:root {
  --primary: #0A3D91;
  --primary-light: rgba(10, 61, 145, 0.1);
  --primary-hover: #082d6b;
  --accent: #4DA3FF;
  --accent-hover: #318bf0;
  --white: #ffffff;
  --bg-light: #f8fafc;
  --text-main: #334155;
  --text-muted: #64748b;
  --font-main: 'Poppins', sans-serif;
}

body {
  font-family: var(--font-main);
  color: var(--text-main);
  overflow-x: hidden;
  scroll-behavior: auto; /* Handled by JS for smooth scroll */
}

/* Loader */
.loader-overlay {
  position: fixed;
  top: 0; left: 0; width: 100%; height: 100%;
  background: var(--white);
  z-index: 9999;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: opacity 0.5s ease;
}
.loader-overlay.fade-out {
  opacity: 0;
  pointer-events: none;
}
.spinner {
  width: 50px; height: 50px;
  border: 4px solid var(--primary-light);
  border-top-color: var(--accent);
  border-radius: 50%;
  animation: spin 1s linear infinite;
}

/* Utilities */
.text-primary-custom { color: var(--primary) !important; }
.bg-primary-custom { background-color: var(--primary) !important; }
.bg-primary-light { background-color: var(--primary-light) !important; }
.text-accent { color: var(--accent) !important; }
.bg-accent { background-color: var(--accent) !important; }
.section-bg-light { background-color: var(--bg-light); }
.max-w-700 { max-width: 700px; }
.min-h-300 { min-height: 300px; }

/* Buttons */
.btn-primary-custom {
  background-color: var(--primary);
  color: var(--white);
  border: none;
}
.btn-primary-custom:hover {
  background-color: var(--primary-hover);
  color: var(--white);
}
.btn-accent {
  background-color: var(--accent);
  color: var(--white);
  border: none;
}
.btn-accent:hover {
  background-color: var(--accent-hover);
  color: var(--white);
}
.hover-lift {
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}
.hover-lift:hover {
  transform: translateY(-5px);
  box-shadow: 0 10px 25px rgba(0,0,0,0.1) !important;
}

/* Navbar */
.navbar {
  transition: all 0.3s ease;
  padding: 1.5rem 0;
  background: transparent;
}
.navbar.scrolled {
  background: var(--white);
  padding: 0.8rem 0;
  box-shadow: 0 4px 20px rgba(0,0,0,0.05);
}
.nav-link {
  font-weight: 500;
  color: rgba(255,255,255,0.9);
  transition: color 0.3s ease;
  position: relative;
}
.nav-link::after {
  content: '';
  position: absolute;
  bottom: 0; left: 50%;
  width: 0; height: 2px;
  background: var(--accent);
  transition: all 0.3s ease;
  transform: translateX(-50%);
}
.nav-link:hover { color: var(--white); }
.nav-link:hover::after,
.nav-link.active::after {
  width: 80%;
}
.navbar.scrolled .nav-link {
  color: var(--text-main);
}
.navbar.scrolled .nav-link:hover,
.navbar.scrolled .nav-link.active {
  color: var(--primary);
}
.navbar.scrolled .navbar-brand span { color: var(--primary) !important; }
.navbar:not(.scrolled) .navbar-brand span { color: var(--white) !important; }

/* Hero Overlay */
.hero-overlay {
  background: linear-gradient(135deg, rgba(10, 61, 145, 0.9) 0%, rgba(10, 61, 145, 0.8) 100%);
  z-index: 1;
}
.hero-content {
  text-shadow: 0 2px 10px rgba(0,0,0,0.2);
}

/* --- IMAGE PLACEHOLDER SPECS --- */
.img-placeholder-wrapper {
  position: relative;
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
  background-color: rgba(255, 255, 255, 0.85);
  background-image: 
    radial-gradient(rgba(10, 61, 145, 0.1) 2px, transparent 2px),
    linear-gradient(135deg, rgba(240, 244, 248, 0.6) 0%, rgba(226, 232, 240, 0.6) 100%);
  background-size: 20px 20px, 100% 100%;
  border-radius: 12px;
  border: 1px solid rgba(10, 61, 145, 0.15);
  box-shadow: 0 4px 20px rgba(0,0,0,0.08);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  transition: transform 0.4s ease, box-shadow 0.4s ease;
}

/* Light effect / Shine */
.img-placeholder-wrapper::before {
  content: '';
  position: absolute;
  top: 0; left: -100%;
  width: 50%; height: 100%;
  background: linear-gradient(to right, rgba(255,255,255,0) 0%, rgba(255,255,255,0.7) 50%, rgba(255,255,255,0) 100%);
  transform: skewX(-25deg);
  z-index: 5;
  pointer-events: none;
}

/* Hover States for Placeholder */
.img-placeholder-wrapper:hover {
  transform: scale(1.03) rotate(0.5deg);
  box-shadow: 0 10px 30px rgba(10, 61, 145, 0.15);
}
.img-placeholder-wrapper:hover::before {
  animation: shine 0.75s ease-in-out;
}

@keyframes shine {
  100% { left: 200%; }
}

.placeholder-content {
  position: relative;
  z-index: 2;
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.5rem;
  color: var(--primary);
  padding: 1rem;
}
.placeholder-content i {
  font-size: 2.5rem;
  opacity: 0.4;
}
.placeholder-content span {
  font-weight: 500;
}
.placeholder-content small {
  opacity: 0.7;
}

.placeholder-img {
  position: absolute;
  top: 0; left: 0;
  width: 100%; height: 100%;
  object-fit: cover;
  z-index: 3;
  transition: transform 0.5s ease;
}
.placeholder-img[src=""] {
  display: none !important;
}

