/* ============================================================
   CIS Linux Tutorial — base styles
   ============================================================ */

:root {
  --bg:               #0f1419;
  --surface:          #1a2028;
  --surface-2:        #232b36;
  --border:           #2d3845;
  --text:             #e6edf3;
  --text-muted:       #8b9ba8;
  --accent:           #4fc3f7;
  --accent-dim:       #2a8db5;
  --success:          #4caf50;
  --warn:             #ffb74d;
  --danger:           #ef5350;
  --critical:         #d32f2f;
  --high:             #f57c00;
  --medium:           #fbc02d;
  --code-bg:          #0a0e13;
  --radius:           6px;
  --gap:              16px;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  font-size: 15px;
  line-height: 1.6;
  background: var(--bg);
  color: var(--text);
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

code, pre, .mono { font-family: "SF Mono", Menlo, Consolas, monospace; }

/* ---- Layout ---- */

.layout {
  display: grid;
  grid-template-columns: 280px 1fr;
  min-height: calc(100vh - 56px);
}
.sidebar {
  background: var(--surface);
  border-right: 1px solid var(--border);
  padding: 16px 0;
  overflow-y: auto;
}
.main {
  padding: 32px 48px;
  max-width: 920px;
}

/* ---- Header ---- */

.header {
  height: 56px;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  padding: 0 16px;
  gap: 16px;
  position: sticky;
  top: 0;
  z-index: 10;
}
.header-title { font-weight: 600; font-size: 16px; }
.header-progress { flex: 1; display: flex; align-items: center; gap: 12px; max-width: 400px; }
.progress-text { font-size: 12px; color: var(--text-muted); white-space: nowrap; }
.progress-bar {
  flex: 1;
  height: 6px;
  background: var(--surface-2);
  border-radius: 3px;
  overflow: hidden;
}
.progress-fill {
  height: 100%;
  background: var(--accent);
  transition: width 0.3s ease;
}
.header-actions { display: flex; align-items: center; gap: 8px; }
.btn-icon {
  background: none; border: none; color: var(--text-muted);
  font-size: 18px; cursor: pointer; padding: 4px 8px; border-radius: var(--radius);
}
.btn-icon:hover { background: var(--surface-2); color: var(--text); }

/* ---- Sidebar nav ---- */

.nav-section-label {
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-muted);
  padding: 12px 16px 4px;
}
.nav-item {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 16px;
  color: var(--text-muted);
  cursor: pointer;
  font-size: 14px;
  border-left: 3px solid transparent;
}
.nav-item:hover { background: var(--surface-2); color: var(--text); }
.nav-item.active {
  background: var(--surface-2);
  color: var(--text);
  border-left-color: var(--accent);
}
.nav-item .check {
  width: 16px; height: 16px;
  border-radius: 50%;
  border: 1px solid var(--border);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 11px;
}
.nav-item.complete .check {
  background: var(--success);
  border-color: var(--success);
  color: white;
}
.nav-item-num { font-size: 11px; color: var(--text-muted); min-width: 16px; }

/* ---- Main content ---- */

h1 { font-size: 28px; margin: 0 0 8px; }
h2 { font-size: 20px; margin: 32px 0 12px; }
h3 { font-size: 16px; margin: 20px 0 8px; }
p  { margin: 0 0 12px; }

.lesson-meta {
  font-size: 12px;
  color: var(--text-muted);
  display: flex;
  gap: 12px;
  margin-bottom: 24px;
}
.lesson-meta span:not(:last-child)::after { content: "·"; margin-left: 12px; }

.lesson-block {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px 24px;
  margin: 16px 0;
}
.lesson-block .block-icon {
  display: inline-block;
  margin-right: 8px;
  font-size: 18px;
}
.lesson-block h2 { margin-top: 0; }

/* ---- Code blocks ---- */

pre {
  background: var(--code-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 12px 16px;
  overflow-x: auto;
  margin: 8px 0;
  position: relative;
}
pre code { font-size: 13px; color: var(--text); white-space: pre; }
.copy-btn {
  position: absolute;
  top: 8px; right: 8px;
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: 4px;
  color: var(--text-muted);
  font-size: 11px;
  padding: 2px 8px;
  cursor: pointer;
}
.copy-btn:hover { color: var(--text); }
code:not(pre code) {
  background: var(--code-bg);
  border-radius: 3px;
  padding: 1px 6px;
  font-size: 13px;
}

