/* ═══════════════════════════════════════════
   SQLMentor — Main Stylesheet
   Mobile-first responsive design
═══════════════════════════════════════════ */

@import url('https://fonts.googleapis.com/css2?family=IBM+Plex+Mono:wght@400;600&family=Fraunces:ital,wght@0,300;0,600;0,900;1,300&family=DM+Sans:wght@300;400;500&display=swap');

/* ── VARIABLES ── */
:root {
  --bg:        #0e0f11;
  --surface:   #16181c;
  --surface2:  #1e2127;
  --border:    #2a2d35;
  --accent:    #f0c040;
  --accent2:   #4af0a0;
  --accent3:   #f04070;
  --blue:      #4a8cf0;
  --text:      #e8eaf0;
  --muted:     #7a7f8e;
  --code-bg:   #12141a;
  --sidebar-w: 240px;
  --header-h:  60px;
  --radius:    10px;
  --transition: 0.2s ease;
}

/* ── RESET ── */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; font-size: 15px; }
body {
  font-family: 'DM Sans', sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
}
body.no-scroll { overflow: hidden; }
a { color: var(--accent2); text-decoration: none; }
a:hover { text-decoration: underline; }
img { max-width: 100%; display: block; }

/* ── HEADER ── */
header {
  position: sticky;
  top: 0;
  z-index: 200;
  height: var(--header-h);
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
}

.header-inner {
  width: 100%;
  max-width: 1400px;
  margin: 0 auto;
  padding: 0 1.5rem;
  display: flex;
  align-items: center;
  gap: 1rem;
}

.header-brand {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  flex-shrink: 0;
}

.site-logo {
  width: 28px;
  height: 28px;
  flex-shrink: 0;
  display: block;
  filter: drop-shadow(0 1px 2px rgba(0, 0, 0, 0.4));
  transition: transform var(--transition);
}

.site-logo:hover {
  transform: rotate(-6deg) scale(1.05);
}

.site-title {
  font-family: 'Fraunces', serif;
  font-size: 1.4rem;
  font-weight: 900;
  color: var(--accent);
  letter-spacing: -0.5px;
  white-space: nowrap;
}

.site-sub {
  font-size: 11px;
  color: var(--muted);
  font-family: 'IBM Plex Mono', monospace;
  white-space: nowrap;
}

.header-nav {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: 0.25rem;
}

.header-nav a {
  padding: 0.4rem 0.8rem;
  font-size: 13px;
  font-family: 'IBM Plex Mono', monospace;
  color: var(--muted);
  border-radius: 6px;
  transition: all var(--transition);
  white-space: nowrap;
}

.header-nav a:hover,
.header-nav a.active {
  color: var(--accent);
  background: rgba(240,192,64,0.08);
  text-decoration: none;
}

/* ── HAMBURGER ── */
.hamburger {
  display: none;
  background: none;
  border: 1px solid var(--border);
  color: var(--muted);
  padding: 6px 10px;
  border-radius: 6px;
  cursor: pointer;
  font-size: 16px;
  line-height: 1;
  transition: all var(--transition);
  flex-shrink: 0;
}

.hamburger:hover {
  color: var(--accent);
  border-color: var(--accent);
}

/* ── APP LAYOUT ── */
.app-layout {
  display: flex;
  min-height: calc(100vh - var(--header-h));
  position: relative;
}

/* ── SIDEBAR ── */
.sidebar {
  width: var(--sidebar-w);
  flex-shrink: 0;
  background: var(--surface);
  border-right: 1px solid var(--border);
  position: sticky;
  top: var(--header-h);
  height: calc(100vh - var(--header-h));
  overflow-y: auto;
  overflow-x: hidden;
  scrollbar-width: thin;
  scrollbar-color: var(--border) transparent;
}

.sidebar::-webkit-scrollbar { width: 4px; }
.sidebar::-webkit-scrollbar-track { background: transparent; }
.sidebar::-webkit-scrollbar-thumb { background: var(--border); border-radius: 2px; }

.sidebar-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1rem 1rem 0.5rem;
}

.toc-title {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 10px;
  font-weight: 600;
  letter-spacing: 0.15em;
  color: var(--muted);
  text-transform: uppercase;
}

.sidebar-close {
  display: none;
  background: none;
  border: none;
  color: var(--muted);
  font-size: 16px;
  cursor: pointer;
  padding: 2px 6px;
  border-radius: 4px;
}

.sidebar-close:hover { color: var(--text); background: var(--surface2); }

#sidebar-nav { padding: 0.5rem 0 2rem; }

.toc-group-label {
  display: block;
  font-family: 'IBM Plex Mono', monospace;
  font-size: 10px;
  letter-spacing: 0.12em;
  color: var(--accent);
  text-transform: uppercase;
  padding: 1rem 1rem 0.3rem;
  font-weight: 600;
}

.toc-link {
  display: block;
  padding: 5px 1rem;
  font-size: 13px;
  color: var(--muted);
  text-decoration: none;
  border-radius: 0;
  transition: all var(--transition);
  border-left: 2px solid transparent;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.toc-link:hover {
  color: var(--text);
  background: var(--surface2);
  text-decoration: none;
}

.toc-link.active {
  color: var(--accent);
  background: rgba(240,192,64,0.07);
  border-left-color: var(--accent);
  font-weight: 500;
}

/* ── SIDEBAR OVERLAY (mobile) ── */
.sidebar-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.6);
  z-index: 149;
  backdrop-filter: blur(2px);
}

