/* Copyright (c) Microsoft Corporation.
   Licensed under the MIT License. */

/* Ensures padding/border are included in width/height */
*,
*::before,
*::after {
  box-sizing: border-box;
}

/* Ensures the page fills the panel height */
html {
  height: 100%;
}

:root {
  color-scheme: light dark;

  /* Shared corner rounding for badges, code blocks, buttons... */
  --radius: 4px;
  /* Page background. Matches the VS Code editor so the panel blends in */
  --bg: var(--vscode-editor-background, transparent);
  /* Body text color. */
  --fg: var(--vscode-editor-foreground, #1a1a1a);
  /* De-emphasized text for labels, breadcrumbs... */
  --muted: var(--vscode-descriptionForeground, #6a6a6a);
  /* Interactive/link color — hyperlinks, active indicators, default output accent */
  --accent: var(--vscode-textLink-foreground, #06c);
  /* Hovered link color */
  --accent-hover: var(--vscode-textLink-activeForeground, var(--accent));
  /* Separators and outlines throughout the panel  */
  --border: var(--vscode-widget-border, var(--vscode-panel-border, #e0e0e0));
  /* Green for passed checks */
  --success: var(
    --vscode-charts-green,
    var(--vscode-testing-iconPassed, #1a7f37)
  );
  /* Red for failed checks and error messages */
  --fail: var(--vscode-errorForeground, var(--vscode-charts-red, #cf222e));
  /* Subtle tinted background for code blocks, badges, and the output card */
  --code-bg: var(--vscode-textCodeBlock-background, rgb(127 127 127 / 8%));
  /* Primary action button fill (e.g., "Check", "Next") */
  --btn-bg: var(--vscode-button-background, var(--accent));
  /* Primary action button text */
  --btn-fg: var(--vscode-button-foreground, #fff);
  /* Primary action button on hover */
  --btn-hover-bg: var(
    --vscode-button-hoverBackground,
    color-mix(in srgb, var(--accent) 85%, black)
  );
  /* Secondary button fill (e.g., "Back", "Hint") */
  --btn-secondary-bg: var(--vscode-button-secondaryBackground, transparent);
  /* Secondary button text */
  --btn-secondary-fg: var(--vscode-button-secondaryForeground, var(--fg));
  /* Hover tint for secondary buttons and the progress footer */
  --btn-secondary-hover-bg: var(
    --vscode-button-secondaryHoverBackground,
    rgb(127 127 127 / 10%)
  );
  /* Keyboard-focus ring shown on all interactive elements */
  --focus-border: var(--vscode-focusBorder, var(--accent));
  /* UI (sans-serif) font used for all non-code text */
  --ui-font: var(
    --vscode-font-family,
    system-ui,
    -apple-system,
    "Segoe UI",
    sans-serif
  );
  /* Monospace font for inline code and fenced code blocks */
  --mono-font: var(
    --vscode-editor-font-family,
    ui-monospace,
    "Cascadia Mono",
    Menlo,
    Monaco,
    Consolas,
    monospace
  );

  /* Font sizes — all text sizes in the panel, largest to smallest */
  --font-h1: 17px;
  --font-h2: 16px;
  --font-h3: 15px;
  --font-icon: 14px;
  --body-font-size: var(--vscode-font-size, 13px);
  --font-sm: var(--vscode-bodyFontSize-small, 12px);
  --font-xs: var(--vscode-bodyFontSize-xSmall, 11px);
}

/* Sets up a flex column layout so the panel stacks: branding → header → content → output → action-bar → progress-bar. */
body {
  font: var(--body-font-size) / 1.45 var(--ui-font);
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  display: flex;
  flex-direction: column;
  height: 100%;
}

/* Logo and text at the top of the panel. */
.branding {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 7px 12px;
  border-bottom: 1px solid var(--border);
  /* Prevent this bar from shrinking when the flex column is tight */
  flex-shrink: 0;
}

/* Logo icon rendered as a CSS mask so it inherits the current theme color. */
.branding-icon {
  width: 18px;
  height: 18px;
  /* Don't let the logo shrink if the text beside it is long */
  flex-shrink: 0;
  background-color: var(--fg);
  mask-image: var(--mobius-url);
  mask-size: contain;
  mask-repeat: no-repeat;
}

