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

:root {
    --primary-color: #4f46e5;
    --primary-hover: #4338ca;
    --secondary-color: #64748b;
    --background: #f8fafc;
    --card-background: #ffffff;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --border-color: #e2e8f0;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --danger-color: #ef4444;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Helvetica', 'Arial', sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
    padding: 20px;
}

.container {
    max-width: 700px;
    margin: 0 auto;
}

header {
    text-align: center;
    margin-bottom: 40px;
    color: white;
}

header h1 {
    font-size: 3rem;
    font-weight: 800;
    margin-bottom: 10px;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.2);
}

.subtitle {
    font-size: 1.2rem;
    opacity: 0.95;
    font-weight: 400;
}

main {
    background: var(--card-background);
    border-radius: 20px;
    padding: 40px;
    box-shadow: var(--shadow-lg);
    margin-bottom: 30px;
}

.password-display {
    display: flex;
    gap: 10px;
    margin-bottom: 30px;
}

#password-output {
    flex: 1;
    padding: 18px 20px;
    font-size: 1.1rem;
    font-family: 'Monaco', 'Menlo', 'Courier New', monospace;
    border: 2px solid var(--border-color);
    border-radius: 12px;
    background: var(--background);
    color: var(--text-primary);
    transition: all 0.3s ease;
}

#password-output:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.1);
}

.icon-btn {
    padding: 18px;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 12px;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
}

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

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

.controls {
    margin-bottom: 30px;
}

.quick-actions {
    display: flex;
    gap: 10px;
    margin-bottom: 30px;
    flex-wrap: wrap;
}

.btn {
    padding: 14px 24px;
    font-size: 1rem;
    font-weight: 600;
    border: none;
    border-radius: 12px;
    cursor: pointer;
    transition: all 0.3s ease;
    flex: 1;
    min-width: 150px;
}

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

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

.btn-secondary {
    background: var(--background);
    color: var(--text-primary);
    border: 2px solid var(--border-color);
}

.btn-secondary:hover {
    background: var(--border-color);
    transform: translateY(-2px);
}

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

.slider-group label {
    display: flex;
    justify-content: space-between;
    margin-bottom: 10px;
    font-weight: 600;
    color: var(--text-primary);
}

.slider-group .value {
    color: var(--primary-color);
    font-weight: 700;
    min-width: 30px;
    text-align: right;
}

input[type="range"] {
    width: 100%;
    height: 8px;
    border-radius: 5px;
    background: var(--border-color);
    outline: none;
    -webkit-appearance: none;
}

input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 24px;
    height: 24px;
    border-radius: 50%;
    background: var(--primary-color);
    cursor: pointer;
    transition: all 0.3s ease;
}

input[type="range"]::-webkit-slider-thumb:hover {
    transform: scale(1.2);
    box-shadow: 0 0 0 8px rgba(79, 70, 229, 0.1);
}

input[type="range"]::-moz-range-thumb {
    width: 24px;
    height: 24px;
    border-radius: 50%;
    background: var(--primary-color);
    cursor: pointer;
    border: none;
    transition: all 0.3s ease;
}

input[type="range"]::-moz-range-thumb:hover {
    transform: scale(1.2);
    box-shadow: 0 0 0 8px rgba(79, 70, 229, 0.1);
}

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

.checkbox-group label {
    display: flex;
    align-items: center;
    cursor: pointer;
    font-weight: 500;
}

.checkbox-group input[type="checkbox"] {
    width: 20px;
    height: 20px;
    margin-right: 12px;
    cursor: pointer;
    accent-color: var(--primary-color);
}

.strength-indicator {
    margin-top: 30px;
    padding-top: 30px;
    border-top: 2px solid var(--border-color);
}

.strength-bar {
    height: 12px;
    background: var(--border-color);
    border-radius: 6px;
    overflow: hidden;
    margin-bottom: 10px;
}

.strength-fill {
    height: 100%;
    width: 0%;
    transition: all 0.4s ease;
    border-radius: 6px;
}

.strength-text {
    display: block;
    text-align: center;
    font-weight: 600;
    font-size: 0.95rem;
}

.referral-section {
    background: var(--card-background);
    border-radius: 20px;
    padding: 40px;
    box-shadow: var(--shadow-lg);
    margin-bottom: 30px;
}

.referral-card h2 {
    font-size: 2rem;
    margin-bottom: 20px;
    color: var(--text-primary);
    text-align: center;
}

.referral-text {
    font-size: 1.15rem;
    text-align: center;
    margin-bottom: 25px;
    color: var(--text-secondary);
}

.features-list {
    list-style: none;
    margin: 25px 0;
    padding: 0;
}

.features-list li {
    padding: 12px 0;
    font-size: 1.05rem;
    color: var(--text-primary);
    border-bottom: 1px solid var(--border-color);
}

.features-list li:last-child {
    border-bottom: none;
}

.referral-cta {
    text-align: center;
    font-size: 1.1rem;
    font-weight: 600;
    margin: 25px 0;
    color: var(--text-primary);
}

.btn-cta {
    display: block;
    width: 100%;
    padding: 18px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    text-align: center;
    text-decoration: none;
    font-size: 1.2rem;
    font-weight: 700;
    margin: 20px 0;
    box-shadow: var(--shadow);
}

.btn-cta:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-lg);
}

.referral-note {
    text-align: center;
    color: var(--text-secondary);
    font-style: italic;
}

footer {
    text-align: center;
    color: white;
    opacity: 0.9;
    padding: 20px;
}

footer p {
    margin-bottom: 10px;
}

.privacy-note {
    font-size: 0.95rem;
    opacity: 0.85;
}

.seo-footer {
    font-size: 0.85rem;
    opacity: 0.75;
    margin-top: 15px;
    font-style: italic;
}

.notification {
    position: fixed;
    bottom: 30px;
    right: 30px;
    background: var(--success-color);
    color: white;
    padding: 16px 24px;
    border-radius: 12px;
    box-shadow: var(--shadow-lg);
    opacity: 0;
    transform: translateY(20px);
    transition: all 0.3s ease;
    font-weight: 600;
    pointer-events: none;
}

.notification.show {
    opacity: 1;
    transform: translateY(0);
}

@media (max-width: 768px) {
    body {
        padding: 10px;
    }

    header h1 {
        font-size: 2rem;
    }

    .subtitle {
        font-size: 1rem;
    }

    main, .referral-section {
        padding: 25px;
        border-radius: 15px;
    }

    .quick-actions {
        flex-direction: column;
    }

    .btn {
        min-width: 100%;
    }

    .referral-card h2 {
        font-size: 1.5rem;
    }

    .notification {
        bottom: 20px;
        right: 20px;
        left: 20px;
        text-align: center;
    }
}