/* ==========================================================================
   bateria-la-frig / style.css
   Bilingual editorial microsite on low-temperature Li-ion electrochemistry
   Conforming to V2 standards, dual theming (WCAG AAA), zero hardcoded colors
   ========================================================================== */

:root {
  --bg-canvas: #f8fafc;
  --bg-surface: #ffffff;
  --bg-surface-elevated: #f1f5f9;
  --bg-muted: #e2e8f0;
  
  --text-primary: #0f172a;
  --text-secondary: #334155;
  --text-muted: #64748b;
  
  --border-subtle: #cbd5e1;
  --border-strong: #94a3b8;
  
  --accent-cold: #0284c7;
  --accent-cold-bg: #e0f2fe;
  --accent-warm: #16a34a;
  --accent-warm-bg: #dcfce7;
  --accent-alert: #dc2626;
  --accent-alert-bg: #fee2e2;
  --accent-amber: #d97706;
  --accent-amber-bg: #fef3c7;
  
  --chart-grid: #e2e8f0;
  --chart-axis: #64748b;
  --chart-line: #0284c7;
  --chart-cutoff: #dc2626;
  --chart-point: #0f172a;

  --focus-ring: #0284c7;
  --topbar-height: 48px;
  --content-max-width: 760px;
  --wide-max-width: 980px;
  
  --font-body: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", monospace;
}

[data-theme="dark"] {
  --bg-canvas: #090d16;
  --bg-surface: #111827;
  --bg-surface-elevated: #1e293b;
  --bg-muted: #334155;
  
  --text-primary: #f8fafc;
  --text-secondary: #cbd5e1;
  --text-muted: #94a3b8;
  
  --border-subtle: #334155;
  --border-strong: #475569;
  
  --accent-cold: #38bdf8;
  --accent-cold-bg: #0c4a6e;
  --accent-warm: #4ade80;
  --accent-warm-bg: #064e3b;
  --accent-alert: #f87171;
  --accent-alert-bg: #7f1d1d;
  --accent-amber: #fbbf24;
  --accent-amber-bg: #78350f;
  
  --chart-grid: #1e293b;
  --chart-axis: #94a3b8;
  --chart-line: #38bdf8;
  --chart-cutoff: #f87171;
  --chart-point: #f8fafc;

  --focus-ring: #38bdf8;
}

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

html {
  font-family: var(--font-body);
  font-size: 17px;
  line-height: 1.68;
  color: var(--text-primary);
  background-color: var(--bg-canvas);
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  padding: 0;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* ==========================================================================
   Topbar (Standing standard from templates/topbar.md)
   ========================================================================== */
.topbar {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--topbar-height);
  background-color: var(--bg-surface);
  border-bottom: 1px solid var(--border-subtle);
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 0 16px;
  white-space: nowrap;
}

.topbar .home {
  font-weight: 600;
  font-size: 15px;
  color: var(--text-primary);
  text-decoration: none;
  flex-shrink: 0;
}

.topbar .home:hover,
.topbar .home:focus-visible {
  text-decoration: underline;
}

.topnav {
  display: flex;
  align-items: center;
  gap: 14px;
  overflow-x: auto;
  scrollbar-width: none;
  -webkit-overflow-scrolling: touch;
}

.topnav::-webkit-scrollbar {
  display: none;
}

.topnav a {
  font-size: 14px;
  color: var(--text-secondary);
  text-decoration: none;
  padding: 4px 6px;
  border-radius: 4px;
}

.topnav a:hover,
.topnav a:focus-visible {
  color: var(--text-primary);
  background-color: var(--bg-muted);
}

.topnav a[aria-current="true"] {
  color: var(--accent-cold);
  font-weight: 600;
}

.topbar .spacer {
  flex-grow: 1;
}

.topbar .chip {
  font-size: 13px;
  font-weight: 500;
  padding: 4px 10px;
  border-radius: 9999px;
  border: 1px solid var(--border-subtle);
  background: var(--bg-surface-elevated);
  color: var(--text-secondary);
  text-decoration: none;
  flex-shrink: 0;
}

