:root {
    --bg-primary: #0d1117;
    --bg-secondary: #161b22;
    --bg-tertiary: #21262d;
    --border-color: #30363d;
    --text-primary: #c9d1d9;
    --text-secondary: #8b949e;
    --accent-green: #2ea043;
    --accent-green-dim: #238636;
    --accent-red: #f85149;
    --accent-yellow: #d29922;
    --header-h: 55px;
    --glider-h: 45px;
}

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

body {
    background: var(--bg-primary);
    color: var(--text-primary);
    font-family: 'Courier New', monospace;
    height: 100vh;
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

/* Header */
header {
    height: var(--header-h);
    background: var(--bg-secondary);
    padding: 0 15px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.brand {
    display: flex;
    align-items: center;
    gap: 8px;
    color: var(--accent-green);
    font-size: 16px;
    font-weight: bold;
    letter-spacing: 2px;
    background: linear-gradient(45deg, var(--accent-green), #00ff41);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    text-shadow: 0 0 10px rgba(46, 160, 67, 0.3);
}

.brand img {
    border-radius: 4px;
    object-fit: cover;
}

.btn-group {
    display: flex;
    gap: 6px;
}

button {
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    padding: 6px 10px;
    border-radius: 6px;
    cursor: pointer;
    font-size: 14px;
    transition: all 0.2s;
}

button:hover {
    background: var(--border-color);
    border-color: var(--text-secondary);
}

/* Glider Tabs */
.glider {
    height: var(--glider-h);
    background: var(--bg-secondary);
    display: flex;
    overflow-x: auto;
    border-bottom: 1px solid var(--border-color);
    z-index: 999;
}

.glider::-webkit-scrollbar {
    height: 3px;
}

.glider::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: 3px;
}

.tab {
    padding: 0 15px;
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 12px;
    color: var(--text-secondary);
    border-right: 1px solid var(--border-color);
    white-space: nowrap;
    cursor: pointer;
    transition: all 0.2s;
}

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

.tab.active {
    background: var(--bg-tertiary);
    color: var(--accent-green);
    border-bottom: 2px solid var(--accent-green);
}

.tab i.ri-close-line {
    opacity: 0.5;
    transition: opacity 0.2s;
}

.tab i.ri-close-line:hover {
    opacity: 1;
    color: var(--accent-red);
}

/* Workspace */
.workspace {
    flex: 1;
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

.pane {
    position: relative;
    flex: 1;
    display: flex;
    flex-direction: column;
    min-height: 100px;
    transition: flex 0.3s;
    border-bottom: 1px solid var(--border-color);
}

.pane-bar {
    background: var(--bg-secondary);
    padding: 5px 12px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid var(--border-color);
}

.pane-title {
    font-size: 11px;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

/* Editor */
.editor-wrapper {
    position: relative;
    flex: 1;
    overflow: hidden;
    background: var(--bg-primary);
}

#editing-area, #highlighting-area {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    padding: 16px;
    font-size: 14px;
    line-height: 1.6;
    tab-size: 4;
    white-space: pre;
    overflow: auto;
    border: none;
    outline: none;
    font-family: 'Courier New', monospace;
}

#editing-area {
    background: transparent;
    color: transparent;
    caret-color: var(--accent-green);
    z-index: 10;
    resize: none;
}

#editing-area::placeholder {
    color: var(--text-secondary);
    opacity: 0.5;
}

#highlighting-area {
    z-index: 5;
    pointer-events: none;
    background: var(--bg-primary);
}

/* Preview */
#preview-frame {
    width: 100%;
    height: 100%;
    border: none;
    background: white;
}

.sync-btn {
    background: var(--accent-green-dim);
    border-color: var(--accent-green);
    color: white;
}

.sync-btn:hover {
    background: var(--accent-green);
}

/* Modal */
.overlay {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.8);
    display: none;
    align-items: center;
    justify-content: center;
    z-index: 9999;
}

.modal {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 24px;
    width: 90%;
    max-width: 350px;
    text-align: center;
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.5);
}

.modal-title {
    color: var(--accent-green);
    font-size: 18px;
    font-weight: bold;
    margin-bottom: 12px;
}

.modal-text {
    color: var(--text-primary);
    font-size: 14px;
    margin-bottom: 20px;
    line-height: 1.5;
}

.modal-actions {
    display: flex;
    gap: 12px;
    justify-content: center;
}

