 100%);
  --gradient-card:    linear-gradient(135deg, rgba(96,165,250,0.05) 0%, rgba(167,139,250,0.05) 100%);

  --shadow-sm:        0 1px 3px rgba(0,0,0,0.3);
  --shadow-md:        0 4px 16px rgba(0,0,0,0.4);
  --shadow-lg:        0 8px 32px rgba(0,0,0,0.5);
  --shadow-glow:      0 0 24px rgba(96,165,250,0.15);

  --radius-sm:        8px;
  --radius-md:        12px;
  --radius-lg:        16px;
  --radius-xl:        24px;

  --sidebar-width:    240px;

  --font-sans:        'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono:        'JetBrains Mono', 'Fira Code', monospace;

  --transition:       all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-sans);
  background: var(--bg-primary);
  color: var(--text-primary);
  min-height: 100vh;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

.hidden { display: none !important; }

/* ═══════════════════════════════════════════════════════════
 *  LANDING OVERLAY
 * ═══════════════════════════════════════════════════════════ */
.landing-overlay {
  position: fixed;
  inset: 0;
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--bg-primary);
  overflow: hidden;
}

.landing-content {
  position: relative;
  z-index: 2;
  text-align: center;
  max-width: 520px;
  padding: 2rem;
  animation: fadeInUp 0.8s ease-out;
}

@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(30px); }
  to   { opacity: 1; transform: translateY(0); }
}

.landing-logo {
  margin-bottom: 1.5rem;
}

.logo-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 80px;
  height: 80px;
  border-radius: 50%;
  background: rgba(96,165,250,0.08);
  margin-bottom: 1rem;
  animation: pulse-glow 3s ease-in-out infinite;
}

@keyframes pulse-glow {
  0%, 100% { box-shadow: 0 0 20px rgba(96,165,250,0.15); }
  50%      { box-shadow: 0 0 40px rgba(96,165,250,0.3); }
}

.landing-title {
  font-size: 3rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  background: var(--gradient-main);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.landing-subtitle {
  font-size: 1.1rem;
  color: var(--text-secondary);
  font-weight: 400;
  margin-top: 0.25rem;
}

.landing-desc {
  color: var(--text-muted);
  line-height: 1.7;
  margin: 1.5rem 0 2rem;
  font-size: 0.95rem;
}

.landing-actions {
  display: flex;
  gap: 0.75rem;
  justify-content: center;
  flex-wrap: wrap;
}

.landing-note {
  margin-top: 1rem;
  font-size: 0.8rem;
  color: var(--text-muted);
}

/* Background shapes */
.landing-bg-shapes {
  position: absolute;
  inset: 0;
  pointer-events: none;
  overflow: hidden;
}

.shape {
  position: absolute;
  border-radius: 50%;
  filter: blur(80px);
  opacity: 0.35;
}

.shape-1 {
  width: 400px; height: 400px;
  background: radial-gradient(circle, rgba(96,165,250,0.4), transparent 70%);
  top: -10%; right: -5%;
  animation: float1 12s ease-in-out infinite;
}
.shape-2 {
  width: 350px; height: 350px;
  background: radial-gradient(circle, rgba(167,139,250,0.4), transparent 70%);
  bottom: -15%; left: -10%;
  animation: float2 15s ease-in-out infinite;
}
.shape-3 {
  width: 250px; height: 250px;
  background: radial-gradient(circle, rgba(34,211,238,0.25), transparent 70%);
  top: 40%; left: 50%;
  animation: float3 10s ease-in-out infinite;
}

@keyframes float1 { 0%,100% { transform: translate(0,0); } 50% { transform: translate(-30px, 40px); } }
@keyframes float2 { 0%,100% { transform: translate(0,0); } 50% { transform: translate(40px, -20px); } }
@keyframes float3 { 0%,100% { transform: translate(0,0); } 50% { transform: translate(-20px, -30px); } }

/* ═══════════════════════════════════════════════════════════
 *  BUTTONS
 * ═══════════════════════════════════════════════════════════ */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.65rem 1.5rem;
  border: none;
  border-radius: var(--radius-md);
  font-family: var(--font-sans);
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
  text-decoration: none;
}

