/* Star Math Tutor - Clean Professional Styles */
:root {
  --primary: #1e3a5f;
  --primary-light: #2c5282;
  --accent: #3182ce;
  --accent-hover: #2b6cb0;
  --bg: #f7fafc;
  --white: #ffffff;
  --text: #2d3748;
  --text-light: #4a5568;
  --border: #e2e8f0;
  --success: #38a169;
  --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --radius: 8px;
}

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

body {
  font-family: 'Segoe UI', system-ui, -apple-system, BlinkMacSystemFont, sans-serif;
  line-height: 1.6;
  color: var(--text);
  background: var(--bg);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* Header & Nav */
header {
  background: var(--primary);
  color: var(--white);
  padding: 0.75rem 0;
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: var(--shadow);
}

.nav-container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 1.25rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--white);
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.logo span {
  color: #90cdf4;
}

nav ul {
  list-style: none;
  display: flex;
  gap: 1.75rem;
}

nav a {
  color: #e2e8f0;
  text-decoration: none;
  font-weight: 500;
  font-size: 0.95rem;
  transition: color 0.2s;
}

nav a:hover,
nav a.active {
  color: #90cdf4;
}

.menu-toggle {
  display: none;
  background: none;
  border: none;
  color: white;
  font-size: 1.5rem;
  cursor: pointer;
}

/* Main content */
main {
  flex: 1;
  max-width: 1100px;
  margin: 0 auto;
  padding: 2rem 1.25rem;
  width: 100%;
}

/* Hero */
.hero {
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-light) 100%);
  color: white;
  border-radius: var(--radius);
  padding: 3rem 2rem;
  text-align: center;
  margin-bottom: 2.5rem;
  box-shadow: var(--shadow);
}

.hero h1 {
  font-size: 2.25rem;
  margin-bottom: 0.75rem;
  font-weight: 700;
}

.hero p {
  font-size: 1.15rem;
  opacity: 0.95;
  max-width: 600px;
  margin: 0 auto 1.5rem;
}

.btn {
  display: inline-block;
  background: var(--accent);
  color: white;
  padding: 0.75rem 1.75rem;
  border-radius: var(--radius);
  text-decoration: none;
  font-weight: 600;
  transition: background 0.2s, transform 0.15s;
  border: none;
  cursor: pointer;
  font-size: 1rem;
}

.btn:hover {
  background: var(--accent-hover);
  transform: translateY(-1px);
}

.btn-outline {
  background: transparent;
  border: 2px solid white;
  margin-left: 0.75rem;
}

.btn-outline:hover {
  background: rgba(255,255,255,0.15);
}

.btn-secondary {
  background: var(--primary);
}

.btn-success {
  background: var(--success);
}

.btn-success:hover {
  background: #2f855a;
}

/* Cards & Grid */
.section-title {
  font-size: 1.75rem;
  color: var(--primary);
  margin-bottom: 1.25rem;
  text-align: center;
}

.cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 1.5rem;
  margin: 1.5rem 0 2.5rem;
}

.card {
  background: var(--white);
  border-radius: var(--radius);
  padding: 1.5rem;
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
  transition: transform 0.2s, box-shadow 0.2s;
}

.card:hover {
  transform: translateY(-3px);
  box-shadow: 0 10px 15px -3px rgba(0,0,0,0.1);
}

.card h3 {
  color: var(--primary);
  margin-bottom: 0.5rem;
  font-size: 1.2rem;
}

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

.card .price {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--accent);
  margin: 0.75rem 0 0.5rem;
}

/* Content pages */
.page-header {
  margin-bottom: 2rem;
  text-align: center;
}

.page-header h1 {
  color: var(--primary);
  font-size: 2rem;
  margin-bottom: 0.5rem;
}

.page-header p {
  color: var(--text-light);
  max-width: 650px;
  margin: 0 auto;
}

.content-block {
  background: var(--white);
  border-radius: var(--radius);
  padding: 1.75rem;
  box-shadow: var(--shadow);
  margin-bottom: 1.5rem;
  border: 1px solid var(--border);
}

.content-block h2 {
  color: var(--primary);
  margin-bottom: 0.75rem;
  font-size: 1.35rem;
}

