/* ==========================================================================
   NEWTON’S LAWS OF MOTION ON MARS — SCIENTIFIC EXHIBIT STYLESHEET
   Design direction: Restrained, editorial, technical museum microsite.
   Zero neon, no heavy gradients, no bubbly glassmorphism.
   ========================================================================== */

:root {
  /* Mars & Charcoal Editorial Palette */
  --bg-canvas: #111113;
  --bg-surface: #17171a;
  --bg-subtle: #1f1f23;
  --bg-inset: #0c0c0e;
  --bg-highlight: #28282e;

  /* Typography Colors */
  --text-primary: #ede9e1;     /* Warm off-white, high legibility */
  --text-secondary: #b8b3a8;   /* Dusty beige-grey */
  --text-tertiary: #7d776c;    /* Subdued scientific annotation grey */
  --text-inverse: #111113;

  /* Muted Martian Iron-Oxide Accents */
  --accent-rust: #c86446;      /* Muted Martian iron oxide */
  --accent-rust-hover: #db7657;
  --accent-rust-dim: rgba(200, 100, 70, 0.14);
  --accent-sand: #d4cbbe;      /* Weathered regolith tone */

  /* Hairline Borders & Dividers */
  --border-hairline: #262523;
  --border-subtle: #363430;
  --border-strong: #54504a;

  /* Typography Stacks */
  --font-sans: 'Instrument Sans', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-mono: 'JetBrains Mono', "SF Mono", Menlo, Consolas, monospace;

  /* Layout */
  --container-max: 1140px;
  --header-height: 56px;
  --radius-sm: 2px;
  --radius-md: 4px;

  /* Transitions */
  --trans-fast: 0.15s ease-out;
  --trans-mid: 0.25s ease-out;
}

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

html {
  font-family: var(--font-sans);
  background-color: var(--bg-canvas);
  color: var(--text-primary);
  font-size: 16px;
  line-height: 1.6;
  scroll-behavior: smooth;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background-color: var(--bg-canvas);
}

/* Accessibility Focus States */
:focus-visible {
  outline: 2px solid var(--accent-rust);
  outline-offset: 3px;
}

/* Global Container */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin-left: auto;
  margin-right: auto;
  padding-left: clamp(1rem, 4vw, 2rem);
  padding-right: clamp(1rem, 4vw, 2rem);
}

/* Typography Utilities */
h1, h2, h3, h4 {
  color: var(--text-primary);
  font-weight: 600;
  line-height: 1.25;
  letter-spacing: -0.02em;
}

p {
  color: var(--text-secondary);
}

a {
  color: inherit;
  text-decoration: none;
  transition: color var(--trans-fast);
}

var {
  font-style: italic;
  font-family: var(--font-sans);
}

code, .code {
  font-family: var(--font-mono);
  font-size: 0.88em;
  background: var(--bg-subtle);
  padding: 0.15em 0.4em;
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  border: 1px solid var(--border-hairline);
}

.rust { color: var(--accent-rust); }
.cream { color: var(--text-primary); }
.font-bold { font-weight: 600; }

/* ==========================================================================
   1. SITE HEADER
   ========================================================================== */

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: rgba(17, 17, 19, 0.94);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border-hairline);
  height: var(--header-height);
}

.header-inner {
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.92rem;
  font-weight: 600;
  letter-spacing: 0.04em;
}

.brand-title {
  color: var(--text-primary);
}

.brand-title:hover {
  color: var(--accent-rust);
}

.brand-sep {
  color: var(--border-strong);
  font-weight: 300;
}

.brand-subtitle {
  color: var(--text-secondary);
  font-weight: 400;
  font-size: 0.84rem;
}

.site-nav .nav-list {
  display: flex;
  list-style: none;
  gap: 1.5rem;
}

.nav-link {
  font-size: 0.86rem;
  color: var(--text-secondary);
  padding: 0.35rem 0.1rem;
  position: relative;
  font-weight: 450;
  letter-spacing: 0.01em;
}

