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

:root {
    --primary-color: #6366f1;
    --primary-hover: #4f46e5;
    --secondary-color: #8b5cf6;
    --success-color: #10b981;
    --error-color: #ef4444;
    --bg-color: #f8fafc;
    --card-bg: #ffffff;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --border-color: #e2e8f0;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
}

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

.container {
    max-width: 800px;
    margin: 0 auto;
}

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

header h1 {
    font-size: 2.5rem;
    margin-bottom: 10px;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.2);
}

.subtitle {
    font-size: 1.1rem;
    opacity: 0.9;
}

.tabs {
    display: flex;
    gap: 10px;
    margin-bottom: 20px;
    background: var(--card-bg);
    padding: 8px;
    border-radius: 12px;
    box-shadow: var(--shadow);
}

.tab-btn {
    flex: 1;
    padding: 12px 20px;
    border: none;
    background: transparent;
    color: var(--text-secondary);
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    border-radius: 8px;
    transition: all 0.3s ease;
}

.tab-btn:hover {
    background: var(--bg-color);
    color: var(--text-primary);
}

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

.tab-content {
    display: none;
}

.tab-content.active {
    display: block;
    animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.tool-card {
    background: var(--card-bg);
    border-radius: 16px;
    padding: 30px;
    box-shadow: var(--shadow-lg);
}

.tool-card h2 {
    font-size: 1.8rem;
    margin-bottom: 10px;
    color: var(--text-primary);
}

.tool-description {
    color: var(--text-secondary);
    margin-bottom: 25px;
    font-size: 0.95rem;
}

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

.input-group input[type="url"],
.input-group input[type="text"],
.input-group textarea {
    width: 100%;
    padding: 14px 16px;
    border: 2px solid var(--border-color);
    border-radius: 10px;
    font-size: 1rem;
    transition: all 0.3s ease;
    font-family: inherit;
}

.input-group input[type="url"]:focus,
.input-group input[type="text"]:focus,
.input-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.input-group textarea {
    resize: vertical;
    min-height: 100px;
}

.btn {
    padding: 12px 24px;
    border: none;
    border-radius: 10px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    font-family: inherit;
}

.btn-primary {
    background: var(--primary-color);
    color: white;
    width: 100%;
}

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

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

.btn-secondary:hover {
    background: #7c3aed;
    transform: translateY(-2px);
}

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

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

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

.setting-item {
    margin-bottom: 20px;
}

.setting-item label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
    color: var(--text-primary);
}

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

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

.setting-item input[type="range"]::-moz-range-thumb {
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: var(--primary-color);
    cursor: pointer;
    border: none;
}

.checkboxes {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 15px;
    margin-top: 15px;
}

.checkbox-label {
    display: flex;
    align-items: center;
    gap: 8px;
    cursor: pointer;
    padding: 10px;
    border-radius: 8px;
    transition: background 0.2s ease;
}

.checkbox-label:hover {
    background: var(--bg-color);
}

.checkbox-label input[type="checkbox"] {
    width: 18px;
    height: 18px;
    cursor: pointer;
}

.color-pickers {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 15px;
    margin-top: 15px;
}

.color-picker {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.color-picker label {
    font-weight: 500;
    color: var(--text-primary);
}

.color-picker input[type="color"] {
    width: 100%;
    height: 50px;
    border: 2px solid var(--border-color);
    border-radius: 10px;
    cursor: pointer;
}

.result-container {
    margin-top: 25px;
    padding: 20px;
    background: var(--bg-color);
    border-radius: 12px;
    animation: slideIn 0.3s ease;
}

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateY(-10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.result-box {
    margin-bottom: 15px;
}

.result-box label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
    color: var(--text-primary);
}

.copyable-input {
    display: flex;
    gap: 10px;
}

.copyable-input input {
    flex: 1;
    background: white;
}

.btn-copy {
    padding: 12px 20px;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 10px;
    cursor: pointer;
    font-weight: 500;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 6px;
    white-space: nowrap;
}

.btn-copy:hover {
    background: var(--primary-hover);
    transform: scale(1.05);
}

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

.btn-copy.copied .copy-text::after {
    content: '✓ Copied!';
}

.result-actions {
    display: flex;
    gap: 10px;
    margin-top: 20px;
}

.result-actions .btn {
    flex: 1;
}

.password-strength {
    margin-top: 20px;
}

.password-strength label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
}

.strength-bar {
    width: 100%;
    height: 10px;
    background: var(--border-color);
    border-radius: 5px;
    overflow: hidden;
    margin-bottom: 8px;
}

.strength-fill {
    height: 100%;
    transition: all 0.3s ease;
    border-radius: 5px;
}

.strength-fill.weak {
    width: 33%;
    background: var(--error-color);
}

.strength-fill.medium {
    width: 66%;
    background: #f59e0b;
}

.strength-fill.strong {
    width: 100%;
    background: var(--success-color);
}

.qr-display {
    text-align: center;
    margin-bottom: 20px;
    padding: 20px;
    background: white;
    border-radius: 12px;
}

.qr-display img {
    max-width: 100%;
    height: auto;
    border-radius: 8px;
}

.error-message {
    margin-top: 15px;
    padding: 12px 16px;
    background: #fee2e2;
    color: var(--error-color);
    border-radius: 8px;
    border-left: 4px solid var(--error-color);
}

.hidden {
    display: none !important;
}

footer {
    text-align: center;
    margin-top: 30px;
    color: white;
    opacity: 0.8;
}

/* Responsive Design */
@media (max-width: 768px) {
    header h1 {
        font-size: 2rem;
    }

    .tabs {
        flex-direction: column;
    }

    .tool-card {
        padding: 20px;
    }

    .checkboxes,
    .color-pickers {
        grid-template-columns: 1fr;
    }

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