/* ---- Callouts ---- */

.callout {
  border-left: 4px solid var(--accent);
  padding: 12px 16px;
  margin: 16px 0;
  background: var(--surface-2);
  border-radius: 4px;
}
.callout.warn   { border-left-color: var(--warn); }
.callout.danger { border-left-color: var(--danger); }
.callout-title  { font-weight: 600; margin-bottom: 4px; }

details.refresher { margin: 12px 0; }
details.refresher > summary {
  cursor: pointer;
  color: var(--text-muted);
  font-size: 13px;
  padding: 6px 0;
}
details.refresher[open] > summary { color: var(--text); margin-bottom: 8px; }

/* ---- Checks ---- */

.check-list { list-style: none; padding: 0; margin: 8px 0; }
.check-list li {
  display: flex;
  gap: 12px;
  padding: 8px 0;
  border-bottom: 1px solid var(--border);
}
.check-list li:last-child { border-bottom: none; }
.check-list input[type=checkbox] {
  margin-top: 4px;
  accent-color: var(--accent);
  cursor: pointer;
}
.check-list .severity {
  display: inline-block;
  font-size: 10px;
  padding: 1px 6px;
  border-radius: 8px;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  margin-left: 8px;
  vertical-align: middle;
}
.severity-critical { background: var(--critical); color: white; }
.severity-high     { background: var(--high);     color: white; }
.severity-medium   { background: var(--medium);   color: black; }

/* ---- Notes ---- */

textarea {
  width: 100%;
  min-height: 80px;
  background: var(--code-bg);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 8px 12px;
  font-family: inherit;
  font-size: 14px;
  resize: vertical;
}

/* ---- Footer / Prev-Next ---- */

.lesson-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-top: 48px;
  padding-top: 24px;
  border-top: 1px solid var(--border);
  gap: 12px;
}
.btn {
  background: var(--surface-2);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 10px 18px;
  border-radius: var(--radius);
  font-size: 14px;
  cursor: pointer;
  text-decoration: none;
}
.btn:hover { background: var(--accent-dim); color: white; border-color: var(--accent-dim); }
.btn-primary { background: var(--accent); border-color: var(--accent); color: var(--bg); font-weight: 600; }
.btn-primary:hover { background: var(--accent-dim); color: white; }
.btn[disabled], .btn.disabled { opacity: 0.5; cursor: not-allowed; }

/* ---- Settings overlay ---- */

.overlay {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.7);
  display: none;
  align-items: center;
  justify-content: center;
  z-index: 100;
}
.overlay.open { display: flex; }
.panel {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  max-width: 480px;
  width: 90%;
}
.form-group { margin-bottom: 16px; }
.form-group label {
  display: block;
  font-size: 13px;
  margin-bottom: 4px;
  color: var(--text-muted);
}
.form-group input {
  width: 100%;
  padding: 8px 12px;
  background: var(--code-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  color: var(--text);
  font-size: 14px;
}
.danger-btn {
  background: transparent;
  border: 1px solid var(--danger);
  color: var(--danger);
}
.danger-btn:hover { background: var(--danger); color: white; }

/* ---- Lab path cards (Lesson 0) ---- */

.path-cards { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 16px; }
.path-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
  cursor: pointer;
}
.path-card:hover { border-color: var(--accent); }
.path-card.recommended { border-color: var(--accent); }
.path-card .pill {
  display: inline-block;
  font-size: 10px;
  text-transform: uppercase;
  background: var(--accent);
  color: var(--bg);
  padding: 2px 6px;
  border-radius: 3px;
  margin-bottom: 8px;
}

/* ---- Findings table (report) ---- */

table.findings {
  width: 100%;
  border-collapse: collapse;
  font-size: 14px;
  margin: 16px 0;
}
table.findings th, table.findings td {
  text-align: left;
  padding: 8px 12px;
  border-bottom: 1px solid var(--border);
}
table.findings th { background: var(--surface-2); font-weight: 600; font-size: 13px; }
.status-pass { color: var(--success); font-weight: 600; }
.status-fail { color: var(--danger);  font-weight: 600; }
.status-na   { color: var(--text-muted); font-weight: 600; }