.btn-primary {
  background: var(--gradient-main);
  color: #fff;
  box-shadow: 0 2px 12px rgba(96,165,250,0.3);
}
.btn-primary:hover {
  box-shadow: 0 4px 20px rgba(96,165,250,0.5);
  transform: translateY(-1px);
}
.btn-primary:active { transform: translateY(0); }

.btn-outline {
  background: transparent;
  color: var(--text-secondary);
  border: 1.5px solid var(--border);
}
.btn-outline:hover {
  border-color: var(--accent-blue);
  color: var(--accent-blue);
  background: rgba(96,165,250,0.05);
}

.btn-lg { padding: 0.85rem 2rem; font-size: 1rem; }
.btn-sm { padding: 0.5rem 1rem; font-size: 0.8rem; }

.btn-icon { font-size: 1.1em; }

.btn-calc {
  width: 100%;
  justify-content: center;
  margin-top: 0.5rem;
}

/* ═══════════════════════════════════════════════════════════
 *  APP SHELL — Sidebar + Main
 * ═══════════════════════════════════════════════════════════ */
.app-shell {
  display: flex;
  min-height: 100vh;
}

/* ─── Sidebar ─── */
.sidebar {
  width: var(--sidebar-width);
  background: var(--bg-sidebar);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  position: fixed;
  top: 0;
  left: 0;
  bottom: 0;
  z-index: 100;
  transition: transform 0.3s ease;
}

.sidebar-header {
  padding: 1.25rem 1.25rem 1rem;
  border-bottom: 1px solid var(--border);
}

.sidebar-logo {
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

.sidebar-brand {
  font-size: 1.2rem;
  font-weight: 800;
  background: var(--gradient-main);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.sidebar-nav {
  list-style: none;
  padding: 0.75rem 0.75rem;
  flex: 1;
  overflow-y: auto;
}

.nav-item {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  width: 100%;
  padding: 0.7rem 0.85rem;
  border: none;
  border-radius: var(--radius-sm);
  background: transparent;
  color: var(--text-secondary);
  font-family: var(--font-sans);
  font-size: 0.88rem;
  font-weight: 500;
  cursor: pointer;
  transition: var(--transition);
  text-align: left;
}

.nav-item:hover {
  background: rgba(96,165,250,0.08);
  color: var(--text-primary);
}

.nav-item.active {
  background: rgba(96,165,250,0.12);
  color: var(--accent-blue);
  box-shadow: inset 3px 0 0 var(--accent-blue);
}

.nav-icon { font-size: 1.15rem; width: 24px; text-align: center; }

.nav-divider {
  height: 1px;
  background: var(--border);
  margin: 0.5rem 0.85rem;
}

.sidebar-footer {
  padding: 1rem 1.25rem;
  border-top: 1px solid var(--border);
}

.guest-badge {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.78rem;
  color: var(--text-muted);
}

.guest-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--accent-amber);
  animation: blink 2s ease-in-out infinite;
}

@keyframes blink {
  0%,100% { opacity: 1; }
  50%     { opacity: 0.3; }
}

/* ─── Main Content ─── */
.main-content {
  margin-left: var(--sidebar-width);
  flex: 1;
  padding: 2rem 2.5rem;
  max-width: 900px;
}

/* ═══════════════════════════════════════════════════════════
 *  CALC SECTIONS
 * ═══════════════════════════════════════════════════════════ */
.calc-section {
  display: none;
  animation: fadeIn 0.35s ease-out;
}
.calc-section.active { display: block; }

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(8px); }
  to   { opacity: 1; transform: translateY(0); }
}

.section-header {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 0.75rem;
  margin-bottom: 1.5rem;
}

.section-title {
  font-size: 1.5rem;
  font-weight: 700;
  letter-spacing: -0.01em;
}

