:root {
    --dark-bg: #1e1e1e;
    --darker-bg: #181818;
    --sidebar-bg: #252526;
    --tab-bg: #2d2d2d;
    --tab-active: #007acc;
    --accent-blue: #007acc;
    --accent-green: #4ec9b0;
    --accent-yellow: #dcdcaa;
    --accent-orange: #ce9178;
    --text-primary: #cccccc;
    --text-secondary: #969696;
    --border-color: #3e3e3e;
    --run-btn: #4ec9b0;
    --edit-btn: #569cd6;
}

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

body {
    background-color: var(--dark-bg);
    color: var(--text-primary);
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    overflow-x: hidden;
    height: 100vh;
    display: flex;
    flex-direction: column;
}

.header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 2rem;
    background-color: var(--darker-bg);
    border-bottom: 1px solid var(--border-color);
}

.header-title {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.title-icon {
    font-size: 1.5rem;
}

.header h1 {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--text-primary);
}

.back-button {
    color: var(--text-primary);
    text-decoration: none;
    font-weight: 500;
    padding: 0.5rem 1rem;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    transition: all 0.3s ease;
}

.back-button:hover {
    background-color: rgba(255, 255, 255, 0.05);
    border-color: var(--accent-blue);
}

.container {
    flex: 1;
    display: flex;
    flex-direction: column;
    padding: 2rem;
    gap: 1.5rem;
    overflow: hidden;
}

.intro-section {
    max-width: 800px;
}

.intro-text {
    font-size: 1.1rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

.playground-container {
    flex: 1;
    display: flex;
    flex-direction: column;
    background: var(--darker-bg);
    border-radius: 8px;
    border: 1px solid var(--border-color);
    overflow: hidden;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
}

.editor-tabs {
    display: flex;
    background: var(--tab-bg);
    padding: 0;
    margin: 0;
    flex-shrink: 0;
    border-bottom: 1px solid var(--border-color);
}

.tab-btn {
    background: none;
    border: none;
    color: var(--text-secondary);
    padding: 0.75rem 1.25rem;
    cursor: pointer;
    font-size: 0.9rem;
    transition: all 0.3s ease;
    position: relative;
    font-weight: 500;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.tab-btn:hover {
    background: rgba(255, 255, 255, 0.05);
    color: var(--text-primary);
}

.tab-btn.active {
    background: rgba(0, 122, 204, 0.15);
    color: var(--text-primary);
}

.tab-btn.active::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 2px;
    background: var(--tab-active);
}

.edit-code-btn {
    margin-left: auto;
    background: var(--edit-btn);
    color: white;
    border: none;
    padding: 0 1.25rem;
    cursor: pointer;
    font-weight: 600;
    font-size: 0.9rem;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.edit-code-btn:hover {
    background: #4d76b5;
}

.run-btn {
    background: var(--run-btn);
    color: white;
    border: none;
    padding: 0 1.5rem;
    cursor: pointer;
    font-weight: 600;
    font-size: 0.9rem;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.run-btn:hover {
    background: #3db39b;
}

.editor-panes {
    flex: 1;
    position: relative;
    overflow: hidden;
    background: var(--dark-bg);
}

.editor-pane {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    display: none;
    overflow: auto;
}

.editor-pane.active {
    display: block;
}

.CodeMirror {
    height: 100% !important;
    font-size: 14px;
    line-height: 1.5;
    padding: 1rem 0;
}

.CodeMirror-vscrollbar, .CodeMirror-hscrollbar {
    background: rgba(255, 255, 255, 0.05);
}

.CodeMirror-gutters {
    background: var(--darker-bg);
    border-right: 1px solid var(--border-color);
}

#result-pane {
    display: flex;
}

#result-frame {
    width: 100%;
    height: 100%;
    border: none;
    background: white;
}

/* How to Use Section */
.how-to-use {
    background: var(--tab-bg);
    color: white;
    border-top: 1px solid var(--border-color);
}

.how-to-use-btn {
    background: none;
    border: none;
    color: var(--text-secondary);
    padding: 0.75rem 1.25rem;
    cursor: pointer;
    font-size: 0.9rem;
    width: 100%;
    text-align: left;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    transition: all 0.3s ease;
    font-weight: 500;
}

.how-to-use-btn:hover {
    background: rgba(255, 255, 255, 0.05);
    color: var(--text-primary);
}

.how-to-use-content {
    padding: 1.25rem;
    display: none;
    background: rgba(0, 0, 0, 0.2);
    border-top: 1px solid var(--border-color);
}

