:root {
  --primary: #0f172a;
  --secondary: #1e293b;
  --accent: #38bdf8;
  --text: #e2e8f0;
  --muted: #64748b;
  --success: #22c55e;
  --danger: #ef4444;
  --warning: #f59e0b;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}
html {
  scroll-behavior: smooth;
}
body {
  font-family: "Inter", sans-serif;
  background: var(--primary);
  color: var(--text);
  line-height: 1.5;
  overflow-x: hidden;
}
h1,
h2,
h3,
h4 {
  font-family: "Poppins", sans-serif;
  line-height: 1.2;
}

/* Utilities */
.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 20px;
}
.section {
  padding: 80px 0;
}
.pt-32 {
  padding-top: 100px;
}
.btn {
  display: inline-block;
  padding: 12px 28px;
  border-radius: 8px;
  font-weight: 600;
  font-size: 14px;
  cursor: pointer;
  transition: 0.3s;
  border: none;
  text-decoration: none;
  font-family: "Poppins", sans-serif;
}
.btn-primary {
  background: var(--accent);
  color: #000;
}

/* RGB Button */
.btn-rgb {
  position: relative;
  z-index: 1;
  color: #fff;
  background: #000;
  overflow: hidden;
}
.btn-rgb::before {
  content: "";
  position: absolute;
  inset: -3px;
  background: linear-gradient(
    45deg,
    #ff0000,
    #ff7300,
    #fffb00,
    #48ff00,
    #00ffd5,
    #002bff,
    #7a00ff,
    #ff00c8,
    #ff0000
  );
  background-size: 400%;
  z-index: -2;
  filter: blur(6px);
  animation: glow 20s linear infinite;
  border-radius: 8px;
}
.btn-rgb::after {
  content: "";
  position: absolute;
  inset: 1px;
  background: #000;
  border-radius: 7px;
  z-index: -1;
}
@keyframes glow {
  0% {
    background-position: 0 0;
  }
  50% {
    background-position: 400% 0;
  }
  100% {
    background-position: 0 0;
  }
}

/* Glass */
.glass {
  background: rgba(30, 41, 59, 0.6);
  backdrop-filter: blur(12px);
  border: 1px solid rgba(255, 255, 255, 0.05);
  border-radius: 16px;
}

/* Navbar */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  padding: 15px 0;
  transition: 0.3s;
  background: transparent;
}
.navbar.scrolled {
  background: rgba(15, 23, 42, 0.95);
  padding: 10px 0;
  box-shadow: 0 4px 30px rgba(0, 0, 0, 0.3);
}
.nav-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 20px;
}
.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: #fff;
  font-weight: 700;
  font-size: 18px;
}
.logo-icon {
  width: 36px;
  height: 36px;
  background: linear-gradient(135deg, #6366f1, #22d3ee);
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
}
.nav-links {
  display: flex;
  gap: 25px;
}
.nav-links a {
  color: var(--muted);
  text-decoration: none;
  font-size: 14px;
  font-weight: 500;
  transition: 0.2s;
}
.nav-links a:hover,
.nav-links a.active {
  color: #fff;
}
.nav-links a.highlight {
  color: var(--accent);
}

/* Mobile Menu */
.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 5px;
}
.hamburger span {
  width: 24px;
  height: 2px;
  background: #fff;
  transition: 0.3s;
}
.mobile-menu {
  display: none;
  position: fixed;
  inset: 0;
  background: var(--primary);
  z-index: 99;
  padding: 80px 20px;
  flex-direction: column;
  gap: 20px;
}
.mobile-menu.active {
  display: flex;
}
.mobile-menu a {
  color: #fff;
  text-decoration: none;
  font-size: 18px;
}
@media (max-width: 768px) {
  .hamburger {
    display: flex;
  }
  .nav-links {
    display: none;
  }
}

