:root {
  --ink: #1e293b;
  --bg: #f8fafc;
  --surface: #ffffff;
  --line: #e2e8f0;
  --force-red: #ef4444;
  --force-blue: #3b82f6;
  --force-amber: #f59e0b;
  --font-display: "Bricolage Grotesque", system-ui, sans-serif;
  --font-body: "Lexend", system-ui, sans-serif;
  --shadow: 0 8px 24px rgba(59, 130, 246, 0.08);
  --shadow-hover: 0 16px 36px rgba(59, 130, 246, 0.16);
  --radius-lg: 20px;
  --radius-md: 12px;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  -webkit-tap-highlight-color: transparent;
}

body {
  font-family: var(--font-body);
  background: var(--bg);
  color: var(--ink);
  line-height: 1.5;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

header {
  background: #0f172a;
  color: #fff;
  padding: 0.9rem 1.4rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
  border-bottom: 3px solid #f59e0b;
  position: sticky;
  top: 0;
  z-index: 50;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.8rem;
  text-decoration: none;
  color: #fff;
}

.brand-icon {
  font-size: 2.2rem;
  background: rgba(245, 158, 11, 0.2);
  padding: 0.4rem;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.brand h1 {
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: 800;
  color: #fef08a;
  letter-spacing: -0.01em;
}

.brand p {
  font-size: 0.8rem;
  color: #cbd5e1;
}

.controls-bar {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  flex-wrap: wrap;
}

.tab-pills {
  display: flex;
  background: rgba(0, 0, 0, 0.25);
  padding: 0.25rem;
  border-radius: 999px;
  gap: 0.3rem;
}

.tab-btn {
  background: transparent;
  border: none;
  color: #cbd5e1;
  font-family: var(--font-body);
  font-size: 0.85rem;
  font-weight: 700;
  padding: 0.45rem 1rem;
  border-radius: 999px;
  cursor: pointer;
  transition: all 0.2s;
}

.tab-btn:hover {
  color: #fff;
}

.tab-btn.active {
  background: #f59e0b;
  color: #0f172a;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
}

.btn-header {
  background: rgba(255, 255, 255, 0.12);
  color: #fff;
  border: 1px solid rgba(255, 255, 255, 0.2);
  padding: 0.45rem 0.9rem;
  border-radius: 999px;
  font-family: var(--font-body);
  font-size: 0.82rem;
  font-weight: 700;
  text-decoration: none;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  transition: all 0.2s;
}

.btn-header:hover {
  background: rgba(255, 255, 255, 0.25);
}

.game-container {
  max-width: 1200px;
  margin: 1.5rem auto;
  padding: 0 1.2rem;
  width: 100%;
  flex: 1;
}

.tab-pane {
  display: none;
  animation: fadeIn 0.25s ease-out;
}

.tab-pane.active {
  display: block;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(6px); }
  to { opacity: 1; transform: translateY(0); }
}

.section-intro {
  margin-bottom: 1.5rem;
}

.section-intro h2 {
  font-family: var(--font-display);
  font-size: 1.5rem;
  color: #0f172a;
}

.section-desc {
  color: #64748b;
  font-size: 0.95rem;
  margin-top: 0.3rem;
}

/* ================== TAB 1: RAMP & FRICTION ================== */
.ramp-layout {
  display: grid;
  grid-template-columns: 280px 1fr;
  gap: 1.5rem;
}

.ramp-controls {
  background: #ffffff;
  border: 2px solid var(--line);
  border-radius: var(--radius-lg);
  padding: 1.4rem;
  box-shadow: var(--shadow);
  display: flex;
  flex-direction: column;
  gap: 1.1rem;
}

.ramp-controls h3 {
  font-family: var(--font-display);
  font-size: 1.15rem;
  color: #0f172a;
}

.control-box {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.control-box label {
  font-size: 0.85rem;
  font-weight: 700;
  color: #475569;
}

.control-box input[type="range"] {
  width: 100%;
  accent-color: var(--force-amber);
  cursor: pointer;
}

.surface-btns {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.surface-btn {
  background: #f8fafc;
  border: 1.5px solid #cbd5e1;
  border-radius: var(--radius-md);
  padding: 0.55rem 0.8rem;
  font-family: var(--font-body);
  font-size: 0.82rem;
  font-weight: 700;
  color: var(--ink);
  cursor: pointer;
  text-align: left;
  transition: all 0.2s;
}

.surface-btn:hover {
  background: #f1f5f9;
  border-color: var(--force-amber);
}