.sidebar-overlay.visible { display: block; }

/* ── CONTENT AREA ── */
.content-area {
  flex: 1;
  min-width: 0;
  padding: 2.5rem 2rem 4rem;
  max-width: 860px;
}

/* ── LOADING / ERROR ── */
.loading, .error-msg {
  padding: 3rem;
  text-align: center;
  font-family: 'IBM Plex Mono', monospace;
  font-size: 13px;
}

.loading { color: var(--muted); }

.loading::after {
  content: '';
  display: inline-block;
  width: 6px;
  height: 6px;
  background: var(--accent);
  border-radius: 50%;
  margin-left: 8px;
  animation: pulse 1s infinite;
}

@keyframes pulse { 0%,100%{opacity:1} 50%{opacity:0.3} }

.error-msg {
  color: var(--accent3);
  border: 1px solid var(--accent3);
  border-radius: var(--radius);
  background: rgba(240,64,112,0.07);
}

/* ── CONTENT TYPOGRAPHY ── */
.content-area h1 {
  font-family: 'Fraunces', serif;
  font-size: 2.2rem;
  font-weight: 900;
  color: var(--text);
  letter-spacing: -0.5px;
  line-height: 1.2;
  margin-bottom: 1.25rem;
}

.content-area h2 {
  font-family: 'Fraunces', serif;
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text);
  margin: 2.5rem 0 0.75rem;
  letter-spacing: -0.3px;
  line-height: 1.3;
  padding-top: 0.5rem;
  border-top: 1px solid var(--border);
}

.content-area h2:first-child { border-top: none; margin-top: 0; }

.content-area h3 {
  font-family: 'Fraunces', serif;
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--text);
  margin: 1.8rem 0 0.6rem;
}

.content-area h4 {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent2);
  margin: 1.5rem 0 0.5rem;
}

.content-area p { color: #c8cad4; margin-bottom: 0.85rem; }

.content-area strong { color: var(--text); }

.content-area ul, .content-area ol {
  padding-left: 1.4rem;
  margin-bottom: 0.85rem;
}

.content-area li { color: #c8cad4; margin-bottom: 4px; }

.content-area hr {
  border: none;
  border-top: 1px solid var(--border);
  margin: 2rem 0;
}

/* ── INLINE CODE ── */
.content-area p code,
.content-area li code,
.content-area td code {
  background: var(--surface2);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 1px 6px;
  font-size: 12.5px;
  font-family: 'IBM Plex Mono', monospace;
  color: var(--accent2);
  white-space: nowrap;
}

/* ── CODE BLOCKS ── */
.code-block {
  background: var(--code-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  margin: 1rem 0;
}

.code-header {
  background: var(--surface2);
  border-bottom: 1px solid var(--border);
  padding: 0.45rem 1rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
}

.code-lang {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 10px;
  color: var(--muted);
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.code-dots { display: flex; gap: 5px; }
.dot { width: 10px; height: 10px; border-radius: 50%; }
.dot-r { background: #f04070; }
.dot-y { background: #f0c040; }
.dot-g { background: #4af0a0; }

.code-block pre {
  margin: 0 !important;
  border-radius: 0 !important;
  background: transparent !important;
  padding: 1.1rem 1.25rem !important;
  overflow-x: auto;
  font-family: 'IBM Plex Mono', monospace !important;
  font-size: 13px !important;
  line-height: 1.75 !important;
}

.code-block pre code {
  font-family: 'IBM Plex Mono', monospace !important;
  font-size: 13px !important;
  background: transparent !important;
  border: none !important;
  padding: 0 !important;
  color: inherit;
  white-space: pre;
}

/* ── highlight.js theme override ── */
.hljs { background: transparent !important; }

/* ── TABLES ── */
.table-wrap {
  overflow-x: auto;
  margin: 1rem 0;
  border-radius: var(--radius);
  border: 1px solid var(--border);
}

.content-area table {
  width: 100%;
  border-collapse: collapse;
  font-size: 13px;
  font-family: 'IBM Plex Mono', monospace;
  min-width: 400px;
}

.content-area thead tr { background: var(--surface2); }

.content-area thead th {
  padding: 0.6rem 1rem;
  text-align: left;
  color: var(--accent);
  font-size: 11px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  border-bottom: 1px solid var(--border);
  white-space: nowrap;
}

.content-area tbody tr { border-bottom: 1px solid var(--border); }
.content-area tbody tr:last-child { border-bottom: none; }
.content-area tbody tr:hover { background: var(--surface); }
.content-area tbody td { padding: 0.5rem 1rem; color: #c8cad4; }

/* ── CALLOUTS ── */
.callout {
  border-radius: 8px;
  padding: 0.85rem 1.1rem;
  margin: 1rem 0;
  border-left: 3px solid;
  font-size: 13.5px;
}

.callout-tip  { background: rgba(74,240,160,0.07);  border-color: var(--accent2); }
.callout-warn { background: rgba(240,192,64,0.07);  border-color: var(--accent); }
.callout-info { background: rgba(74,140,240,0.07);  border-color: var(--blue); }
.callout-danger { background: rgba(240,64,112,0.07); border-color: var(--accent3); }

.callout-icon {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 10px;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  margin-bottom: 4px;
}

.callout-tip  .callout-icon { color: var(--accent2); }
.callout-warn .callout-icon { color: var(--accent); }
.callout-info .callout-icon { color: var(--blue); }
.callout-danger .callout-icon { color: var(--accent3); }

/* ── CARDS ── */
.cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: 10px;
  margin: 1rem 0;
}

