/* ========== CSS Reset & Variables ========== */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --primary: #2563eb;
  --primary-dark: #1d4ed8;
  --secondary: #7c3aed;
  --accent: #059669;
  --accent-square: #006aff; /* Square brand blue */
  --bg: #f8fafc;
  --surface: #ffffff;
  --text: #1e293b;
  --text-muted: #64748b;
  --border: #e2e8f0;
  --shadow: 0 4px 6px -1px rgba(0,0,0,.1), 0 2px 4px -1px rgba(0,0,0,.06);
  --shadow-lg: 0 10px 15px -3px rgba(0,0,0,.1), 0 4px 6px -2px rgba(0,0,0,.05);
  --radius: 12px;
  --font: 'Segoe UI', system-ui, -apple-system, sans-serif;
}

/* ========== Base ========== */
html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
}

/* ========== Navigation ========== */
header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  box-shadow: var(--shadow);
}

nav {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.nav-brand {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--primary);
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.nav-brand svg {
  flex-shrink: 0;
}

.nav-links {
  list-style: none;
  display: flex;
  gap: 0.25rem;
}

.nav-links a {
  display: block;
  padding: 0.5rem 1rem;
  color: var(--text-muted);
  text-decoration: none;
  border-radius: 8px;
  font-size: 0.95rem;
  font-weight: 500;
  transition: background 0.15s, color 0.15s;
}

.nav-links a:hover,
.nav-links a.active {
  background: #eff6ff;
  color: var(--primary);
}

.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.5rem;
  color: var(--text);
}

/* ========== Hero ========== */
.hero {
  background: linear-gradient(135deg, #1e3a8a 0%, #2563eb 50%, #7c3aed 100%);
  color: #fff;
  padding: 5rem 1.5rem 4rem;
  text-align: center;
}

.hero h1 {
  font-size: clamp(2rem, 5vw, 3.5rem);
  font-weight: 800;
  margin-bottom: 1rem;
  line-height: 1.2;
}

.hero p {
  font-size: clamp(1rem, 2.5vw, 1.25rem);
  opacity: 0.9;
  max-width: 600px;
  margin: 0 auto 2.5rem;
}

.hero-buttons {
  display: flex;
  gap: 1rem;
  justify-content: center;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.75rem 1.75rem;
  border-radius: 8px;
  font-size: 1rem;
  font-weight: 600;
  text-decoration: none;
  border: none;
  cursor: pointer;
  transition: transform 0.15s, box-shadow 0.15s, opacity 0.15s;
}

.btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 20px rgba(0,0,0,.25);
}

.btn:active {
  transform: translateY(0);
}

.btn-white {
  background: #fff;
  color: var(--primary);
}

.btn-outline-white {
  background: transparent;
  color: #fff;
  border: 2px solid rgba(255,255,255,0.7);
}

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

.btn-primary {
  background: var(--primary);
  color: #fff;
}

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

.btn-secondary {
  background: var(--secondary);
  color: #fff;
}

.btn-accent {
  background: var(--accent);
  color: #fff;
}

.btn-square {
  background: var(--accent-square);
  color: #fff;
}

/* ========== Sections ========== */
.section {
  padding: 5rem 1.5rem;
  max-width: 1100px;
  margin: 0 auto;
}

.section-header {
  text-align: center;
  margin-bottom: 3rem;
}

.section-tag {
  display: inline-block;
  padding: 0.3rem 1rem;
  border-radius: 999px;
  font-size: 0.8rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 0.75rem;
}

.tag-tutoring {
  background: #eff6ff;
  color: var(--primary);
}

.tag-square {
  background: #eff6ff;
  color: var(--accent-square);
}

.tag-meeting {
  background: #f0fdf4;
  color: var(--accent);
}

.section-header h2 {
  font-size: clamp(1.6rem, 4vw, 2.4rem);
  font-weight: 800;
  margin-bottom: 0.75rem;
  color: var(--text);
}

.section-header p {
  color: var(--text-muted);
  font-size: 1.05rem;
  max-width: 560px;
  margin: 0 auto;
}

/* ========== Cards ========== */
.cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.5rem;
  margin-bottom: 3rem;
}

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.75rem;
  box-shadow: var(--shadow);
  transition: box-shadow 0.2s, transform 0.2s;
}

.card:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-3px);
}

.card-icon {
  width: 52px;
  height: 52px;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1.25rem;
  font-size: 1.6rem;
}

.icon-blue   { background: #eff6ff; }
.icon-purple { background: #f5f3ff; }
.icon-green  { background: #f0fdf4; }
.icon-orange { background: #fff7ed; }

.card h3 {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
}

.card p {
  color: var(--text-muted);
  font-size: 0.95rem;
  margin-bottom: 1.25rem;
}

.card-price {
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--primary);
  margin-bottom: 1rem;
}

.card-price span {
  font-size: 0.9rem;
  font-weight: 400;
  color: var(--text-muted);
}

