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

:root {
    --bg-primary: #1e1e2e;
    --bg-secondary: #282a36;
    --bg-tertiary: #2d2f3f;
    --text-primary: #f8f8f2;
    --text-secondary: #6272a4;
    --accent-green: #50fa7b;
    --accent-red: #ff5555;
    --accent-yellow: #f1fa8c;
    --border: #44475a;
    --header-height: 56px;
    --font-mono: 'SF Mono', 'Fira Code', 'Consolas', monospace;
    --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', system-ui, sans-serif;
}

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

/* Header */
header {
    height: var(--header-height);
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 20px;
    flex-shrink: 0;
}

header h1 {
    font-size: 18px;
    font-weight: 600;
    letter-spacing: -0.3px;
}

header h1 .subtitle {
    font-size: 13px;
    font-weight: 400;
    color: var(--text-secondary);
    margin-left: 8px;
}

.controls {
    display: flex;
    align-items: center;
    gap: 10px;
}

.btn {
    font-family: var(--font-sans);
    font-size: 13px;
    font-weight: 600;
    padding: 8px 20px;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    transition: opacity 0.15s, transform 0.1s;
}

.btn:active {
    transform: scale(0.97);
}

.btn:disabled {
    opacity: 0.4;
    cursor: not-allowed;
    transform: none;
}

.btn-run {
    background: var(--accent-green);
    color: var(--bg-primary);
}

.btn-stop {
    background: var(--accent-red);
    color: white;
}

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

.editor-toolbar {
    display: flex;
    align-items: center;
    padding: 0 10px;
    background: #21222c;
    border-bottom: 1px solid var(--border);
    height: 30px;
    flex-shrink: 0;
}

.panel-label-inline {
    font-size: 10px;
    text-transform: uppercase;
    letter-spacing: 1.5px;
    color: #6272a4;
    font-family: var(--font-mono);
}

.editor-toolbar-right {
    margin-left: auto;
    display: flex;
    align-items: center;
    gap: 2px;
}

.toolbar-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 26px;
    height: 22px;
    border: none;
    border-radius: 4px;
    background: transparent;
    color: #8be9fd;
    cursor: pointer;
    padding: 0;
    transition: background 0.12s;
}

.toolbar-btn:hover {
    background: rgba(139, 233, 253, 0.15);
}

.toolbar-btn:active {
    background: rgba(139, 233, 253, 0.25);
}

.toolbar-btn svg {
    display: block;
}

.file-indicator {
    font-size: 11px;
    color: #6272a4;
    font-family: var(--font-mono);
    margin-right: 6px;
    max-width: 100px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.file-note {
    font-size: 12px;
    font-weight: 400;
    color: var(--text-secondary);
    margin-left: 8px;
}

.file-list {
    flex: 1;
    overflow-y: auto;
    padding: 12px 20px;
}

.file-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 10px 12px;
    border-radius: 6px;
    margin-bottom: 4px;
    cursor: pointer;
    transition: background 0.15s;
}

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

.file-item-name {
    font-family: var(--font-mono);
    font-size: 13px;
}

.btn-file-delete {
    background: transparent;
    border: none;
    color: var(--text-secondary);
    font-size: 14px;
    cursor: pointer;
    padding: 2px 8px;
    border-radius: 4px;
}

.btn-file-delete:hover {
    background: var(--accent-red);
    color: white;
}

.example-select {
    font-family: var(--font-sans);
    font-size: 12px;
    padding: 6px 10px;
    border: 1px solid var(--border);
    border-radius: 6px;
    background: var(--bg-tertiary);
    color: var(--text-primary);
    cursor: pointer;
    min-width: 140px;
}

.example-select:focus {
    outline: none;
    border-color: var(--accent-green);
}

.status {
    font-size: 12px;
    color: var(--text-secondary);
    padding: 4px 12px;
    border-radius: 4px;
    background: var(--bg-tertiary);
}

.status-ready {
    color: var(--accent-green);
}

.status-running {
    color: var(--accent-yellow);
}

.status-error {
    color: var(--accent-red);
}

/* Main layout */
main {
    display: flex;
    flex: 1;
    overflow: hidden;
}

/* Editor panel */
.editor-panel {
    flex: 1;
    display: flex;
    flex-direction: column;
    border-right: 1px solid var(--border);
    min-width: 0;
}

.panel-label {
    font-size: 10px;
    text-transform: uppercase;
    letter-spacing: 1.5px;
    color: var(--text-secondary);
    padding: 6px 14px;
    background: var(--bg-tertiary);
    border-bottom: 1px solid var(--border);
    font-family: var(--font-mono);
}

/* Overlay / modal for README */
.overlay {
    position: fixed;
    inset: 0;
    z-index: 1000;
    display: flex;
    align-items: center;
    justify-content: center;
}

.overlay.hidden {
    display: none;
}

.overlay-backdrop {
    position: absolute;
    inset: 0;
    background: rgba(0,0,0,0.7);
}

.overlay-content {
    position: relative;
    width: 80%;
    max-width: 800px;
    max-height: 85vh;
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 8px;
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

.overlay-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 16px 20px;
    border-bottom: 1px solid var(--border);
    flex-shrink: 0;
}

.overlay-header h2 {
    font-size: 18px;
    font-weight: 600;
}

.btn-close {
    background: transparent;
    border: none;
    color: var(--text-secondary);
    font-size: 24px;
    cursor: pointer;
    padding: 0 4px;
    line-height: 1;
}

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

#readme-body {
    flex: 1;
    overflow-y: auto;
    padding: 20px;
}

#readme-body.markdown-body {
    background: var(--bg-secondary);
    color: var(--text-primary);
}

#readme-body.markdown-body code {
    background: var(--bg-tertiary);
    border-radius: 3px;
}

#readme-body.markdown-body pre {
    background: var(--bg-tertiary);
    border: 1px solid var(--border);
    border-radius: 4px;
}

.CodeMirror {
    flex: 1;
    height: auto !important;
    font-size: 14px;
    line-height: 1.5;
}

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

/* Canvas panel */
.canvas-panel {
    width: 820px;
    min-width: 400px;
    display: flex;
    flex-direction: column;
    flex-shrink: 0;
}

.canvas-controls {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 6px 12px;
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border);
    flex-shrink: 0;
}

.canvas-wrapper {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-primary);
    padding: 20px;
    min-height: 0;
}

#game-canvas {
    border: 1px solid var(--border);
    border-radius: 4px;
    background: grey;
    max-width: 100%;
    max-height: 100%;
}

#game-canvas:focus {
    outline: none;
    border-color: var(--accent-green);
}

.console-wrapper {
    height: 140px;
    display: flex;
    flex-direction: column;
    border-top: 1px solid var(--border);
    flex-shrink: 0;
}

#console {
    flex: 1;
    background: var(--bg-secondary);
    color: var(--text-primary);
    font-family: var(--font-mono);
    font-size: 12px;
    padding: 8px 14px;
    overflow-y: auto;
    white-space: pre-wrap;
    line-height: 1.4;
}