/* Math Shortcut HSC BSC - Official Design System */
@import url('https://fonts.googleapis.com/css2?family=Hind+Siliguri:wght@400;500;600;700&family=Inter:wght@400;500;600;700;800&display=swap');

:root {
  --primary: #0d9488;
  --primary-hover: #0f766e;
  --primary-light: #ccfbf1;
  --primary-dark: #115e59;
  --secondary: #0284c7;
  --secondary-light: #e0f2fe;
  --accent: #f59e0b;
  --accent-light: #fef3c7;
  
  --bg-main: #f8fafc;
  --bg-card: #ffffff;
  --bg-card-hover: #f1f5f9;
  --bg-header: rgba(255, 255, 255, 0.92);
  --border-color: #e2e8f0;
  
  --text-main: #0f172a;
  --text-muted: #64748b;
  --text-light: #94a3b8;
  --text-inverse: #ffffff;
  
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
  --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
  
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --radius-full: 9999px;
  
  --font-bn: 'Hind Siliguri', 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-en: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
}

[data-theme="dark"] {
  --bg-main: #0f172a;
  --bg-card: #1e293b;
  --bg-card-hover: #334155;
  --bg-header: rgba(15, 23, 42, 0.92);
  --border-color: #334155;
  
  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --text-light: #64748b;
  --primary-light: #134e4a;
  --secondary-light: #075985;
}

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

body {
  font-family: var(--font-bn);
  background-color: var(--bg-main);
  color: var(--text-main);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--primary);
  text-decoration: none;
  transition: all 0.2s ease;
}

a:hover {
  color: var(--primary-hover);
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

/* Header & Navigation */
header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: var(--bg-header);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-color);
}

.navbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 76px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
}

.brand-icon {
  width: 44px;
  height: 44px;
  background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 22px;
  font-weight: 700;
  box-shadow: 0 4px 12px rgba(13, 148, 136, 0.3);
}

.brand-text {
  display: flex;
  flex-direction: column;
}

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

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

.nav-links {
  display: flex;
  align-items: center;
  gap: 24px;
  list-style: none;
}

.nav-links a {
  color: var(--text-muted);
  font-weight: 500;
  font-size: 0.95rem;
  padding: 6px 12px;
  border-radius: var(--radius-sm);
  transition: all 0.2s;
}

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

.nav-cta {
  background: var(--primary);
  color: white !important;
  font-weight: 600 !important;
  padding: 10px 20px !important;
  border-radius: var(--radius-full) !important;
  box-shadow: 0 4px 14px rgba(13, 148, 136, 0.35);
  display: inline-flex;
  align-items: center;
  gap: 8px;
}

.nav-cta:hover {
  background: var(--primary-hover) !important;
  transform: translateY(-1px);
}

.mobile-toggle {
  display: none;
  background: none;
  border: none;
  font-size: 26px;
  color: var(--text-main);
  cursor: pointer;
}

/* Hero Section */
.hero {
  padding: 80px 0 60px;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 16px;
  background: var(--primary-light);
  color: var(--primary-dark);
  border-radius: var(--radius-full);
  font-size: 0.9rem;
  font-weight: 600;
  margin-bottom: 24px;
  border: 1px solid rgba(13, 148, 136, 0.2);
}

.hero h1 {
  font-size: 3rem;
  font-weight: 800;
  line-height: 1.25;
  margin-bottom: 18px;
  background: linear-gradient(135deg, var(--text-main) 30%, var(--primary) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-subtitle {
  font-size: 1.25rem;
  color: var(--text-muted);
  max-width: 720px;
  margin: 0 auto 36px;
}

.hero-cta-group {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
  margin-bottom: 48px;
}

.btn-playstore {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  background: #0f172a;
  color: white;
  padding: 14px 28px;
  border-radius: var(--radius-md);
  font-family: var(--font-en);
  font-weight: 600;
  box-shadow: var(--shadow-lg);
  border: 1px solid #334155;
  transition: all 0.2s ease;
}

.btn-playstore:hover {
  background: #1e293b;
  color: white;
  transform: translateY(-2px);
  box-shadow: var(--shadow-xl);
}

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

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

.btn-playstore-text span {
  font-size: 0.75rem;
  color: #94a3b8;
  text-transform: uppercase;
}

.btn-playstore-text strong {
  font-size: 1.1rem;
  color: #ffffff;
}

.btn-secondary {
  padding: 14px 28px;
  background: var(--bg-card);
  color: var(--text-main);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  font-weight: 600;
  display: inline-flex;
  align-items: center;
  gap: 8px;
}

.btn-secondary:hover {
  background: var(--bg-card-hover);
  color: var(--primary);
}

/* Feature Highlights Grid */
.section-title-wrap {
  text-align: center;
  max-width: 650px;
  margin: 0 auto 50px;
}

.section-tag {
  color: var(--primary);
  font-weight: 700;
  font-size: 0.9rem;
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-bottom: 8px;
  display: block;
}

.section-title {
  font-size: 2.2rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 12px;
}

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

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 24px;
  margin-bottom: 60px;
}

.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 32px;
  transition: all 0.3s ease;
  position: relative;
  display: flex;
  flex-direction: column;
}

.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: rgba(13, 148, 136, 0.3);
}

