/* ── 2026 Next-Gen 3D Spatial Depth, Glassmorphism & Holographic Sheen ── */

/* 3D Perspective Context */
.perspective-container {
  perspective: 1200px;
  transform-style: preserve-3d;
}

/* Ambient Canvas Background */
#ambientCanvas {
  position: fixed;
  inset: 0;
  width: 100vw;
  height: 100vh;
  pointer-events: none;
  z-index: -1;
  opacity: 0.65;
  transition: opacity 0.5s ease;
}

/* 3D Glass Surface Elevation */
.card, .section-block, .topic-node-card, .mock-card, .preset-tile {
  position: relative;
  transform-style: preserve-3d;
  will-change: transform;
  transition: transform 0.28s cubic-bezier(0.16, 1, 0.3, 1), box-shadow 0.28s cubic-bezier(0.16, 1, 0.3, 1), border-color 0.2s ease;
  /* Multi-stop specular glass border */
  border: 1px solid rgba(255, 255, 255, 0.09) !important;
  box-shadow:
    0 1px 2px rgba(0, 0, 0, 0.4),
    0 4px 12px rgba(0, 0, 0, 0.3),
    0 16px 36px -8px rgba(0, 0, 0, 0.5),
    inset 0 1px 0 rgba(255, 255, 255, 0.12) !important;
}

/* Holographic Cursor Sheen Glare */
.card-sheen-overlay {
  position: absolute;
  inset: 0;
  border-radius: inherit;
  pointer-events: none;
  opacity: 0;
  background: radial-gradient(
    circle 240px at var(--mouse-x, 50%) var(--mouse-y, 50%),
    rgba(255, 255, 255, 0.12),
    rgba(255, 255, 255, 0.03) 40%,
    transparent 80%
  );
  transition: opacity 0.3s ease;
  mix-blend-mode: overlay;
  z-index: 2;
}

.card:hover .card-sheen-overlay,
.subject-card:hover .card-sheen-overlay,
.topic-node-card:hover .card-sheen-overlay,
.mock-card:hover .card-sheen-overlay,
.preset-tile:hover .card-sheen-overlay {
  opacity: 1;
}

/* Dynamic Spotlight Border on Hover */
.subject-card, .topic-node-card, .mock-card, .preset-tile, .section-switch-card {
  overflow: hidden;
}

.subject-card::before, .mock-card::before, .preset-tile::before {
  content: "";
  position: absolute;
  inset: -1px;
  border-radius: inherit;
  padding: 1px;
  background: radial-gradient(
    circle 200px at var(--mouse-x, 50%) var(--mouse-y, 50%),
    rgba(255, 255, 255, 0.35),
    transparent 70%
  );
  -webkit-mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
  -webkit-mask-composite: xor;
  mask-composite: exclude;
  pointer-events: none;
  opacity: 0;
  transition: opacity 0.3s ease;
  z-index: 1;
}

.subject-card:hover::before, .mock-card:hover::before, .preset-tile:hover::before {
  opacity: 1;
}

/* 3D Floating Glyphs with Dynamic Shadow */
.card-glyph, .section-icon-box, .switch-icon {
  transform: translateZ(24px);
  box-shadow: 0 8px 20px -4px rgba(0, 0, 0, 0.6);
  animation: floatLevitate 4s ease-in-out infinite;
  transition: transform 0.25s ease;
}

@keyframes floatLevitate {
  0%, 100% { transform: translateZ(24px) translateY(0); }
  50% { transform: translateZ(24px) translateY(-3px); }
}

/* Physical Haptic Button Depress */
button, .btn, .btn-launch, .btn-next, .btn-skip, .topic-drill-btn, .segment-btn, .nav-tab {
  will-change: transform;
  transition: transform 0.16s cubic-bezier(0.34, 1.56, 0.64, 1), box-shadow 0.16s ease, background 0.16s ease;
}

button:active, .btn:active, .btn-launch:active, .btn-next:active {
  transform: scale(0.96) translateY(2px) !important;
}

/* 3D Realistic Option Cards in Quiz Canvas */
.options-grid {
  perspective: 900px;
}