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1rem;
  transition: border-color var(--transition);
}

.card:hover { border-color: var(--accent); }
.card-icon { font-size: 1.25rem; margin-bottom: 0.4rem; }

.card-title {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 12px;
  font-weight: 600;
  color: var(--accent);
  margin-bottom: 4px;
}

.card-desc { font-size: 12.5px; color: var(--muted); line-height: 1.5; }

/* ── OUTPUT BOX ── */
.output {
  background: var(--surface2);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 0.85rem 1rem;
  margin: 0.5rem 0 1rem;
  overflow-x: auto;
}

.output-label {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 10px;
  letter-spacing: 0.12em;
  color: var(--accent2);
  text-transform: uppercase;
  margin-bottom: 0.5rem;
  font-weight: 600;
}

/* ── JOIN VISUALIZER ── */
.join-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: 10px;
  margin: 1rem 0;
}

.join-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1rem;
  text-align: center;
  transition: border-color var(--transition);
}

.join-card:hover { border-color: var(--blue); }

.venn { display: flex; justify-content: center; margin-bottom: 0.5rem; }

.circle {
  width: 42px; height: 42px;
  border-radius: 50%;
  border: 2px solid;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 9px;
  font-family: 'IBM Plex Mono', monospace;
  font-weight: 600;
}

.circle-l  { border-color: var(--blue);   background: rgba(74,140,240,0.2);  margin-right: -12px; color: var(--blue); }
.circle-r  { border-color: var(--accent3); background: rgba(240,64,112,0.2);  margin-left:  -12px; color: var(--accent3); }
.circle-l.active  { background: rgba(74,140,240,0.55); }
.circle-r.active  { background: rgba(240,64,112,0.55); }
.circle-both      { background: rgba(74,240,160,0.55); border-color: var(--accent2); color: var(--accent2); }

.join-name { font-family: 'IBM Plex Mono', monospace; font-size: 12px; font-weight: 600; color: var(--accent); margin-bottom: 4px; }
.join-desc { font-size: 12px; color: var(--muted); }

/* ── PRACTICE QUESTIONS ── */
.practice-q {
  background: var(--surface);
  border: 1px solid var(--border);
  border-left: 3px solid var(--accent);
  border-radius: 8px;
  padding: 1rem 1.25rem;
  margin: 0.75rem 0;
}

.q-num {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 10px;
  color: var(--accent);
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  margin-bottom: 4px;
}

.q-text { font-size: 14px; color: var(--text); }

.practice-q details summary {
  cursor: pointer;
  font-family: 'IBM Plex Mono', monospace;
  font-size: 12px;
  color: var(--accent2);
  margin-top: 0.75rem;
  user-select: none;
  list-style: none;
}

.practice-q details[open] summary { margin-bottom: 0.5rem; }

/* ── TOPIC NAVIGATION ── */
.topic-nav {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  margin-top: 3rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border);
}

.btn-nav {
  background: var(--surface);
  border: 1px solid var(--border);
  color: var(--muted);
  padding: 0.6rem 1.1rem;
  border-radius: 8px;
  font-family: 'IBM Plex Mono', monospace;
  font-size: 12px;
  cursor: pointer;
  transition: all var(--transition);
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
}

.btn-nav:hover {
  color: var(--accent);
  border-color: var(--accent);
  background: rgba(240,192,64,0.06);
  text-decoration: none;
}

.btn-nav:disabled, .btn-nav.hidden {
  opacity: 0.3;
  cursor: default;
  pointer-events: none;
}

/* ── FOOTER ── */
footer {
  background: var(--surface);
  border-top: 1px solid var(--border);
  padding: 1.25rem 1.5rem;
  text-align: center;
}

.footer-inner {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 11px;
  color: var(--muted);
  letter-spacing: 0.05em;
}

/* ═══════════════════════════════════════════
   HOME PAGE (index.html)
═══════════════════════════════════════════ */

.home-wrap {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

.hero {
  padding: 5rem 0 4rem;
  text-align: center;
}

.hero-label {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 11px;
  letter-spacing: 0.2em;
  color: var(--accent);
  text-transform: uppercase;
  margin-bottom: 1rem;
}

.hero h1 {
  font-family: 'Fraunces', serif;
  font-size: 3.5rem;
  font-weight: 900;
  color: var(--text);
  letter-spacing: -1.5px;
  line-height: 1.1;
  margin-bottom: 1.25rem;
}

.hero h1 span { color: var(--accent); }

.hero-desc {
  font-size: 1.05rem;
  color: var(--muted);
  max-width: 540px;
  margin: 0 auto 2rem;
  line-height: 1.7;
}

.hero-actions {
  display: flex;
  gap: 1rem;
  justify-content: center;
  flex-wrap: wrap;
}

.btn-primary {
  background: var(--accent);
  color: #0e0f11;
  border: none;
  padding: 0.75rem 1.75rem;
  border-radius: 8px;
  font-family: 'IBM Plex Mono', monospace;
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
  text-decoration: none;
  display: inline-block;
  transition: all var(--transition);
}

.btn-primary:hover {
  background: #f8d060;
  text-decoration: none;
  transform: translateY(-1px);
}

.btn-secondary {
  background: var(--surface);
  color: var(--text);
  border: 1px solid var(--border);
  padding: 0.75rem 1.75rem;
  border-radius: 8px;
  font-family: 'IBM Plex Mono', monospace;
  font-size: 13px;
  cursor: pointer;
  text-decoration: none;
  display: inline-block;
  transition: all var(--transition);
}

