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

:root {
    --primary-color: #667eea;
    --text-primary: #2d3748;
    --text-secondary: rgba(0, 0, 0, 0.6);
    --bg-secondary: #ffffff;
    --gradient-1: linear-gradient(150deg, #667eea 0%, #764ba2 200%);
    --border-color: #e2e8f0;
}

body {
    font-family: 'Segoe', sans-serif;
    background: var(--gradient-1);
    color: var(--text-primary);
}

.container {
    max-width: 800px;
    margin: 20px auto;
    background: var(--bg-secondary);
    border-radius: 20px;
}

header {
    padding: 30px;
    text-align: center;
    color: white;
    background: var(--gradient-1);
}

.stats {
    display: flex;
    justify-content: space-around;
    padding: 12px;
}

.stat {
    background: white;
    padding: 10px;
    border-radius: 10px;
    text-align: center;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
    transition: all 0.4s ease;
}

.stat:hover {
    transform: translateY(-2px);
}

.stat-number {
    font-size: 1.8em;
    font-weight: bold;
    color: var(--primary-color);
    display: block;
}

.stat-label {
    font-size: 0.9em;
    color: var(--text-secondary);
    margin-top: 5px;
}

.btn-primary {
    background: var(--gradient-1);
    color: white;
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.3);
    border: none;
    padding: 12px;
    border-radius: 12px;
    font-size: 1.1rem;
    width: 200px;
}

.input-section {
    padding: 12px;
}

.input-container {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

input,
select,
textarea {
    width: 100%;
    padding: 12px 15px;
    border: 2px solid var(--border-color);
    border-radius: 10px;
}

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

.filters {
    display: flex;
    gap: 10px;
    align-items: center;
    margin-bottom: 15px;
}

.filter-btn {
    padding: 8px 12px;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    background: #e2e8f0;
    color: var(--text-primary);
}

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

.search-box {
    flex: 1;
}

#todo-container {
    min-height: 200px;
}

.empty-state {
    text-align: center;
    color: var(--text-secondary);
    padding: 40px;
}