/* ---- Narrow / mobile ---- */

@media (max-width: 800px) {
  .layout { grid-template-columns: 1fr; }
  .sidebar { display: none; }
  .main { padding: 20px; }
  .header-progress { display: none; }
}

/* ---- Save status ---- */
.save-status {
  font-size: 12px;
  color: var(--text-muted);
  min-width: 60px;
  text-align: right;
}
.save-status.saving { color: var(--warn); }
.save-status.saved  { color: var(--success); }

/* ============================================================
   v86 lab edition — embedded Linux side-by-side
   Shared by all lessons/NNa-*-vm.html pages.
   ============================================================ */

.main-lab          { max-width: none; padding: 24px 32px; }
.lab-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: 24px;
  align-items: start;
}
@media (max-width: 1200px) {
  .lab-grid     { grid-template-columns: 1fr; }
  .vm-panel     { position: static !important; height: auto !important; }
}

.lab-blurb {
  background: var(--surface);
  border: 1px solid var(--border);
  border-left: 3px solid var(--accent);
  padding: 12px 16px;
  border-radius: var(--radius);
  margin-bottom: 16px;
}
.lab-instructions pre { font-size: 12.5px; }

.vm-panel {
  position: sticky;
  top: 72px;
  align-self: start;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  max-height: calc(100vh - 88px);
}
.vm-toolbar {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 12px;
  background: var(--surface-2);
  border-bottom: 1px solid var(--border);
  flex-wrap: wrap;
}
.vm-toolbar button {
  background: var(--surface);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 6px 10px;
  font-size: 13px;
  cursor: pointer;
  font-family: inherit;
}
.vm-toolbar button:hover:not(:disabled) {
  background: var(--accent-dim);
  border-color: var(--accent);
  color: white;
}
.vm-toolbar button:disabled { opacity: 0.4; cursor: not-allowed; }

.vm-status {
  margin-left: auto;
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  color: var(--text-muted);
  padding: 4px 8px;
  border-radius: var(--radius);
  background: var(--surface);
}
.vm-status.s-stopped { color: var(--text-muted); }
.vm-status.s-booting { color: var(--warn); }
.vm-status.s-staging { color: var(--warn); }
.vm-status.s-ready   { color: var(--success); }
.vm-status.s-error   { color: var(--danger); }

.vm-screen {
  background: #000;
  flex: 1;
  min-height: 360px;
  overflow: auto;
  padding: 8px;
  outline: 2px solid transparent;
  outline-offset: -2px;
  transition: outline-color 0.15s ease;
}
.vm-screen:focus,
.vm-screen.has-focus { outline-color: var(--accent); }
.vm-screen > div {
  font-family: "SF Mono", Menlo, Consolas, monospace;
  font-size: 13px;
  line-height: 1.2;
  color: #d6d6d6;
  white-space: pre;
}
.vm-screen > canvas { display: block; }

.vm-input {
  display: flex;
  gap: 6px;
  padding: 6px 8px;
  background: var(--code-bg);
  border-top: 1px solid var(--border);
}
.vm-input span {
  color: var(--accent);
  font-family: "SF Mono", Menlo, Consolas, monospace;
  font-size: 13px;
  align-self: center;
}
.vm-input input {
  flex: 1;
  background: transparent;
  border: none;
  color: var(--text);
  font-family: "SF Mono", Menlo, Consolas, monospace;
  font-size: 13px;
  outline: none;
}
.vm-input input::placeholder { color: var(--text-muted); opacity: 0.6; }
.vm-input input:disabled     { opacity: 0.4; }

.vm-hint {
  padding: 8px 12px;
  font-size: 12px;
  color: var(--text-muted);
  background: var(--surface-2);
  border-top: 1px solid var(--border);
}
.vm-hint code {
  background: var(--code-bg);
  padding: 1px 5px;
  border-radius: 3px;
}

.send-cmd {
  display: inline-block;
  margin-top: 6px;
  padding: 3px 8px;
  font-size: 11px;
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  color: var(--accent);
  cursor: pointer;
}
.send-cmd:hover                  { border-color: var(--accent); }
.send-cmd:disabled               { opacity: 0.3; cursor: not-allowed; }