/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #e74c3c;
    --primary-hover: #c0392b;
    --secondary-color: #3498db;
    --success-color: #27ae60;
    --success-hover: #219a52;
    --dark-color: #2c3e50;
    --light-color: #ecf0f1;
    --gray-light: #f8f9fa;
    --gray: #ddd;
    --text-dark: #2c3e50;
    --shadow: 0 10px 30px rgba(0,0,0,0.3);
    --border-radius: 10px;
    --transition: all 0.3s ease;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    padding: 20px;
    line-height: 1.6;
    color: #333;
}

/* Container */
.container {
    max-width: 800px;
    margin: 0 auto;
    background: white;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    overflow: hidden;
}

/* Header */
.header {
    background: var(--dark-color);
    color: white;
    padding: 30px 20px;
    text-align: center;
}

.header h1 {
    font-size: clamp(1.8rem, 4vw, 2.5rem);
    margin-bottom: 10px;
    color: white;
    line-height: 1.2;
}

.header p {
    opacity: 0.8;
    font-size: clamp(1rem, 2vw, 1.1rem);
    color: var(--light-color);
}

/* Content */
.content {
    padding: 30px 20px;
}

/* Settings */
.settings {
    background: var(--gray-light);
    padding: 25px 20px;
    border-radius: 8px;
    margin-bottom: 30px;
}

.setting-group {
    margin-bottom: 25px;
}

.setting-group label {
    display: block;
    margin-bottom: 10px;
    font-weight: 600;
    color: var(--text-dark);
    font-size: 1rem;
}

.length-control {
    display: flex;
    align-items: center;
    gap: 15px;
}

.length-control input {
    flex: 1;
}

#lengthValue {
    font-weight: bold;
    color: var(--primary-color);
    min-width: 30px;
    font-size: 1.1rem;
}

/* Input Styles */
input[type="range"] {
    width: 100%;
    height: 8px;
    border-radius: 4px;
    background: var(--gray);
    outline: none;
    -webkit-appearance: none;
}

input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: var(--primary-color);
    cursor: pointer;
    transition: var(--transition);
}

input[type="range"]::-webkit-slider-thumb:hover {
    background: var(--primary-hover);
    transform: scale(1.1);
}

input[type="number"] {
    width: 80px;
    padding: 10px 12px;
    border: 2px solid var(--gray);
    border-radius: 6px;
    font-size: 16px;
    transition: var(--transition);
}

input[type="number"]:focus {
    border-color: var(--primary-color);
    outline: none;
}

/* Checkbox Groups */
.checkbox-group {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 12px;
    margin-top: 10px;
}

.checkbox-item {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 8px 0;
}

.checkbox-item input[type="checkbox"] {
    width: 20px;
    height: 20px;
    accent-color: var(--primary-color);
}

.checkbox-item label {
    margin: 0;
    font-weight: normal;
    cursor: pointer;
    user-select: none;
}

/* Buttons */
.generate-btn {
    background: var(--primary-color);
    color: white;
    border: none;
    padding: 16px 30px;
    font-size: 18px;
    border-radius: 8px;
    cursor: pointer;
    width: 100%;
    transition: var(--transition);
    font-weight: 600;
    margin-top: 10px;
}

.generate-btn:hover {
    background: var(--primary-hover);
    transform: translateY(-2px);
}

.copy-btn {
    background: var(--success-color);
    color: white;
    border: none;
    padding: 14px 25px;
    border-radius: 8px;
    cursor: pointer;
    width: 100%;
    font-size: 16px;
    transition: var(--transition);
    font-weight: 600;
}

.copy-btn:hover {
    background: var(--success-hover);
}

/* Results */
.result {
    margin-top: 30px;
}

.password-display {
    background: var(--dark-color);
    color: white;
    padding: 20px;
    border-radius: 8px;
    font-size: clamp(1.1rem, 3vw, 1.5rem);
    text-align: center;
    word-break: break-all;
    margin-bottom: 20px;
    font-family: 'Courier New', monospace;
    line-height: 1.4;
    border: 2px solid transparent;
    transition: var(--transition);
}