/* Logo text label. */
.branding-text {
  font-size: var(--font-sm);
  font-weight: 600;
  letter-spacing: 0.02em;
  color: var(--muted);
}

/* Breadcrumb bar showing "Unit › Activity" and a type badge. */
.header {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 6px 12px;
  border-bottom: 1px solid var(--border);
  font-size: var(--font-xs);
  color: var(--muted);
  /* Keep this bar fixed-height even when content pushes the flex column */
  flex-shrink: 0;
}

/* Breadcrumb text — truncates with ellipsis when the panel is narrow. */
.header .crumb {
  flex: 1;
  /* Required for ellipsis to work inside a flex item */
  min-width: 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

/* Type badge ("lesson", "example", "exercise", "✔ done"). */
.header .badge {
  text-transform: uppercase;
  letter-spacing: 0.05em;
  padding: 1px 6px;
  border-radius: 3px;
  background: var(--code-bg);
  /* Slightly stronger than the muted crumb text so the badge pops */
  color: var(--fg);
}

/* Badge variant: completed exercise — green "done" state. */
.header .badge.complete {
  background: var(--success);
  color: #fff;
}

/* Main scrollable area holding rendered Markdown (lessons, examples, exercises). */
.content {
  padding: 12px 16px;
  overflow-y: auto; /* this is the panel's scroll container */
  flex: 1; /* fill all remaining vertical space */
  min-height: 0; /* let flex item shrink below content size so overflow scrolls */
}

/* Markdown headings — tighter margins than browser defaults. */
.content h1,
.content h2,
.content h3 {
  margin: 6px 0 5px;
}

.content h1 {
  font-size: var(--font-h1);
}

.content h2 {
  font-size: var(--font-h2);
}

.content h3 {
  font-size: var(--font-h3);
}

/* Markdown paragraphs. */
.content p {
  margin: 6px 0;
}

/* Markdown lists. */
.content ul,
.content ol {
  margin: 6px 0;
  padding-left: 21px;
}

/* Fenced code blocks. */
.content pre {
  background: var(--code-bg);
  padding: 6px 8px;
  border-radius: var(--radius);
  overflow-x: auto; /* horizontal scroll for wide code */
  font-size: var(--font-sm);
  margin: 5px 0;
}

/* Inline and block code. */
.content code {
  font-family: var(--mono-font);
}

/* Markdown tables. */
.content table {
  border-collapse: collapse;
  margin: 4px 0;
  font-size: var(--font-sm);
}

.content th,
.content td {
  border: 1px solid var(--border);
  padding: 2px 6px;
  text-align: left; /* override default center-align on <th> */
}

/* Small muted note below content: "Your code file should be open…" */
.content .file-path {
  font-size: var(--font-xs);
  color: var(--muted);
  margin-top: 8px;
}

/* "open it here" link inside the file-path note. */
.content .file-path-link {
  color: var(--accent);
  text-decoration: none;
}

.content .file-path-link:hover {
  text-decoration: underline;
}

.content .file-path-link:focus-visible {
  outline: 1px solid var(--focus-border);
  outline-offset: 1px;
}

/* Green "✓ Correct!" banner shown when an exercise is complete. */
.content .completion-banner {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  margin-top: 10px;
  padding: 5px 11px;
  border-radius: var(--radius);
  background: color-mix(in srgb, var(--success) 12%, transparent);
  color: var(--success);
  font-size: var(--font-sm);
  font-weight: 600;
}

/* Used by: <Exercise /> — the "✓" checkmark <span> inside the completion banner. */
.completion-banner .completion-icon {
  font-size: var(--font-icon);
}

/* Result/output card between content and action bar. Color-coded left border
   indicates status (accent = neutral, green = pass, red = fail). */
.output {
  margin: 0 16px 8px;
  padding: 6px 10px;
  border-radius: var(--radius);
  background: var(--code-bg);
  font-size: var(--font-sm);
  border-left: 3px solid var(--accent);
  position: relative; /* anchors the absolute dismiss button */
  flex-shrink: 0;
}

/* Left-border override: tests passed. */
.output.pass {
  border-left-color: var(--success);
}

/* Left-border override: check failed or error. */
.output.fail {
  border-left-color: var(--fail);
}

