:root {
  --primary: #1e3a8a;
  --primary-light: #2563eb;
  --accent: #3b82f6;
  --success: #10b981;
  --warning: #f59e0b;
  --danger: #ef4444;
  --dark: #0f172a;
  --slate: #334155;
  --muted: #64748b;
  --light: #f8fafc;
  --card-bg: #ffffff;
  --border: #e2e8f0;
  --radius: 16px;
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.05);
  --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.08), 0 2px 4px -2px rgba(0,0,0,0.05);
  --shadow-lg: 0 20px 25px -5px rgba(30, 58, 138, 0.12), 0 8px 10px -6px rgba(30, 58, 138, 0.08);
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: 'Kantumruy Pro', 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  background-color: var(--light);
  color: var(--dark);
  line-height: 1.6;
  overflow-x: hidden;
}

/* NAVBAR */
.navbar {
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  background: rgba(255, 255, 255, 0.85);
  border-bottom: 1px solid var(--border);
  padding: 1rem 0;
}

.container {
  max-width: 1180px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

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

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: var(--dark);
}

.brand-icon {
  width: 42px;
  height: 42px;
  border-radius: 12px;
  object-fit: cover;
  box-shadow: 0 4px 10px rgba(30, 58, 138, 0.2);
}

.brand-text h1 {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--primary);
  line-height: 1.2;
}

.brand-text span {
  font-size: 0.8rem;
  color: var(--muted);
  font-weight: 500;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 1.5rem;
}

.nav-links a {
  text-decoration: none;
  color: var(--slate);
  font-size: 0.95rem;
  font-weight: 600;
  transition: color 0.2s;
}

.nav-links a:hover {
  color: var(--primary-light);
}

.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: linear-gradient(135deg, var(--primary), var(--primary-light));
  color: #fff !important;
  padding: 0.65rem 1.4rem;
  border-radius: 9999px;
  font-weight: 700;
  text-decoration: none;
  box-shadow: 0 4px 14px rgba(37, 99, 235, 0.3);
  transition: transform 0.2s, box-shadow 0.2s;
  border: none;
  cursor: pointer;
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(37, 99, 235, 0.4);
}

.btn-outline {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: #fff;
  color: var(--primary) !important;
  border: 1.5px solid var(--border);
  padding: 0.65rem 1.4rem;
  border-radius: 9999px;
  font-weight: 700;
  text-decoration: none;
  transition: all 0.2s;
  cursor: pointer;
}

.btn-outline:hover {
  border-color: var(--primary-light);
  background: #f1f5f9;
}

/* HERO SECTION */
.hero {
  padding: 5rem 0 3.5rem;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -150px;
  right: -100px;
  width: 550px;
  height: 550px;
  background: radial-gradient(circle, rgba(37, 99, 235, 0.12) 0%, rgba(255,255,255,0) 70%);
  border-radius: 50%;
  z-index: -1;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 3rem;
  align-items: center;
}

.badge-tag {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: rgba(37, 99, 235, 0.1);
  color: var(--primary-light);
  padding: 6px 14px;
  border-radius: 999px;
  font-size: 0.85rem;
  font-weight: 700;
  margin-bottom: 1.25rem;
  border: 1px solid rgba(37, 99, 235, 0.2);
}

.hero-title {
  font-size: 2.75rem;
  font-weight: 800;
  line-height: 1.3;
  color: var(--dark);
  margin-bottom: 1.25rem;
}

.hero-title span {
  background: linear-gradient(135deg, var(--primary), var(--primary-light));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-desc {
  font-size: 1.15rem;
  color: var(--slate);
  margin-bottom: 2rem;
  line-height: 1.7;
}

.hero-actions {
  display: flex;
  gap: 1rem;
  align-items: center;
  flex-wrap: wrap;
}

.google-play-btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  background: #000;
  color: #fff;
  padding: 10px 22px;
  border-radius: 14px;
  text-decoration: none;
  box-shadow: 0 4px 15px rgba(0,0,0,0.15);
  transition: transform 0.2s;
}

.google-play-btn:hover {
  transform: translateY(-2px);
}

.google-play-btn svg {
  width: 28px;
  height: 28px;
}

.gp-text {
  display: flex;
  flex-direction: column;
  line-height: 1.1;
  text-align: left;
}

.gp-text span {
  font-size: 0.7rem;
  text-transform: uppercase;
  color: #cbd5e1;
}

.gp-text strong {
  font-size: 1rem;
  color: #fff;
}

/* HERO PHONE CARD MOCKUP */
.hero-visual {
  position: relative;
  display: flex;
  justify-content: center;
}

.paper-card-preview {
  width: 100%;
  max-width: 380px;
  background: #ffffff;
  border-radius: 20px;
  padding: 24px;
  box-shadow: var(--shadow-lg);
  border: 1px solid var(--border);
  position: relative;
  background-image: linear-gradient(#e2e8f0 1px, transparent 1px);
  background-size: 100% 28px;
  line-height: 28px;
}

.paper-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-bottom: 12px;
  margin-bottom: 16px;
  border-bottom: 2px solid #ef4444;
}

.paper-title {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--primary);
}

.paper-badge {
  background: #10b981;
  color: #fff;
  font-size: 0.75rem;
  padding: 3px 8px;
  border-radius: 6px;
  font-weight: 700;
}