.content-block ul {
  margin-left: 1.25rem;
  margin-top: 0.5rem;
}

.content-block li {
  margin-bottom: 0.4rem;
}

/* Pricing table style */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1.25rem;
}

.price-card {
  background: var(--white);
  border: 2px solid var(--border);
  border-radius: var(--radius);
  padding: 1.75rem;
  text-align: center;
  transition: border-color 0.2s;
}

.price-card.featured {
  border-color: var(--accent);
  position: relative;
}

.price-card.featured::before {
  content: "Most Popular";
  position: absolute;
  top: -12px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--accent);
  color: white;
  font-size: 0.75rem;
  padding: 0.2rem 0.75rem;
  border-radius: 20px;
  font-weight: 600;
}

.price-card h3 {
  color: var(--primary);
  margin-bottom: 0.5rem;
}

.price-card .amount {
  font-size: 2.25rem;
  font-weight: 700;
  color: var(--accent);
  margin: 0.75rem 0;
}

.price-card .amount span {
  font-size: 1rem;
  font-weight: 500;
  color: var(--text-light);
}

.price-card ul {
  list-style: none;
  margin: 1rem 0 1.5rem;
  text-align: left;
}

.price-card li {
  padding: 0.35rem 0;
  color: var(--text-light);
  font-size: 0.95rem;
}

.price-card li::before {
  content: "✓ ";
  color: var(--success);
  font-weight: bold;
}

/* Booking / Form */
.form-group {
  margin-bottom: 1.15rem;
}

.form-group label {
  display: block;
  margin-bottom: 0.35rem;
  font-weight: 500;
  color: var(--text);
}

.form-group input,
.form-group select,
.form-group textarea {
  width: 100%;
  padding: 0.7rem 0.9rem;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-size: 1rem;
  font-family: inherit;
  transition: border-color 0.2s;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(49, 130, 206, 0.15);
}

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}

.calendar-placeholder {
  background: #edf2f7;
  border: 2px dashed var(--border);
  border-radius: var(--radius);
  padding: 2.5rem 1.5rem;
  text-align: center;
  color: var(--text-light);
  margin: 1.5rem 0;
}

.calendar-placeholder strong {
  color: var(--primary);
  display: block;
  margin-bottom: 0.5rem;
}

.stripe-note {
  background: #ebf8ff;
  border-left: 4px solid var(--accent);
  padding: 1rem 1.25rem;
  margin: 1.5rem 0;
  border-radius: 0 var(--radius) var(--radius) 0;
  font-size: 0.95rem;
}

/* About */
.bio-grid {
  display: grid;
  grid-template-columns: 1fr 2fr;
  gap: 2rem;
  align-items: start;
}

.bio-photo {
  background: var(--primary);
  color: white;
  border-radius: var(--radius);
  height: 220px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 3rem;
  font-weight: 700;
}

/* Footer */
footer {
  background: var(--primary);
  color: #a0aec0;
  text-align: center;
  padding: 1.75rem 1.25rem;
  margin-top: 2rem;
  font-size: 0.9rem;
}

footer a {
  color: #90cdf4;
  text-decoration: none;
}

footer a:hover {
  text-decoration: underline;
}

/* Responsive */
@media (max-width: 768px) {
  .menu-toggle {
    display: block;
  }

  nav ul {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--primary);
    flex-direction: column;
    padding: 1rem;
    gap: 0.75rem;
    box-shadow: var(--shadow);
  }

  nav ul.open {
    display: flex;
  }

  .hero h1 {
    font-size: 1.75rem;
  }

  .hero p {
    font-size: 1rem;
  }

  .btn-outline {
    margin-left: 0;
    margin-top: 0.75rem;
    display: block;
  }

  .form-row {
    grid-template-columns: 1fr;
  }

  .bio-grid {
    grid-template-columns: 1fr;
  }

  .bio-photo {
    height: 160px;
  }
}

/* Utility */
.text-center { text-align: center; }
.mt-1 { margin-top: 1rem; }
.mb-1 { margin-bottom: 1rem; }
.mb-2 { margin-bottom: 2rem; }
.hidden { display: none; }