/* "RESULT" / "OUTPUT" label at the top of the card. */
.output .out-label {
  font-size: var(--font-xs);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--muted);
  margin-bottom: 4px;
}

/* "×" dismiss button pinned to the top-right corner. */
.output .out-dismiss {
  position: absolute;
  top: 4px;
  right: 4px;
  background: none; /* reset UA button style */
  border: none; /* reset UA button style */
  color: var(--muted);
  cursor: pointer;
  font-size: var(--font-icon);
  line-height: 1; /* prevent extra height from line-height on the "×" glyph */
  padding: 2px 5px;
}

.output .out-dismiss:hover {
  color: var(--fg);
}

.output .out-dismiss:focus-visible {
  outline: 1px solid var(--focus-border);
  outline-offset: 1px;
}

/* Green "✔ All tests passed!" text. */
.output .success {
  color: var(--success);
  white-space: pre-wrap;
}

/* Red "✘ Check failed" or error message text. */
.output .out-fail {
  color: var(--fail);
  white-space: pre-wrap;
}

/* Runtime messages (DumpMachine output, etc.) shown in mono. */
.output .message {
  font-family: var(--mono-font);
  white-space: pre-wrap;
}

/* Bottom toolbar with grouped action buttons (Back, Next, Check, Run, Hint…). */
.action-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 5px;
  padding: 6px 12px;
  border-top: 1px solid var(--border);
  flex-shrink: 0;
}

/* Button group — separated from siblings by a vertical rule. */
.action-group {
  display: flex;
  gap: 4px;
}

.action-group:not(:last-child) {
  padding-right: 6px;
  border-right: 1px solid var(--border);
}

/* Base button style (secondary appearance by default). */
.action-bar button {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  font: inherit; /* buttons don't inherit font by default */
  font-size: var(--font-sm);
  background: var(--btn-secondary-bg);
  color: var(--btn-secondary-fg);
  border: 1px solid var(--border);
  padding: 3px 9px;
  border-radius: var(--radius);
  cursor: pointer;
}

.action-bar button:hover {
  background: var(--btn-secondary-hover-bg);
  border-color: var(--accent);
}

.action-bar button:focus-visible {
  outline: 1px solid var(--focus-border);
  outline-offset: 1px;
}

/* Primary action button ("Check", "Next") — filled accent background. */
.action-bar button.primary {
  background: var(--btn-bg);
  color: var(--btn-fg);
  border-color: var(--btn-bg);
}

.action-bar button.primary:hover {
  background: var(--btn-hover-bg);
  border-color: var(--btn-hover-bg);
}

/* Disabled state while a check/run is in progress. */
.action-bar button:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

/* Clickable footer showing completion stats and activity dots.
   Opens the progress tree view on click. */
.progress-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  align-items: center;
  font-size: var(--font-xs);
  padding: 5px 12px;
  color: var(--muted);
  border-top: 1px solid var(--border);
  flex-shrink: 0;
  cursor: pointer;
}

.progress-bar:hover {
  background: var(--btn-secondary-hover-bg);
}

.progress-bar:focus-visible {
  outline: 1px solid var(--focus-border);
  outline-offset: -1px; /* inset because this sits at the viewport edge */
}

/* Row of small colored dots (one per activity in the current unit). */
.pb-segments {
  display: inline-flex;
  gap: 2px;
}

/* Individual activity dot — gray (not started) by default. */
.pb-seg {
  display: inline-block;
  width: 8px;
  height: 8px;
  border-radius: 2px;
  background: var(--border);
}

/* Completed activity dot (green). */
.pb-seg.done {
  background: var(--success);
}

/* Currently active activity dot (accent blue). */
.pb-seg.current {
  background: var(--accent);
}

/* "What went wrong?" link — opens Copilot Chat with a help prompt. */
.chat-link {
  display: inline-block;
  margin-top: 7px;
  font-size: var(--font-sm);
  color: var(--accent);
  cursor: pointer;
  text-decoration: none;
}

.chat-link:hover {
  text-decoration: underline;
  color: var(--accent-hover);
}

.chat-link:focus-visible {
  outline: 1px solid var(--focus-border);
  outline-offset: 1px;
}

/* "Loading…" / "Working…" placeholder text. */
.loading {
  color: var(--muted);
  font-style: italic;
}