.btn-secondary:hover {
  border-color: var(--accent);
  color: var(--accent);
  text-decoration: none;
}

.stats-row {
  display: flex;
  justify-content: center;
  gap: 3rem;
  padding: 3rem 0;
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  flex-wrap: wrap;
}

.stat-item { text-align: center; }

.stat-num {
  font-family: 'Fraunces', serif;
  font-size: 2.5rem;
  font-weight: 900;
  color: var(--accent);
  line-height: 1;
  margin-bottom: 0.3rem;
}

.stat-label {
  font-size: 12px;
  color: var(--muted);
  font-family: 'IBM Plex Mono', monospace;
  letter-spacing: 0.05em;
}

.home-section { padding: 4rem 0; }

.section-heading {
  font-family: 'Fraunces', serif;
  font-size: 1.75rem;
  font-weight: 900;
  color: var(--text);
  margin-bottom: 0.5rem;
}

.section-sub {
  color: var(--muted);
  font-size: 14px;
  margin-bottom: 2rem;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  column-gap: 3rem;
  row-gap: 1.4rem;
}

.feature-card {
  display: flex;
  align-items: flex-start;
  gap: 0.75rem;
}

.feature-icon {
  font-size: 1rem;
  line-height: 1.6;
  flex-shrink: 0;
  color: var(--muted);
}

.feature-body { flex: 1; min-width: 0; }

.feature-title {
  font-size: 13.5px;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 0.2rem;
}

.feature-desc { font-size: 13px; color: var(--muted); line-height: 1.6; }

@media (max-width: 560px) {
  .feature-grid { grid-template-columns: 1fr; }
}

/* ── Oracle Certification Section ── */
.cert-oracle-badge {
  display: inline-block;
  background: #c74634;
  color: #fff;
  font-size: .68rem;
  font-weight: 700;
  letter-spacing: .08em;
  text-transform: uppercase;
  padding: .18rem .55rem;
  border-radius: 3px;
}

.cert-info-list {
  display: flex;
  flex-direction: column;
  gap: 0;
  max-width: 680px;
}

.cert-info-row {
  display: grid;
  grid-template-columns: 140px 1fr;
  gap: .5rem 1.5rem;
  padding: .85rem 0;
  border-bottom: 1px solid var(--border);
  align-items: baseline;
}

.cert-info-row:last-child { border-bottom: none; }

.cert-info-row dt {
  font-size: .82rem;
  font-weight: 600;
  color: var(--text);
  white-space: nowrap;
}

.cert-info-row dd {
  font-size: .84rem;
  color: var(--muted);
  line-height: 1.65;
}

.cert-info-row dd a {
  color: var(--accent);
  text-decoration: none;
  white-space: nowrap;
}

.cert-info-row dd a:hover { text-decoration: underline; }

@media (max-width: 520px) {
  .cert-info-row { grid-template-columns: 1fr; gap: .2rem; }
}

/* ── Topic list ── */
.topic-list-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 10px;
}

.topic-pill {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 0.7rem 1rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 13px;
  color: var(--muted);
  transition: all var(--transition);
  text-decoration: none;
}

.topic-pill:hover {
  color: var(--accent);
  border-color: var(--accent);
  background: rgba(240,192,64,0.06);
  text-decoration: none;
}

.topic-pill-num {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 10px;
  color: var(--accent);
  min-width: 20px;
}

/* ═══════════════════════════════════════════
   SQL EDITOR PAGE
═══════════════════════════════════════════ */

.editor-layout {
  max-width: 1000px;
  margin: 0 auto;
  padding: 2rem 1.5rem 4rem;
}

.editor-layout h1 {
  font-family: 'Fraunces', serif;
  font-size: 2rem;
  font-weight: 900;
  color: var(--text);
  margin-bottom: 0.25rem;
}

.editor-desc {
  color: var(--muted);
  font-size: 13px;
  margin-bottom: 1.5rem;
  font-family: 'IBM Plex Mono', monospace;
}

.editor-wrap {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1rem;
}

.editor-panel {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  overflow: hidden;
}

.panel-header {
  background: var(--surface2);
  border-bottom: 1px solid var(--border);
  padding: 0.6rem 1rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.panel-title {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 11px;
  color: var(--muted);
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

#query-input {
  width: 100%;
  background: var(--code-bg);
  color: var(--text);
  border: none;
  outline: none;
  padding: 1.25rem;
  font-family: 'IBM Plex Mono', monospace;
  font-size: 13px;
  line-height: 1.7;
  resize: vertical;
  min-height: 180px;
}

#query-input::placeholder { color: var(--muted); }

.editor-toolbar {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.75rem 1rem;
  background: var(--surface2);
  border-top: 1px solid var(--border);
  flex-wrap: wrap;
}

.btn-run {
  background: var(--accent2);
  color: #0e0f11;
  border: none;
  padding: 0.5rem 1.25rem;
  border-radius: 6px;
  font-family: 'IBM Plex Mono', monospace;
  font-size: 12px;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition);
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

.btn-run:hover { background: #6fffc0; }

.btn-clear {
  background: var(--surface);
  color: var(--muted);
  border: 1px solid var(--border);
  padding: 0.5rem 1rem;
  border-radius: 6px;
  font-family: 'IBM Plex Mono', monospace;
  font-size: 12px;
  cursor: pointer;
  transition: all var(--transition);
}

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

.editor-status {
  margin-left: auto;
  font-family: 'IBM Plex Mono', monospace;
  font-size: 11px;
  color: var(--muted);
}

