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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    padding: 20px;
    color: #333;
}

.container {
    max-width: 800px;
    margin: 0 auto;
}

header {
    text-align: center;
    color: white;
    margin-bottom: 30px;
}

header h1 {
    font-size: 2.5rem;
    margin-bottom: 10px;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.2);
}

.subtitle {
    font-size: 1rem;
    opacity: 0.9;
}

.card {
    background: white;
    border-radius: 12px;
    padding: 25px;
    margin-bottom: 25px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.2);
}

.card h2 {
    margin-bottom: 20px;
    color: #667eea;
    font-size: 1.5rem;
}

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

.input {
    width: 100%;
    padding: 12px 15px;
    border: 2px solid #e0e0e0;
    border-radius: 8px;
    font-size: 1rem;
    transition: all 0.3s;
}

.input:focus {
    outline: none;
    border-color: #667eea;
}

textarea.input {
    resize: vertical;
    font-family: inherit;
}

.btn {
    padding: 12px 24px;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s;
    text-decoration: none;
    display: inline-block;
}

.btn-primary {
    background: #667eea;
    color: white;
    width: 100%;
}

.btn-primary:hover {
    background: #5568d3;
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(102, 126, 234, 0.4);
}

.btn-sm {
    padding: 8px 16px;
    font-size: 0.875rem;
}

.btn-success {
    background: #10b981;
    color: white;
}

.btn-success:hover {
    background: #059669;
}

.btn-secondary {
    background: #6b7280;
    color: white;
}

.btn-secondary:hover {
    background: #4b5563;
}

.btn-danger {
    background: #ef4444;
    color: white;
}

.btn-danger:hover {
    background: #dc2626;
}

.tasks {
    background: white;
    border-radius: 12px;
    padding: 25px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.2);
}

.tasks h2 {
    margin-bottom: 20px;
    color: #667eea;
    font-size: 1.5rem;
}

.task-item {
    background: #f9fafb;
    border-radius: 8px;
    padding: 15px;
    margin-bottom: 15px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 15px;
    transition: all 0.3s;
}

.task-item:hover {
    transform: translateX(5px);
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
}

.task-item.completed {
    opacity: 0.6;
}

.task-item.completed h3 {
    text-decoration: line-through;
    color: #6b7280;
}

.task-content {
    flex: 1;
}

.task-content h3 {
    font-size: 1.1rem;
    margin-bottom: 5px;
    color: #1f2937;
}

.task-content p {
    color: #6b7280;
    font-size: 0.9rem;
    margin-bottom: 8px;
}

.task-date {
    font-size: 0.75rem;
    color: #9ca3af;
}

.task-actions {
    display: flex;
    gap: 8px;
    flex-shrink: 0;
}

.empty-state {
    text-align: center;
    padding: 40px;
    color: #6b7280;
}

.empty-state p {
    margin-bottom: 10px;
}

.text-muted {
    font-size: 0.9rem;
    opacity: 0.7;
}

.alert {
    padding: 15px;
    border-radius: 8px;
    margin-bottom: 20px;
    font-weight: 500;
}

.alert-success {
    background: #d1fae5;
    color: #065f46;
    border-left: 4px solid #10b981;
}

.alert-error {
    background: #fee2e2;
    color: #991b1b;
    border-left: 4px solid #ef4444;
}

footer {
    text-align: center;
    color: white;
    margin-top: 30px;
    padding: 20px;
    opacity: 0.8;
}

@media (max-width: 640px) {
    .task-item {
        flex-direction: column;
        align-items: flex-start;
    }
    
    .task-actions {
        width: 100%;
        justify-content: flex-end;
    }
    
    header h1 {
        font-size: 2rem;
    }
}