* {
    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;
    padding: 20px;
}

.main-container {
    display: flex;
    max-width: 1400px;
    margin: 0 auto;
    background: white;
    border-radius: 15px;
    box-shadow: 0 20px 40px rgba(0,0,0,0.1);
    overflow: hidden;
    min-height: 90vh;
}

/* Sidebar Styles */
.sidebar {
    width: 280px;
    background: linear-gradient(180deg, #2c3e50 0%, #34495e 100%);
    color: white;
    padding: 0;
    overflow-y: auto;
}

.sidebar-header {
    padding: 30px 20px;
    text-align: center;
    border-bottom: 1px solid #34495e;
}

.sidebar-header h2 {
    font-size: 1.5em;
    margin-bottom: 5px;
}

.sidebar-header p {
    font-size: 0.9em;
    opacity: 0.8;
}

.sidebar-menu {
    padding: 20px 0;
}

.menu-item {
    display: flex;
    align-items: center;
    padding: 15px 20px;
    color: #ecf0f1;
    text-decoration: none;
    transition: all 0.3s ease;
    border-left: 4px solid transparent;
    cursor: pointer;
}

.menu-item:hover {
    background: rgba(255, 255, 255, 0.1);
    border-left-color: #3498db;
    transform: translateX(5px);
}

.menu-item.active {
    background: rgba(52, 152, 219, 0.2);
    border-left-color: #3498db;
    color: #3498db;
}

.menu-item i {
    width: 20px;
    margin-right: 12px;
    font-size: 1.1em;
}

.menu-item span {
    font-weight: 500;
}

/* Main Content */
.main-content {
    flex: 1;
    display: flex;
    flex-direction: column;
}

.header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 30px;
    text-align: center;
}

.header h1 {
    font-size: 2.5em;
    margin-bottom: 10px;
}

.header p {
    font-size: 1.1em;
    opacity: 0.9;
}

.content {
    padding: 40px;
    flex: 1;
}

.tool-section {
    background: #f8f9fa;
    border-radius: 10px;
    padding: 30px;
    margin-bottom: 30px;
    border-left: 5px solid #667eea;
    display: none;
}

.tool-section.active {
    display: block;
}

.tool-title {
    font-size: 1.5em;
    color: #333;
    margin-bottom: 20px;
    display: flex;
    align-items: center;
    gap: 10px;
}

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

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    color: #555;
}

.form-control {
    width: 100%;
    padding: 12px 15px;
    border: 2px solid #e1e5e9;
    border-radius: 8px;
    font-size: 14px;
    transition: border-color 0.3s ease;
}

.form-control:focus {
    outline: none;
    border-color: #667eea;
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.checkbox-group {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 20px;
}

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

.btn {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border: none;
    padding: 12px 30px;
    border-radius: 8px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 20px rgba(102, 126, 234, 0.3);
}

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

.result-section {
    background: #f8f9fa;
    border-radius: 10px;
    padding: 30px;
    margin-top: 30px;
}

.result-title {
    font-size: 1.3em;
    color: #333;
    margin-bottom: 15px;
    display: flex;
    align-items: center;
    gap: 10px;
}

.result-content {
    background: white;
    border: 2px solid #e1e5e9;
    border-radius: 8px;
    padding: 20px;
    min-height: 100px;
    font-family: 'Courier New', monospace;
    white-space: pre-wrap;
    word-wrap: break-word;
    max-height: 400px;
    overflow-y: auto;
}

.example-section {
    background: #e8f4fd;
    border-radius: 8px;
    padding: 20px;
    margin-top: 20px;
    border-left: 4px solid #2196f3;
}

.example-title {
    font-weight: 600;
    color: #1976d2;
    margin-bottom: 10px;
}

.example-text {
    font-family: 'Courier New', monospace;
    background: white;
    padding: 10px;
    border-radius: 5px;
    margin-bottom: 10px;
}

.stats {
    display: flex;
    gap: 20px;
    margin-top: 15px;
    flex-wrap: wrap;
}

.stat-item {
    background: white;
    padding: 10px 15px;
    border-radius: 6px;
    border: 1px solid #e1e5e9;
    font-size: 14px;
}

.stat-label {
    font-weight: 600;
    color: #666;
}

.stat-value {
    color: #333;
    font-weight: 600;
}

/* Welcome Section */
.welcome-section {
    text-align: center;
    padding: 60px 20px;
    color: #666;
}

.welcome-section i {
    font-size: 4em;
    color: #667eea;
    margin-bottom: 20px;
}

.welcome-section h2 {
    font-size: 2em;
    margin-bottom: 15px;
    color: #333;
}

.welcome-section p {
    font-size: 1.1em;
    line-height: 1.6;
    max-width: 600px;
    margin: 0 auto;
}

/* Popup Styles */
.popup-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 1000;
}

.popup-content {
    background: white;
    border-radius: 8px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
    width: 90%;
    max-width: 400px;
    max-height: 80vh;
    overflow-y: auto;
}

.popup-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px;
    border-bottom: 1px solid #eee;
}

.popup-header h3 {
    margin: 0;
    color: #333;
}

.popup-close {
    background: none;
    border: none;
    font-size: 24px;
    cursor: pointer;
    color: #666;
    padding: 0;
    width: 30px;
    height: 30px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.popup-close:hover {
    color: #333;
}

.popup-body {
    padding: 20px;
}

.popup-footer {
    display: flex;
    gap: 10px;
    padding: 20px;
    border-top: 1px solid #eee;
    justify-content: flex-end;
}

/* Utility Buttons */
.utility-buttons {
    margin-top: 20px;
    padding: 15px;
    background: #f8f9fa;
    border-radius: 8px;
    border: 1px solid #e9ecef;
}

.utility-buttons h4 {
    margin-bottom: 15px;
    color: #333;
    font-size: 14px;
    font-weight: 600;
}

.btn-small {
    padding: 8px 12px;
    font-size: 12px;
    border-radius: 6px;
    background: #007bff;
    color: white;
    border: none;
    cursor: pointer;
    transition: background 0.3s;
}

.btn-small:hover {
    background: #0056b3;
}

.btn-secondary {
    background: #6c757d;
}

.btn-secondary:hover {
    background: #545b62;
}

/* Responsive Design */
@media (max-width: 1024px) {
    .main-container {
        flex-direction: column;
    }
    
    .sidebar {
        width: 100%;
        max-height: 200px;
    }
    
    .sidebar-menu {
        display: flex;
        overflow-x: auto;
        padding: 10px;
    }
    
    .menu-item {
        min-width: 150px;
        flex-shrink: 0;
    }
}

@media (max-width: 768px) {
    .content {
        padding: 20px;
    }
    
    .header h1 {
        font-size: 2em;
    }
    
    .stats {
        flex-direction: column;
    }
    
    .sidebar-header h2 {
        font-size: 1.2em;
    }
}