/* ========== Forms ========== */
.form-container {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 2.5rem;
  box-shadow: var(--shadow);
  max-width: 700px;
  margin: 0 auto;
}

.form-container h3 {
  font-size: 1.3rem;
  font-weight: 700;
  margin-bottom: 0.4rem;
}

.form-container .form-subtitle {
  color: var(--text-muted);
  font-size: 0.95rem;
  margin-bottom: 2rem;
}

.form-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.25rem;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.form-group.full-width {
  grid-column: 1 / -1;
}

.form-group label {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text);
}

.form-group input,
.form-group select,
.form-group textarea {
  padding: 0.65rem 0.9rem;
  border: 1.5px solid var(--border);
  border-radius: 8px;
  font-size: 0.95rem;
  font-family: var(--font);
  color: var(--text);
  background: var(--bg);
  transition: border-color 0.15s, box-shadow 0.15s;
  outline: none;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(37,99,235,.12);
}

.form-group textarea {
  resize: vertical;
  min-height: 100px;
}

.form-actions {
  display: flex;
  justify-content: flex-end;
  gap: 1rem;
  margin-top: 1.75rem;
}

/* ========== Success alert ========== */
.alert {
  display: none;
  align-items: center;
  gap: 0.75rem;
  padding: 1rem 1.25rem;
  border-radius: 8px;
  margin-top: 1.25rem;
  font-weight: 500;
}

.alert.show {
  display: flex;
}

.alert-success {
  background: #f0fdf4;
  color: #15803d;
  border: 1px solid #bbf7d0;
}

.alert-error {
  background: #fef2f2;
  color: #b91c1c;
  border: 1px solid #fecaca;
}

/* ========== Square section ========== */
.square-embed-wrapper {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
  max-width: 800px;
  margin: 0 auto;
}

.square-embed-placeholder {
  padding: 3rem 2rem;
  text-align: center;
  background: linear-gradient(135deg, #f0f4ff 0%, #e8eeff 100%);
}

.square-embed-placeholder .square-logo {
  width: 120px;
  margin-bottom: 1.25rem;
}

.square-embed-placeholder h3 {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
}

.square-embed-placeholder p {
  color: var(--text-muted);
  margin-bottom: 1.75rem;
  max-width: 420px;
  margin-left: auto;
  margin-right: auto;
}

.square-steps {
  display: flex;
  gap: 1.5rem;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 2rem;
  text-align: left;
}

.square-step {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1rem 1.25rem;
  width: 200px;
  font-size: 0.88rem;
}

.square-step strong {
  display: block;
  font-size: 0.75rem;
  color: var(--accent-square);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin-bottom: 0.25rem;
}

/* ========== Divider ========== */
.section-divider {
  border: none;
  border-top: 1px solid var(--border);
  max-width: 1100px;
  margin: 0 auto;
}

/* ========== Footer ========== */
footer {
  background: #0f172a;
  color: #94a3b8;
  padding: 3rem 1.5rem;
  text-align: center;
  margin-top: 4rem;
}

footer .footer-brand {
  font-size: 1.2rem;
  font-weight: 700;
  color: #fff;
  margin-bottom: 0.5rem;
}

footer p {
  font-size: 0.9rem;
}

footer a {
  color: #60a5fa;
  text-decoration: none;
}

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

/* ========== Slot Picker ========== */
.slot-picker {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-top: 0.5rem;
}

.slot-btn {
  padding: 0.5rem 1rem;
  border: 1.5px solid var(--border);
  border-radius: 8px;
  background: var(--bg);
  color: var(--text);
  font-size: 0.88rem;
  font-weight: 500;
  cursor: pointer;
  transition: border-color 0.15s, background 0.15s, color 0.15s;
  font-family: var(--font);
}

.slot-btn:hover {
  border-color: var(--primary);
  background: #eff6ff;
  color: var(--primary);
}

.slot-btn.selected {
  border-color: var(--primary);
  background: var(--primary);
  color: #fff;
}

.slot-empty {
  color: var(--text-muted);
  font-size: 0.92rem;
  padding: 0.5rem 0;
}

/* ========== Responsive ========== */
@media (max-width: 768px) {
  .nav-links {
    display: none;
    flex-direction: column;
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    background: var(--surface);
    border-bottom: 1px solid var(--border);
    padding: 0.75rem 1rem;
    box-shadow: var(--shadow);
  }

  .nav-links.open {
    display: flex;
  }

  .nav-toggle {
    display: flex;
  }

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

  .form-group.full-width {
    grid-column: auto;
  }

  .form-actions {
    flex-direction: column-reverse;
  }

  .form-container {
    padding: 1.5rem;
  }
}

@media (max-width: 480px) {
  .hero {
    padding: 3rem 1rem 2.5rem;
  }

  .section {
    padding: 3rem 1rem;
  }
}