.topbar .chip:hover,
.topbar .chip:focus-visible {
  color: var(--text-primary);
  border-color: var(--border-strong);
}

.icon-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  border: 1px solid var(--border-subtle);
  background-color: var(--bg-surface-elevated);
  color: var(--text-primary);
  cursor: pointer;
  padding: 0;
  flex-shrink: 0;
}

.icon-btn:hover,
.icon-btn:focus-visible {
  border-color: var(--border-strong);
}

.icon-btn svg {
  display: block;
}

.icon-btn svg[hidden] {
  display: none !important;
}

/* ==========================================================================
   Layout Containers
   ========================================================================== */
main {
  flex-grow: 1;
  padding: 32px 20px 64px 20px;
}

section {
  scroll-margin-top: calc(var(--topbar-height) + 16px);
}

.container {
  max-width: var(--content-max-width);
  margin: 0 auto;
}

.container-wide {
  max-width: var(--wide-max-width);
  margin: 0 auto;
}

/* ==========================================================================
   Typography & Editorial
   ========================================================================== */
h1 {
  font-size: clamp(2rem, 5vw, 2.75rem);
  line-height: 1.2;
  font-weight: 750;
  letter-spacing: -0.025em;
  color: var(--text-primary);
  margin: 0 0 16px 0;
}

.deck {
  font-size: clamp(1.1rem, 2.5vw, 1.28rem);
  line-height: 1.55;
  color: var(--text-secondary);
  margin: 0 0 32px 0;
  font-weight: 400;
}

.meta-bar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 16px;
  padding: 12px 0 24px 0;
  margin-bottom: 32px;
  border-bottom: 1px solid var(--border-subtle);
  font-size: 14px;
  color: var(--text-muted);
}

.meta-item {
  display: flex;
  align-items: center;
  gap: 6px;
}

h2 {
  font-size: clamp(1.45rem, 3.5vw, 1.85rem);
  line-height: 1.3;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--text-primary);
  margin: 48px 0 16px 0;
}

h3 {
  font-size: 1.25rem;
  line-height: 1.4;
  font-weight: 650;
  color: var(--text-primary);
  margin: 28px 0 12px 0;
}

p {
  margin: 0 0 20px 0;
  color: var(--text-secondary);
}

strong {
  color: var(--text-primary);
  font-weight: 600;
}

a {
  color: var(--accent-cold);
  text-decoration-thickness: 1px;
  text-underline-offset: 2px;
}

a:hover, a:focus-visible {
  color: var(--text-primary);
}

/* ==========================================================================
   Editorial Callouts & Summary Blocks
   ========================================================================== */
.callout {
  background-color: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-left: 4px solid var(--accent-cold);
  border-radius: 6px;
  padding: 20px 24px;
  margin: 28px 0;
}

.callout.alert {
  border-left-color: var(--accent-alert);
  background-color: var(--bg-surface);
}

.callout.warm {
  border-left-color: var(--accent-warm);
}

.callout h3 {
  margin-top: 0;
  margin-bottom: 8px;
}

.callout p:last-child {
  margin-bottom: 0;
}

/* ==========================================================================
   Interactive Battery Lab
   ========================================================================== */
.lab-card {
  background-color: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: 12px;
  padding: 28px;
  margin: 36px 0;
  box-shadow: 0 4px 20px -2px rgba(0, 0, 0, 0.05);
}

.lab-header {
  display: flex;
  flex-direction: column;
  gap: 6px;
  margin-bottom: 24px;
}

.lab-title {
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--text-primary);
  margin: 0;
}

.lab-subtitle {
  font-size: 0.95rem;
  color: var(--text-muted);
  margin: 0;
}

.controls-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
  margin-bottom: 28px;
}