#output-area {
  padding: 1.25rem;
  font-family: 'IBM Plex Mono', monospace;
  font-size: 12.5px;
  min-height: 120px;
  overflow-x: auto;
  color: var(--text);
}

.output-error { color: var(--accent3); }
.output-success { color: var(--accent2); }

.output-table-wrap { overflow-x: auto; }

.output-table {
  border-collapse: collapse;
  font-size: 12px;
  min-width: 400px;
}

.output-table th {
  background: var(--surface2);
  color: var(--accent);
  padding: 0.4rem 0.75rem;
  text-align: left;
  border: 1px solid var(--border);
  font-size: 10px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  white-space: nowrap;
}

.output-table td {
  padding: 0.35rem 0.75rem;
  border: 1px solid var(--border);
  color: #c8cad4;
}

.output-table tr:hover td { background: var(--surface); }

.sample-queries {
  margin-top: 1.5rem;
}

.sample-label {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 10px;
  letter-spacing: 0.12em;
  color: var(--muted);
  text-transform: uppercase;
  margin-bottom: 0.75rem;
}

.sample-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.sample-chip {
  background: var(--surface);
  border: 1px solid var(--border);
  color: var(--muted);
  padding: 0.35rem 0.75rem;
  border-radius: 20px;
  font-family: 'IBM Plex Mono', monospace;
  font-size: 11px;
  cursor: pointer;
  transition: all var(--transition);
}

.sample-chip:hover {
  color: var(--accent2);
  border-color: var(--accent2);
}

/* ═══════════════════════════════════════════
   QUIZ PAGE
═══════════════════════════════════════════ */

.quiz-layout {
  max-width: 720px;
  margin: 0 auto;
  padding: 2rem 1.5rem 4rem;
}

.quiz-layout h1 {
  font-family: 'Fraunces', serif;
  font-size: 2rem;
  font-weight: 900;
  color: var(--text);
  margin-bottom: 0.25rem;
}

.quiz-controls {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: 1.5rem;
  flex-wrap: wrap;
}

.quiz-filter {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.filter-btn {
  background: var(--surface);
  border: 1px solid var(--border);
  color: var(--muted);
  padding: 0.35rem 0.8rem;
  border-radius: 6px;
  font-family: 'IBM Plex Mono', monospace;
  font-size: 11px;
  cursor: pointer;
  transition: all var(--transition);
}

.filter-btn:hover, .filter-btn.active {
  color: var(--accent);
  border-color: var(--accent);
  background: rgba(240,192,64,0.08);
}

.quiz-progress-bar {
  width: 100%;
  height: 3px;
  background: var(--border);
  border-radius: 2px;
  margin-bottom: 2rem;
  overflow: hidden;
}

.quiz-progress-fill {
  height: 100%;
  background: var(--accent);
  border-radius: 2px;
  transition: width 0.4s ease;
}

.quiz-score-bar {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 1.5rem;
  flex-wrap: wrap;
  gap: 0.75rem;
}

.score-nums {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 12px;
  color: var(--muted);
}

.score-nums span { color: var(--accent2); font-weight: 600; }

.quiz-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 1.75rem;
  margin-bottom: 1rem;
}

.q-meta {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 1rem;
}

.q-index {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 11px;
  color: var(--muted);
}

.q-topic-tag {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 10px;
  padding: 2px 8px;
  border-radius: 4px;
  background: var(--surface2);
  border: 1px solid var(--border);
  color: var(--accent);
}

.q-difficulty {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 10px;
  margin-left: auto;
}

.q-difficulty.easy   { color: var(--accent2); }
.q-difficulty.medium { color: var(--accent); }
.q-difficulty.hard   { color: var(--accent3); }

.q-question {
  font-size: 1rem;
  color: var(--text);
  font-weight: 500;
  margin-bottom: 1.25rem;
  line-height: 1.5;
}

.q-options { display: flex; flex-direction: column; gap: 0.5rem; }

.q-option {
  display: flex;
  align-items: flex-start;
  gap: 0.75rem;
  background: var(--surface2);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 0.75rem 1rem;
  cursor: pointer;
  transition: all var(--transition);
  text-align: left;
  width: 100%;
  color: var(--text);
  font-size: 13.5px;
}

.q-option:hover:not(:disabled) {
  border-color: var(--accent);
  background: rgba(240,192,64,0.06);
}

.q-option.correct {
  border-color: var(--accent2);
  background: rgba(74,240,160,0.1);
  color: var(--accent2);
}

.q-option.wrong {
  border-color: var(--accent3);
  background: rgba(240,64,112,0.1);
  color: var(--accent3);
}

.q-option:disabled { cursor: default; }

.option-letter {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 11px;
  font-weight: 600;
  color: var(--muted);
  min-width: 18px;
  padding-top: 1px;
}

.q-option.correct .option-letter { color: var(--accent2); }
.q-option.wrong   .option-letter { color: var(--accent3); }

.q-explanation {
  margin-top: 1rem;
  padding: 0.75rem 1rem;
  background: var(--surface2);
  border-radius: 8px;
  border-left: 3px solid var(--accent2);
  font-size: 13px;
  color: var(--muted);
  display: none;
}

.q-explanation.visible { display: block; }

.quiz-actions {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-top: 1.5rem;
  gap: 1rem;
}

.btn-quiz {
  background: var(--surface);
  border: 1px solid var(--border);
  color: var(--muted);
  padding: 0.6rem 1.25rem;
  border-radius: 8px;
  font-family: 'IBM Plex Mono', monospace;
  font-size: 12px;
  cursor: pointer;
  transition: all var(--transition);
}