.password-display:hover {
    border-color: var(--primary-color);
}

/* Multiple Passwords */
.multiple-passwords {
    margin-top: 30px;
}

.multiple-passwords h3 {
    margin-bottom: 15px;
    color: var(--text-dark);
    font-size: 1.2rem;
}

.password-list {
    background: var(--gray-light);
    border-radius: 8px;
    padding: 15px;
    max-height: 300px;
    overflow-y: auto;
}

.password-item {
    padding: 12px;
    border-bottom: 1px solid var(--gray);
    font-family: 'Courier New', monospace;
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 15px;
}

.password-item:last-child {
    border-bottom: none;
}

.copy-small {
    background: var(--secondary-color);
    color: white;
    border: none;
    padding: 8px 15px;
    border-radius: 6px;
    cursor: pointer;
    font-size: 14px;
    transition: var(--transition);
    white-space: nowrap;
}

.copy-small:hover {
    opacity: 0.9;
    transform: translateY(-1px);
}

/* SEO Content */
.seo-content {
    margin-top: 40px;
    padding: 25px;
    background: var(--gray-light);
    border-radius: 8px;
}

.seo-content h2 {
    color: var(--text-dark);
    margin-bottom: 15px;
    font-size: 1.4rem;
}

.seo-content h3 {
    color: var(--text-dark);
    margin: 20px 0 15px 0;
    font-size: 1.2rem;
}

.seo-content p {
    margin-bottom: 15px;
    line-height: 1.7;
}

.seo-content ul {
    list-style: none;
    padding-left: 0;
}

.seo-content li {
    padding: 8px 0;
    font-size: 1rem;
}

/* Modal */
.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0,0,0,0.5);
    backdrop-filter: blur(5px);
}

.modal-content {
    background-color: white;
    margin: 15% auto;
    padding: 25px;
    border-radius: var(--border-radius);
    width: 90%;
    max-width: 500px;
    text-align: center;
    box-shadow: var(--shadow);
}

.modal-content h3 {
    margin-bottom: 15px;
    color: var(--text-dark);
}

.modal-content p {
    margin-bottom: 20px;
    line-height: 1.6;
}

.modal-buttons {
    display: flex;
    gap: 15px;
    justify-content: center;
    flex-wrap: wrap;
}

.btn-primary {
    background: var(--primary-color);
    color: white;
    border: none;
    padding: 12px 25px;
    border-radius: 6px;
    cursor: pointer;
    transition: var(--transition);
    font-weight: 600;
}

.btn-primary:hover {
    background: var(--primary-hover);
}

.btn-secondary {
    background: var(--gray);
    color: var(--text-dark);
    border: none;
    padding: 12px 25px;
    border-radius: 6px;
    cursor: pointer;
    transition: var(--transition);
    font-weight: 600;
}

.btn-secondary:hover {
    background: #ccc;
}

/* Mobile Optimizations */
@media (max-width: 768px) {
    body {
        padding: 10px;
    }
    
    .content {
        padding: 20px 15px;
    }
    
    .settings {
        padding: 20px 15px;
    }
    
    .checkbox-group {
        grid-template-columns: 1fr;
        gap: 8px;
    }
    
    .checkbox-item {
        padding: 6px 0;
    }
    
    .length-control {
        flex-direction: column;
        align-items: stretch;
        gap: 10px;
    }
    
    .password-item {
        flex-direction: column;
        align-items: stretch;
        gap: 10px;
        text-align: center;
    }
    
    .password-display {
        padding: 15px;
        font-size: 1.1rem;
    }
    
    .modal-content {
        margin: 10% auto;
        padding: 20px;
    }
    
    .modal-buttons {
        flex-direction: column;
    }
    
    .seo-content {
        padding: 20px;
    }
}

@media (max-width: 480px) {
    .header {
        padding: 20px 15px;
    }
    
    .content {
        padding: 15px 10px;
    }
    
    input[type="number"] {
        width: 100%;
    }
    
    .generate-btn,
    .copy-btn {
        padding: 14px 20px;
        font-size: 16px;
    }
}

/* Accessibility */
@media (prefers-reduced-motion: reduce) {
    * {
        transition: none !important;
    }
}

/* Focus styles for accessibility */
button:focus,
input:focus {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

/* Loading state */
.generate-btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none !important;
}