* {
    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);
    backdrop-filter: blur(10px);
    border-radius: 20px;
    padding: 40px;
    width: 100%;
    max-width: 500px;
    box-shadow: 0 15px 35px rgba(0, 0, 0, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
}

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

.header h1 {
    color: #2d3748;
    font-size: 2.2rem;
    font-weight: 700;
    margin-bottom: 8px;
}

.header p {
    color: #718096;
    font-size: 1rem;
}

.password-display {
    position: relative;
    margin-bottom: 30px;
}

.password-output {
    width: 100%;
    padding: 16px 50px 16px 16px;
    border: 2px solid #e2e8f0;
    border-radius: 12px;
    font-size: 1.1rem;
    font-family: "Courier New", monospace;
    background: #f7fafc;
    color: #2d3748;
    outline: none;
    transition: border-color 0.3s ease;
}

.password-output:focus {
    border-color: #667eea;
}

.copy-btn {
    position: absolute;
    right: 8px;
    top: 50%;
    transform: translateY(-50%);
    background: #667eea;
    color: white;
    border: none;
    padding: 8px 12px;
    border-radius: 8px;
    cursor: pointer;
    font-size: 0.9rem;
    transition: background-color 0.3s ease;
}

.copy-btn:hover {
    background: #5a67d8;
}

.options {
    margin-bottom: 30px;
}

.option-group {
    margin-bottom: 20px;
}

.length-control {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 20px;
}

.length-control label {
    font-weight: 600;
    color: #2d3748;
    font-size: 1rem;
}

.length-input {
    display: flex;
    align-items: center;
    gap: 10px;
}

.length-slider {
    width: 150px;
    height: 6px;
    border-radius: 5px;
    background: #e2e8f0;
    outline: none;
    -webkit-appearance: none;
}

.length-slider::-webkit-slider-thumb {
    appearance: none;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: #667eea;
    cursor: pointer;
}

.length-value {
    background: #667eea;
    color: white;
    padding: 4px 12px;
    border-radius: 8px;
    font-weight: 600;
    min-width: 40px;
    text-align: center;
}

.checkbox-group {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 15px;
}

.checkbox-item {
    display: flex;
    align-items: center;
    gap: 10px;
}

.checkbox-item input[type="checkbox"] {
    width: 18px;
    height: 18px;
    accent-color: #667eea;
    cursor: pointer;
}

.checkbox-item label {
    color: #2d3748;
    font-weight: 500;
    cursor: pointer;
}

.generate-btn {
    width: 100%;
    padding: 16px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border: none;
    border-radius: 12px;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.generate-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(102, 126, 234, 0.4);
}

.generate-btn:active {
    transform: translateY(0);
}

.strength-indicator {
    margin-top: 15px;
    padding: 12px;
    border-radius: 8px;
    text-align: center;
    font-weight: 600;
    display: none;
}

.strength-weak {
    background: #fed7d7;
    color: #c53030;
}

.strength-medium {
    background: #faf089;
    color: #d69e2e;
}

.strength-strong {
    background: #c6f6d5;
    color: #38a169;
}

@media (max-width: 480px) {
    .container {
        padding: 30px 20px;
    }

    .header h1 {
        font-size: 1.8rem;
    }

    .checkbox-group {
        grid-template-columns: 1fr;
    }
}