.btn-quiz:hover { color: var(--text); border-color: var(--muted); }
.btn-quiz.primary { background: var(--accent); color: #0e0f11; border-color: var(--accent); font-weight: 600; }
.btn-quiz.primary:hover { background: #f8d060; }
.btn-quiz:disabled { opacity: 0.4; cursor: default; }

.quiz-result-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 3rem 2rem;
  text-align: center;
  margin-top: 2rem;
}

.result-score {
  font-family: 'Fraunces', serif;
  font-size: 5rem;
  font-weight: 900;
  color: var(--accent);
  line-height: 1;
  margin-bottom: 0.5rem;
}

.result-label {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 12px;
  color: var(--muted);
  margin-bottom: 1.5rem;
}

.result-msg {
  font-size: 1.1rem;
  color: var(--text);
  margin-bottom: 2rem;
}

/* ═══════════════════════════════════════════
   RESPONSIVE — TABLET (≤1024px)
═══════════════════════════════════════════ */

@media (max-width: 1024px) {
  .site-sub { display: none; }
}

/* ═══════════════════════════════════════════
   RESPONSIVE — MOBILE (≤768px)
═══════════════════════════════════════════ */

@media (max-width: 768px) {
  :root { --header-h: 56px; }

  /* Show hamburger, hide desktop nav links */
  .hamburger { display: flex; align-items: center; }
  .header-nav { display: none; }

  /* Sidebar becomes a slide-in drawer */
  .sidebar {
    position: fixed;
    top: 0;
    left: 0;
    height: 100vh;
    z-index: 150;
    transform: translateX(-100%);
    transition: transform 0.28s ease;
    width: 280px;
  }

  .sidebar.open { transform: translateX(0); }
  .sidebar-close { display: block; }

  /* Content area takes full width */
  .content-area { padding: 1.5rem 1rem 3rem; }

  /* Hero */
  .hero h1 { font-size: 2.25rem; }
  .hero { padding: 3rem 0 2.5rem; }

  /* Stat row */
  .stats-row { gap: 2rem; }
  .stat-num { font-size: 2rem; }

  /* Tables always scrollable */
  .content-area table { min-width: 480px; }

  /* Editor */
  .editor-layout { padding: 1.5rem 1rem 3rem; }

  /* Quiz */
  .quiz-layout { padding: 1.5rem 1rem 3rem; }
  .quiz-card { padding: 1.25rem; }
}

@media (max-width: 480px) {
  .hero h1 { font-size: 1.85rem; }
  .hero-actions { flex-direction: column; align-items: stretch; }
  .btn-primary, .btn-secondary { text-align: center; }
  .cards { grid-template-columns: 1fr 1fr; }
  .join-grid { grid-template-columns: 1fr 1fr; }
  .topic-nav { flex-direction: column; }
  .quiz-controls { flex-direction: column; align-items: flex-start; }
}

/* ═══════════════════════════════════════════
   CERT PRACTICE (1Z0-071) — setup, exam, results
═══════════════════════════════════════════ */
.cert-layout {
  max-width: 1200px;
  margin: 0 auto;
  padding: 2.5rem 1.5rem 4rem;
}

/* ── HERO / SETUP ── */
.cert-hero { margin-bottom: 2rem; }
.cert-hero-label {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 11px;
  color: var(--accent2);
  letter-spacing: 0.15em;
  text-transform: uppercase;
  margin-bottom: 0.5rem;
}
.cert-hero h1 {
  font-family: 'Fraunces', serif;
  font-size: clamp(1.8rem, 4vw, 2.8rem);
  font-weight: 900;
  line-height: 1.1;
  letter-spacing: -1px;
  margin-bottom: 0.75rem;
}
.cert-hero-desc {
  color: var(--muted);
  max-width: 680px;
  font-size: 1rem;
}
.cert-hero-desc strong { color: var(--text); }

.cert-rules {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 0.75rem;
  margin: 1.5rem 0 2.5rem;
}
.cert-rule {
  display: flex;
  align-items: center;
  gap: 0.85rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 0.85rem 1rem;
  font-size: 13px;
  color: var(--muted);
}
.cert-rule-num {
  font-family: 'IBM Plex Mono', monospace;
  color: var(--accent);
  font-weight: 600;
  font-size: 1.15rem;
}

.cert-section-h {
  font-family: 'Fraunces', serif;
  font-weight: 600;
  font-size: 1.4rem;
  margin: 1.5rem 0 1rem;
  letter-spacing: -0.3px;
}

.cert-set-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1rem;
  margin-bottom: 2rem;
}
.cert-set-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem 1.25rem 1rem;
  display: flex;
  flex-direction: column;
  transition: border-color var(--transition), transform var(--transition);
}
.cert-set-card:hover {
  border-color: var(--accent);
  transform: translateY(-2px);
}
.cert-set-num {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 11px;
  color: var(--accent);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  margin-bottom: 0.4rem;
}
.cert-set-title {
  font-family: 'Fraunces', serif;
  font-weight: 600;
  font-size: 1.1rem;
  margin-bottom: 0.4rem;
}
.cert-set-desc {
  font-size: 13px;
  color: var(--muted);
  flex: 1;
  margin-bottom: 0.75rem;
}
.cert-set-meta {
  display: flex;
  gap: 1rem;
  font-family: 'IBM Plex Mono', monospace;
  font-size: 11px;
  color: var(--muted);
  margin-bottom: 0.85rem;
}
.cert-set-btn { width: 100%; text-align: center; }