.nav-link:hover {
  color: var(--text-primary);
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0%;
  height: 1px;
  background-color: var(--accent-rust);
  transition: width var(--trans-mid);
}

.nav-link:hover::after {
  width: 100%;
}

.header-meta {
  display: flex;
  align-items: center;
}

.mission-tag {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--text-tertiary);
  display: flex;
  align-items: center;
  gap: 0.45rem;
  padding: 0.25rem 0.6rem;
  border: 1px solid var(--border-hairline);
  background: var(--bg-inset);
  border-radius: var(--radius-sm);
  letter-spacing: 0.06em;
}

.pulse-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background-color: var(--accent-rust);
  display: inline-block;
}

/* ==========================================================================
   2. HERO SECTION
   ========================================================================== */

.hero-section {
  padding-top: clamp(2.5rem, 6vw, 4.5rem);
  padding-bottom: clamp(2rem, 5vw, 3.5rem);
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.15fr 0.95fr;
  gap: clamp(2rem, 5vw, 3.5rem);
  align-items: start;
}

.section-kicker {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.12em;
  color: var(--accent-rust);
  font-weight: 500;
  margin-bottom: 0.75rem;
}

.hero-title {
  font-size: clamp(2.2rem, 4.5vw, 3.4rem);
  font-weight: 600;
  line-height: 1.12;
  letter-spacing: -0.03em;
  color: var(--text-primary);
  margin-bottom: 1.25rem;
}

.hero-lead {
  font-size: clamp(1.05rem, 1.8vw, 1.2rem);
  line-height: 1.6;
  color: var(--text-secondary);
  margin-bottom: 2rem;
  max-width: 58ch;
}

/* Factual Detail Panel */
.spec-panel {
  border: 1px solid var(--border-hairline);
  background: var(--bg-surface);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.spec-panel-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0.65rem 1rem;
  background: var(--bg-subtle);
  border-bottom: 1px solid var(--border-hairline);
}

.spec-panel-label {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  color: var(--text-secondary);
  font-weight: 500;
}

.spec-panel-code {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--text-tertiary);
}

.spec-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1px;
  background: var(--border-hairline);
}

.spec-item {
  background: var(--bg-surface);
  padding: 0.85rem 1rem;
}

.spec-item dt {
  font-size: 0.78rem;
  color: var(--text-tertiary);
  margin-bottom: 0.25rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  font-family: var(--font-mono);
}

.spec-item dd {
  font-size: 0.95rem;
  color: var(--text-primary);
  font-weight: 500;
}

.spec-item .unit {
  font-size: 0.82rem;
  color: var(--text-secondary);
  font-family: var(--font-mono);
  font-weight: 400;
}

/* Hero Media & Frame */
.hero-figure {
  margin: 0;
}

.figure-frame {
  position: relative;
  border: 1px solid var(--border-subtle);
  background: var(--bg-inset);
  line-height: 0;
  overflow: hidden;
}

.hero-img {
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 10;
  object-fit: cover;
  display: block;
  filter: contrast(102%) brightness(96%);
}

/* Reticle marks for technical aesthetic */
.figure-reticle {
  position: absolute;
  width: 10px;
  height: 10px;
  pointer-events: none;
}

.figure-reticle.top-left {
  top: 6px;
  left: 6px;
  border-top: 1.5px solid var(--accent-rust);
  border-left: 1.5px solid var(--accent-rust);
}

.figure-reticle.top-right {
  top: 6px;
  right: 6px;
  border-top: 1.5px solid var(--accent-rust);
  border-right: 1.5px solid var(--accent-rust);
}

.figure-reticle.bottom-left {
  bottom: 6px;
  left: 6px;
  border-bottom: 1.5px solid var(--accent-rust);
  border-left: 1.5px solid var(--accent-rust);
}

.figure-reticle.bottom-right {
  bottom: 6px;
  right: 6px;
  border-bottom: 1.5px solid var(--accent-rust);
  border-right: 1.5px solid var(--accent-rust);
}

.hero-figcaption {
  padding-top: 0.75rem;
  font-size: 0.8rem;
  line-height: 1.5;
  color: var(--text-secondary);
  display: flex;
  flex-direction: column;
  gap: 0.2rem;
}