/* SPA Page System */
.page {
  display: none;
  opacity: 0;
  animation: fadeIn 0.5s forwards;
}
.page.active {
  display: block;
}
@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* Hero */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
  padding-top: 60px;
}
.hero-bg {
  position: absolute;
  inset: 0;
  z-index: -1;
}
.gradient-orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(80px);
  opacity: 0.6;
  animation: float 20s infinite;
}
.orb-1 {
  width: 600px;
  height: 600px;
  background: #6366f1;
  top: -200px;
  right: -100px;
}
.orb-2 {
  width: 500px;
  height: 500px;
  background: #22d3ee;
  bottom: -100px;
  left: -100px;
}
@keyframes float {
  0%,
  100% {
    transform: translate(0, 0);
  }
  50% {
    transform: translate(20px, 30px);
  }
}
.grid-pattern {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.03) 1px, transparent 1px);
  background-size: 50px 50px;
}
.hero-content {
  text-align: center;
  max-width: 900px;
  padding: 20px;
  z-index: 2;
}
.badge {
  display: inline-block;
  padding: 6px 16px;
  border-radius: 20px;
  background: rgba(56, 189, 248, 0.1);
  color: var(--accent);
  font-size: 13px;
  font-weight: 600;
  margin-bottom: 20px;
  border: 1px solid rgba(56, 189, 248, 0.2);
}
.hero-title {
  font-size: 52px;
  margin-bottom: 20px;
  color: #fff;
  line-height: 1.1;
}
.typing-text {
  border-right: 3px solid var(--accent);
  padding-right: 5px;
  animation: blink 1s infinite;
}
@keyframes blink {
  from,
  to {
    border-color: transparent;
  }
  50% {
    border-color: var(--accent);
  }
}
.gradient-text {
  background: linear-gradient(135deg, #fff, var(--accent));
  background-clip: text;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}
.hero-desc {
  font-size: 18px;
  color: var(--muted);
  margin-bottom: 30px;
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}
.hero-actions {
  display: flex;
  gap: 15px;
  justify-content: center;
  flex-wrap: wrap;
}

/* Stats */
.stats-section {
  background: var(--secondary);
  padding: 60px 0;
  border-top: 1px solid rgba(255, 255, 255, 0.05);
}
.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 30px;
  text-align: center;
}
.stat-item {
  padding: 20px;
}
.stat-number {
  font-size: 36px;
  font-weight: 800;
  color: #fff;
  display: inline;
}
.plus {
  font-size: 36px;
  font-weight: 800;
  color: var(--accent);
}
.stat-label {
  font-size: 14px;
  color: var(--muted);
  margin-top: 5px;
  display: block;
}

/* Sections */
.section-title {
  font-size: 32px;
  margin-bottom: 10px;
  text-align: center;
  color: #fff;
}
.section-desc {
  text-align: center;
  color: var(--muted);
  margin-bottom: 40px;
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}
.alt-bg {
  background: rgba(30, 41, 59, 0.3);
}
.intro-badge {
  text-align: center;
  display: block;
  margin: 0 auto 10px;
  color: var(--accent);
  font-weight: 600;
  font-size: 12px;
  letter-spacing: 1px;
  text-transform: uppercase;
}

/* Steps Grid (How it Works) */
.steps-grid {
  display: grid;
  grid-template-columns: 1fr 50px 1fr 50px 1fr;
  gap: 20px;
  align-items: center;
  margin-top: 40px;
}
@media (max-width: 768px) {
  .steps-grid {
    display: block;
  }
  .step-arrow {
    display: none;
  }
  .step-item {
    margin-bottom: 30px;
  }
}
.step-item {
  text-align: center;
  padding: 30px;
  background: rgba(255, 255, 255, 0.02);
  border-radius: 16px;
  border: 1px solid transparent;
  transition: 0.3s;
  cursor: pointer;
}
.step-item:hover {
  border-color: rgba(56, 189, 248, 0.3);
  background: rgba(56, 189, 248, 0.05);
}
.step-num {
  width: 50px;
  height: 50px;
  background: var(--accent);
  color: #000;
  font-weight: 800;
  font-size: 20px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 15px;
}
.step-item h4 {
  font-size: 18px;
  color: #fff;
  margin-bottom: 5px;
}
.step-item p {
  font-size: 14px;
  color: var(--muted);
  margin-bottom: 10px;
}
.step-link {
  font-size: 12px;
  color: var(--accent);
  font-weight: 600;
}
.step-arrow {
  color: #334155;
  font-size: 24px;
  font-weight: bold;
  text-align: center;
}

