/* css variables for consistent theming across the page */
:root {
  --primary:    #5B21B6;
  --accent:     #8B5CF6;
  --bg:         #F9F9F9;
  --card-bg:    #FFFFFF;
  --text-dark:  #1A1A1A;
  --text-muted: #6B7280;
  --border:     #E5E7EB;
}

/* reset default browser margin and padding */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

/* base body styles */
body {
  font-family: 'Segoe UI', sans-serif;
  background-color: var(--bg);
  color: var(--text-dark);
  line-height: 1.6;
}

a {
  text-decoration: none;
  color: inherit;
}

img { max-width: 100%; display: block; }

/* max width wrapper, centred on the page */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

/* navbar - sticks to top while scrolling */
.navbar {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--card-bg);
  border-bottom: 1px solid var(--border);
  height: 64px;
}

.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

/* logo text */
.nav-logo {
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--primary);
}

/* desktop nav links */
.nav-links {
  list-style: none;
  display: flex;
  gap: 32px;
}

.nav-links a {
  color: var(--text-dark);
  font-size: 0.95rem;
  position: relative;
  transition: color 0.3s ease;
}

/* animated underline that grows on hover */
.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -3px; left: 0;
  width: 0; height: 2px;
  background: var(--primary);
  transition: width 0.3s ease;
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--primary);
  font-weight: 600;
}

.nav-links a:hover::after { width: 100%; }

/* hidden on desktop, shown on mobile */
.hamburger {
  display: none;
  background: none;
  border: none;
  font-size: 1.6rem;
  cursor: pointer;
  color: var(--text-dark);
}

/* base button styles */
.btn {
  display: inline-block;
  padding: 12px 28px;
  border-radius: 8px;
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s ease;
  border: 2px solid transparent;
}

/* filled purple button */
.btn-primary {
  background: var(--primary);
  color: #fff;
  border-color: var(--primary);
}

.btn-primary:hover {
  background: #3B0764;
  transform: translateY(-2px);
}

/* white button for use on dark backgrounds */
.btn-light {
  background: #fff;
  color: var(--primary);
  border-color: #fff;
}

.btn-light:hover {
  background: #F5F3FF;
  transform: translateY(-2px);
}

/* transparent button with purple border */
.btn-outline {
  background: transparent;
  color: var(--primary);
  border-color: var(--primary);
}

.btn-outline:hover {
  background: var(--primary);
  color: #fff;
  transform: translateY(-2px);
}

/* hero section - full screen with background image */
.hero {
  position: relative;
  min-height: 90vh;
  background: url('https://images.unsplash.com/photo-1545205597-3d9d02c29597?w=1600&q=80&fit=crop') center/cover no-repeat;
  background-color: #3B0764;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  overflow: hidden;
}

/* semi-transparent overlay to darken the image so text is readable */
.hero-overlay {
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.52);
}

/* starts invisible - js adds .loaded class to trigger the fade-in */
.hero-content {
  position: relative;
  z-index: 1;
  color: #fff;
  max-width: 720px;
  padding: 0 24px;
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 1s ease, transform 1s ease;
}

/* final visible state after the animation runs */
.hero-content.loaded {
  opacity: 1;
  transform: translateY(0);
}

/* small pill tag above the main heading */
.hero-tag {
  display: inline-block;
  background: rgba(139, 92, 246, 0.25);
  border: 1px solid rgba(139, 92, 246, 0.6);
  color: #C4B5FD;
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 1px;
  text-transform: uppercase;
  padding: 5px 14px;
  border-radius: 999px;
  margin-bottom: 20px;
}

.hero-content h1 {
  font-size: clamp(2.2rem, 5vw, 3.5rem);
  font-weight: 700;
  margin-bottom: 18px;
  line-height: 1.2;
}

.hero-content p {
  font-size: 1.1rem;
  margin-bottom: 36px;
  color: rgba(255,255,255,0.85);
}

/* row of two buttons in the hero */
.hero-buttons {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 48px;
}

/* frosted glass stats bar */
.hero-stats {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0;
  background: rgba(255,255,255,0.1);
  border: 1px solid rgba(255,255,255,0.2);
  border-radius: 12px;
  padding: 16px 32px;
  backdrop-filter: blur(6px);
  flex-wrap: wrap;
}

.hero-stat {
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 0 28px;
}

.hero-stat strong {
  font-size: 1.6rem;
  font-weight: 700;
  color: #fff;
  line-height: 1;
}

.hero-stat span {
  font-size: 0.78rem;
  color: rgba(255,255,255,0.7);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-top: 4px;
}

/* thin vertical line between each stat */
.hero-stat-divider {
  width: 1px;
  height: 36px;
  background: rgba(255,255,255,0.25);
}