.fig-label {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  color: var(--text-tertiary);
}

.fig-credit {
  color: var(--text-tertiary);
  font-size: 0.74rem;
  font-family: var(--font-mono);
}

/* ==========================================================================
   SECTION DIVIDERS
   ========================================================================== */

.section-divider {
  display: flex;
  align-items: center;
  gap: 1.25rem;
  margin-top: clamp(2rem, 5vw, 3.5rem);
  margin-bottom: clamp(2rem, 5vw, 3.5rem);
}

.divider-line {
  flex: 1;
  height: 1px;
  background-color: var(--border-hairline);
}

.divider-mark {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--text-tertiary);
  letter-spacing: 0.1em;
}

/* ==========================================================================
   3. THE THREE LAWS WRAPPER & LAW SECTIONS
   ========================================================================== */

.laws-wrapper {
  display: flex;
  flex-direction: column;
  gap: 0;
}

.law-section {
  padding-top: 1rem;
  padding-bottom: 1rem;
}

.law-header {
  margin-bottom: 2rem;
}

.law-num-badge {
  font-family: var(--font-mono);
  font-size: 0.76rem;
  font-weight: 500;
  letter-spacing: 0.1em;
  color: var(--accent-rust);
  margin-bottom: 0.5rem;
}

.law-title {
  font-size: clamp(1.6rem, 3.2vw, 2.3rem);
  color: var(--text-primary);
  margin-bottom: 0.85rem;
  font-weight: 600;
}

.law-formal-statement {
  border-left: 2px solid var(--accent-rust);
  padding-left: 1.25rem;
  font-size: clamp(1.05rem, 1.8vw, 1.25rem);
  color: var(--text-primary);
  font-style: italic;
  line-height: 1.5;
  margin-top: 0.75rem;
  max-width: 70ch;
}

.law-equation-callout {
  display: inline-flex;
  align-items: baseline;
  gap: 1.25rem;
  margin-top: 0.85rem;
  padding: 0.5rem 1rem;
  background: var(--bg-surface);
  border: 1px solid var(--border-hairline);
  border-left: 3px solid var(--accent-rust);
}

.equation-main {
  font-family: var(--font-mono);
  font-size: 1.7rem;
  font-weight: 600;
  color: var(--text-primary);
  letter-spacing: 0.05em;
}

.equation-sub {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--text-secondary);
}

.eq-alt {
  color: var(--accent-rust);
}

/* Grid Layout for Law Content */
.law-content-grid {
  display: grid;
  grid-template-columns: 1.05fr 1.15fr;
  gap: clamp(2rem, 4vw, 3.5rem);
  align-items: start;
}

.law-explanation {
  display: flex;
  flex-direction: column;
  gap: 1.15rem;
}

.law-text {
  font-size: 1.02rem;
  line-height: 1.7;
  color: var(--text-secondary);
}

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

/* Physics Note Aside */
.physics-aside {
  background: var(--bg-surface);
  border: 1px solid var(--border-hairline);
  padding: 1.15rem 1.25rem;
  border-radius: var(--radius-sm);
  margin-top: 0.5rem;
}

.physics-aside.alert-aside {
  border-left: 3px solid var(--accent-rust);
}

.aside-label {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  color: var(--accent-rust);
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.physics-aside p {
  font-size: 0.92rem;
  line-height: 1.6;
  color: var(--text-secondary);
}

.code-box-equation {
  background: var(--bg-surface);
  border: 1px solid var(--border-hairline);
  border-left: 3px solid var(--accent-rust);
  padding: 0.75rem 1rem;
  border-radius: var(--radius-sm);
  font-family: var(--font-mono);
  font-size: 0.88rem;
  line-height: 1.6;
  margin: 0.5rem 0;
}

.code-box-equation code {
  background: transparent;
  border: none;
  padding: 0;
  display: block;
}

.sub-aside-text {
  margin-top: 0.6rem;
  font-size: 0.86rem;
  color: var(--text-tertiary);
}

