/* Sutucon Design System & Main Stylesheet */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800&display=swap');

:root {
  --primary: #FF6B00;
  --primary-hover: #E05E00;
  --primary-light: #FFE0CC;
  --bg-page: #F8FAFC;
  --bg-sidebar: #FFFFFF;
  --bg-surface: #FFFFFF;
  --text-main: #0F172A;
  --text-muted: #64748B;
  --border-color: #E2E8F0;
  --success: #10B981;
  --success-bg: #D1FAE5;
  --error: #EF4444;
  --error-bg: #FEE2E2;
  --warning: #F59E0B;
  --warning-bg: #FEF3C7;
  
  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.05);
  --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.08), 0 2px 4px -1px rgba(0,0,0,0.04);
  --shadow-lg: 0 10px 15px -3px rgba(0,0,0,0.06), 0 4px 6px -2px rgba(0,0,0,0.03);
  --transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
  --radius-lg: 16px;
  --radius-md: 12px;
  --radius-pill: 9999px;
}

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

body {
  font-family: var(--font-family);
  background-color: var(--bg-page);
  color: var(--text-main);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  min-height: 100vh;
}

/* App Layout */
.app-container {
  display: flex;
  min-height: 100vh;
}

/* Sidebar Styling */
.sidebar {
  width: 280px;
  background-color: var(--bg-sidebar);
  border-right: 1px solid var(--border-color);
  padding: 2rem 1.5rem;
  display: flex;
  flex-direction: column;
  position: fixed;
  height: 100vh;
  left: 0;
  top: 0;
  z-index: 100;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 2.5rem;
}

.brand-icon {
  width: 40px;
  height: 40px;
  background-color: var(--primary);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-weight: 800;
  font-size: 1.25rem;
}

.brand-name {
  font-weight: 800;
  font-size: 1.25rem;
  letter-spacing: 0.05em;
  color: var(--text-main);
}

.nav-menu {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  flex-grow: 1;
}

.nav-item {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.85rem 1rem;
  border-radius: var(--radius-md);
  color: var(--text-muted);
  text-decoration: none;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
}

.nav-item:hover, .nav-item.active {
  background-color: var(--primary-light);
  color: var(--primary);
}

.user-progress-widget {
  margin-top: auto;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1rem;
  background-color: var(--bg-page);
}

.streak-counter {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 0.5rem;
}

.streak-fire {
  font-size: 1.25rem;
  animation: pulse 1.5s infinite;
}

.xp-counter {
  font-size: 0.85rem;
  color: var(--text-muted);
  font-weight: 600;
}

/* Main Content Area */
.main-content {
  flex-grow: 1;
  margin-left: 280px;
  padding: 2.5rem;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* Dashboard Styles */
.dashboard-header {
  margin-bottom: 2rem;
}

.dashboard-title {
  font-size: 2rem;
  font-weight: 800;
  margin-bottom: 0.5rem;
  color: var(--text-main);
}

.dashboard-subtitle {
  color: var(--text-muted);
  font-size: 1.1rem;
}

/* Learning Path Map */
.learning-path {
  display: flex;
  flex-direction: column;
  gap: 2.5rem;
  max-width: 900px;
  margin: 0 auto;
  width: 100%;
}

.module-card {
  background-color: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  box-shadow: var(--shadow-sm);
}

.module-info {
  margin-bottom: 1.5rem;
  border-bottom: 2px solid var(--bg-page);
  padding-bottom: 1rem;
}

.module-tag {
  background-color: var(--primary-light);
  color: var(--primary);
  padding: 0.25rem 0.75rem;
  border-radius: var(--radius-pill);
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  display: inline-block;
  margin-bottom: 0.5rem;
}

.module-title {
  font-size: 1.5rem;
  font-weight: 800;
}

.units-grid {
  display: flex;
  flex-direction: column;
  gap: 2rem;
}

.unit-container {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.unit-title {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.challenges-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 1rem;
}

.challenge-card {
  background-color: var(--bg-surface);
  border: 2px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.25rem;
  cursor: pointer;
  transition: var(--transition);
  position: relative;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  min-height: 150px;
}

.challenge-card:hover {
  border-color: var(--primary);
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
}

.challenge-card.completed {
  border-color: var(--success);
  background-color: rgba(16, 185, 129, 0.02);
}

.challenge-card.completed::after {
  content: '✓';
  position: absolute;
  top: 10px;
  right: 12px;
  color: var(--success);
  font-weight: 800;
  font-size: 1.1rem;
}

.challenge-name {
  font-weight: 700;
  font-size: 1.1rem;
  margin-bottom: 0.35rem;
}

.challenge-desc {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 1rem;
  flex-grow: 1;
}

.challenge-status {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.8rem;
  font-weight: 600;
}

.stars-container {
  color: #FBBF24; /* Vàng kim */
  display: flex;
  gap: 2px;
}

.btn-start {
  background-color: var(--primary);
  color: white;
  border: none;
  padding: 0.5rem 1rem;
  border-radius: var(--radius-pill);
  font-weight: 700;
  font-size: 0.8rem;
  cursor: pointer;
  transition: var(--transition);
  align-self: flex-start;
}

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

.challenge-card.completed .btn-start {
  background-color: var(--success);
}

/* Animations */
@keyframes pulse {
  0% { transform: scale(1); }
  50% { transform: scale(1.08); }
  100% { transform: scale(1); }
}

/* Responsive design */
@media (max-width: 768px) {
  .sidebar {
    display: none; /* In production, we'd build a burger menu, but for MVP keep it simple */
  }
  .main-content {
    margin-left: 0;
    padding: 1.5rem;
  }
  .challenges-grid {
    grid-template-columns: 1fr;
  }
}