/* CTA Box */
.cta-box {
  text-align: center;
  padding: 40px;
  margin-top: 50px;
  border: 1px dashed var(--accent);
  background: rgba(56, 189, 248, 0.03);
}
.cta-box h3 {
  font-size: 24px;
  margin-bottom: 10px;
  color: #fff;
}
.cta-box p {
  margin-bottom: 20px;
  color: var(--muted);
}

/* Subjects Grid */
.subjects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 20px;
}
.card {
  padding: 20px;
  transition: 0.3s;
  display: flex;
  flex-direction: column;
}
.card:hover {
  transform: translateY(-3px);
  border-color: rgba(56, 189, 248, 0.2);
}
.card-icon {
  width: 40px;
  height: 40px;
  border-radius: 8px;
  background: linear-gradient(135deg, #6366f1, #22d3ee);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 15px;
}
.card h3 {
  font-size: 18px;
  margin-bottom: 5px;
}
.card p {
  font-size: 13px;
  color: var(--muted);
  margin-bottom: 15px;
  flex-grow: 1;
}
.card-footer {
  display: flex;
  gap: 10px;
  margin-top: auto;
}
.btn-card {
  padding: 6px 12px;
  font-size: 12px;
  border-radius: 6px;
  background: #334155;
  color: #fff;
  text-decoration: none;
  font-weight: 600;
  transition: 0.2s;
}
.btn-card.primary {
  background: var(--accent);
  color: #000;
}
.btn-card:hover {
  opacity: 0.8;
}

/* Video Grid (Recommended) */
.video-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 20px;
}
.video-card {
  overflow: hidden;
  transition: 0.3s;
}
.video-card:hover {
  transform: translateY(-5px);
  border-color: rgba(56, 189, 248, 0.3);
}
.vid-thumb {
  position: relative;
  height: 180px;
  overflow: hidden;
}
.vid-thumb img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: 0.3s;
}
.video-card:hover .vid-thumb img {
  transform: scale(1.1);
}
.play-btn {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 50px;
  height: 50px;
  background: rgba(0, 0, 0, 0.7);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-size: 20px;
  text-decoration: none;
  transition: 0.3s;
}
.video-card:hover .play-btn {
  background: var(--accent);
  color: #000;
  transform: translate(-50%, -50%) scale(1.1);
}
.vid-info {
  padding: 15px;
}
.vid-info h3 {
  font-size: 16px;
  margin-bottom: 5px;
}
.vid-info p {
  font-size: 13px;
  color: var(--muted);
  margin-bottom: 10px;
}
.tag {
  display: inline-block;
  padding: 3px 8px;
  border-radius: 4px;
  font-size: 10px;
  font-weight: 600;
  text-decoration: none;
}
.tag.blue {
  background: rgba(59, 130, 246, 0.2);
  color: #60a5fa;
}
.tag.green {
  background: rgba(34, 197, 94, 0.2);
  color: #4ade80;
}
.tag.purple {
  background: rgba(139, 92, 246, 0.2);
  color: #a78bfa;
}
.tag.orange {
  background: rgba(249, 115, 22, 0.2);
  color: #fb923c;
}

/* Lab Layout */
.lab-layout {
  display: grid;
  grid-template-columns: 280px 1fr;
  gap: 20px;
}
@media (max-width: 900px) {
  .lab-layout {
    grid-template-columns: 1fr;
  }
}
.sidebar {
  display: flex;
  flex-direction: column;
  gap: 20px;
}
.profile-card {
  padding: 20px;
}
.profile-header {
  display: flex;
  align-items: center;
  gap: 15px;
  margin-bottom: 15px;
}
.avatar {
  width: 50px;
  height: 50px;
  background: linear-gradient(135deg, #6366f1, #22d3ee);
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-weight: bold;
}
.rank-title {
  font-weight: 600;
  color: #fff;
}
.xp-info {
  font-size: 12px;
  color: var(--muted);
}
.xp-bar-container {
  height: 6px;
  background: #1e293b;
  border-radius: 3px;
  overflow: hidden;
  margin-bottom: 10px;
}
.xp-bar {
  height: 100%;
  background: linear-gradient(90deg, #22d3ee, #6366f1);
  transition: width 0.5s;
}
.xp-meta {
  display: flex;
  justify-content: space-between;
  font-size: 11px;
  color: var(--muted);
}
.leaderboard {
  padding: 15px;
}
.leaderboard h4 {
  font-size: 14px;
  margin-bottom: 10px;
  color: #fff;
}
.lb-item {
  display: flex;
  justify-content: space-between;
  font-size: 12px;
  padding: 5px 0;
  border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}
.lb-item.you {
  color: var(--accent);
  font-weight: 600;
}