/* Physics Pairs List for Law Three */
.physics-pair-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
  margin: 0.5rem 0;
}

.physics-pair-list li {
  display: flex;
  gap: 0.85rem;
  align-items: flex-start;
  font-size: 0.96rem;
  color: var(--text-secondary);
  line-height: 1.55;
}

.pair-icon {
  width: 22px;
  height: 22px;
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--bg-subtle);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--accent-rust);
  font-weight: 600;
  margin-top: 0.15rem;
}

/* ==========================================================================
   DIAGRAM CARDS & SCHEMATIC CONTAINERS
   ========================================================================== */

.law-diagram-card {
  border: 1px solid var(--border-hairline);
  background: var(--bg-surface);
  border-radius: var(--radius-md);
  padding: 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 1.15rem;
}

.diagram-card-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-bottom: 0.75rem;
  border-bottom: 1px solid var(--border-hairline);
  gap: 0.5rem;
}

.diagram-tag {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.06em;
  color: var(--text-secondary);
  font-weight: 500;
}

.diagram-state-indicator {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--text-tertiary);
  padding: 0.15rem 0.5rem;
  background: var(--bg-subtle);
  border: 1px solid var(--border-hairline);
  border-radius: var(--radius-sm);
}

.diagram-state-indicator.live {
  color: var(--accent-rust);
  border-color: rgba(200, 100, 70, 0.4);
}

.diagram-canvas-wrap {
  background: var(--bg-inset);
  border: 1px solid var(--border-hairline);
  border-radius: var(--radius-sm);
  padding: 0.5rem;
  overflow: hidden;
}

.schematic-svg {
  width: 100%;
  height: auto;
  display: block;
}

/* SVG Typography Classes */
.svg-label-sub {
  font-family: var(--font-mono);
  font-size: 9px;
  letter-spacing: 0.08em;
  fill: #68635a;
}

.svg-rover-text {
  font-family: var(--font-mono);
  font-size: 9px;
  fill: #ede9e1;
  letter-spacing: 0.04em;
}

.svg-label-mono {
  font-family: var(--font-mono);
  font-size: 10px;
  fill: #b8b3a8;
}

.svg-vec-label {
  font-family: var(--font-mono);
  font-size: 11px;
  fill: #ede9e1;
}

.svg-vec-label.rust {
  fill: #c86446;
}

.svg-label-bold {
  font-family: var(--font-mono);
  font-size: 11px;
  fill: #ede9e1;
  font-weight: 600;
}

/* Diagram Controls / Phase Switcher */
.diagram-controls-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
}

.step-connector {
  color: var(--text-tertiary);
  font-size: 0.9rem;
}

.phase-btn {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  background: var(--bg-subtle);
  border: 1px solid var(--border-hairline);
  color: var(--text-secondary);
  padding: 0.55rem 0.65rem;
  font-family: var(--font-sans);
  font-size: 0.82rem;
  cursor: pointer;
  border-radius: var(--radius-sm);
  transition: all var(--trans-fast);
}

.phase-btn:hover {
  background: var(--bg-highlight);
  color: var(--text-primary);
  border-color: var(--border-subtle);
}

.phase-btn.active {
  background: var(--bg-inset);
  color: var(--text-primary);
  border-color: var(--accent-rust);
}

.btn-step-num {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--accent-rust);
}

.diagram-footer-note {
  font-size: 0.84rem;
  line-height: 1.55;
  color: var(--text-secondary);
  border-top: 1px solid var(--border-hairline);
  padding-top: 0.75rem;
}

/* ==========================================================================
   4. LAW TWO INTERACTIVE LAB (F = ma)
   ========================================================================== */

.interactive-lab {
  gap: 1.25rem;
}

.equation-visualizer {
  display: grid;
  grid-template-columns: 1fr auto 1fr auto 1fr;
  align-items: center;
  gap: 0.5rem;
  background: var(--bg-inset);
  border: 1px solid var(--border-hairline);
  padding: 0.85rem;
  border-radius: var(--radius-sm);
}

