:root {
    --primary-color: #3b82f6;
    /* Modern Blue */
    --primary-hover: #2563eb;
    --bg-color: #0f172a;
    /* Dark sleek background */
    --container-bg: #1e293b;
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --border-color: #334155;
    --input-bg: #0f172a;
    --error-bg: #7f1d1d;
    --error-border: #ef4444;
}

body {
    font-family: 'Inter', system-ui, -apple-system, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-primary);
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    margin: 0;
    padding: 20px;
    box-sizing: border-box;
}

.container {
    background-color: var(--container-bg);
    padding: 40px;
    border-radius: 16px;
    box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.5), 0 8px 10px -6px rgba(0, 0, 0, 0.3);
    border: 1px solid rgba(255, 255, 255, 0.05);
    max-width: 500px;
    width: 100%;
}

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

h1 {
    color: var(--primary-color);
    margin: 0 0 10px 0;
    font-size: 28px;
    font-weight: 700;
    letter-spacing: -0.5px;
}

.header p {
    color: var(--text-secondary);
    margin: 0;
    font-size: 14px;
}

.settings-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
    margin-bottom: 25px;
}

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

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
    font-size: 14px;
    color: var(--text-secondary);
}

.form-group input[type="number"] {
    width: 100%;
    padding: 12px 15px;
    background-color: var(--input-bg);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    border-radius: 8px;
    font-size: 16px;
    box-sizing: border-box;
    transition: all 0.2s ease;
    outline: none;
}

.form-group input[type="number"]:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.2);
}

.options-container {
    background-color: rgba(0, 0, 0, 0.15);
    padding: 20px;
    border-radius: 10px;
    margin-bottom: 25px;
    border: 1px solid var(--border-color);
}

.options-title {
    margin: 0 0 15px 0;
    font-size: 14px;
    font-weight: 600;
    color: var(--text-secondary);
}

.checkbox-group {
    margin-bottom: 12px;
}

.checkbox-group:last-child {
    margin-bottom: 0;
}

.checkbox-group label {
    display: flex;
    align-items: center;
    font-weight: normal;
    cursor: pointer;
    font-size: 15px;
    color: var(--text-primary);
    margin: 0;
    transition: color 0.2s;
}

.checkbox-group label:hover {
    color: var(--primary-color);
}

.checkbox-group input {
    display: none;
    /* Hide default checkbox */
}

.custom-checkbox {
    width: 20px;
    height: 20px;
    border: 2px solid var(--border-color);
    border-radius: 6px;
    margin-right: 12px;
    display: inline-flex;
    justify-content: center;
    align-items: center;
    transition: all 0.2s;
    background-color: var(--input-bg);
}

.checkbox-group input:checked+.custom-checkbox {
    background-color: var(--primary-color);
    border-color: var(--primary-color);
}

.checkbox-group input:checked+.custom-checkbox::after {
    content: '\2714';
    font-size: 14px;
    color: white;
}

.btn {
    width: 100%;
    padding: 14px;
    background-color: var(--primary-color);
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
    box-shadow: 0 4px 6px -1px rgba(59, 130, 246, 0.3);
}

.btn:hover {
    background-color: var(--primary-hover);
    transform: translateY(-1px);
    box-shadow: 0 6px 8px -1px rgba(59, 130, 246, 0.4);
}

.btn:active {
    transform: translateY(1px);
}

.error {
    color: #fca5a5;
    background-color: var(--error-bg);
    padding: 15px;
    border-radius: 8px;
    margin-top: 25px;
    font-size: 14px;
    text-align: center;
    border: 1px solid var(--error-border);
}

.result-section {
    margin-top: 35px;
    border-top: 1px solid var(--border-color);
    padding-top: 25px;
}

.result-section h2 {
    font-size: 18px;
    margin: 0 0 5px 0;
    color: var(--primary-color);
}

.hint {
    font-size: 12px;
    color: var(--text-secondary);
    margin: 0 0 15px 0;
}

.password-list {
    list-style-type: none;
    padding: 0;
    margin: 0;
    max-height: 280px;
    overflow-y: auto;
    scrollbar-width: thin;
    scrollbar-color: var(--border-color) transparent;
}

.password-list::-webkit-scrollbar {
    width: 6px;
}

.password-list::-webkit-scrollbar-thumb {
    background-color: var(--border-color);
    border-radius: 10px;
}

.password-list li {
    margin-bottom: 12px;
    opacity: 0;
    animation: slideInRight 0.3s ease forwards;
}

.password-list li:last-child {
    margin-bottom: 0;
}

.password-output {
    width: 100%;
    padding: 12px;
    font-family: 'Courier New', Courier, monospace;
    font-size: 16px;
    background-color: var(--input-bg);
    color: var(--text-primary);
    border: 1px dashed var(--border-color);
    border-radius: 8px;
    box-sizing: border-box;
    cursor: pointer;
    text-align: center;
    letter-spacing: 2px;
    transition: all 0.2s;
}

.password-output:hover {
    border-color: var(--primary-color);
    background-color: rgba(59, 130, 246, 0.05);
}

.password-output:focus {
    outline: none;
    border-color: var(--primary-color);
    border-style: solid;
    background-color: rgba(59, 130, 246, 0.1);
}

/* Animations */
.slide-up {
    animation: slideUp 0.5s ease-out;
}

.animate-pop {
    animation: popIn 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

.animate-fade-in {
    animation: fadeIn 0.4s ease-in;
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes popIn {
    from {
        opacity: 0;
        transform: scale(0.9);
    }

    to {
        opacity: 1;
        transform: scale(1);
    }
}

@keyframes fadeIn {
    from {
        opacity: 0;
    }

    to {
        opacity: 1;
    }
}

@keyframes slideInRight {
    from {
        opacity: 0;
        transform: translateX(15px);
    }

    to {
        opacity: 1;
        transform: translateX(0);
    }
}

@media (max-width: 480px) {
    .settings-grid {
        grid-template-columns: 1fr;
        gap: 15px;
    }

    .container {
        padding: 25px;
    }
}