* {
    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;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
}

.container {
    background: rgba(255, 255, 255, 0.95);
    border-radius: 20px;
    padding: 30px;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.1);
    max-width: 600px;
    width: 100%;
    backdrop-filter: blur(10px);
}

h1 {
    text-align: center;
    color: #333;
    margin-bottom: 30px;
    font-size: 2.5em;
    font-weight: 300;
}

.timer-section {
    text-align: center;
    margin-bottom: 40px;
}

.timer-display {
    font-size: 4em;
    font-weight: bold;
    color: #667eea;
    margin-bottom: 20px;
    font-family: 'Courier New', monospace;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.1);
}

.timer-controls {
    display: flex;
    gap: 15px;
    justify-content: center;
    align-items: center;
    flex-wrap: wrap;
}

#minutesInput {
    padding: 10px 15px;
    border: 2px solid #ddd;
    border-radius: 10px;
    font-size: 16px;
    width: 100px;
    text-align: center;
}

.btn {
    padding: 12px 24px;
    border: none;
    border-radius: 10px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    text-transform: uppercase;
    letter-spacing: 1px;
}

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

.btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none;
}

.btn-primary {
    background: linear-gradient(45deg, #667eea, #764ba2);
    color: white;
}

.btn-secondary {
    background: linear-gradient(45deg, #f093fb, #f5576c);
    color: white;
}

.btn-danger {
    background: linear-gradient(45deg, #ff6b6b, #ee5a24);
    color: white;
}

.reminder-section {
    margin-bottom: 30px;
    padding: 20px;
    background: rgba(255, 255, 255, 0.5);
    border-radius: 15px;
    border: 1px solid rgba(255, 255, 255, 0.3);
}

.reminder-section h3 {
    color: #333;
    margin-bottom: 15px;
    font-size: 1.3em;
}

.checkbox-container {
    display: flex;
    align-items: center;
    cursor: pointer;
    margin-bottom: 15px;
    font-size: 16px;
    font-weight: 500;
}

.checkbox-container input {
    display: none;
}

.checkmark {
    width: 20px;
    height: 20px;
    background: #fff;
    border: 2px solid #ddd;
    border-radius: 4px;
    margin-right: 10px;
    position: relative;
    transition: all 0.3s ease;
}

.checkbox-container input:checked + .checkmark {
    background: #667eea;
    border-color: #667eea;
}

.checkbox-container input:checked + .checkmark::after {
    content: '✓';
    position: absolute;
    color: white;
    font-size: 14px;
    top: -2px;
    left: 3px;
}

.time-options {
    margin-top: 15px;
    opacity: 0.5;
    transition: opacity 0.3s ease;
}

.time-options.enabled {
    opacity: 1;
}

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

.radio-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    color: #555;
}

.radio-options {
    display: flex;
    gap: 15px;
    flex-wrap: wrap;
}

.radio-container {
    display: flex;
    align-items: center;
    cursor: pointer;
    font-size: 14px;
    font-weight: normal !important;
}

.radio-container input {
    display: none;
}

.radio-mark {
    width: 16px;
    height: 16px;
    border: 2px solid #ddd;
    border-radius: 50%;
    margin-right: 8px;
    position: relative;
    transition: all 0.3s ease;
}

.radio-container input:checked + .radio-mark {
    border-color: #667eea;
    background: #667eea;
}

.radio-container input:checked + .radio-mark::after {
    content: '';
    position: absolute;
    width: 6px;
    height: 6px;
    background: white;
    border-radius: 50%;
    top: 3px;
    left: 3px;
}

.status-section {
    text-align: center;
    padding: 15px;
    background: rgba(102, 126, 234, 0.1);
    border-radius: 10px;
    border-left: 4px solid #667eea;
}

#statusDisplay {
    font-size: 16px;
    color: #333;
    font-weight: 500;
}

@media (max-width: 768px) {
    .container {
        padding: 20px;
        margin: 10px;
    }
    
    .timer-display {
        font-size: 3em;
    }
    
    .timer-controls {
        flex-direction: column;
    }
    
    .radio-options {
        flex-direction: column;
        gap: 10px;
    }
}