.eq-box {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
}

.eq-box.highlight .eq-val {
  color: var(--accent-rust);
}

.eq-label {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.06em;
  color: var(--text-tertiary);
  margin-bottom: 0.25rem;
}

.eq-val {
  font-family: var(--font-mono);
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--text-primary);
}

.eq-val .unit {
  font-size: 0.75em;
  color: var(--text-secondary);
  font-weight: 400;
}

.eq-op {
  font-family: var(--font-mono);
  font-size: 1.2rem;
  color: var(--text-tertiary);
  text-align: center;
}

.sim-visual-stage {
  background: var(--bg-inset);
  border: 1px solid var(--border-hairline);
  border-radius: var(--radius-sm);
  padding: 0.5rem;
  overflow: hidden;
}

.sim-svg {
  width: 100%;
  height: auto;
  display: block;
}

/* Slider Controls */
.slider-control-card {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.slider-header-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.slider-label {
  font-family: var(--font-mono);
  font-size: 0.76rem;
  letter-spacing: 0.05em;
  color: var(--text-secondary);
  font-weight: 500;
}

.slider-value-badge {
  font-family: var(--font-mono);
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--accent-rust);
  background: var(--bg-inset);
  border: 1px solid var(--border-hairline);
  padding: 0.2rem 0.6rem;
  border-radius: var(--radius-sm);
}

/* Custom Accessible Range Slider */
input[type="range"] {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 6px;
  background: var(--bg-inset);
  border: 1px solid var(--border-subtle);
  border-radius: 3px;
  cursor: pointer;
  outline: none;
}

input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 18px;
  height: 18px;
  border-radius: 2px;
  background: var(--accent-rust);
  border: 2px solid var(--text-primary);
  cursor: grab;
  box-shadow: 0 1px 3px rgba(0,0,0,0.5);
  transition: transform var(--trans-fast), background var(--trans-fast);
}

input[type="range"]::-webkit-slider-thumb:active {
  cursor: grabbing;
  transform: scale(1.15);
  background: var(--accent-rust-hover);
}

input[type="range"]::-moz-range-thumb {
  width: 18px;
  height: 18px;
  border-radius: 2px;
  background: var(--accent-rust);
  border: 2px solid var(--text-primary);
  cursor: grab;
  box-shadow: 0 1px 3px rgba(0,0,0,0.5);
}

.slider-scale-ticks {
  display: flex;
  justify-content: space-between;
  font-family: var(--font-mono);
  font-size: 0.68rem;
  color: var(--text-tertiary);
  padding: 0 0.2rem;
}

/* Preset Buttons */
.preset-buttons-row {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  flex-wrap: wrap;
  padding-top: 0.35rem;
}

.preset-lead {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--text-tertiary);
  letter-spacing: 0.05em;
}

.preset-btn {
  background: var(--bg-subtle);
  border: 1px solid var(--border-hairline);
  color: var(--text-secondary);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  padding: 0.3rem 0.6rem;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--trans-fast);
}

.preset-btn:hover {
  color: var(--text-primary);
  background: var(--bg-highlight);
  border-color: var(--border-subtle);
}

.preset-btn.active {
  background: var(--bg-inset);
  color: var(--accent-rust);
  border-color: var(--accent-rust);
}

/* Simulation Action Strip */
.sim-actions-strip {
  display: flex;
  align-items: center;
  gap: 0.85rem;
  padding-top: 0.75rem;
  border-top: 1px solid var(--border-hairline);
  flex-wrap: wrap;
}

.sim-run-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background: var(--accent-rust);
  color: var(--text-primary);
  border: 1px solid transparent;
  padding: 0.55rem 1rem;
  font-size: 0.85rem;
  font-weight: 500;
  font-family: var(--font-sans);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: background var(--trans-fast);
}

.sim-run-btn:hover {
  background: var(--accent-rust-hover);
}

.sim-reset-btn {
  background: transparent;
  color: var(--text-secondary);
  border: 1px solid var(--border-hairline);
  padding: 0.55rem 0.85rem;
  font-size: 0.82rem;
  font-family: var(--font-sans);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--trans-fast);
}