.surface-btn.active {
  background: #fef3c7;
  border-color: #d97706;
  color: #92400e;
}

.results-box {
  background: #f8fafc;
  border: 1.5px solid #e2e8f0;
  border-radius: var(--radius-md);
  padding: 0.9rem;
  font-size: 0.88rem;
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
}

.results-box h4 {
  font-size: 0.85rem;
  color: #0f172a;
  text-transform: uppercase;
}

.canvas-panel {
  display: flex;
  flex-direction: column;
  gap: 0.8rem;
}

#ramp-canvas {
  background: #ffffff;
  border: 2px solid var(--line);
  border-radius: var(--radius-lg);
  width: 100%;
  height: 440px;
  box-shadow: var(--shadow);
  display: block;
}

.canvas-banner {
  background: #f8fafc;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  padding: 0.8rem 1.2rem;
  font-size: 0.9rem;
  color: #475569;
}

/* ================== TAB 2: TUG OF WAR ================== */
.tug-stage {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.tug-hud {
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: #ffffff;
  border: 2px solid var(--line);
  border-radius: var(--radius-lg);
  padding: 1.2rem 2rem;
  box-shadow: var(--shadow);
  flex-wrap: wrap;
  gap: 1rem;
}

.hud-team {
  font-family: var(--font-display);
  font-size: 1.3rem;
  font-weight: 800;
}

.hud-left { color: var(--force-blue); }
.hud-right { color: var(--force-red); }

.hud-center {
  text-align: center;
}

.balance-badge {
  font-size: 0.8rem;
  font-weight: 800;
  padding: 0.25rem 0.8rem;
  border-radius: 999px;
  background: #dcfce7;
  color: #15803d;
  display: inline-block;
  margin-top: 0.3rem;
}

.balance-badge.unbalanced {
  background: #fee2e2;
  color: #dc2626;
}

.tug-arena {
  background: #e2e8f0;
  border: 3px solid #cbd5e1;
  border-radius: var(--radius-lg);
  padding: 3rem 1.5rem;
  overflow: hidden;
  box-shadow: inset 0 4px 14px rgba(0,0,0,0.06);
}

.tug-rope-wrap {
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  transition: transform 0.6s cubic-bezier(0.2, 0.8, 0.2, 1);
}

.rope-line {
  height: 12px;
  width: 480px;
  background: #78350f;
  border-radius: 6px;
  position: relative;
  box-shadow: 0 2px 4px rgba(0,0,0,0.2);
}

.rope-ribbon {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  font-size: 1.8rem;
  transition: left 0.5s ease;
}

.tug-team {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  min-width: 140px;
}

.puller-icon {
  font-size: 2rem;
  animation: pullStruggle 1s infinite alternate;
}

@keyframes pullStruggle {
  from { transform: rotate(-5deg); }
  to { transform: rotate(5deg); }
}

.tug-controls-grid {
  display: grid;
  grid-template-columns: 1fr 200px 1fr;
  gap: 1.5rem;
  align-items: start;
}

.team-panel {
  background: #ffffff;
  border: 2px solid var(--line);
  border-radius: var(--radius-lg);
  padding: 1.4rem;
  display: flex;
  flex-direction: column;
  gap: 0.8rem;
}

.left-panel { border-color: #93c5fd; }
.right-panel { border-color: #fca5a5; }

.add-buttons {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.add-puller-btn {
  background: #f8fafc;
  border: 1.5px solid #cbd5e1;
  border-radius: var(--radius-md);
  padding: 0.55rem 0.9rem;
  font-family: var(--font-body);
  font-size: 0.85rem;
  font-weight: 700;
  cursor: pointer;
  transition: all 0.2s;
  text-align: left;
}

.add-puller-btn:hover {
  background: #f1f5f9;
  transform: translateX(3px);
}

.btn-clear-team {
  background: #fee2e2;
  border: 1px solid #fca5a5;
  color: #dc2626;
  border-radius: 999px;
  padding: 0.35rem 0.8rem;
  font-size: 0.75rem;
  font-weight: 800;
  cursor: pointer;
  align-self: flex-start;
}

.tug-action-center {
  display: flex;
  flex-direction: column;
  gap: 0.8rem;
  align-items: center;
  justify-content: center;
}

/* ================== TAB 3: PARACHUTE ================== */
.chute-stage {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.chute-controls {
  display: flex;
  gap: 1rem;
  justify-content: center;
}