.cert-tips {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 0.75rem 1rem;
  font-size: 13px;
  color: var(--muted);
}
.cert-tips summary {
  cursor: pointer;
  color: var(--text);
  font-family: 'IBM Plex Mono', monospace;
  font-size: 12px;
}
.cert-tips ul { margin: 0.6rem 0 0 1.1rem; }
.cert-tips li { margin: 0.2rem 0; }

/* ── EXAM BAR (sticky) ── */
.exam-bar {
  position: sticky;
  top: var(--header-h);
  z-index: 50;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 0.75rem 1rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  flex-wrap: wrap;
  margin-bottom: 1rem;
}
.exam-bar-left, .exam-bar-right {
  display: flex;
  align-items: center;
  gap: 0.85rem;
  flex-wrap: wrap;
}
.exam-set-tag {
  font-family: 'Fraunces', serif;
  font-weight: 600;
  font-size: 0.95rem;
}
.exam-counter {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 12px;
  color: var(--muted);
  padding: 0.2rem 0.55rem;
  border: 1px solid var(--border);
  border-radius: 6px;
}
.exam-flag-count {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 11px;
  color: var(--accent3);
}
.exam-timer {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--accent);
  background: rgba(240,192,64,0.08);
  border: 1px solid var(--accent);
  border-radius: 6px;
  padding: 0.4rem 0.85rem;
  min-width: 100px;
  text-align: center;
}
.exam-timer.critical {
  color: var(--accent3);
  border-color: var(--accent3);
  background: rgba(240,64,112,0.12);
  animation: pulse-critical 1.2s infinite;
}
@keyframes pulse-critical {
  0%, 100% { opacity: 1; }
  50%      { opacity: 0.65; }
}

/* ── EXAM BODY: main + side grid ── */
.exam-body {
  display: grid;
  grid-template-columns: 1fr 280px;
  gap: 1.25rem;
  align-items: start;
}
.exam-main { min-width: 0; }
.exam-side {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 0.85rem;
  position: sticky;
  top: calc(var(--header-h) + 88px);
  max-height: calc(100vh - var(--header-h) - 100px);
  overflow-y: auto;
}
.exam-side-title {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 10px;
  letter-spacing: 0.15em;
  color: var(--muted);
  text-transform: uppercase;
  margin-bottom: 0.6rem;
}
.exam-grid {
  display: grid;
  grid-template-columns: repeat(7, 1fr);
  gap: 4px;
  margin-bottom: 0.85rem;
}
.exam-grid-cell {
  background: var(--surface2);
  border: 1px solid var(--border);
  color: var(--muted);
  font-family: 'IBM Plex Mono', monospace;
  font-size: 11px;
  border-radius: 5px;
  padding: 0.35rem 0;
  cursor: pointer;
  transition: all var(--transition);
}
.exam-grid-cell:hover { color: var(--text); border-color: var(--muted); }
.exam-grid-cell.answered {
  background: rgba(74,240,160,0.12);
  border-color: var(--accent2);
  color: var(--accent2);
}
.exam-grid-cell.flagged {
  background: rgba(240,64,112,0.12);
  border-color: var(--accent3);
  color: var(--accent3);
}
.exam-grid-cell.flagged.answered {
  background: rgba(240,64,112,0.15);
  border-color: var(--accent3);
  color: var(--accent3);
}
.exam-grid-cell.current {
  background: var(--accent);
  border-color: var(--accent);
  color: #0e0f11;
  font-weight: 700;
}

.exam-legend {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.4rem;
  font-family: 'IBM Plex Mono', monospace;
  font-size: 10px;
  color: var(--muted);
}
.exam-legend > div { display: flex; align-items: center; gap: 0.4rem; }
.legend-dot { width: 10px; height: 10px; border-radius: 2px; display: inline-block; border: 1px solid var(--border); }
.legend-current  { background: var(--accent); border-color: var(--accent); }
.legend-answered { background: rgba(74,240,160,0.4); border-color: var(--accent2); }
.legend-flagged  { background: rgba(240,64,112,0.4); border-color: var(--accent3); }
.legend-empty    { background: var(--surface2); }

/* ── EXAM QUESTION CARD ── */
.exam-question-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
}
.exam-q-meta {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--muted);
  text-transform: uppercase;
  margin-bottom: 0.6rem;
}
.exam-q-text {
  font-size: 1.05rem;
  line-height: 1.55;
  margin-bottom: 1.1rem;
  color: var(--text);
}
.exam-options {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}
.exam-option {
  text-align: left;
  background: var(--surface2);
  border: 1px solid var(--border);
  color: var(--text);
  font: inherit;
  font-size: 14px;
  border-radius: 8px;
  padding: 0.75rem 0.9rem;
  cursor: pointer;
  display: flex;
  align-items: flex-start;
  gap: 0.75rem;
  transition: all var(--transition);
}
.exam-option:hover {
  border-color: var(--muted);
  background: var(--surface);
}
.exam-option.selected {
  border-color: var(--accent);
  background: rgba(240,192,64,0.10);
}
.exam-option .option-letter {
  font-family: 'IBM Plex Mono', monospace;
  font-weight: 600;
  font-size: 12px;
  color: var(--accent);
  background: rgba(240,192,64,0.12);
  border-radius: 4px;
  padding: 1px 6px;
  min-width: 22px;
  text-align: center;
}

