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

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  min-height: 100vh;
  padding: 20px;
  display: flex;
  justify-content: center;
  align-items: center;
}

.container {
  width: 100%;
  max-width: 800px;
  background: rgba(255, 255, 255, 0.95);
  border-radius: 20px;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
  overflow: hidden;
  animation: slideIn 0.5s ease-out;
}

@keyframes slideIn {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.header {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  padding: 30px;
  text-align: center;
  color: white;
}

.header h1 {
  font-size: 2.5em;
  font-weight: 700;
  margin-bottom: 5px;
}

.header p {
  opacity: 0.9;
  font-size: 1.1em;
}

.content {
  padding: 30px;
}

.auth-section {
  max-width: 400px;
  margin: 0 auto;
}

.auth-section h2 {
  color: #333;
  margin-bottom: 20px;
  font-size: 1.5em;
  text-align: center;
}

.form-group {
  margin-bottom: 15px;
}

.form-group label {
  display: block;
  margin-bottom: 5px;
  color: #555;
  font-weight: 500;
}

input, select {
  width: 100%;
  padding: 12px 15px;
  border: 2px solid #e0e0e0;
  border-radius: 10px;
  font-size: 1em;
  transition: all 0.3s ease;
  background: white;
}

input:focus, select:focus {
  outline: none;
  border-color: #667eea;
  box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

button {
  width: 100%;
  padding: 12px;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  border: none;
  border-radius: 10px;
  font-size: 1em;
  font-weight: 600;
  cursor: pointer;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
  margin-top: 10px;
}

button:hover {
  transform: translateY(-2px);
  box-shadow: 0 5px 15px rgba(102, 126, 234, 0.4);
}

button:active {
  transform: translateY(0);
}

.secondary-btn {
  background: white;
  color: #667eea;
  border: 2px solid #667eea;
  margin-top: 10px;
}

.secondary-btn:hover {
  background: #f5f7ff;
}

.task-section {
  animation: fadeIn 0.5s ease-out;
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

.user-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 25px;
  padding-bottom: 15px;
  border-bottom: 2px solid #e0e0e0;
}

.user-info {
  color: #333;
  font-weight: 600;
}

.logout-btn {
  width: auto;
  padding: 8px 20px;
  background: #ff6b6b;
  font-size: 0.9em;
  margin-top: 0;
}

.logout-btn:hover {
  background: #ee5a5a;
}

.section-title {
  margin-bottom: 15px;
  color: #333;
}

.input-group {
  display: grid;
  grid-template-columns: 1fr auto auto auto;
  gap: 10px;
  margin-bottom: 20px;
}

.input-group input {
  margin: 0;
}

.input-group select {
  width: 150px;
}

.input-group button {
  width: auto;
  padding: 0 25px;
  margin: 0;
}

.stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 15px;
  margin-bottom: 25px;
}

.stat-card {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  padding: 20px;
  border-radius: 10px;
  text-align: center;
}

.stat-card h3 {
  font-size: 2em;
  margin-bottom: 5px;
}

.stat-card p {
  opacity: 0.9;
  font-size: 0.9em;
}

ul {
  list-style: none;
}

li {
  background: white;
  border: 2px solid #e0e0e0;
  margin-bottom: 10px;
  padding: 15px;
  border-radius: 10px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  transition: all 0.3s ease;
  cursor: pointer;
}

li:hover {
  border-color: #667eea;
  transform: translateX(5px);
}

li.completed {
  opacity: 0.6;
  background: #f5f5f5;
}

li.completed .task-info strong {
  text-decoration: line-through;
}

.task-info {
  flex-grow: 1;
}

.task-info strong {
  color: #333;
  font-size: 1.1em;
  display: block;
  margin-bottom: 5px;
}

.task-meta {
  display: flex;
  gap: 15px;
  font-size: 0.9em;
  color: #666;
}

.category-badge {
  display: inline-block;
  padding: 3px 10px;
  border-radius: 20px;
  font-size: 0.85em;
  font-weight: 600;
}

.category-work { background: #ffeaa7; color: #d63031; }
.category-personal { background: #dfe6e9; color: #2d3436; }
.category-study { background: #a29bfe; color: #6c5ce7; }

.delete-btn {
  background: #ff6b6b;
  color: white;
  border: none;
  border-radius: 8px;
  padding: 8px 15px;
  cursor: pointer;
  font-size: 0.9em;
  font-weight: 600;
  transition: all 0.2s ease;
  width: auto;
  margin: 0;
}

.delete-btn:hover {
  background: #ee5a5a;
  transform: scale(1.05);
}

.hidden {
  display: none;
}

.divider {
  text-align: center;
  margin: 20px 0;
  color: #999;
}

.empty-state {
  text-align: center;
  padding: 40px;
  color: #999;
}

.empty-state span {
  font-size: 3em;
  display: block;
  margin-bottom: 10px;
}

@media (max-width: 768px) {
  .input-group {
    grid-template-columns: 1fr;
  }

  .input-group select {
    width: 100%;
  }

  .stats {
    grid-template-columns: 1fr;
  }

  .header h1 {
    font-size: 2em;
  }
}