.option-row {
  transform-style: preserve-3d;
  transition: all 0.2s cubic-bezier(0.16, 1, 0.3, 1) !important;
  border: 1px solid rgba(255, 255, 255, 0.08) !important;
  box-shadow:
    0 2px 6px rgba(0, 0, 0, 0.3),
    inset 0 1px 0 rgba(255, 255, 255, 0.06);
}

.option-row:hover {
  transform: translateX(6px) translateZ(8px) scale(1.01) !important;
  background: #161c2a !important;
  border-color: rgba(99, 102, 241, 0.4) !important;
  box-shadow:
    0 8px 24px -4px rgba(0, 0, 0, 0.5),
    0 0 16px -2px rgba(99, 102, 241, 0.25),
    inset 0 1px 0 rgba(255, 255, 255, 0.12) !important;
}

.option-row.selected {
  transform: translateX(6px) translateZ(12px) !important;
  border-color: var(--accent-indigo) !important;
  box-shadow:
    0 0 0 1px var(--accent-indigo),
    0 10px 30px -4px var(--accent-indigo-glow),
    inset 0 1px 0 rgba(255, 255, 255, 0.2) !important;
}

.option-row.correct {
  transform: translateX(6px) translateZ(12px) !important;
  border-color: var(--accent-emerald) !important;
  box-shadow:
    0 0 0 1px var(--accent-emerald),
    0 10px 30px -4px var(--accent-emerald-glow),
    inset 0 1px 0 rgba(255, 255, 255, 0.25) !important;
}

.option-row.incorrect {
  transform: translateX(6px) translateZ(12px) !important;
  border-color: var(--accent-coral) !important;
  box-shadow:
    0 0 0 1px var(--accent-coral),
    0 10px 30px -4px var(--accent-coral-glow),
    inset 0 1px 0 rgba(255, 255, 255, 0.25) !important;
}

.option-key {
  transform: translateZ(14px);
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.4);
}

/* 3D Glowing Launch Button */
.btn-launch {
  position: relative;
  overflow: hidden;
  box-shadow:
    0 4px 14px rgba(99, 102, 241, 0.4),
    0 12px 28px -6px rgba(99, 102, 241, 0.5),
    inset 0 1px 0 rgba(255, 255, 255, 0.35) !important;
}

.btn-launch::after {
  content: "";
  position: absolute;
  top: -50%;
  left: -60%;
  width: 50%;
  height: 200%;
  background: linear-gradient(
    90deg,
    transparent,
    rgba(255, 255, 255, 0.25),
    transparent
  );
  transform: rotate(25deg);
  animation: shineSweep 4.5s ease-in-out infinite;
}

@keyframes shineSweep {
  0% { left: -70%; }
  30%, 100% { left: 140%; }
}

/* 3D Realistic Circular Gauge */
.circle-gauge {
  filter: drop-shadow(0 0 20px var(--accent-emerald-glow));
  animation: gaugePulse 3s ease-in-out infinite;
}

@keyframes gaugePulse {
  0%, 100% { transform: scale(1); }
  50% { transform: scale(1.025); }
}

/* Nav Tab 3D Active Pill */
.nav-tab.active {
  box-shadow:
    0 4px 16px rgba(99, 102, 241, 0.3),
    0 0 1px 1px rgba(99, 102, 241, 0.4),
    inset 0 1px 0 rgba(255, 255, 255, 0.2) !important;
}

/* Shimmer Progress Track */
.quiz-progress-bar {
  position: relative;
  overflow: hidden;
}

.quiz-progress-bar::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.4), transparent);
  animation: shimmerProgress 2s linear infinite;
}

@keyframes shimmerProgress {
  0% { transform: translateX(-100%); }
  100% { transform: translateX(100%); }
}

/* Modern Gradient Headline Shimmer */
.gradient-text {
  background: linear-gradient(135deg, #ffffff 20%, #cbd5e1 50%, #94a3b8 80%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  text-shadow: 0 0 30px rgba(255, 255, 255, 0.15);
}


/* ── 2026 Sleek SVG Vector Iconography & Micro-Interactions ── */
.svg-icon {
  display: inline-block;
  vertical-align: middle;
  stroke-linecap: round;
  stroke-linejoin: round;
  flex-shrink: 0;
  transition: transform 0.2s cubic-bezier(0.16, 1, 0.3, 1), stroke 0.2s ease;
}

.nav-tab:hover .svg-icon,
.subject-card:hover .svg-icon,
.preset-tile:hover .svg-icon {
  transform: scale(1.12);
}