@media (min-width: 680px) {
  .controls-grid {
    grid-template-columns: 1.4fr 1fr;
  }
}

.control-group {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.control-label {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  font-weight: 600;
  font-size: 0.95rem;
  color: var(--text-primary);
}

.control-value {
  font-family: var(--font-mono);
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--accent-cold);
}

.range-slider {
  width: 100%;
  height: 8px;
  border-radius: 4px;
  background: var(--bg-muted);
  outline: none;
  accent-color: var(--accent-cold);
  cursor: pointer;
  margin: 6px 0;
}

.presets-container {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.preset-btn {
  font-size: 13px;
  font-weight: 500;
  padding: 6px 12px;
  border-radius: 6px;
  border: 1px solid var(--border-subtle);
  background-color: var(--bg-surface-elevated);
  color: var(--text-secondary);
  cursor: pointer;
  transition: all 0.15s ease;
}

.preset-btn:hover,
.preset-btn:focus-visible {
  border-color: var(--accent-cold);
  color: var(--text-primary);
}

.preset-btn.active {
  background-color: var(--accent-cold);
  color: #ffffff;
  border-color: var(--accent-cold);
}

.load-buttons {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.load-btn {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 10px 14px;
  border-radius: 8px;
  border: 1px solid var(--border-subtle);
  background-color: var(--bg-surface-elevated);
  color: var(--text-secondary);
  cursor: pointer;
  text-align: left;
  font-size: 14px;
  transition: all 0.15s ease;
}

.load-btn:hover,
.load-btn:focus-visible {
  border-color: var(--border-strong);
  color: var(--text-primary);
}

.load-btn.active {
  border-color: var(--accent-cold);
  background-color: var(--accent-cold-bg);
  color: var(--text-primary);
  font-weight: 600;
}

.load-current {
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 600;
  color: var(--accent-cold);
}

/* ==========================================================================
   Visualizer Canvas / SVG & Gauges
   ========================================================================== */
.viz-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
  margin-bottom: 24px;
}

@media (min-width: 720px) {
  .viz-layout {
    grid-template-columns: 1.3fr 1fr;
  }
}

.chart-card {
  border: 1px solid var(--border-subtle);
  border-radius: 8px;
  background-color: var(--bg-surface-elevated);
  padding: 16px;
  position: relative;
}

.chart-heading {
  font-size: 0.9rem;
  font-weight: 650;
  color: var(--text-secondary);
  margin: 0 0 12px 0;
  display: flex;
  justify-content: space-between;
}

.chart-svg {
  width: 100%;
  height: 220px;
  overflow: visible;
}

.status-card {
  border: 1px solid var(--border-subtle);
  border-radius: 8px;
  background-color: var(--bg-surface-elevated);
  padding: 20px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.phone-mockup {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 16px;
  border-radius: 12px;
  background-color: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  margin-bottom: 16px;
}

.battery-icon-container {
  width: 52px;
  height: 96px;
  border: 3px solid var(--text-primary);
  border-radius: 8px;
  position: relative;
  padding: 3px;
  display: flex;
  flex-direction: column-reverse;
  flex-shrink: 0;
}

.battery-icon-container::before {
  content: "";
  position: absolute;
  top: -8px;
  left: 50%;
  transform: translateX(-50%);
  width: 20px;
  height: 5px;
  background-color: var(--text-primary);
  border-radius: 3px 3px 0 0;
}

.battery-fill {
  width: 100%;
  background-color: var(--accent-warm);
  border-radius: 3px;
  transition: height 0.3s ease, background-color 0.3s ease;
}

.battery-fill.dead {
  background-color: var(--accent-alert);
}

.phone-readout {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.phone-screen-status {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-primary);
}

.phone-screen-desc {
  font-size: 0.85rem;
  color: var(--text-muted);
}

.telemetry-row {
  display: flex;
  justify-content: space-between;
  padding: 6px 0;
  border-bottom: 1px solid var(--border-subtle);
  font-size: 0.9rem;
}

