:root {
  --primary: #0B6EF3;
  --primary-hover: #0958c5;
  --accent: #00B894;
  --accent-hover: #00a181;
  --bg-page: #F5F7FB;
  --text-main: #111827;
  --text-muted: #6B7280;
  --white: #ffffff;
  --border: #E5E7EB;
  --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
}

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

body {
  font-family: 'Inter', system-ui, -apple-system, sans-serif;
  background-color: var(--bg-page);
  color: var(--text-main);
  line-height: 1.6;
}

h1, h2, h3, h4, h5, h6 {
  font-family: 'Poppins', sans-serif;
  font-weight: 600;
  color: var(--text-main);
  margin-bottom: 0.75rem;
}

a {
  text-decoration: none;
  color: inherit;
}

/* Utilities */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

.btn {
  display: inline-block;
  padding: 0.75rem 1.5rem;
  border-radius: 8px;
  font-weight: 500;
  transition: all 0.2s;
  cursor: pointer;
  border: none;
  font-family: 'Inter', sans-serif;
}

.btn-primary {
  background-color: var(--primary);
  color: var(--white);
}

.btn-primary:hover {
  background-color: var(--primary-hover);
}

.btn-accent {
  background-color: var(--accent);
  color: var(--white);
}

.btn-accent:hover {
  background-color: var(--accent-hover);
}

.btn-outline {
  background-color: transparent;
  border: 1px solid var(--border);
  color: var(--text-main);
}

.btn-outline:hover {
  border-color: var(--primary);
  color: var(--primary);
}

.text-center { text-align: center; }
.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mt-4 { margin-top: 2rem; }
.mb-4 { margin-bottom: 2rem; }

/* Layout */
header {
  background: var(--white);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
}

nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 70px;
}

.logo {
  font-family: 'Poppins', sans-serif;
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--primary);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

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

.nav-links a {
  font-weight: 500;
  color: var(--text-muted);
  transition: color 0.2s;
}

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

.auth-buttons {
  display: flex;
  gap: 1rem;
}

footer {
  background: var(--white);
  padding: 4rem 0;
  margin-top: 4rem;
  border-top: 1px solid var(--border);
}

.footer-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 2rem;
}

.footer-col h4 {
  margin-bottom: 1rem;
}

.footer-links {
  list-style: none;
}

.footer-links li {
  margin-bottom: 0.5rem;
}

.footer-links a {
  color: var(--text-muted);
}

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

/* Components */
.card {
  background: var(--white);
  border-radius: 12px;
  padding: 1.5rem;
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
  transition: transform 0.2s;
}

.card:hover {
  transform: translateY(-4px);
}

.hero {
  padding: 5rem 0;
  background: linear-gradient(135deg, #eff6ff 0%, #F5F7FB 100%);
  position: relative;
  overflow: hidden;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4rem;
  align-items: center;
}

.hero-img {
  width: 100%;
  border-radius: 16px;
  box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
  margin-top: 3rem;
}

.feature-icon {
  width: 48px;
  height: 48px;
  background: #EBF5FF;
  color: var(--primary);
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1rem;
  font-size: 1.5rem;
}

/* Form Styles */
.form-group {
  margin-bottom: 1.5rem;
}

label {
  display: block;
  margin-bottom: 0.5rem;
  font-weight: 500;
}

input, textarea, select {
  width: 100%;
  padding: 0.75rem;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-family: 'Inter', sans-serif;
  font-size: 1rem;
  transition: border-color 0.2s;
}

input:focus, textarea:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(11, 110, 243, 0.1);
}

/* Dashboard Styles */
.dashboard-grid {
  display: grid;
  grid-template-columns: 280px 1fr;
  gap: 2rem;
  margin-top: 2rem;
}

.sidebar {
  background: var(--white);
  border-radius: 12px;
  padding: 1.5rem;
  height: fit-content;
}

.sidebar-nav {
  list-style: none;
}

.sidebar-nav li {
  margin-bottom: 0.5rem;
}

.sidebar-nav a {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.75rem;
  border-radius: 8px;
  color: var(--text-muted);
  font-weight: 500;
}

.sidebar-nav a:hover, .sidebar-nav a.active {
  background: #F3F4F6;
  color: var(--primary);
}

.stat-card {
  background: var(--white);
  padding: 1.5rem;
  border-radius: 12px;
  display: flex;
  align-items: center;
  gap: 1.5rem;
  border: 1px solid var(--border);
}

.stat-value {
  font-size: 2rem;
  font-weight: 700;
  color: var(--text-main);
}

.progress-bar {
  width: 100%;
  height: 8px;
  background: #E5E7EB;
  border-radius: 4px;
  overflow: hidden;
  margin-top: 0.5rem;
}

.progress-fill {
  height: 100%;
  background: var(--accent);
  border-radius: 4px;
}

/* Quiz Styles */
.quiz-container {
  background: var(--white);
  border-radius: 16px;
  padding: 2rem;
  max-width: 800px;
  margin: 0 auto;
  box-shadow: var(--shadow);
}

.quiz-option {
  display: block;
  padding: 1rem;
  border: 2px solid var(--border);
  border-radius: 8px;
  margin-bottom: 1rem;
  cursor: pointer;
  transition: all 0.2s;
}

.quiz-option:hover {
  border-color: var(--primary);
  background: #F8FAFC;
}

.quiz-option.selected {
  border-color: var(--primary);
  background: #eff6ff;
}

.quiz-option.correct {
  border-color: var(--accent);
  background: #ecfdf5;
}

.quiz-option.wrong {
  border-color: #ef4444;
  background: #fef2f2;
}

@media (max-width: 768px) {
  .hero-grid, .dashboard-grid {
    grid-template-columns: 1fr;
  }
  
  .nav-links {
    display: none;
  }
  
  .hero-img {
    order: -1;
  }
}