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

:root {
    --bg-primary: #0d1117;
    --bg-secondary: #161b22;
    --bg-tertiary: #21262d;
    --bg-hover: #30363d;
    --border: #30363d;
    --text-primary: #e6edf3;
    --text-secondary: #8b949e;
    --text-muted: #6e7681;
    --accent: #58a6ff;
    --accent-hover: #79b8ff;
    --html-color: #e34c26;
    --css-color: #264de4;
    --js-color: #f7df1e;
    --success: #3fb950;
    --warning: #d29922;
    --error: #f85149;
    --font-mono: 'JetBrains Mono', 'Fira Code', 'Consolas', monospace;
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
}

html, body {
    height: 100%;
    overflow: hidden;
}

body {
    font-family: var(--font-sans);
    background: var(--bg-primary);
    color: var(--text-primary);
    display: flex;
    flex-direction: column;
}

/* ===== HEADER ===== */
.header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 16px;
    height: 52px;
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border);
    flex-shrink: 0;
}

.back-link {
    display: flex;
    align-items: center;
    gap: 8px;
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 14px;
    padding: 6px 10px;
    border-radius: 6px;
    transition: all 0.2s;
}

.back-link:hover {
    color: var(--text-primary);
    background: var(--bg-hover);
}

.title {
    font-size: 16px;
    font-weight: 600;
    color: var(--text-primary);
}

.header-actions {
    display: flex;
    align-items: center;
    gap: 8px;
}

/* ===== BUTTONS ===== */
.btn {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    padding: 8px 12px;
    background: var(--bg-tertiary);
    border: 1px solid var(--border);
    border-radius: 6px;
    color: var(--text-primary);
    font-size: 13px;
    font-family: var(--font-sans);
    cursor: pointer;
    transition: all 0.2s;
}

.btn:hover {
    background: var(--bg-hover);
    border-color: var(--text-muted);
}

.btn-icon {
    padding: 8px;
}

.btn-sm {
    padding: 4px 8px;
    font-size: 12px;
}

.btn-xs {
    padding: 2px 6px;
    font-size: 11px;
}

/* ===== CUSTOM DROPDOWN ===== */
.dropdown {
    position: relative;
}

.dropdown-toggle {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 8px 12px;
    background: linear-gradient(135deg, var(--bg-tertiary) 0%, #282e36 100%);
    border: 1px solid var(--border);
    border-radius: 8px;
    color: var(--text-primary);
    font-size: 13px;
    font-family: var(--font-sans);
    cursor: pointer;
    transition: all 0.2s;
}

.dropdown-toggle:hover {
    background: linear-gradient(135deg, var(--bg-hover) 0%, #363d47 100%);
    border-color: var(--text-muted);
}

.dropdown-toggle:focus {
    outline: none;
    border-color: var(--accent);
    box-shadow: 0 0 0 2px rgba(88, 166, 255, 0.2);
}

.dropdown-arrow {
    transition: transform 0.2s;
}

.dropdown.open .dropdown-arrow {
    transform: rotate(180deg);
}

.dropdown-menu {
    position: absolute;
    top: calc(100% + 6px);
    right: 0;
    min-width: 220px;
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 10px;
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.4);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-8px);
    transition: all 0.2s ease;
    z-index: 100;
    padding: 6px;
    max-height: 320px;
    overflow-y: auto;
}

.dropdown.open .dropdown-menu {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.dropdown-item {
    display: flex;
    align-items: center;
    gap: 12px;
    width: 100%;
    padding: 10px 12px;
    background: transparent;
    border: none;
    border-radius: 6px;
    color: var(--text-primary);
    font-size: 13px;
    font-family: var(--font-sans);
    cursor: pointer;
    transition: all 0.15s;
    text-align: left;
}

.dropdown-item:hover {
    background: var(--bg-hover);
}

.dropdown-item:active {
    background: var(--accent);
    color: #000;
}

.dropdown-item-icon {
    width: 24px;
    height: 24px;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    color: var(--accent);
}

.dropdown-item-icon svg {
    width: 20px;
    height: 20px;
}

.dropdown-item-title {
    font-weight: 500;
    margin-bottom: 2px;
}

.dropdown-item-desc {
    font-size: 11px;
    color: var(--text-muted);
}

.dropdown-item:hover .dropdown-item-desc {
    color: var(--text-secondary);
}

/* ===== MAIN LAYOUT ===== */
.main {
    flex: 1;
    display: flex;
    overflow: hidden;
}

/* ===== EDITORS PANEL ===== */
.editors-panel {
    width: 50%;
    min-width: 300px;
    display: flex;
    flex-direction: column;
    background: var(--bg-primary);
}

/* Tabs */
.tabs {
    display: flex;
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border);
    padding: 0 8px;
}

.tab {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 10px 16px;
    background: transparent;
    border: none;
    border-bottom: 2px solid transparent;
    color: var(--text-secondary);
    font-size: 13px;
    font-family: var(--font-sans);
    cursor: pointer;
    transition: all 0.2s;
}

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

.tab.active {
    color: var(--text-primary);
    border-bottom-color: var(--accent);
}

.tab-icon {
    font-family: var(--font-mono);
    font-size: 12px;
    font-weight: 600;
    padding: 2px 4px;
    border-radius: 3px;
}

.html-icon {
    background: rgba(227, 76, 38, 0.2);
    color: var(--html-color);
}

.css-icon {
    background: rgba(38, 77, 228, 0.2);
    color: var(--css-color);
}

.js-icon {
    background: rgba(247, 223, 30, 0.2);
    color: var(--js-color);
}

/* Editors */
.editors {
    flex: 1;
    position: relative;
    overflow: hidden;
}

.editor-container {
    position: absolute;
    inset: 0;
    display: none;
    flex-direction: column;
}