.modal-btn {
    padding: 8px 20px;
    border-radius: 6px;
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
    border: none;
}

.modal-btn.cancel {
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
}

.modal-btn.cancel:hover {
    background: var(--border-color);
}

.modal-btn.confirm {
    background: var(--accent-red);
    border: 1px solid var(--accent-red);
    color: white;
}

.modal-btn.confirm:hover {
    background: #ff6b6b;
}

/* Toast Notifications */
.toast-container {
    position: fixed;
    bottom: 20px;
    right: 20px;
    z-index: 10000;
}

.toast {
    background: var(--bg-secondary);
    border-left: 4px solid var(--accent-green);
    border-radius: 6px;
    padding: 12px 20px;
    margin-top: 10px;
    color: var(--text-primary);
    font-size: 14px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
    animation: slideIn 0.3s ease;
    border: 1px solid var(--border-color);
    display: flex;
    align-items: center;
}

.toast.error {
    border-left-color: var(--accent-red);
}

.toast.warning {
    border-left-color: var(--accent-yellow);
}

.toast i {
    font-size: 18px;
}

@keyframes slideIn {
    from {
        transform: translateX(100%);
        opacity: 0;
    }
    to {
        transform: translateX(0);
        opacity: 1;
    }
}

@keyframes slideOut {
    from {
        transform: translateX(0);
        opacity: 1;
    }
    to {
        transform: translateX(100%);
        opacity: 0;
    }
}

/* PWA Install Prompt */
.pwa-prompt {
    position: fixed;
    bottom: 20px;
    left: 20px;
    right: 20px;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 16px;
    z-index: 10001;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.4);
    animation: slideUp 0.3s ease;
    max-width: 400px;
    margin: 0 auto;
}

@keyframes slideUp {
    from {
        transform: translateY(100%);
        opacity: 0;
    }
    to {
        transform: translateY(0);
        opacity: 1;
    }
}

.pwa-prompt-content {
    display: flex;
    align-items: center;
    gap: 12px;
}

.pwa-prompt-content img {
    border-radius: 12px;
    border: 1px solid var(--border-color);
}

.pwa-prompt-text {
    flex: 1;
}

.pwa-prompt-text h3 {
    color: var(--text-primary);
    font-size: 16px;
    margin-bottom: 4px;
}

.pwa-prompt-text p {
    color: var(--text-secondary);
    font-size: 12px;
    line-height: 1.4;
}

.pwa-prompt-actions {
    display: flex;
    gap: 8px;
}

.pwa-btn {
    padding: 6px 12px;
    border-radius: 6px;
    font-size: 12px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
    border: none;
}

.pwa-btn.decline {
    background: var(--bg-tertiary);
    color: var(--text-secondary);
    border: 1px solid var(--border-color);
}

.pwa-btn.decline:hover {
    background: var(--border-color);
    color: var(--text-primary);
}

.pwa-btn.install {
    background: var(--accent-green-dim);
    color: white;
    border: 1px solid var(--accent-green);
}

.pwa-btn.install:hover {
    background: var(--accent-green);
}

/* Icon Colors */
.ri-html5-fill { color: #e34c26; }
.ri-css3-fill { color: #264de4; }
.ri-javascript-fill { color: #f7df1e; }
.ri-terminal-box-fill { color: #3572A5; }
.ri-file-json-fill { color: #f7df1e; }

/* Utility Classes */
.expanded { flex: 5 !important; }
.hidden { display: none !important; }

/* Language Select */
#lang-select {
    background: var(--bg-tertiary);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
    padding: 4px 8px;
    border-radius: 4px;
    font-size: 11px;
    cursor: pointer;
    outline: none;
}

#lang-select:hover {
    border-color: var(--accent-green);
}

#lang-select option {
    background: var(--bg-secondary);
    color: var(--text-primary);
}

/* Responsive */
@media (max-width: 768px) {
    .brand {
        font-size: 14px;
    }
    
    button {
        padding: 4px 8px;
    }
}

@media (max-width: 480px) {
    .pwa-prompt-content {
        flex-direction: column;
        text-align: center;
    }
    
    .pwa-prompt-actions {
        width: 100%;
    }
    
    .pwa-btn {
        flex: 1;
    }
    
    .btn-group {
        gap: 4px;
    }
    
    button {
        padding: 4px 6px;
        font-size: 12px;
    }
}