.telemetry-row:last-child {
  border-bottom: none;
}

.telemetry-label {
  color: var(--text-muted);
}

.telemetry-val {
  font-family: var(--font-mono);
  font-weight: 650;
  color: var(--text-primary);
}

.telemetry-val.alert {
  color: var(--accent-alert);
}

.telemetry-val.good {
  color: var(--accent-warm);
}

.shutdown-banner {
  padding: 12px 16px;
  border-radius: 6px;
  font-size: 0.9rem;
  font-weight: 600;
  display: flex;
  align-items: center;
  gap: 10px;
  margin-top: 14px;
}

.shutdown-banner.ok {
  background-color: var(--accent-warm-bg);
  color: var(--text-primary);
  border: 1px solid var(--accent-warm);
}

.shutdown-banner.cut {
  background-color: var(--accent-alert-bg);
  color: var(--text-primary);
  border: 1px solid var(--accent-alert);
}

.warm-action-box {
  margin-top: 16px;
  padding-top: 16px;
  border-top: 1px solid var(--border-subtle);
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.warm-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 18px;
  border-radius: 8px;
  border: none;
  background-color: var(--accent-warm);
  color: #ffffff;
  font-weight: 650;
  font-size: 0.95rem;
  cursor: pointer;
  transition: opacity 0.2s ease;
}

.warm-btn:hover {
  opacity: 0.9;
}

.warm-btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

/* ==========================================================================
   Figures, Images, Attribution
   ========================================================================== */
figure {
  margin: 36px 0;
  padding: 0;
}

.figure-wrapper {
  background-color: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: 8px;
  padding: 16px;
  text-align: center;
}

figure img, figure svg {
  max-width: 100%;
  height: auto;
  border-radius: 4px;
  display: block;
  margin: 0 auto;
}

figcaption {
  margin-top: 12px;
  font-size: 0.88rem;
  line-height: 1.5;
  color: var(--text-secondary);
  text-align: left;
}

figcaption .attribution {
  display: block;
  margin-top: 4px;
  font-size: 0.8rem;
  color: var(--text-muted);
}

/* ==========================================================================
   Tables & Structured Data
   ========================================================================== */
.table-wrap {
  overflow-x: auto;
  margin: 28px 0;
  border: 1px solid var(--border-subtle);
  border-radius: 8px;
  background-color: var(--bg-surface);
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.92rem;
  text-align: left;
}

th, td {
  padding: 12px 16px;
  border-bottom: 1px solid var(--border-subtle);
}

th {
  background-color: var(--bg-surface-elevated);
  font-weight: 650;
  color: var(--text-primary);
}

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

/* ==========================================================================
   Footer
   ========================================================================== */
footer {
  margin-top: auto;
  padding: 40px 20px;
  border-top: 1px solid var(--border-subtle);
  background-color: var(--bg-surface);
  font-size: 0.88rem;
  color: var(--text-muted);
}

.footer-content {
  max-width: var(--content-max-width);
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

@media (min-width: 600px) {
  .footer-content {
    flex-direction: row;
    justify-content: space-between;
    align-items: center;
  }
}

.footer-nav {
  display: flex;
  gap: 16px;
}

.footer-nav a {
  color: var(--text-secondary);
  text-decoration: none;
}

.footer-nav a:hover,
.footer-nav a:focus-visible {
  text-decoration: underline;
  color: var(--text-primary);
}

/* ==========================================================================
   Reduced Motion & Print
   ========================================================================== */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

@media print {
  .topbar, .icon-btn, .warm-btn, .preset-btn, .range-slider {
    display: none !important;
  }
  body {
    background: #ffffff !important;
    color: #000000 !important;
  }
  .lab-card, .chart-card, .status-card {
    border: 1px solid #000000 !important;
    box-shadow: none !important;
  }
}