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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    padding: 20px;
}

.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;
}

header p {
    font-size: 1.2rem;
    opacity: 0.9;
}

.card {
    background: rgba(255, 255, 255, 0.95);
    border-radius: 15px;
    padding: 25px;
    margin-bottom: 25px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
    backdrop-filter: blur(10px);
}

.card h2 {
    color: #333;
    margin-bottom: 20px;
    display: flex;
    align-items: center;
    gap: 10px;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.form-group label {
    font-weight: 600;
    color: #555;
}

.form-group input {
    padding: 12px 15px;
    border: 2px solid #ddd;
    border-radius: 8px;
    font-size: 16px;
    transition: border-color 0.3s;
}

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

.btn-primary, .btn-secondary, .btn-danger {
    padding: 12px 20px;
    border: none;
    border-radius: 8px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
}

.btn-primary {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
}

.btn-secondary {
    background: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    color: white;
}

.btn-danger {
    background: linear-gradient(135deg, #ff6b6b 0%, #ee5a24 100%);
    color: white;
    padding: 15px 30px;
    font-size: 18px;
}

.btn-primary:hover, .btn-secondary:hover, .btn-danger:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
}

.status-container {
    text-align: center;
}

.timer-display {
    font-size: 3rem;
    font-weight: 700;
    color: #333;
    margin: 20px 0;
    font-family: 'Courier New', monospace;
}

.progress-bar {
    width: 100%;
    height: 20px;
    background-color: #eee;
    border-radius: 10px;
    overflow: hidden;
    margin: 20px 0;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, #4facfe 0%, #00f2fe 100%);
    width: 0%;
    transition: width 0.5s ease;
}

.controls {
    text-align: center;
}

.hint {
    color: #666;
    margin-top: 15px;
    font-style: italic;
}

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

.notification {
    position: fixed;
    top: 20px;
    right: 20px;
    padding: 15px 25px;
    border-radius: 8px;
    color: white;
    font-weight: 600;
    transform: translateX(400px);
    transition: transform 0.3s ease;
    z-index: 1000;
}

.notification.show {
    transform: translateX(0);
}

.notification.success {
    background: linear-gradient(135deg, #56ab2f 0%, #a8e6cf 100%);
}

.notification.error {
    background: linear-gradient(135deg, #ff416c 0%, #ff4b2b 100%);
}

@media (max-width: 768px) {
    .container {
        padding: 10px;
    }
    
    header h1 {
        font-size: 2rem;
    }
    
    .card {
        padding: 20px;
    }
    
    .timer-display {
        font-size: 2rem;
    }
}