.editor-container.active {
    display: flex;
}

.editor-header {
    display: flex;
    align-items: center;
    padding: 6px 12px;
    background: var(--bg-tertiary);
    border-bottom: 1px solid var(--border);
    font-size: 12px;
    color: var(--text-secondary);
}

.editor-wrapper {
    flex: 1;
    display: flex;
    overflow: hidden;
    position: relative;
}

/* CodeMirror Overrides */
.editor-wrapper .CodeMirror {
    position: absolute;
    inset: 0;
    width: 100%;
    height: 100%;
    font-family: var(--font-mono);
    font-size: 13px;
    line-height: 1.6;
    background: var(--bg-primary);
}

.CodeMirror-gutters {
    background: var(--bg-secondary) !important;
    border-right: 1px solid var(--border) !important;
}

.CodeMirror-linenumber {
    color: var(--text-muted) !important;
    padding: 0 8px 0 4px !important;
}

.CodeMirror-cursor {
    border-left: 2px solid var(--accent) !important;
}

.CodeMirror-selected {
    background: rgba(88, 166, 255, 0.2) !important;
}

.CodeMirror-matchingbracket {
    color: var(--success) !important;
    background: rgba(63, 185, 80, 0.2) !important;
}

/* ===== RESIZER ===== */
.resizer {
    width: 6px;
    background: var(--bg-secondary);
    cursor: col-resize;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background 0.2s;
}

.resizer:hover {
    background: var(--accent);
}

.resizer-line {
    width: 2px;
    height: 40px;
    background: var(--border);
    border-radius: 1px;
}

.resizer:hover .resizer-line {
    background: var(--text-primary);
}

/* ===== PREVIEW PANEL ===== */
.preview-panel {
    flex: 1;
    min-width: 300px;
    display: flex;
    flex-direction: column;
    background: var(--bg-secondary);
}

.preview-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 8px 12px;
    background: var(--bg-tertiary);
    border-bottom: 1px solid var(--border);
}

.preview-title {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 13px;
    color: var(--text-secondary);
}

.preview-actions {
    display: flex;
    gap: 4px;
}

.preview-container {
    flex: 1;
    background: #ffffff;
    overflow: hidden;
}

#preview {
    width: 100%;
    height: 100%;
    border: none;
    background: #ffffff;
}

/* ===== CONSOLE ===== */
.console-panel {
    height: 120px;
    display: flex;
    flex-direction: column;
    background: var(--bg-primary);
    border-top: 1px solid var(--border);
}

.console-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 6px 12px;
    background: var(--bg-tertiary);
    border-bottom: 1px solid var(--border);
    font-size: 12px;
    color: var(--text-secondary);
}

.console-output {
    flex: 1;
    padding: 8px 12px;
    overflow-y: auto;
    font-family: var(--font-mono);
    font-size: 12px;
    line-height: 1.5;
}

.console-line {
    padding: 2px 0;
    border-bottom: 1px solid var(--border);
}

.console-line:last-child {
    border-bottom: none;
}

.console-log {
    color: var(--text-primary);
}

.console-warn {
    color: var(--warning);
}

.console-error {
    color: var(--error);
}

.console-info {
    color: var(--accent);
}

/* ===== MOBILE TABS ===== */
.mobile-tabs {
    display: none;
    background: var(--bg-secondary);
    border-top: 1px solid var(--border);
    padding: 8px;
    gap: 8px;
}

.mobile-tab {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 12px;
    background: var(--bg-tertiary);
    border: 1px solid var(--border);
    border-radius: 8px;
    color: var(--text-secondary);
    font-size: 14px;
    font-family: var(--font-sans);
    cursor: pointer;
    transition: all 0.2s;
}

.mobile-tab:hover {
    background: var(--bg-hover);
}

.mobile-tab.active {
    background: var(--accent);
    border-color: var(--accent);
    color: #000;
}

/* ===== RESPONSIVE ===== */
@media (max-width: 900px) {
    .main {
        flex-direction: column;
    }

    .editors-panel {
        width: 100%;
        height: 50%;
        min-width: auto;
    }

    .preview-panel {
        min-width: auto;
    }

    .resizer {
        width: 100%;
        height: 6px;
        cursor: row-resize;
    }

    .resizer-line {
        width: 40px;
        height: 2px;
    }

    .console-panel {
        height: 80px;
    }
}

@media (max-width: 600px) {
    .header {
        padding: 0 12px;
        height: 48px;
    }

    .back-link span {
        display: none;
    }

    .title {
        font-size: 14px;
    }

    .dropdown-toggle span {
        display: none;
    }

    .dropdown-toggle {
        padding: 8px 10px;
    }

    .dropdown-menu {
        right: -8px;
        min-width: 200px;
    }

    .main {
        flex-direction: column;
    }

    .editors-panel,
    .preview-panel {
        position: absolute;
        inset: 48px 0 56px 0;
        width: 100%;
        height: auto;
        transition: transform 0.3s ease;
    }

    .preview-panel {
        transform: translateX(100%);
    }

    body.show-preview .editors-panel {
        transform: translateX(-100%);
    }

    body.show-preview .preview-panel {
        transform: translateX(0);
    }

    .resizer {
        display: none;
    }

    .mobile-tabs {
        display: flex;
    }

    .console-panel {
        height: 60px;
    }

    .console-output {
        font-size: 11px;
    }
}

/* ===== SCROLLBAR ===== */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

::-webkit-scrollbar-track {
    background: var(--bg-secondary);
}

::-webkit-scrollbar-thumb {
    background: var(--bg-hover);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--text-muted);
}

/* ===== SELECTION ===== */
::selection {
    background: rgba(88, 166, 255, 0.3);
}