/* Apply specific border-radius overrides */
#hero .img-placeholder-wrapper { border-radius: 0; }
.rounded-circle.img-placeholder-wrapper { border-radius: 50% !important; }

/* Global CSS3 Animations */
@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(40px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-6px); }
}

@keyframes pulseGlow {
  0%, 100% { box-shadow: 0 4px 20px rgba(10, 61, 145, 0.08); }
  50% { box-shadow: 0 4px 30px rgba(77, 163, 255, 0.35); }
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

/* Animation Classes applied via JS */
.fade-element {
  opacity: 0;
}
.fade-element.visible {
  animation: fadeInUp 0.8s cubic-bezier(0.2, 0.8, 0.2, 1) forwards;
}

/* Combine float and pulse glow for the placeholder wrapper inner elements or specific wrappers */
.placeholder-float-wrapper {
  animation: float 3s ease-in-out infinite;
  height: 100%;
}
.pulse-glow-effect {
  animation: pulseGlow 4s ease-in-out infinite;
}

/* Feature Course */
.feature-course-card {
  transition: all 0.4s ease;
}
.feature-course-card:hover {
  transform: translateY(-10px);
  box-shadow: 0 20px 40px rgba(10, 61, 145, 0.15) !important;
}
.image-frame-enhanced {
  min-height: 360px;
}
.image-frame-enhanced .img-placeholder-wrapper {
  min-height: 360px;
  border-radius: 0;
}
@media (max-width: 767.8px) {
  .image-frame-enhanced {
    min-height: 280px;
  }
  .image-frame-enhanced .img-placeholder-wrapper {
    min-height: 280px;
    border-radius: 0;
  }
}
.course-content {
  background: var(--white);
}
.course-bg-glow {
  position: absolute;
  top: -50px; right: -50px;
  width: 150px; height: 150px;
  background: radial-gradient(circle, rgba(77, 163, 255, 0.15) 0%, transparent 70%);
  border-radius: 50%;
  z-index: 0;
  pointer-events: none;
}

/* Gallery */
.gallery-item {
  cursor: pointer;
}
.gallery-overlay {
  position: absolute;
  top: 0; left: 0; right: 0; bottom: 0;
  background: linear-gradient(to top, rgba(10, 61, 145, 0.9), transparent);
  z-index: 4;
  display: flex;
  align-items: flex-end;
  padding: 1.5rem;
  opacity: 0;
  transition: opacity 0.3s ease;
}
.gallery-item:hover .gallery-overlay {
  opacity: 1;
}
.gallery-item:hover .placeholder-img {
  transform: scale(1.1);
}

/* Accordion Custom */
.custom-accordion .accordion-button:not(.collapsed) {
  background-color: var(--primary-light);
  color: var(--primary);
  box-shadow: none;
}
.custom-accordion .accordion-button:focus {
  box-shadow: none;
  border-color: rgba(0,0,0,0.1);
}

/* Tilt Card */
.tilt-card {
  transition: transform 0.1s ease-out;
  transform-style: preserve-3d;
  will-change: transform;
}

/* Floating & Top Buttons */
.floating-cta {
  position: fixed;
  bottom: 30px;
  right: 30px;
  background-color: var(--accent);
  color: var(--white);
  padding: 14px 28px;
  border-radius: 50px;
  font-weight: 600;
  font-size: 1.1rem;
  z-index: 1000;
  display: flex;
  align-items: center;
  gap: 8px;
  opacity: 0;
  transform: translateY(20px);
  pointer-events: none;
  transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
  animation: cta-pulse 3s infinite;
  box-shadow: 0 4px 15px rgba(77, 163, 255, 0.4);
}
.floating-cta.visible {
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
}
.floating-cta:hover {
  color: var(--white);
  transform: scale(1.05) translateY(-5px) !important;
  box-shadow: 0 15px 25px rgba(77, 163, 255, 0.5) !important;
  animation: none;
}

@keyframes cta-pulse {
  0% { box-shadow: 0 0 0 0 rgba(77, 163, 255, 0.7); }
  70% { box-shadow: 0 0 0 15px rgba(77, 163, 255, 0); }
  100% { box-shadow: 0 0 0 0 rgba(77, 163, 255, 0); }
}

.back-to-top {
  position: fixed;
  bottom: 90px;
  right: 30px;
  width: 45px;
  height: 45px;
  background-color: var(--primary);
  color: var(--white);
  border: none;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 999;
  opacity: 0;
  transform: translateY(20px);
  pointer-events: none;
  transition: all 0.3s ease;
  box-shadow: 0 4px 15px rgba(10, 61, 145, 0.3);
}
.back-to-top.visible {
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
}
.back-to-top:hover {
  background-color: var(--primary-hover);
  transform: translateY(-5px);
}

/* Media Queries */
@media (max-width: 991px) {
  .navbar { background: var(--white); padding: 0.8rem 0; box-shadow: 0 4px 20px rgba(0,0,0,0.05); }
  .navbar .nav-link { color: var(--text-main); }
  .navbar .navbar-brand span { color: var(--primary) !important; }
  .navbar-toggler { border: none; }
  .navbar-toggler:focus { box-shadow: none; }
  .navbar-collapse { padding: 1rem 0; }
  .hero-section { text-align: center; }
  .hero-section .d-flex { justify-content: center; }
}

@media (max-width: 768px) {
  .display-3 { font-size: 2.5rem; }
  .floating-cta { bottom: 20px; right: 20px; font-size: 1rem; padding: 10px 20px; }
  .back-to-top { bottom: 80px; right: 20px; }
}