.section-desc {
  font-size: 0.88rem;
  color: var(--text-muted);
  flex: 1;
}

.btn-theory {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.4rem 0.85rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: rgba(167,139,250,0.08);
  color: var(--accent-violet);
  font-family: var(--font-sans);
  font-size: 0.78rem;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
}
.btn-theory:hover {
  background: rgba(167,139,250,0.18);
  border-color: var(--accent-violet);
  box-shadow: 0 0 12px rgba(167,139,250,0.15);
}

/* ═══════════════════════════════════════════════════════════
 *  CARDS
 * ═══════════════════════════════════════════════════════════ */
.calc-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  box-shadow: var(--shadow-md);
  background-image: var(--gradient-card);
}

/* ─── Tabs ─── */
.card-tabs {
  display: flex;
  gap: 0.25rem;
  background: var(--bg-input);
  border-radius: var(--radius-sm);
  padding: 4px;
  margin-bottom: 1.25rem;
}

.tab {
  flex: 1;
  padding: 0.5rem 0.75rem;
  border: none;
  border-radius: 6px;
  background: transparent;
  color: var(--text-muted);
  font-family: var(--font-sans);
  font-size: 0.82rem;
  font-weight: 500;
  cursor: pointer;
  transition: var(--transition);
}
.tab:hover { color: var(--text-secondary); }
.tab.active {
  background: rgba(96,165,250,0.15);
  color: var(--accent-blue);
  box-shadow: var(--shadow-sm);
}

.tab-content { display: none; animation: fadeIn 0.25s ease; }
.tab-content.active { display: block; }

/* ═══════════════════════════════════════════════════════════
 *  FORMS
 * ═══════════════════════════════════════════════════════════ */
.calc-form {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
  flex: 1;
}

.form-group label {
  font-size: 0.78rem;
  font-weight: 500;
  color: var(--text-secondary);
  letter-spacing: 0.02em;
}

.form-group input,
.form-group select {
  padding: 0.65rem 0.85rem;
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--bg-input);
  color: var(--text-primary);
  font-family: var(--font-mono);
  font-size: 0.9rem;
  transition: var(--transition);
  outline: none;
}

.form-group input:focus,
.form-group select:focus {
  border-color: var(--border-focus);
  box-shadow: 0 0 0 3px rgba(96,165,250,0.1);
}

.form-group input::placeholder {
  color: var(--text-muted);
  font-family: var(--font-sans);
}

.form-group select {
  cursor: pointer;
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath d='M2 4l4 4 4-4' stroke='%2364748b' stroke-width='1.5' fill='none'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 0.75rem center;
  padding-right: 2rem;
}

.form-row {
  display: flex;
  gap: 0.75rem;
}

/* ═══════════════════════════════════════════════════════════
 *  RESULT BOX
 * ═══════════════════════════════════════════════════════════ */
.result-box {
  display: flex;
  align-items: baseline;
  gap: 0.5rem;
  margin-top: 1.25rem;
  padding: 1rem 1.25rem;
  background: rgba(96,165,250,0.06);
  border: 1px solid rgba(96,165,250,0.12);
  border-radius: var(--radius-md);
  flex-wrap: wrap;
}

.result-box.result-secondary {
  background: rgba(167,139,250,0.05);
  border-color: rgba(167,139,250,0.1);
  margin-top: 0.5rem;
  flex-direction: column;
  gap: 0.35rem;
}

.result-box.result-sm {
  padding: 0.75rem 1rem;
  margin-top: 0.75rem;
  justify-content: center;
}

.result-row {
  display: flex;
  gap: 0.5rem;
  align-items: baseline;
}

.result-label {
  font-size: 0.85rem;
  color: var(--text-secondary);
  font-weight: 500;
}

.result-value {
  font-family: var(--font-mono);
  font-size: 1.4rem;
  font-weight: 600;
  color: var(--accent-cyan);
  transition: var(--transition);
}

.result-box.result-sm .result-value { font-size: 1.15rem; }
.result-box.result-secondary .result-value { font-size: 1rem; }

.result-unit {
  font-size: 0.85rem;
  color: var(--text-muted);
  font-weight: 500;
}

.result-value.animate {
  animation: resultPop 0.4s ease;
}

@keyframes resultPop {
  0%   { transform: scale(0.85); opacity: 0.5; }
  60%  { transform: scale(1.05); }
  100% { transform: scale(1); opacity: 1; }
}