.feature-icon-box {
  width: 56px;
  height: 56px;
  border-radius: var(--radius-md);
  background: var(--primary-light);
  color: var(--primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 26px;
  margin-bottom: 20px;
}

.feature-title {
  font-size: 1.3rem;
  font-weight: 700;
  margin-bottom: 10px;
  color: var(--text-main);
}

.feature-text {
  color: var(--text-muted);
  font-size: 0.98rem;
  line-height: 1.6;
}

/* Exam Badge Strip */
.exam-strip {
  background: linear-gradient(135deg, #0f172a 0%, #1e293b 100%);
  color: white;
  border-radius: var(--radius-lg);
  padding: 40px;
  margin: 60px 0;
  text-align: center;
}

.exam-tags-wrap {
  display: flex;
  justify-content: center;
  gap: 12px;
  flex-wrap: wrap;
  margin-top: 24px;
}

.exam-pill {
  padding: 10px 20px;
  background: rgba(255, 255, 255, 0.1);
  border: 1px solid rgba(255, 255, 255, 0.15);
  border-radius: var(--radius-full);
  font-weight: 600;
  font-size: 0.95rem;
  backdrop-filter: blur(8px);
}

/* App Mockup Preview */
.app-preview-wrap {
  position: relative;
  max-width: 900px;
  margin: 0 auto 80px;
  padding: 24px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-xl);
}

.preview-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 20px;
}

.preview-item {
  background: var(--bg-main);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 24px;
  text-align: center;
}

.preview-item h4 {
  font-size: 1.1rem;
  margin: 12px 0 6px;
}

.preview-item p {
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* Content Page Layouts (Privacy, Terms, About, etc.) */
.page-header {
  background: linear-gradient(180deg, var(--primary-light) 0%, var(--bg-main) 100%);
  padding: 60px 0 40px;
  text-align: center;
  border-bottom: 1px solid var(--border-color);
}

.page-header h1 {
  font-size: 2.5rem;
  font-weight: 800;
  margin-bottom: 12px;
  color: var(--text-main);
}

.page-header p {
  color: var(--text-muted);
  font-size: 1.1rem;
}

.content-article {
  max-width: 850px;
  margin: 40px auto 80px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 48px;
  box-shadow: var(--shadow-sm);
}

.content-article h2 {
  font-size: 1.5rem;
  font-weight: 700;
  margin: 32px 0 16px;
  color: var(--text-main);
  border-bottom: 2px solid var(--primary-light);
  padding-bottom: 8px;
}

.content-article h3 {
  font-size: 1.2rem;
  font-weight: 600;
  margin: 24px 0 12px;
}

.content-article p,
.content-article ul,
.content-article ol {
  font-size: 1rem;
  line-height: 1.75;
  color: var(--text-muted);
  margin-bottom: 18px;
}

.content-article ul,
.content-article ol {
  padding-left: 24px;
}

.content-article li {
  margin-bottom: 8px;
}

.content-box {
  background: var(--bg-main);
  border-left: 4px solid var(--primary);
  padding: 18px 24px;
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  margin: 24px 0;
}

/* FAQ Accordion */
.faq-list {
  display: flex;
  flex-direction: column;
  gap: 16px;
  max-width: 850px;
  margin: 0 auto 60px;
}

.faq-item {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 24px;
  transition: all 0.2s;
}

.faq-item:hover {
  border-color: var(--primary);
}

.faq-question {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 8px;
}

.faq-answer {
  color: var(--text-muted);
  font-size: 0.98rem;
  line-height: 1.6;
}

/* Footer */
footer {
  background: #0f172a;
  color: #94a3b8;
  padding: 60px 0 30px;
  border-top: 1px solid #1e293b;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 40px;
}

.footer-brand h3 {
  color: white;
  font-size: 1.3rem;
  margin-bottom: 12px;
}

.footer-brand p {
  font-size: 0.9rem;
  line-height: 1.6;
  max-width: 320px;
}

.footer-col h4 {
  color: white;
  font-size: 1rem;
  margin-bottom: 18px;
  font-weight: 600;
}

.footer-col ul {
  list-style: none;
}

.footer-col li {
  margin-bottom: 10px;
}

.footer-col a {
  color: #94a3b8;
  font-size: 0.9rem;
}

.footer-col a:hover {
  color: white;
}

.footer-bottom {
  padding-top: 24px;
  border-top: 1px solid #1e293b;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 16px;
  font-size: 0.85rem;
}

.footer-legal-notice {
  font-size: 0.8rem;
  color: #64748b;
  margin-top: 8px;
}

/* Responsive */
@media (max-width: 900px) {
  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 768px) {
  .hero h1 {
    font-size: 2.2rem;
  }
  
  .navbar .nav-links {
    display: none;
    position: absolute;
    top: 76px;
    left: 0;
    width: 100%;
    background: var(--bg-card);
    flex-direction: column;
    padding: 24px;
    border-bottom: 1px solid var(--border-color);
    box-shadow: var(--shadow-lg);
  }
  
  .navbar .nav-links.open {
    display: flex;
  }
  
  .mobile-toggle {
    display: block;
  }
  
  .footer-grid {
    grid-template-columns: 1fr;
  }
  
  .content-article {
    padding: 24px;
  }
}