.how-to-use-content.active {
    display: block;
    animation: fadeIn 0.3s ease-out;
}

.how-to-use-content h3 {
    margin-top: 0;
    color: var(--accent-blue);
    font-size: 1.2rem;
    margin-bottom: 1rem;
}

.how-to-use-content ol {
    padding-left: 1.5rem;
    margin: 0.5rem 0;
    font-size: 0.9rem;
}

.how-to-use-content li {
    margin-bottom: 0.5rem;
    line-height: 1.5;
}

.how-to-use-content kbd {
    background: var(--accent-blue);
    color: white;
    padding: 0.2rem 0.4rem;
    border-radius: 3px;
    font-family: monospace;
    font-size: 0.8rem;
}

.how-to-use-content p {
    margin: 1rem 0 0;
    font-size: 0.9rem;
    color: var(--text-secondary);
}

/* Modal Styles */
.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.7);
    animation: fadeIn 0.3s ease-out;
}

.modal-content {
    background-color: var(--darker-bg);
    margin: 2% auto;
    padding: 0;
    border: 1px solid var(--border-color);
    width: 90%;
    height: 85%;
    border-radius: 8px;
    display: flex;
    flex-direction: column;
    overflow: hidden;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.5);
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 1.5rem;
    background-color: var(--tab-bg);
    border-bottom: 1px solid var(--border-color);
}

.modal-header h2 {
    font-size: 1.25rem;
    font-weight: 600;
}

.close-modal {
    color: var(--text-secondary);
    font-size: 1.5rem;
    font-weight: bold;
    cursor: pointer;
    transition: color 0.3s ease;
}

.close-modal:hover {
    color: var(--text-primary);
}

.modal-body {
    flex: 1;
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

.modal-tabs {
    display: flex;
    background: var(--tab-bg);
    padding: 0;
    margin: 0;
    border-bottom: 1px solid var(--border-color);
}

.modal-tab-btn {
    background: none;
    border: none;
    color: var(--text-secondary);
    padding: 0.75rem 1.25rem;
    cursor: pointer;
    font-size: 0.9rem;
    transition: all 0.3s ease;
    position: relative;
}

.modal-tab-btn:hover {
    background: rgba(255, 255, 255, 0.05);
    color: var(--text-primary);
}

.modal-tab-btn.active {
    background: rgba(0, 122, 204, 0.15);
    color: var(--text-primary);
}

.modal-tab-btn.active::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 2px;
    background: var(--tab-active);
}

.modal-editors {
    flex: 1;
    position: relative;
    overflow: hidden;
    background: var(--dark-bg);
}

.modal-editor-pane {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    display: none;
    overflow: auto;
}

.modal-editor-pane.active {
    display: block;
}

.modal-footer {
    display: flex;
    justify-content: flex-end;
    gap: 0.75rem;
    padding: 1rem 1.5rem;
    background-color: var(--tab-bg);
    border-top: 1px solid var(--border-color);
}

.apply-btn, .close-btn {
    padding: 0.5rem 1.25rem;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-weight: 600;
    font-size: 0.9rem;
    transition: all 0.3s ease;
}

.apply-btn {
    background: var(--accent-green);
    color: white;
}

.apply-btn:hover {
    background: #3db39b;
}

.close-btn {
    background: var(--tab-bg);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}

.close-btn:hover {
    background: rgba(255, 255, 255, 0.1);
}

/* Animations */
@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

/* Responsive styles */
@media (max-width: 768px) {
    .header {
        padding: 0.75rem 1rem;
    }
    
    .container {
        padding: 1rem;
    }
    
    .editor-tabs {
        flex-wrap: wrap;
    }
    
    .tab-btn {
        flex: 1;
        min-width: 25%;
        padding: 0.6rem 0.5rem;
        font-size: 0.8rem;
    }
    
    .run-btn, .edit-code-btn {
        min-width: auto;
        padding: 0.6rem 0.75rem;
    }
    
    .modal-content {
        width: 95%;
        height: 90%;
        margin: 5% auto;
    }
}

@media (max-width: 576px) {
    .header h1 {
        font-size: 1.25rem;
    }
    
    .tab-btn {
        font-size: 0.7rem;
        padding: 0.5rem 0.3rem;
    }
    
    .CodeMirror {
        font-size: 12px;
    }
    
    .how-to-use-content ol {
        font-size: 0.8rem;
        padding-left: 1rem;
    }
}