.chute-dropzone {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
  background: #ffffff;
  border: 2px solid var(--line);
  border-radius: var(--radius-lg);
  padding: 1.8rem;
  min-height: 480px;
  box-shadow: var(--shadow);
}

.drop-lane {
  background: #f0f9ff;
  border: 2px dashed #bae6fd;
  border-radius: var(--radius-md);
  padding: 1rem;
  display: flex;
  flex-direction: column;
  align-items: center;
  position: relative;
  overflow: hidden;
}

.lane-label {
  font-size: 0.85rem;
  font-weight: 800;
  color: #0369a1;
  text-align: center;
  margin-bottom: 0.5rem;
}

.sky-column {
  flex: 1;
  width: 100%;
  position: relative;
  display: flex;
  justify-content: center;
}

.fall-object {
  position: absolute;
  top: 10px;
  display: flex;
  flex-direction: column;
  align-items: center;
  transition: top 0.1s linear;
}

.canopy {
  line-height: 1;
}

.canopy-sm { font-size: 2.2rem; }
.canopy-lg { font-size: 3.8rem; }

.weight-box {
  background: #0f172a;
  color: #fff;
  font-size: 0.75rem;
  font-weight: 800;
  padding: 0.2rem 0.5rem;
  border-radius: 4px;
}

.lane-stat {
  font-size: 0.85rem;
  font-weight: 800;
  color: #0c4a6e;
  margin-top: 0.5rem;
}

.chute-explanation {
  background: #fefce8;
  border: 1.5px solid #fef08a;
  border-radius: var(--radius-md);
  padding: 1rem 1.4rem;
  font-size: 0.95rem;
  color: #854d0e;
}

/* ================== TAB 4: QUIZ ================== */
.quiz-stage {
  max-width: 760px;
  margin: 0 auto;
}

.quiz-hud {
  display: flex;
  justify-content: space-between;
  background: #ffffff;
  padding: 0.8rem 1.4rem;
  border-radius: var(--radius-md);
  border: 1px solid var(--line);
  margin-bottom: 1.2rem;
}

.quiz-card {
  background: #ffffff;
  border: 2px solid var(--line);
  border-radius: var(--radius-lg);
  padding: 2.2rem;
  box-shadow: var(--shadow);
  display: flex;
  flex-direction: column;
  gap: 1.2rem;
}

.quiz-badge {
  align-self: flex-start;
  font-size: 0.8rem;
  font-weight: 800;
  padding: 0.3rem 0.8rem;
  border-radius: 999px;
  background: #e0f2fe;
  color: #0369a1;
  text-transform: uppercase;
}

.quiz-question {
  font-family: var(--font-display);
  font-size: 1.5rem;
  color: #0f172a;
}

.quiz-options {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}

.quiz-opt-btn {
  background: #f8fafc;
  border: 2px solid #cbd5e1;
  border-radius: var(--radius-md);
  padding: 1rem;
  font-family: var(--font-body);
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--ink);
  cursor: pointer;
  transition: all 0.2s;
  text-align: left;
}

.quiz-opt-btn:hover {
  background: #f1f5f9;
  border-color: #0f172a;
  transform: translateY(-2px);
}

.quiz-opt-btn.correct {
  background: #dcfce7 !important;
  border-color: #16a34a !important;
  color: #14532d !important;
}

.quiz-opt-btn.wrong {
  background: #fee2e2 !important;
  border-color: #dc2626 !important;
  color: #7f1d1d !important;
}

.quiz-feedback {
  background: #f8fafc;
  border: 1.5px solid #cbd5e1;
  border-radius: var(--radius-md);
  padding: 1rem;
  font-size: 0.95rem;
  color: #334155;
}

.quiz-footer {
  display: flex;
  justify-content: flex-end;
}

.btn-action {
  font-family: var(--font-body);
  font-size: 0.88rem;
  font-weight: 800;
  background: #0f172a;
  color: #fff;
  border: none;
  padding: 0.6rem 1.4rem;
  border-radius: 999px;
  cursor: pointer;
  transition: all 0.2s;
  text-align: center;
}

.btn-action:hover {
  background: #1e293b;
  transform: translateY(-2px);
}

.btn-large {
  font-size: 1rem;
  padding: 0.75rem 1.8rem;
}

.btn-secondary {
  background: #ffffff;
  color: #0f172a;
  border: 1.5px solid var(--line);
}

.btn-secondary:hover {
  background: #f1f5f9;
}

@media (max-width: 900px) {
  .ramp-layout, .tug-controls-grid, .chute-dropzone, .quiz-options {
    grid-template-columns: 1fr;
  }
}