:root {
    --bg-color: #f5f7fa;
    --primary-color: #7b97c9;
    --secondary-color: #e8eef8;
    --accent-color: #5b79ad;
    --text-color: #333;
    --border-color: #d8e3f3;
    --section-bg: #ffffff;
    --success-color: #86c3a9;
    --danger-color: #e88e7d;
    --warning-color: #f4c542;
    --sidebar-width: 300px;
    --muted-text: #999;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    display: flex;
    min-height: 100vh;
}

/* Sidebar */
.sidebar {
    width: var(--sidebar-width);
    background-color: var(--section-bg);
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
    padding: 20px;
    position: fixed;
    height: 100vh;
    overflow-y: auto;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
}

.main-content {
    margin-left: var(--sidebar-width);
    padding: 20px;
    width: calc(100% - var(--sidebar-width));
}

.container {
    max-width: 1200px;
    margin: 0 auto;
}

/* Typography */
h1 {
    color: var(--accent-color);
    margin-bottom: 15px;
    font-size: 24px;
}

h2 {
    color: var(--accent-color);
    margin-bottom: 10px;
    font-size: 20px;
}

h3 {
    color: var(--accent-color);
    margin-bottom: 15px;
    font-size: 16px;
}

/* Home button */
.home-button {
    display: inline-flex;
    align-items: center;
    background-color: #edf2f9;
    color: var(--accent-color);
    padding: 8px 15px;
    text-decoration: none;
    border-radius: 6px;
    font-weight: 500;
    margin-bottom: 15px;
    border: 1px solid var(--border-color);
    font-size: 14px;
    transition: all 0.2s ease;
}

.home-button i {
    margin-right: 10px;
}

.home-button:hover {
    background-color: var(--secondary-color);
    color: var(--primary-color);
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0,0,0,0.05);
}

.description {
    margin-bottom: 20px;
    line-height: 1.6;
    color: var(--text-color);
    font-size: 14px;
}

/* Settings */
.base64-settings {
    background-color: var(--section-bg);
    border-radius: 8px;
    padding: 15px;
    margin-bottom: 20px;
    border: 1px solid var(--border-color);
}

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

.setting-item {
    margin-bottom: 12px;
}

.setting-item label {
    display: flex;
    align-items: center;
    gap: 8px;
    cursor: pointer;
    font-size: 14px;
    color: var(--text-color);
    font-weight: 500;
}

.setting-item input[type="radio"],
.setting-item input[type="checkbox"] {
    margin: 0;
}

.divider {
    border: none;
    border-top: 1px solid var(--border-color);
    margin: 20px 0;
}

.file-upload {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.btn {
    background-color: var(--primary-color);
    color: white;
    border: none;
    padding: 8px 15px;
    border-radius: 6px;
    cursor: pointer;
    font-size: 14px;
    transition: all 0.2s ease;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    font-weight: 500;
}

.btn:hover {
    background-color: var(--accent-color);
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0,0,0,0.1);
}

.btn.secondary {
    background-color: #f0f2f5;
    color: var(--text-color);
}

.btn.secondary:hover {
    background-color: #e1e4e9;
}

.btn.mini {
    padding: 5px 10px;
    font-size: 12px;
}

.file-info {
    color: var(--muted-text);
    font-size: 12px;
    margin-top: 5px;
}

.features {
    background-color: var(--secondary-color);
    padding: 15px;
    border-radius: 8px;
    margin-top: 20px;
    margin-bottom: 20px;
}

.features h4 {
    color: var(--accent-color);
    margin-bottom: 10px;
    font-size: 14px;
}

.features ul {
    padding-left: 20px;
    color: var(--text-color);
}

.features li {
    margin-bottom: 5px;
    font-size: 14px;
}

.footer {
    border-top: 1px solid var(--border-color);
    padding-top: 15px;
    font-size: 12px;
    color: var(--muted-text);
    text-align: center;
}

/* Main Content Styles */
.panel {
    background: var(--section-bg);
    border-radius: 8px;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.05);
    margin-bottom: 20px;
    border: 1px solid var(--border-color);
    overflow: hidden;
}

.panel-header {
    padding: 15px 20px;
    background: #f8f9fb;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.panel-header h2 {
    font-size: 16px;
    font-weight: 600;
    margin: 0;
    color: var(--accent-color);
}

