/* General Reset with Enhanced Variables */
:root {
  --primary-color: #2563eb;   /* was #cc0000 */
  --primary-light: #4f86ff;   /* was #ff3333 */
  --primary-dark: #1e40af;    /* was #990000 */
  --text-light: #ffffff;
  --text-dark: #2c3e50;       /* was #333333 */
  --shadow-light: rgba(0, 0, 0, 0.1);
  --shadow-medium: rgba(0, 0, 0, 0.2);
  --shadow-dark: rgba(0, 0, 0, 0.3);
  --transition-fast: 0.2s ease;
  --transition-medium: 0.3s ease;
  --transition-slow: 0.5s ease;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: 'Segoe UI', 'Roboto', 'Helvetica Neue', sans-serif;
  background: linear-gradient(135deg, #f7f9fc 0%, #eff4ff 100%); /* was #f5f7fa -> #e4e8ed */
  color: var(--text-dark);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  line-height: 1.6;
}

/* Enhanced Header */
header {
  background: rgba(255, 255, 255, 0.98);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  padding: 1.2rem 2.5rem;
  position: sticky;
  top: 0;
  z-index: 1000;
  border-bottom: 1px solid rgba(0, 0, 0, 0.08);
  box-shadow: 0 4px 12px var(--shadow-light);
  display: flex;
  justify-content: space-between;
  align-items: center;
  transition: all var(--transition-medium);
}

header:hover {
  box-shadow: 0 6px 16px var(--shadow-medium);
}

.logo-text {
  font-size: 1.8rem;
  font-weight: 700;
  color: var(--primary-color);
  letter-spacing: -0.5px;
  text-shadow: 0 2px 4px var(--shadow-light);
  transition: all var(--transition-medium);
}

.nav-links {
  display: flex;
  gap: 2rem;
  list-style: none;
}

.nav-links a {
  color: var(--primary-color);
  text-decoration: none;
  font-weight: 600;
  font-size: 1.1rem;
  padding: 0.5rem 0;
  position: relative;
  transition: all var(--transition-fast);
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background-color: var(--primary-light);
  transition: width var(--transition-medium);
}

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

.nav-links a:hover {
  color: var(--primary-light);
}

/* Main Content Enhancements */
main {
  flex: 1;
  padding: 3rem 2rem;
  max-width: 1200px;
  margin: 0 auto;
  width: 100%;
}

.container {
  width: 100%;
  padding: 0 1.5rem;
}

.section-title {
  font-size: 2.2rem;
  margin-bottom: 1.5rem;
  color: var(--primary-dark);
  position: relative;
  display: inline-block;
}

.section-title::after {
  content: '';
  position: absolute;
  bottom: -8px;
  left: 0;
  width: 60px;
  height: 4px;
  background: linear-gradient(90deg, var(--primary-light), var(--primary-dark));
  border-radius: 2px;
}

/* Vertical Grade Grid Layout */
.grade-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
  gap: 1.8rem;
  margin-top: 2.5rem;
}

/* Enhanced Grade Card Styling */
.grade-card {
  background: linear-gradient(135deg, var(--primary-light), var(--primary-dark));
  color: var(--text-light);
  padding: 2rem 1.5rem;
  border-radius: 20px;
  text-align: center;
  cursor: pointer;
  font-weight: 600;
  font-size: 1.25rem;
  transition: all var(--transition-medium);
  box-shadow: 0 8px 20px rgba(37, 99, 235, 0.20); /* was rgba(204,0,0,0.2) */
  position: relative;
  overflow: hidden;
  border: none;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: 180px;
}

.grade-card h4 {
  font-size: 1.4rem;
  margin-bottom: 0.5rem;
  position: relative;
  z-index: 2;
}

.grade-card p {
  font-size: 0.9rem;
  opacity: 0.9;
  position: relative;
  z-index: 2;
}