.result-status {
  width: 100%;
  margin-top: 0.4rem;
  font-size: 0.82rem;
  font-weight: 600;
  padding: 0.35rem 0.75rem;
  border-radius: 6px;
}

.result-status.status-ok {
  background: rgba(52,211,153,0.1);
  color: var(--accent-green);
}

.result-status.status-fail {
  background: rgba(248,113,113,0.1);
  color: var(--accent-red);
}

/* ═══════════════════════════════════════════════════════════
 *  CONVERSIONS GRID
 * ═══════════════════════════════════════════════════════════ */
.conversions-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 1rem;
}

.conv-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1.25rem;
  background-image: var(--gradient-card);
  transition: var(--transition);
}
.conv-card:hover {
  border-color: rgba(96,165,250,0.2);
  box-shadow: var(--shadow-glow);
}

.conv-title {
  font-size: 0.95rem;
  font-weight: 600;
  margin-bottom: 1rem;
  color: var(--text-primary);
}

/* ═══════════════════════════════════════════════════════════
 *  THEORY MODAL
 * ═══════════════════════════════════════════════════════════ */
.modal-overlay {
  position: fixed;
  inset: 0;
  z-index: 2000;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(0,0,0,0.6);
  backdrop-filter: blur(6px);
  animation: fadeIn 0.2s ease;
}

.modal {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  width: 90%;
  max-width: 600px;
  max-height: 80vh;
  overflow-y: auto;
  box-shadow: var(--shadow-lg);
  animation: modalIn 0.3s ease;
}

@keyframes modalIn {
  from { opacity: 0; transform: scale(0.95) translateY(10px); }
  to   { opacity: 1; transform: scale(1) translateY(0); }
}

.modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1.25rem 1.5rem;
  border-bottom: 1px solid var(--border);
}

.modal-title {
  font-size: 1.1rem;
  font-weight: 700;
  background: var(--gradient-main);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.modal-close {
  width: 32px; height: 32px;
  display: flex; align-items: center; justify-content: center;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: transparent;
  color: var(--text-muted);
  cursor: pointer;
  font-size: 0.9rem;
  transition: var(--transition);
}
.modal-close:hover {
  background: rgba(248,113,113,0.1);
  color: var(--accent-red);
  border-color: rgba(248,113,113,0.3);
}

.modal-body {
  padding: 1.5rem;
  color: var(--text-secondary);
  font-size: 0.9rem;
  line-height: 1.75;
}

.modal-body h4 {
  color: var(--text-primary);
  font-size: 0.95rem;
  margin: 1.25rem 0 0.5rem;
}
.modal-body h4:first-child { margin-top: 0; }

.modal-body .formula {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.95rem;
  color: var(--accent-cyan);
  background: var(--bg-input);
  padding: 0.85rem 1rem;
  border-radius: var(--radius-sm);
  margin: 0.75rem 0;
  border-left: 3px solid var(--accent-blue);
  overflow-x: auto;
}

.modal-body .norm-tag {
  display: inline-block;
  padding: 0.15rem 0.5rem;
  border-radius: 4px;
  background: rgba(96,165,250,0.1);
  color: var(--accent-blue);
  font-size: 0.78rem;
  font-weight: 600;
  margin: 0.15rem 0;
}

.modal-body ul {
  padding-left: 1.25rem;
  margin: 0.5rem 0;
}
.modal-body li { margin: 0.3rem 0; }

/* ═══════════════════════════════════════════════════════════
 *  RESPONSIVE
 * ═══════════════════════════════════════════════════════════ */
@media (max-width: 768px) {
  .sidebar {
    transform: translateX(-100%);
    width: 260px;
  }
  .sidebar.open { transform: translateX(0); }

  .main-content {
    margin-left: 0;
    padding: 1.25rem;
  }

  .form-row { flex-direction: column; }

  .conversions-grid {
    grid-template-columns: 1fr;
  }

  .landing-title { font-size: 2.2rem; }
}