/* ==================== 1. Reset & Base ==================== */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html, body {
  height: 100%;
  font-family: 'Poppins', sans-serif;
  display: flex;
  flex-direction: column;
}

/* Body & Background */
body {
  background-image: url(blurred-background-vibrant-campus-scene-600nw-2527446029.webp);
  background-size: cover;
  background-repeat: no-repeat;
  background-position: center;
  background-attachment: scroll;
}

body.light { color: #333; }
body.dark { color: #e0e0e0; }

/* ==================== 2. Navbar ==================== */
/* Navbar Container */
.nav-container {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 80px;
  display: flex;
  align-items: center;
  padding: 0 40px;
  z-index: 1000;
  transition: all 0.3s ease;
}

body.light .nav-container {
  background: #fff;
  box-shadow: 0 2px 10px rgba(0,0,0,0.08);
  border-bottom: 1px solid #eaeaea;
}

body.dark .nav-container {
  background: #222;
  box-shadow: 0 2px 10px rgba(0,0,0,0.3);
  border-bottom: 1px solid #333;
}

/* Logo / Brand */
.brand {
  font-size: 24px;
  font-weight: 800;
  background: linear-gradient(135deg, #2652c0, #1ee9c0);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-right: 40px;
}

/* Navigation Links */
.nav-links {
  display: flex;
  align-items: center;
  gap: 40px;
  margin-right: auto;
  margin-left: 30px;
}

.nav-links a {
  text-decoration: none;
  font-size: 18px;
  font-weight: 500;
  color: #4a5568;
  padding: 8px 0;
  position: relative;
  transition: color 0.3s ease;
  white-space: nowrap;
}

body.dark .nav-links a { color: #cbd5e0; }

.nav-links a:hover { color: #2652c0; }
body.dark .nav-links a:hover { color: #a3bffa; }

/* Underline Hover Effect */
.nav-links a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 3px;
  background: linear-gradient(135deg, #2652c0, #1ee9c0);
  border-radius: 2px;
  transition: width 0.3s ease;
}

.nav-links a:hover::after { width: 100%; }

/* Auth Buttons */
.auth-buttons {
  display: flex;
  align-items: center;
  gap: 20px;
  margin-left: auto;
}

.auth-buttons button {
  padding: 10px 24px;
  border-radius: 6px;
  font-weight: 600;
  font-size: 16px;
  cursor: pointer;
  transition: all 0.3s ease;
  border: none;
  white-space: nowrap;
}

#login-btn {
  background: transparent;
  color: #2652c0;
  border: 2px solid #2652c0;
}

body.dark #login-btn {
  color: #a3bffa;
  border-color: #a3bffa;
}

#login-btn:hover {
  background: rgba(38, 82, 192, 0.1);
  transform: translateY(-2px);
}

#register-btn {
  background: linear-gradient(to right, #2652c0, #1ee9c0);
  color: white;
  box-shadow: 0 4px 12px rgba(38, 82, 192, 0.3);
}

#register-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 16px rgba(38, 82, 192, 0.4);
}

/* Theme Toggle Switch */
.switch {
  font-size: 17px;
  position: relative;
  display: inline-block;
  width: 3.5em;
  height: 2em;
  margin-left: 15px;
}

.switch input { opacity: 0; width: 0; height: 0; }

.slider {
  --background: #28096b;
  position: absolute;
  cursor: pointer;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: var(--background);
  transition: 0.5s;
  border-radius: 30px;
}

.slider:before {
  position: absolute;
  content: "";
  height: 1.4em;
  width: 1.4em;
  border-radius: 50%;
  left: 10%;
  bottom: 15%;
  box-shadow: inset 8px -4px 0px 0px #fff000;
  background: var(--background);
  transition: 0.5s;
}

input:checked + .slider {
  background-color: #522ba7;
}

input:checked + .slider:before {
  transform: translateX(100%);
  box-shadow: inset 15px -4px 0px 15px #fff000;
}

/* Hamburger Menu */
.hamburger {
  display: none;
  width: 35px;
  height: 30px;

  flex-direction: column;
  justify-content: space-between;

  background: none;
  border: none;
  cursor: pointer;

  margin-left: auto; 

  z-index: 1001;
}

.hamburger span {
  display: flex;
  height: 4px;
  width: 100%;
  justify-content: space-between;
  background-color: #2652c0;
  border-radius: 2px;
  transition: all 0.3s ease;
}


.hamburger.active span:nth-child(1) { transform: rotate(45deg) translate(8px,8px); }
.hamburger.active span:nth-child(2) { opacity: 0; transform: translateX(20px); }
.hamburger.active span:nth-child(3) { transform: rotate(-45deg) translate(7px,-7px); }

/* Mobile Menu */
.mobile-menu {
  position: fixed;
  top: 0;
  right: -100%;
  width: 300px;
  height: 100vh;
  background: #fff;
  box-shadow: -5px 0 15px rgba(0,0,0,0.1);
  z-index: 999;
  transition: right 0.4s ease;
  padding: 100px 30px;
  display: flex;
  flex-direction: column;
  gap: 30px;
}

body.dark .mobile-menu {
  background: #222;
  box-shadow: -5px 0 15px rgba(0,0,0,0.3);
}