.sim-reset-btn:hover {
  color: var(--text-primary);
  border-color: var(--border-subtle);
  background: var(--bg-subtle);
}

.sim-status-telemetry {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-tertiary);
  margin-left: auto;
}

/* ==========================================================================
   5. MARS ROVER SYSTEMS SECTION
   ========================================================================== */

.rover-section {
  padding-top: 1.5rem;
  padding-bottom: 2rem;
}

.section-header-compact {
  margin-bottom: 2rem;
  max-width: 78ch;
}

.section-header-compact.text-center {
  margin-left: auto;
  margin-right: auto;
  text-align: center;
}

.section-heading {
  font-size: clamp(1.8rem, 3.5vw, 2.5rem);
  font-weight: 600;
  margin-top: 0.35rem;
  margin-bottom: 0.75rem;
}

.section-sub {
  font-size: 1.05rem;
  line-height: 1.6;
  color: var(--text-secondary);
}

.rover-system-grid {
  display: grid;
  grid-template-columns: 1.25fr 0.95fr;
  gap: clamp(1.5rem, 3.5vw, 2.5rem);
  align-items: stretch;
}

.rover-schematic-card {
  border: 1px solid var(--border-hairline);
  background: var(--bg-surface);
  border-radius: var(--radius-md);
  padding: 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.schematic-toolbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-bottom: 1px solid var(--border-hairline);
  padding-bottom: 0.65rem;
}

.schematic-title {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  color: var(--text-secondary);
}

.schematic-instruction {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  color: var(--accent-rust);
}

.schematic-interactive-wrap {
  background: var(--bg-inset);
  border: 1px solid var(--border-hairline);
  border-radius: var(--radius-sm);
  padding: 0.5rem;
}

.rover-tech-svg {
  width: 100%;
  height: auto;
  display: block;
}

/* Clickable Callout Groups inside SVG */
.callout-group {
  cursor: pointer;
  outline: none;
}

.callout-group .tag-bg {
  transition: all var(--trans-fast);
}

.callout-group:hover .tag-bg {
  stroke: var(--accent-rust);
  fill: #222227;
}

.callout-group.active .tag-bg {
  stroke: var(--accent-rust);
  fill: var(--bg-highlight);
}

.callout-group .callout-text {
  font-family: var(--font-mono);
  font-size: 9px;
  letter-spacing: 0.08em;
  fill: #ede9e1;
  font-weight: 600;
  pointer-events: none;
}

.callout-group.active .callout-text {
  fill: var(--accent-rust);
}

/* Hotspot Hover Glow */
.hotspot-target {
  cursor: pointer;
  transition: opacity var(--trans-fast);
}

.hotspot-target:hover {
  opacity: 0.85;
}

/* Part Tab Button Bar */
.part-selector-tabs {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0.4rem;
  margin-top: auto;
}

.part-tab-btn {
  background: var(--bg-subtle);
  border: 1px solid var(--border-hairline);
  color: var(--text-secondary);
  font-family: var(--font-mono);
  font-size: 0.74rem;
  padding: 0.5rem 0.25rem;
  border-radius: var(--radius-sm);
  cursor: pointer;
  text-align: center;
  transition: all var(--trans-fast);
}

.part-tab-btn:hover {
  color: var(--text-primary);
  background: var(--bg-highlight);
  border-color: var(--border-subtle);
}

.part-tab-btn.active {
  background: var(--bg-inset);
  color: var(--accent-rust);
  border-color: var(--accent-rust);
  font-weight: 600;
}

/* Dynamic Spec Detail Card */
.rover-part-detail-card {
  border: 1px solid var(--border-hairline);
  background: var(--bg-surface);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.part-detail-header {
  border-bottom: 1px solid var(--border-hairline);
  padding-bottom: 0.85rem;
}

.part-subsystem-tag {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.1em;
  color: var(--accent-rust);
  margin-bottom: 0.35rem;
}