.paper-math-content {
  font-family: 'Cambria Math', 'Times New Roman', serif;
  font-size: 1.05rem;
  color: #1e293b;
}

.paper-boxed {
  border: 2px solid var(--primary);
  display: inline-block;
  padding: 2px 10px;
  border-radius: 6px;
  font-weight: bold;
  background: rgba(37, 99, 235, 0.05);
  margin-top: 6px;
}

/* FEATURES SECTION */
.features-section {
  padding: 5rem 0;
  background: #fff;
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

.section-head {
  text-align: center;
  max-width: 650px;
  margin: 0 auto 3.5rem;
}

.section-head h2 {
  font-size: 2.2rem;
  font-weight: 800;
  color: var(--dark);
  margin-bottom: 0.75rem;
}

.section-head p {
  font-size: 1.05rem;
  color: var(--muted);
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 2rem;
}

.feature-card {
  background: var(--light);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 2rem;
  transition: transform 0.2s, box-shadow 0.2s;
}

.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}

.feature-icon-box {
  width: 52px;
  height: 52px;
  border-radius: 14px;
  background: linear-gradient(135deg, var(--primary), var(--primary-light));
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  margin-bottom: 1.25rem;
}

.feature-card h3 {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 0.75rem;
  color: var(--dark);
}

.feature-card p {
  color: var(--slate);
  font-size: 0.95rem;
}

/* CURRICULUM GRID */
.curriculum-section {
  padding: 5rem 0;
}

.topic-pills {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  justify-content: center;
  margin-top: 2rem;
}

.topic-pill {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 10px 20px;
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 0.95rem;
  color: var(--dark);
  box-shadow: var(--shadow-sm);
}

.topic-pill i {
  color: var(--primary-light);
}

/* FOOTER */
footer {
  background: #fff;
  border-top: 1px solid var(--border);
  padding: 3rem 0;
  font-size: 0.9rem;
  color: var(--muted);
}

.footer-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1.5rem;
}

.footer-links {
  display: flex;
  gap: 1.5rem;
}

.footer-links a {
  text-decoration: none;
  color: var(--slate);
}

.footer-links a:hover {
  color: var(--primary-light);
}

/* PRIVACY PAGE STYLES */
.policy-container {
  max-width: 860px;
  margin: 3rem auto 5rem;
  background: #fff;
  padding: 3rem;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  box-shadow: var(--shadow-md);
}

.policy-container h1 {
  font-size: 2rem;
  font-weight: 800;
  color: var(--primary);
  margin-bottom: 0.5rem;
}

.policy-container .date {
  font-size: 0.85rem;
  color: var(--muted);
  margin-bottom: 2rem;
}

.policy-container h2 {
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--dark);
  margin-top: 2rem;
  margin-bottom: 0.75rem;
}

.policy-container p, .policy-container li {
  color: var(--slate);
  margin-bottom: 1rem;
  font-size: 0.98rem;
}

.policy-container ul {
  padding-left: 1.5rem;
  margin-bottom: 1.5rem;
}

/* ADMIN PANEL STYLES */
.admin-card {
  max-width: 720px;
  margin: 3rem auto 5rem;
  background: #fff;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  box-shadow: var(--shadow-md);
  padding: 2.5rem;
}

.admin-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 2rem;
  padding-bottom: 1.25rem;
  border-bottom: 1px solid var(--border);
}

.form-group {
  margin-bottom: 1.5rem;
}

.form-group label {
  display: block;
  font-weight: 700;
  font-size: 0.9rem;
  color: var(--dark);
  margin-bottom: 0.4rem;
}

.form-group small {
  display: block;
  color: var(--muted);
  font-size: 0.8rem;
  margin-top: 0.25rem;
}

.form-control {
  width: 100%;
  padding: 0.75rem 1rem;
  border-radius: 10px;
  border: 1px solid var(--border);
  font-family: inherit;
  font-size: 0.95rem;
  background: #f8fafc;
  transition: border-color 0.2s;
}

.form-control:focus {
  outline: none;
  border-color: var(--primary-light);
  background: #fff;
}

.switch-group {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1rem;
  background: #fef2f2;
  border: 1px solid #fee2e2;
  border-radius: 12px;
  margin-bottom: 1.5rem;
}

.switch-group.active {
  background: #fef2f2;
}

.switch-label {
  display: flex;
  flex-direction: column;
}

.switch-label strong {
  color: var(--danger);
  font-size: 1rem;
}

.toggle-switch {
  position: relative;
  display: inline-block;
  width: 52px;
  height: 28px;
}

.toggle-switch input {
  opacity: 0;
  width: 0;
  height: 0;
}

.slider {
  position: absolute;
  cursor: pointer;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: #cbd5e1;
  transition: 0.3s;
  border-radius: 28px;
}

.slider:before {
  position: absolute;
  content: "";
  height: 22px;
  width: 22px;
  left: 3px;
  bottom: 3px;
  background-color: white;
  transition: 0.3s;
  border-radius: 50%;
}

input:checked + .slider {
  background-color: var(--danger);
}

input:checked + .slider:before {
  transform: translateX(24px);
}

/* RESPONSIVE */
@media (max-width: 860px) {
  .hero-grid {
    grid-template-columns: 1fr;
    text-align: center;
  }
  .hero-actions {
    justify-content: center;
  }
  .hero::before {
    display: none;
  }
  .policy-container, .admin-card {
    padding: 1.5rem;
    margin: 1.5rem auto;
  }
}