.mobile-menu.active { right: 0; }

.mobile-menu-links {
  display: flex;
  flex-direction: column;
  gap: 25px;
}

.mobile-menu-links a {
  font-size: 20px;
  font-weight: 500;
  color: #4a5568;
  text-decoration: none;
  padding: 12px 0;
  border-bottom: 1px solid #eaeaea;
  transition: color 0.3s ease;
}

body.dark .mobile-menu-links a {
  color: #cbd5e0;
  border-bottom-color: #333;
}

.mobile-menu-links a:hover { color: #2652c0; }

.mobile-auth-buttons {
  display: flex;
  flex-direction: column;
  gap: 15px;
  margin-top: 20px;
}

.mobile-auth-buttons button {
  padding: 14px;
  border-radius: 6px;
  font-weight: 600;
  font-size: 17px;
  cursor: pointer;
  transition: all 0.3s ease;
  border: none;
}

#mobile-login-btn {
  background: transparent;
  color: #2652c0;
  border: 2px solid #2652c0;
}

#mobile-register-btn {
  background: linear-gradient(135deg, #2652c0, #1ee9c0);
  color: white;
}

.logo{
  max-height: 60px;
  width: auto;       
  display: block;
  margin-right: 30px;    
}

/* ==================== 3. Hero Section ==================== */
main.hero {
  flex: 1;
  padding-top: 100px;
  display: flex;
  flex-direction: column;
  align-items: center;
  width: 100%;
  background: url('blurred-background-vibrant-campus-scene-600nw-2527446029.webp') no-repeat center center/cover;
}

.hero-content {
  text-align: center;
  max-width: 800px;
  padding: 60px 20px;
}

.hero-content h1 {
  font-size: 3.5rem;
  font-weight: 800;
  background-color: #033151;
  /*background: linear-gradient(135deg, #033151);*/
  color: #36454F;
  background-clip: text;
  margin-bottom: 1.5rem;
  line-height: 1.2;
}

.hero-content p {
  font-size: 1.2rem;
  color: whitesmoke;
  background-color: #033151;
  border-radius: 50px;
  margin-bottom: 2.5rem;
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

body.dark .hero-content p { color: #bbb; }

/* ==================== 4. Card Grid ==================== */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 20px;
  width: 90%;
  max-width: 1200px;
  margin: 40px auto;
}

.flip-card { 
  perspective: 1000px;
}

.flip-card-inner {
  position: relative;
  width: 100%;
  height: 300px;
  text-align: center;
  transition: transform 1.6s;
  transform-style: preserve-3d;
}

.flip-card:hover .flip-card-inner { 
  transform: rotateY(180deg);
}

.flip-card-front, .flip-card-back {
  position: absolute;
  width: 100%;
  height: 100%;
  backface-visibility: hidden;
  border-radius: 20px;
  padding: 20px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  box-shadow: 0 5px 20px rgba(0,0,0,0.2);
}

body.light .flip-card-front { background: white; }
body.dark .flip-card-front { background: #1e1e1e; color: white; }

.flip-card-back {
  transform: rotateY(180deg);
  color: black;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  border-radius: 20px;
  padding: 10px;
}

.flip-card-back img {
  width: 80%;
  border-radius: 15px;
  margin-bottom: 10px;
}

/* ==================== 5. Footer ==================== */
footer {
  position: relative;
  bottom: 0;
  width: 100%;
  background: linear-gradient(to right, #2652c0, #1ee9c0);
  color: white;
  padding: 40px 20px 20px;
  text-align: center;
  margin-top: auto;
}

/* ==================== 6. Responsive Design ==================== */
@media (max-width: 1024px) {
  .nav-container { padding: 0 30px; }
  .nav-links { gap: 30px; }
  .nav-links a { font-size: 17px; }
  .auth-buttons button { padding: 8px 20px; font-size: 15px; }
  .hero-content h1 { font-size: 3rem; }
}

@media (max-width: 768px) {
  .nav-container { padding: 0 20px; height: 70px; }
  .nav-links, .auth-buttons { display: none; }
  .hamburger { display: flex; }
  .brand { margin-right: auto; font-size: 22px; }
  .hero-content h1 { font-size: 2.5rem; }
  .hero-content p { font-size: 1.1rem; }
}

@media (max-width: 480px) {
  .nav-container { padding: 0 15px; }
  .mobile-menu { width: 250px; padding: 80px 20px; }
  .mobile-menu-links a { font-size: 18px; }
  .mobile-auth-buttons button { padding: 12px; font-size: 16px; }
  .hero-content h1 { font-size: 2.2rem; }
  .hero-content p { font-size: 1rem; padding: 0 10px; }
  footer { padding: 30px 15px 15px; }
  .footer-section h3 { font-size: 1.1rem; }
  .footer-section p { font-size: 0.85rem; }
}