.exam-actions {
  display: flex;
  gap: 0.6rem;
  flex-wrap: wrap;
  margin-top: 1rem;
}
.btn-quiz.flagged {
  border-color: var(--accent3);
  color: var(--accent3);
}

/* ── RESULT SCREEN ── */
.exam-result-hero {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 2rem;
  text-align: center;
  margin-bottom: 2rem;
  position: relative;
  overflow: hidden;
}
.exam-result-hero.pass { border-color: var(--accent2); }
.exam-result-hero.fail { border-color: var(--accent3); }
.result-status {
  font-family: 'IBM Plex Mono', monospace;
  font-weight: 600;
  font-size: 12px;
  letter-spacing: 0.25em;
  padding: 0.3rem 0.85rem;
  display: inline-block;
  border-radius: 4px;
  margin-bottom: 0.85rem;
}
.exam-result-hero.pass .result-status {
  color: #0e0f11;
  background: var(--accent2);
}
.exam-result-hero.fail .result-status {
  color: #fff;
  background: var(--accent3);
}
.result-score-big {
  font-family: 'Fraunces', serif;
  font-weight: 900;
  font-size: clamp(3rem, 9vw, 5.5rem);
  line-height: 1;
  color: var(--accent);
  margin-bottom: 0.4rem;
}
.exam-result-hero.pass .result-score-big { color: var(--accent2); }
.exam-result-hero.fail .result-score-big { color: var(--accent3); }
.result-detail {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 13px;
  color: var(--muted);
  margin-bottom: 0.8rem;
}
.result-msg {
  font-size: 1rem;
  color: var(--text);
  max-width: 640px;
  margin: 0.5rem auto 1rem;
}
.result-timeout {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 12px;
  color: var(--accent3);
  margin-bottom: 0.6rem;
}
.result-chips {
  display: flex;
  gap: 0.6rem;
  justify-content: center;
  flex-wrap: wrap;
  margin: 1.2rem 0;
}
.result-chip {
  background: var(--surface2);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 0.6rem 0.95rem;
  font-family: 'IBM Plex Mono', monospace;
  font-size: 11px;
  color: var(--muted);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.15rem;
  min-width: 70px;
}
.result-chip span {
  font-size: 1.4rem;
  font-weight: 600;
  color: var(--text);
}

.result-weak {
  margin: 1rem auto 0;
  max-width: 700px;
  background: var(--surface2);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 0.85rem 1rem;
  text-align: left;
}
.result-weak-title {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--muted);
  text-transform: uppercase;
  margin-bottom: 0.5rem;
}
.result-weak-tags { display: flex; flex-wrap: wrap; gap: 0.35rem; }
.weak-tag {
  background: rgba(240,64,112,0.12);
  border: 1px solid var(--accent3);
  color: var(--accent3);
  font-size: 12px;
  padding: 0.25rem 0.55rem;
  border-radius: 6px;
}
.weak-tag em { color: var(--muted); font-style: normal; font-size: 11px; }

.result-actions {
  display: flex;
  justify-content: center;
  gap: 0.75rem;
  flex-wrap: wrap;
  margin-top: 1.4rem;
}

/* ── REVIEW LIST ── */
.exam-review-list {
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
}
.exam-review-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-left: 4px solid var(--border);
  border-radius: 8px;
  padding: 1rem 1.15rem;
}
.exam-review-card.review-right   { border-left-color: var(--accent2); }
.exam-review-card.review-wrong   { border-left-color: var(--accent3); }
.exam-review-card.review-skipped { border-left-color: var(--muted); }
.review-head {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 0.5rem;
  font-family: 'IBM Plex Mono', monospace;
  font-size: 11px;
}
.review-num { color: var(--muted); letter-spacing: 0.12em; }
.review-status {
  letter-spacing: 0.12em;
  text-transform: uppercase;
  padding: 0.15rem 0.5rem;
  border-radius: 4px;
  background: var(--surface2);
  color: var(--muted);
}
.review-right .review-status   { color: var(--accent2); background: rgba(74,240,160,0.10); }
.review-wrong .review-status   { color: var(--accent3); background: rgba(240,64,112,0.12); }
.review-skipped .review-status { color: var(--muted); }
.review-q { font-size: 14px; color: var(--text); margin-bottom: 0.55rem; line-height: 1.5; }
.review-line {
  font-size: 13px;
  font-family: 'IBM Plex Mono', monospace;
  color: var(--text);
  margin: 0.15rem 0;
}
.review-label { color: var(--muted); margin-right: 0.4rem; }
.review-explain {
  margin-top: 0.5rem;
  padding: 0.6rem 0.75rem;
  background: var(--code-bg);
  border-radius: 6px;
  font-size: 13px;
  color: var(--muted);
  border-left: 2px solid var(--accent);
}

/* ── RESPONSIVE ── */
@media (max-width: 900px) {
  .exam-body { grid-template-columns: 1fr; }
  .exam-side {
    position: static;
    max-height: none;
  }
  .exam-grid { grid-template-columns: repeat(10, 1fr); }
}
@media (max-width: 560px) {
  .cert-layout { padding: 1.5rem 1rem 3rem; }
  .exam-bar { padding: 0.6rem 0.75rem; }
  .exam-timer { font-size: 1rem; min-width: 88px; padding: 0.3rem 0.6rem; }
  .exam-question-card { padding: 1.1rem; }
  .exam-grid { grid-template-columns: repeat(8, 1fr); }
  .exam-actions { flex-direction: column; }
  .exam-actions .btn-quiz { width: 100%; text-align: center; }
}