/* ROOT WARNA & DEPTH */
:root {
  --primary: #0d6efd;
  --secondary: #4da3ff;
  --dark: #0047eb;
  --bg: #f8fafc;
  --glass: rgba(255, 255, 255, 0.75);
  --shadow-3d: 0 20px 40px rgba(0, 0, 0, 0.1), 0 10px 10px rgba(0, 0, 0, 0.05);
  --inner-light: inset 0 1px 1px rgba(255, 255, 255, 0.4);
}

/* GLOBAL */
body {
  font-family: 'Segoe UI', Roboto, sans-serif;
  background-color: var(--bg);
  margin: 0;
  color: var(--dark);
  overflow-x: hidden;
}

/* NAVBAR (MODERN GLASSMORPHISM) */
.main-navbar {
  backdrop-filter: blur(15px) saturate(180%);
  -webkit-backdrop-filter: blur(15px) saturate(180%);
  background-color: var(--glass);
  border-bottom: 1px solid rgba(255, 255, 255, 0.3);
  position: sticky;
  top: 0;
  z-index: 1000;
}

.logo {
  height: 45px;
  transition: 0.5s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

.logo:hover {
  transform: scale(1.1) rotate(-3deg);
}

.nav-link {
  font-weight: 600;
  color: var(--dark) !important;
  transition: 0.3s;
}

.nav-link:hover {
  color: var(--primary) !important;
  transform: translateY(-2px);
}

/* HERO SECTION (RESPONSIVE & SMOOTH) */
.hero-section {
  width: 100%;
  overflow: hidden;
  position: relative;
  background: var(--dark);
  /* Lengkungan halus di desktop */
  border-bottom-left-radius: 50% 30px;
  border-bottom-right-radius: 50% 30px;
}

.hero-section img {
  width: 100%;
  height: 65vh; /* Tinggi ideal desktop */
  object-fit: cover;
  object-position: center;
  display: block;
  filter: brightness(0.85);
  transition: transform 1s ease;
}

.hero-section:hover img {
  transform: scale(1.08);
}

/* BUTTON 3D (FLOATING EFFECT) */
.booking-section {
  margin-top: -35px; 
  position: relative;
  z-index: 20;
  padding-bottom: 60px;
  text-align: center;
}

.booking-section .btn {
  padding: 16px 45px;
  font-size: 18px;
  font-weight: 700;
  border-radius: 50px;
  border: none;
  background: linear-gradient(145deg, var(--primary), var(--secondary));
  color: white;
  box-shadow: 0 15px 35px rgba(13, 110, 253, 0.4), var(--inner-light);
  transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
  text-transform: uppercase;
  letter-spacing: 1px;
}

.booking-section .btn:hover {
  transform: translateY(-8px) scale(1.05);
  box-shadow: 0 25px 50px rgba(13, 110, 253, 0.5);
}

.booking-section .btn:active {
  transform: translateY(2px);
}

/* SECTION TITLES */
.section-title {
  color: var(--dark);
  font-weight: 800;
  font-size: 2.5rem;
  letter-spacing: -1px;
}

.section-title span {
  color: var(--primary);
}

/* CARD 3D (LIFT-UP ANIMATION) */
.feature-card, .cert-card {
  background: white;
  border-radius: 25px;
  padding: 40px 30px;
  border: 1px solid rgba(0,0,0,0.03);
  box-shadow: 0 10px 30px rgba(0,0,0,0.05);
  transition: all 0.5s cubic-bezier(0.165, 0.84, 0.44, 1);
  height: 100%;
}

.feature-card:hover, .cert-card:hover {
  transform: translateY(-15px) rotateX(4deg) rotateY(2deg);
  box-shadow: 0 40px 80px rgba(0, 0, 0, 0.1);
}

.cert-card img {
  width: 65px;
  height: 65px;
  margin-bottom: 20px;
  background: linear-gradient(135deg, #e7f1ff, #ffffff);
  padding: 15px;
  border-radius: 18px;
  box-shadow: 0 8px 15px rgba(13, 110, 253, 0.1);
  transition: 0.4s;
}

.cert-card:hover img {
  transform: scale(1.1) translateZ(20px);
  background: var(--primary);
  filter: brightness(0) invert(1);
}

/* PAYMENT LOGOS */
.payment-logo {
  width: 85px;
  margin: 15px;
  filter: grayscale(100%);
  opacity: 0.5;
  transition: 0.4s;
}

.payment-logo:hover {
  filter: grayscale(0%);
  opacity: 1;
  transform: scale(1.15) translateY(-5px);
}

/* CTA SECTION (3D GRADIENT) */
.cta-section {
  background: radial-gradient(circle at top left, var(--secondary), var(--primary));
  color: white;
  padding: 80px 0;
  border-radius: 60px 60px 0 0;
  margin-top: 40px;
}

.cta-section .btn {
  background: white;
  color: var(--primary);
  font-weight: bold;
  padding: 14px 35px;
  border-radius: 50px;
  box-shadow: 0 10px 20px rgba(0,0,0,0.15);
}

/* FOOTER */
.footer {
  background: var(--dark);
  color: rgba(255,255,255,0.6);
  padding: 40px 20px;
  text-align: center;
  font-size: 14px;
}

/* MOBILE RESPONSIVE FIXES */
@media (max-width: 768px) {
  .hero-section {
    border-bottom-left-radius: 0;
    border-bottom-right-radius: 0;
  }

  .hero-section img {
    height: auto;
    aspect-ratio: 16/10; /* Menjaga foto proporsional tidak terpotong */
    min-height: 250px;
  }

  .booking-section {
    margin-top: -25px;
  }

  .booking-section .btn {
    width: 85%;
    font-size: 16px;
    padding: 14px 20px;
  }

  .section-title {
    font-size: 1.8rem;
  }
}