:root {
  --bg-primary: #0a0a0a;
  --bg-secondary: #1a1a1a;
  --bg-card: #1f1f23;
  --bg-card-hover: #2a2a2f;
  --text-primary: #ffffff;
  --text-secondary: #b3b3b3;
  --text-muted: #888888;
  --border: #333333;
  --border-hover: #444444;
  --accent: #007aff;
  --accent-hover: #0056cc;
  --shadow: rgba(0, 0, 0, 0.3);
  --shadow-hover: rgba(0, 0, 0, 0.5);
}

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

body {
  background: linear-gradient(135deg, var(--bg-primary) 0%, var(--bg-secondary) 100%);
  color: var(--text-primary);
  font: 16px/1.6 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
}

.container {
  max-width: 900px;
  width: 100%;
  margin: 0 auto;
}

header {
  text-align: center;
  margin-bottom: 48px;
  padding: 0 20px;
}

h1 {
  font-size: clamp(32px, 5vw, 48px);
  font-weight: 700;
  margin-bottom: 12px;
  background: linear-gradient(135deg, var(--text-primary) 0%, var(--text-secondary) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.subtitle {
  font-size: 18px;
  color: var(--text-muted);
  font-weight: 400;
}

.assessment-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 24px;
  padding: 0 20px;
}

.assessment-card {
  display: block;
  text-decoration: none;
  color: inherit;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 20px;
  padding: 32px 28px;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  position: relative;
  overflow: hidden;
}

.assessment-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--accent) 0%, var(--accent-hover) 100%);
  transform: scaleX(0);
  transition: transform 0.3s ease;
}

.assessment-card:hover {
  background: var(--bg-card-hover);
  border-color: var(--border-hover);
  transform: translateY(-4px);
  box-shadow: 0 12px 40px var(--shadow-hover);
}

.assessment-card:hover::before {
  transform: scaleX(1);
}

.assessment-card:active {
  transform: translateY(-2px);
}

.card-number {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  background: var(--accent);
  color: white;
  border-radius: 12px;
  font-weight: 700;
  font-size: 18px;
  margin-bottom: 20px;
}

.card-title {
  font-size: 22px;
  font-weight: 600;
  margin-bottom: 12px;
  color: var(--text-primary);
  line-height: 1.3;
}

.card-description {
  color: var(--text-secondary);
  font-size: 15px;
  line-height: 1.5;
}

.duration {
  display: inline-block;
  background: var(--bg-secondary);
  color: var(--text-muted);
  padding: 6px 12px;
  border-radius: 8px;
  font-size: 13px;
  font-weight: 500;
  margin-top: 16px;
}

@media (max-width: 768px) {
  .container {
    padding: 0;
  }

  header {
    margin-bottom: 32px;
  }

  .assessment-grid {
    grid-template-columns: 1fr;
    gap: 20px;
    padding: 0 16px;
  }

  .assessment-card {
    padding: 24px 20px;
  }

  h1 {
    font-size: 36px;
  }

  .subtitle {
    font-size: 16px;
  }
}

@media (max-width: 480px) {
  body {
    padding: 16px;
  }

  .assessment-grid {
    padding: 0 8px;
  }
}

/* Smooth scrolling and focus styles */
html {
  scroll-behavior: smooth;
}

.assessment-card:focus {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

/* Loading animation */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.assessment-card {
  animation: fadeInUp 0.6s ease forwards;
}

.assessment-card:nth-child(1) { animation-delay: 0.1s; }
.assessment-card:nth-child(2) { animation-delay: 0.2s; }
.assessment-card:nth-child(3) { animation-delay: 0.3s; }