/* Audio EQ Equalizer Animation */
.sound-eq {
  display: inline-flex;
  align-items: flex-end;
  gap: 2.5px;
  height: 13px;
  padding-left: 2px;
}

.sound-bar {
  width: 2.5px;
  background: var(--accent-indigo);
  border-radius: 1px;
  height: 3px;
  transition: height 0.2s ease;
}

.sound-active .sound-bar:nth-child(1) {
  animation: eqBounce 0.8s ease-in-out infinite alternate;
}
.sound-active .sound-bar:nth-child(2) {
  animation: eqBounce 1.1s ease-in-out 0.2s infinite alternate;
}
.sound-active .sound-bar:nth-child(3) {
  animation: eqBounce 0.9s ease-in-out 0.4s infinite alternate;
}

@keyframes eqBounce {
  0% { height: 3px; }
  100% { height: 13px; }
}

/* Keyboard Command Prompt Badges */
.kbd-badge {
  font-family: var(--font-mono);
  font-size: 10.5px;
  font-weight: 600;
  padding: 2px 7px;
  border-radius: 5px;
  background: rgba(255, 255, 255, 0.07);
  border: 1px solid rgba(255, 255, 255, 0.14);
  color: var(--ink-secondary);
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.4);
  letter-spacing: 0.04em;
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

/* Question Matrix Rail in CBT Quiz Mode */
.question-nav-rail {
  display: flex;
  align-items: center;
  gap: 8px;
  margin: 12px 0 18px;
  overflow-x: auto;
  padding: 6px 2px;
  scrollbar-width: none;
}

.question-nav-rail::-webkit-scrollbar {
  display: none;
}

.q-rail-pill {
  width: 30px;
  height: 30px;
  border-radius: 50%;
  border: 1px solid var(--border-hairline);
  background: rgba(255, 255, 255, 0.03);
  color: var(--ink-muted);
  font-family: var(--font-mono);
  font-size: 11.5px;
  font-weight: 700;
  display: grid;
  place-items: center;
  cursor: pointer;
  transition: all 0.18s cubic-bezier(0.16, 1, 0.3, 1);
  flex-shrink: 0;
}

.q-rail-pill:hover {
  border-color: var(--border-hover);
  color: #fff;
  transform: scale(1.08);
}

.q-rail-pill.active {
  background: #1e2638;
  border-color: var(--accent-indigo);
  color: #fff;
  box-shadow: 0 0 0 2px var(--accent-indigo-glow);
  transform: scale(1.15);
}

.q-rail-pill.answered {
  background: rgba(16, 185, 129, 0.16);
  border-color: var(--accent-emerald);
  color: var(--accent-emerald);
}

.q-rail-pill.skipped {
  background: rgba(245, 158, 11, 0.16);
  border-color: var(--accent-amber);
  color: var(--accent-amber);
}

/* Floating Brand Logo Mark */
.brand-glyph-box {
  width: 34px;
  height: 34px;
  border-radius: 10px;
  background: linear-gradient(135deg, #06b6d4, #6366f1);
  display: grid;
  place-items: center;
  color: #fff;
  box-shadow: 0 0 20px rgba(99, 102, 241, 0.4), inset 0 1px 0 rgba(255, 255, 255, 0.35);
  position: relative;
  overflow: hidden;
  flex-shrink: 0;
}

.brand-glyph-box::after {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at 30% 30%, rgba(255, 255, 255, 0.4), transparent 70%);
}

/* Subject Card Ambient Drop Halos */
.subject-card[data-subject="Physics"] .card-glyph {
  color: var(--accent-cyan);
  filter: drop-shadow(0 0 12px var(--accent-cyan-glow));
}

.subject-card[data-subject="Chemistry"] .card-glyph {
  color: var(--accent-emerald);
  filter: drop-shadow(0 0 12px var(--accent-emerald-glow));
}

.subject-card[data-subject="Mathematics"] .card-glyph {
  color: var(--accent-indigo);
  filter: drop-shadow(0 0 12px var(--accent-indigo-glow));
}

.subject-card[data-subject="Mixed"] .card-glyph {
  color: #ec4899;
  filter: drop-shadow(0 0 12px rgba(236, 72, 153, 0.45));
}