.part-detail-title {
  font-size: 1.35rem;
  color: var(--text-primary);
}

.part-law-badge {
  font-family: var(--font-mono);
  font-size: 0.76rem;
  padding: 0.4rem 0.75rem;
  background: var(--bg-inset);
  border: 1px solid var(--border-hairline);
  border-left: 3px solid var(--accent-rust);
  color: var(--text-secondary);
}

.part-law-badge strong {
  color: var(--text-primary);
}

.part-detail-desc {
  font-size: 0.96rem;
  line-height: 1.65;
  color: var(--text-secondary);
}

.part-metrics-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0.75rem;
  margin-top: auto;
  padding-top: 1rem;
  border-top: 1px solid var(--border-hairline);
}

.metric-cell {
  background: var(--bg-inset);
  border: 1px solid var(--border-hairline);
  padding: 0.65rem 0.75rem;
  border-radius: var(--radius-sm);
  display: flex;
  flex-direction: column;
  gap: 0.2rem;
}

.metric-name {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  color: var(--text-tertiary);
  text-transform: uppercase;
}

.metric-val {
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--text-primary);
}

/* ==========================================================================
   6. QUICK RECAP SECTION
   ========================================================================== */

.recap-section {
  padding-top: 1rem;
  padding-bottom: 2rem;
}

.recap-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: clamp(1rem, 2.5vw, 1.75rem);
  margin-top: 2rem;
}

.recap-col {
  background: var(--bg-surface);
  border: 1px solid var(--border-hairline);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
  position: relative;
  transition: border-color var(--trans-fast);
}

.recap-col:hover {
  border-color: var(--border-subtle);
}

.recap-header {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  border-bottom: 1px solid var(--border-hairline);
  padding-bottom: 0.65rem;
}

.recap-num {
  font-family: var(--font-mono);
  font-size: 1.3rem;
  font-weight: 600;
  color: var(--accent-rust);
}

.recap-law-tag {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  color: var(--text-tertiary);
}

.recap-principle {
  font-size: 1.15rem;
  color: var(--text-primary);
  line-height: 1.35;
}

.recap-rover-statement {
  font-size: 0.92rem;
  line-height: 1.6;
  color: var(--text-secondary);
  border-top: 1px dashed var(--border-hairline);
  padding-top: 0.85rem;
  margin-top: auto;
}

/* ==========================================================================
   7. WHY IT MATTERS SECTION
   ========================================================================== */

.why-section {
  padding-top: 1rem;
  padding-bottom: 3.5rem;
}

.why-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-hairline);
  border-radius: var(--radius-md);
  padding: clamp(1.5rem, 3.5vw, 2.5rem);
}

.why-header {
  margin-bottom: 2rem;
}

.why-columns {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: clamp(1.25rem, 2.5vw, 2rem);
}

.why-item h4 {
  font-size: 1.05rem;
  color: var(--text-primary);
  margin-bottom: 0.6rem;
  font-weight: 600;
}

.why-item p {
  font-size: 0.92rem;
  line-height: 1.65;
  color: var(--text-secondary);
}

/* ==========================================================================
   8. SITE FOOTER
   ========================================================================== */

.site-footer {
  border-top: 1px solid var(--border-hairline);
  background: var(--bg-surface);
  padding-top: 2rem;
  padding-bottom: 2.5rem;
  margin-top: auto;
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 2rem;
  flex-wrap: wrap;
}

.footer-primary {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
}

.footer-purpose {
  font-size: 0.95rem;
  color: var(--text-primary);
  font-weight: 500;
}

.footer-credits {
  font-size: 0.82rem;
  color: var(--text-tertiary);
  font-family: var(--font-mono);
}

.footer-secondary {
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: 0.5rem;
}

.footer-meta {
  font-size: 0.78rem;
  color: var(--text-tertiary);
  font-family: var(--font-mono);
}

.back-to-top {
  font-size: 0.82rem;
  color: var(--accent-rust);
  font-family: var(--font-mono);
}

.back-to-top:hover {
  text-decoration: underline;
}

.footer-actions-row {
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

.footer-cookie-link {
  background: transparent;
  border: none;
  color: var(--text-tertiary);
  font-family: var(--font-mono);
  font-size: 0.8rem;
  cursor: pointer;
  padding: 0;
  transition: color var(--trans-fast);
}