.game-area {
  padding: 20px;
  min-height: 400px;
  display: flex;
  flex-direction: column;
}
.game-tabs {
  display: flex;
  gap: 10px;
  margin-bottom: 20px;
  border-bottom: 1px solid #334155;
  padding-bottom: 10px;
}
.game-tab {
  background: transparent;
  border: none;
  color: var(--muted);
  cursor: pointer;
  padding: 8px 16px;
  border-radius: 6px;
  font-size: 13px;
}
.game-tab.active {
  background: #334155;
  color: #fff;
}
.game-container {
  flex: 1;
}

/* Quiz */
.opt-btn {
  display: block;
  width: 100%;
  text-align: left;
  padding: 12px;
  background: #1e293b;
  border: 1px solid #334155;
  border-radius: 8px;
  color: #fff;
  margin-bottom: 10px;
  cursor: pointer;
  transition: 0.2s;
}
.opt-btn:hover {
  border-color: var(--accent);
}
.opt-btn.correct {
  border-color: var(--success);
  background: rgba(34, 197, 94, 0.1);
}
.opt-btn.wrong {
  border-color: var(--danger);
  background: rgba(239, 68, 68, 0.1);
}

/* Drag Drop */
.drag-zone {
  min-height: 60px;
  background: rgba(0, 0, 0, 0.2);
  border-radius: 8px;
  padding: 10px;
  margin-bottom: 15px;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}
.d-item {
  padding: 8px 12px;
  background: #334155;
  border-radius: 6px;
  cursor: grab;
  font-size: 12px;
}
.drop-zones {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 10px;
}
.drop-zone {
  min-height: 100px;
  border: 2px dashed #334155;
  border-radius: 8px;
  padding: 10px;
  transition: 0.2s;
}
.drop-zone.over {
  border-color: var(--accent);
  background: rgba(56, 189, 248, 0.1);
}

/* Simulator */
.sim-grid {
  display: grid;
  grid-template-columns: repeat(10, 1fr);
  gap: 1px;
  background: #0f172a;
  padding: 2px;
  border-radius: 4px;
  margin: 15px 0;
}
.sim-cell {
  aspect-ratio: 1;
  background: #1e293b;
  cursor: pointer;
  transition: 0.1s;
}
.sim-cell.type-1 {
  background: #3b82f6;
}
.sim-cell.type-2 {
  background: #ef4444;
}

/* Projects */
.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 20px;
}
.project-card {
  padding: 20px;
  display: flex;
  gap: 15px;
}
.p-icon {
  width: 40px;
  height: 40px;
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  font-size: 12px;
  font-weight: bold;
  color: #fff;
}
.p-info h3 {
  font-size: 16px;
  margin-bottom: 4px;
}
.p-info p {
  font-size: 13px;
  color: var(--muted);
  margin-bottom: 8px;
}
.p-link {
  display: block;
  margin-top: 10px;
  font-size: 12px;
  color: var(--accent);
  text-decoration: none;
}

/* Footer */
.footer {
  padding: 30px 0;
  border-top: 1px solid #1e293b;
  text-align: center;
  color: var(--muted);
  font-size: 12px;
}

/* Reveal Animation */
.reveal {
  opacity: 0;
  transform: translateY(20px);
  transition: all 0.6s ease-out;
}
.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}
.reveal-delay-1 {
  transition-delay: 0.1s;
}
.reveal-delay-2 {
  transition-delay: 0.2s;
}
.reveal-delay-3 {
  transition-delay: 0.3s;
}