.grade-card::before {
  content: "";
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: radial-gradient(circle, rgba(255, 255, 255, 0.3) 0%, transparent 70%);
  opacity: 0;
  transition: opacity var(--transition-medium);
}

.grade-card::after {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(135deg, 
    rgba(255, 255, 255, 0.1) 0%, 
    rgba(255, 255, 255, 0) 50%, 
    rgba(0, 0, 0, 0.05) 100%);
  border-radius: 20px;
}

.grade-card:hover::before {
  opacity: 1;
}

.grade-card:hover {
  transform: translateY(-8px) scale(1.03);
  box-shadow: 0 15px 30px rgba(37, 99, 235, 0.30); /* was rgba(204,0,0,0.3) */
}

/* Back Button Styling */
.back-button {
  background: var(--primary-color);
  color: white;
  border: none;
  padding: 0.8rem 1.5rem;
  border-radius: 50px;
  font-weight: 600;
  cursor: pointer;
  margin-bottom: 2rem;
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  transition: all var(--transition-medium);
  box-shadow: 0 4px 12px rgba(37, 99, 235, 0.20); /* was rgba(204,0,0,0.2) */
}

.back-button:hover {
  background: var(--primary-light);
  transform: translateY(-2px);
  box-shadow: 0 6px 16px rgba(37, 99, 235, 0.30); /* was rgba(204,0,0,0.3) */
}

/* Animations */
@keyframes pulse {
  0%   { box-shadow: 0 0 0 0 rgba(79, 134, 255, 0.70); } /* was red */
  70%  { box-shadow: 0 0 0 20px rgba(79, 134, 255, 0); }
  100% { box-shadow: 0 0 0 0 rgba(79, 134, 255, 0); }
}

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50%      { transform: translateY(-10px); }
}

.grade-card:hover {
  animation: pulse 1.5s infinite, float 3s ease-in-out infinite;
}

/* Floating Elements */
.floating-element {
  position: fixed;
  font-size: 2rem;
  opacity: 0.1;
  animation: float 6s ease-in-out infinite;
  z-index: -1;
}

.floating-element:nth-child(1) {
  top: 20%;
  left: 10%;
  animation-delay: 0s;
}

.floating-element:nth-child(2) {
  top: 60%;
  left: 80%;
  animation-delay: 1s;
}

.floating-element:nth-child(3) {
  top: 30%;
  left: 70%;
  animation-delay: 2s;
}

/* Footer Enhancements */
footer {
  background: var(--primary-dark);
  color: var(--text-light);
  text-align: center;
  padding: 2rem 0;
  margin-top: 4rem;
  font-size: 0.95rem;
  box-shadow: 0 -4px 12px var(--shadow-light);
}

.footer-content {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 2rem;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 2rem;
  text-align: left;
}

.footer-section h4 {
  font-size: 1.2rem;
  margin-bottom: 1rem;
  color: rgba(255, 255, 255, 0.9);
}

.footer-section p, .footer-section a {
  color: rgba(255, 255, 255, 0.75); /* slightly brighter */
  margin-bottom: 0.5rem;
  display: block;
  transition: all var(--transition-fast);
}

.footer-section a:hover {
  color: #ffffff;
  transform: translateX(5px);
}

/* Responsive Design */
@media (max-width: 768px) {
  header {
    padding: 1rem 1.5rem;
    flex-direction: column;
    gap: 1rem;
  }
  
  .nav-links {
    gap: 1.5rem;
  }
  
  .grade-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 1.2rem;
  }
  
  .grade-card {
    padding: 1.8rem 1rem;
    min-height: 150px;
  }
  
  .section-title {
    font-size: 1.8rem;
  }
}

@media (max-width: 480px) {
  .grade-grid {
    grid-template-columns: 1fr;
  }
  
  .grade-card {
    min-height: 120px;
    padding: 1.5rem 1rem;
  }
  
  .footer-content {
    grid-template-columns: 1fr;
    text-align: center;
  }
}