/* ─── M2 Tennis Academy — Custom Styles ──────────────────────────────────── */

/* ── Fonts ── */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800;900&display=swap');

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: 'Inter', 'Roboto', 'Noto Sans TC', system-ui, sans-serif;
}

/* ── Navbar scroll state ── */
#navbar {
  background: transparent;
}

#navbar.scrolled {
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid rgba(0, 0, 0, 0.06);
  box-shadow: 0 1px 24px rgba(0, 0, 0, 0.06);
}

/* ── Hamburger animation ── */
#menu-btn.open .hamburger-line:nth-child(1) {
  transform: translateY(8px) rotate(45deg);
}
#menu-btn.open .hamburger-line:nth-child(2) {
  opacity: 0;
  transform: scaleX(0);
}
#menu-btn.open .hamburger-line:nth-child(3) {
  transform: translateY(-8px) rotate(-45deg);
  width: 1.5rem;
}

/* ── Mobile menu slide ── */
#mobile-menu {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.35s cubic-bezier(0.4, 0, 0.2, 1),
              opacity 0.3s ease;
  opacity: 0;
}

#mobile-menu.open {
  max-height: 400px;
  opacity: 1;
}

/* ── Section fade-in on scroll ── */
.fade-in {
  opacity: 0;
  transform: translateY(28px);
  transition: opacity 0.7s cubic-bezier(0.4, 0, 0.2, 1),
              transform 0.7s cubic-bezier(0.4, 0, 0.2, 1);
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

/* Stagger delay helpers */
.fade-in-d1 { transition-delay: 0.1s; }
.fade-in-d2 { transition-delay: 0.2s; }
.fade-in-d3 { transition-delay: 0.3s; }
.fade-in-d4 { transition-delay: 0.4s; }

/* ── Course card subtle glow on hover ── */
.course-card:hover {
  box-shadow: 0 25px 50px -12px rgba(191, 215, 0, 0.18),
              0 10px 25px -8px rgba(0, 0, 0, 0.1);
}

/* ── Select arrow ── */
select {
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 24 24' fill='none' stroke='%239ca3af' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='6 9 12 15 18 9'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 1rem center;
  padding-right: 2.5rem;
}

/* ── Scrollbar ── */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: #f1f5f9; }
::-webkit-scrollbar-thumb { background: #d1d5db; border-radius: 999px; }
::-webkit-scrollbar-thumb:hover { background: #DFFF00; }

/* ── Focus visible ── */
:focus-visible {
  outline: 2px solid #DFFF00;
  outline-offset: 2px;
}

/* ── Tennis green text utility (fallback for older Tailwind CDN) ── */
.text-tennis { color: #DFFF00; }
.bg-tennis   { background-color: #DFFF00; }
.border-tennis { border-color: #DFFF00; }
.ring-tennis   { --tw-ring-color: #DFFF00; }