.panel-controls {
    display: flex;
    gap: 8px;
}

.btn-icon {
    background: none;
    border: none;
    color: var(--muted-text);
    cursor: pointer;
    padding: 6px;
    border-radius: 4px;
    font-size: 14px;
    transition: all 0.2s ease;
}

.btn-icon:hover {
    color: var(--primary-color);
    background-color: #f0f2f5;
}

.panel-body {
    padding: 20px;
}

.text-input,
.text-output {
    width: 100%;
    min-height: 200px;
    padding: 15px;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    font-family: 'Consolas', 'Monaco', monospace;
    font-size: 14px;
    line-height: 1.6;
    resize: vertical;
    transition: border-color 0.2s ease;
    background-color: #fff;
}

.text-input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 2px rgba(123, 151, 201, 0.2);
}

.text-output {
    background: #f8f9fb;
    color: var(--text-color);
}

.text-info {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 10px;
    font-size: 12px;
    color: var(--muted-text);
}

.control-panel {
    margin: 20px 0;
}

.button-group {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
}

.button {
    background-color: var(--primary-color);
    color: white;
    border: none;
    padding: 12px 20px;
    border-radius: 6px;
    cursor: pointer;
    font-size: 14px;
    font-weight: 500;
    transition: all 0.2s ease;
    display: inline-flex;
    align-items: center;
    gap: 8px;
}

.button:hover:not(:disabled) {
    background-color: var(--accent-color);
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0,0,0,0.1);
}

.button.secondary {
    background-color: white;
    color: var(--primary-color);
    border: 1px solid var(--primary-color);
}

.button.secondary:hover:not(:disabled) {
    background-color: var(--primary-color);
    color: white;
}

.button:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    transform: none;
    box-shadow: none;
}

.preview-container {
    border: 1px solid var(--border-color);
    border-radius: 6px;
    padding: 15px;
    background: white;
    margin-top: 15px;
}

.preview-container img {
    max-width: 100%;
    height: auto;
    border-radius: 4px;
}

.preview-container audio,
.preview-container video {
    width: 100%;
    max-width: 100%;
}

.dev-tools {
    display: grid;
    gap: 20px;
}

.tool-section h4 {
    font-size: 14px;
    font-weight: 600;
    margin-bottom: 10px;
    color: var(--accent-color);
}

.info-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 10px;
}

.info-item {
    display: flex;
    justify-content: space-between;
    padding: 10px;
    background: #f8f9fb;
    border-radius: 4px;
    font-size: 12px;
    border: 1px solid #f0f2f5;
}

.info-label {
    font-weight: 500;
    color: var(--muted-text);
}

.info-value {
    font-family: 'Consolas', 'Monaco', monospace;
    color: var(--text-color);
}

.quick-actions {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
}

/* Modal Styles */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 2000;
}

.modal-content {
    background: white;
    border-radius: 8px;
    max-width: 95vw;
    max-height: 90vh;
    overflow: hidden;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.2);
}

.modal-header {
    padding: 15px 20px;
    background: #f8f9fb;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.modal-header h3 {
    margin: 0;
    font-size: 16px;
    color: var(--accent-color);
}

.modal-body {
    padding: 20px;
    max-height: 70vh;
    overflow-y: auto;
}

/* Status and validation styles */
.status-valid {
    color: var(--success-color);
}

.status-invalid {
    color: var(--danger-color);
}

.status-warning {
    color: var(--warning-color);
}

/* Responsive Design */
@media (max-width: 768px) {
    body {
        flex-direction: column;
    }
    
    .sidebar {
        width: 100%;
        height: auto;
        position: relative;
    }
    
    .main-content {
        margin-left: 0;
        width: 100%;
        padding: 15px;
    }
    
    .button-group {
        flex-direction: column;
    }
    
    .info-grid {
        grid-template-columns: 1fr;
    }
    
    .panel-header {
        padding: 12px 15px;
    }
    
    .panel-body {
        padding: 15px;
    }
    
    .text-input,
    .text-output {
        min-height: 150px;
        font-size: 13px;
    }
    
    .button {
        padding: 10px 15px;
        font-size: 13px;
    }
}

/* Loading animation */
@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

.fa-spin {
    animation: spin 1s linear infinite;
}

/* Highlight and selection styles */
.highlighted {
    background: #fff3cd;
    border-color: var(--warning-color);
}

.selected {
    background: #d4edda;
    border-color: var(--success-color);
}