/* why choose us section */
.about {
  background: var(--card-bg);
  padding: 60px 0;
}

/* centered heading with accent underline */
.section-title {
  text-align: center;
  font-size: 2rem;
  color: var(--primary);
  margin-bottom: 48px;
  position: relative;
}

/* short purple line drawn under each section title */
.section-title::after {
  content: '';
  display: block;
  width: 60px;
  height: 4px;
  background: var(--accent);
  margin: 12px auto 0;
  border-radius: 2px;
}

/* 3 feature cards in a flex row */
.features {
  display: flex;
  gap: 24px;
  justify-content: center;
  flex-wrap: wrap;
}

.feature-card {
  flex: 1;
  min-width: 220px;
  max-width: 340px;
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 36px 28px;
  text-align: center;
  box-shadow: 0 2px 12px rgba(0,0,0,0.08);
  transition: all 0.3s ease;
}

.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 24px rgba(0,0,0,0.14);
}

.feature-icon {
  font-size: 2.5rem;
  margin-bottom: 16px;
}

.feature-card h3 {
  font-size: 1.15rem;
  color: var(--primary);
  margin-bottom: 10px;
}

.feature-card p {
  color: var(--text-muted);
  font-size: 0.9rem;
}

/* popular classes section */
.featured-classes {
  background: var(--bg);
  padding: 60px 0;
}

/* responsive grid for class cards */
.class-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 24px;
}

.class-card {
  background: var(--card-bg);
  border-radius: 12px;
  overflow: hidden;
  box-shadow: 0 2px 12px rgba(0,0,0,0.08);
  transition: all 0.3s ease;
}

.class-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 24px rgba(0,0,0,0.14);
}

/* image area at the top of each card */
.class-img {
  height: 200px;
  position: relative;
  overflow: hidden;
}

/* gradient overlay on card images so the tag text is readable */
.card-img-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(to bottom,
    rgba(0,0,0,0.08) 0%,
    rgba(0,0,0,0.50) 100%);
  z-index: 1;
}

/* category label in the bottom left of the image */
.card-category-tag {
  position: absolute;
  bottom: 12px;
  left: 12px;
  z-index: 2;
  background: rgba(255,255,255,0.18);
  border: 1px solid rgba(255,255,255,0.45);
  color: #fff;
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.8px;
  text-transform: uppercase;
  padding: 4px 10px;
  border-radius: 999px;
  backdrop-filter: blur(4px);
}

/* background images per class type, fallback colour if image fails to load */
.yoga-img {
  background: url('https://images.unsplash.com/photo-1544367567-0f2fcb009e0b?w=600&q=80&fit=crop') center/cover no-repeat;
  background-color: #00695C;
}

.cardio-img {
  background: url('https://images.unsplash.com/photo-1571019613454-1cb2f99b2d8b?w=600&q=80&fit=crop') center/cover no-repeat;
  background-color: #E65100;
}

.meditation-img {
  background: url('https://images.unsplash.com/photo-1506126613408-eca07ce68773?w=600&q=80&fit=crop') center/cover no-repeat;
  background-color: #4A148C;
}

.strength-img {
  background: url('https://images.unsplash.com/photo-1534438327276-14e5300c3a48?w=600&q=80&fit=crop') center/cover no-repeat;
  background-color: #B71C1C;
}

.class-body {
  padding: 20px;
}

.class-body h3 {
  font-size: 1.05rem;
  margin-bottom: 8px;
  color: var(--text-dark);
}

.class-body p {
  font-size: 0.88rem;
  color: var(--text-muted);
  margin-bottom: 16px;
}

/* footer */
.footer {
  background: var(--primary);
  color: #fff;
  text-align: center;
  padding: 24px;
  font-size: 0.9rem;
}

/* mobile styles - breakpoint at 768px */
@media (max-width: 768px) {

  /* show hamburger, hide nav links */
  .hamburger { display: block; }

  .nav-links {
    display: none;
    position: absolute;
    top: 64px; left: 0; right: 0;
    background: var(--card-bg);
    flex-direction: column;
    gap: 0;
    border-bottom: 1px solid var(--border);
    box-shadow: 0 4px 12px rgba(0,0,0,0.08);
  }

  /* nav-open class added by js to show the menu */
  .nav-links.nav-open {
    display: flex;
  }

  .nav-links li a {
    display: block;
    padding: 14px 24px;
    border-bottom: 1px solid var(--border);
  }

  /* stack feature cards vertically */
  .features { flex-direction: column; align-items: center; }

  /* single column class grid */
  .class-grid { grid-template-columns: 1fr; }

  .hero-content h1 { font-size: 2rem; }
}