.footer-cookie-link:hover {
  color: var(--text-primary);
  text-decoration: underline;
}

.footer-sep {
  color: var(--border-strong);
  font-size: 0.8rem;
}

/* ==========================================================================
   COOKIE & TELEMETRY POPUP BANNER
   ========================================================================== */

.cookie-banner {
  position: fixed;
  bottom: 1.5rem;
  right: 1.5rem;
  max-width: 420px;
  width: calc(100% - 3rem);
  z-index: 999;
  background: rgba(22, 22, 25, 0.96);
  backdrop-filter: blur(12px);
  border: 1px solid var(--border-subtle);
  border-left: 3px solid var(--accent-rust);
  border-radius: var(--radius-md);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.6);
  padding: 1.15rem 1.25rem;
  transition: transform 0.25s cubic-bezier(0.16, 1, 0.3, 1), opacity 0.25s ease;
  transform: translateY(0);
  opacity: 1;
}

.cookie-banner.hidden {
  transform: translateY(16px);
  opacity: 0;
  pointer-events: none;
}

.cookie-banner-inner {
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
}

.cookie-content {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.cookie-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.cookie-badge {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.08em;
  color: var(--accent-rust);
  font-weight: 600;
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

.cookie-code {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  color: var(--text-tertiary);
  margin-left: auto;
  margin-right: 0.75rem;
}

.cookie-close {
  background: transparent;
  border: none;
  color: var(--text-tertiary);
  font-size: 1.3rem;
  line-height: 1;
  width: 20px;
  height: 20px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-sm);
  transition: color var(--trans-fast);
}

.cookie-close:hover {
  color: var(--text-primary);
}

.cookie-text {
  font-size: 0.84rem;
  line-height: 1.55;
  color: var(--text-secondary);
}

.cookie-actions {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  padding-top: 0.25rem;
}

.cookie-btn {
  font-family: var(--font-sans);
  font-size: 0.8rem;
  font-weight: 500;
  padding: 0.45rem 0.85rem;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--trans-fast);
}

.cookie-accept {
  background: var(--accent-rust);
  color: var(--text-primary);
  border: 1px solid transparent;
}

.cookie-accept:hover {
  background: var(--accent-rust-hover);
}

.cookie-essential {
  background: var(--bg-subtle);
  color: var(--text-secondary);
  border: 1px solid var(--border-hairline);
}

.cookie-essential:hover {
  background: var(--bg-highlight);
  color: var(--text-primary);
  border-color: var(--border-subtle);
}

@media (max-width: 640px) {
  .cookie-banner {
    bottom: 1rem;
    right: 1rem;
    left: 1rem;
    width: auto;
    max-width: none;
  }
}

/* ==========================================================================
   RESPONSIVE DESIGN BREAKPOINTS
   ========================================================================== */

@media (max-width: 992px) {
  .hero-grid {
    grid-template-columns: 1fr;
    gap: 2rem;
  }

  .law-content-grid {
    grid-template-columns: 1fr;
    gap: 2rem;
  }

  .rover-system-grid {
    grid-template-columns: 1fr;
  }

  .why-columns {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }

  .recap-grid {
    grid-template-columns: 1fr;
    gap: 1rem;
  }

  .footer-secondary {
    align-items: flex-start;
  }
}

@media (max-width: 640px) {
  .site-header {
    height: auto;
    padding-top: 0.5rem;
    padding-bottom: 0.5rem;
  }

  .header-inner {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.5rem;
  }

  .site-nav .nav-list {
    gap: 1rem;
  }

  .header-meta {
    display: none;
  }

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

  .equation-visualizer {
    grid-template-columns: 1fr;
    gap: 0.75rem;
  }

  .eq-op {
    display: none;
  }

  .part-selector-tabs {
    grid-template-columns: repeat(2, 1fr);
  }

  .part-metrics-grid {
    grid-template-columns: 1fr;
  }
}