/* ═══════════════════════════════════════
   PHPForge — Complete Responsive CSS
   ═══════════════════════════════════════ */

:root {
  --bg:      #0a0c10;
  --bg2:     #0f1218;
  --bg3:     #161b24;
  --bg4:     #1c2330;
  --border:  #232b38;
  --border2: #2d3848;
  --text:    #c9d4e8;
  --text2:   #7a8fa8;
  --text3:   #4a5a70;
  --accent:  #4fc3f7;
  --accent2: #00e5ff;
  --green:   #69ff87;
  --yellow:  #ffd166;
  --red:     #ff6b6b;
  --purple:  #c084fc;
  --orange:  #ff9f43;
  --php:     #8993c1;
  --sw:      260px;
}

*, *::before, *::after { margin:0; padding:0; box-sizing:border-box; }
html { scroll-behavior:smooth; }
body {
  background:var(--bg); color:var(--text);
  font-family:'JetBrains Mono',monospace;
  font-size:14px; line-height:1.7;
  min-height:100vh; overflow-x:hidden;
}
a { color:inherit; text-decoration:none; }
img { max-width:100%; }
::-webkit-scrollbar { width:5px; height:5px; }
::-webkit-scrollbar-track { background:var(--bg2); }
::-webkit-scrollbar-thumb { background:var(--border2); border-radius:3px; }

/* ══════════════════
   LAYOUT
   ══════════════════ */
#app { display:flex; height:100vh; overflow:hidden; }

/* ── Sidebar ── */
#sidebar {
  width:var(--sw); min-width:var(--sw);
  background:var(--bg2); border-right:1px solid var(--border);
  display:flex; flex-direction:column;
  overflow:hidden; flex-shrink:0; z-index:10;
  transition:width .28s ease, min-width .28s ease;
}
#sidebar.collapsed { width:0; min-width:0; border-right:none; }
.sidebar-inner { width:var(--sw); display:flex; flex-direction:column; height:100%; overflow:hidden; }
.sidebar-header { padding:20px 18px 16px; border-bottom:1px solid var(--border); flex-shrink:0; }
.logo { font-family:'Syne',sans-serif; font-size:20px; font-weight:800; color:var(--accent); letter-spacing:-.5px; display:flex; align-items:center; gap:6px; }
.logo-bracket { color:var(--php); }
.logo-sub { font-size:10px; color:var(--text3); margin-top:3px; letter-spacing:2px; }
.sidebar-nav { flex:1; overflow-y:auto; padding:8px 0; }
.nav-section { padding:14px 18px 4px; }
.nav-section span { font-size:9px; color:var(--text3); letter-spacing:2.5px; text-transform:uppercase; font-weight:600; }
.nav-item { display:flex; align-items:center; gap:10px; padding:8px 18px; color:var(--text2); font-size:12.5px; border-left:2px solid transparent; white-space:nowrap; transition:all .15s; }
.nav-item:hover { color:var(--text); background:var(--bg3); }
.nav-item.active { color:var(--accent); border-left-color:var(--accent); background:rgba(79,195,247,.06); }
.icon { width:16px; text-align:center; flex-shrink:0; font-size:13px; }
.sidebar-footer { padding:14px 18px; border-top:1px solid var(--border); flex-shrink:0; }
.progress-label { font-size:10px; color:var(--text3); margin-bottom:6px; display:flex; justify-content:space-between; }
.progress-bar { height:3px; background:var(--bg4); border-radius:2px; overflow:hidden; }
.progress-fill { height:100%; width:0%; background:linear-gradient(90deg,var(--accent),var(--purple)); border-radius:2px; transition:width .4s; }

/* Backdrop (sibling of sidebar, placed in body) */
#sidebar-backdrop { display:none; position:fixed; inset:0; background:rgba(0,0,0,.6); z-index:199; cursor:pointer; }
#sidebar-backdrop.show { display:block; }

/* ── Main ── */
#main { flex:1; display:flex; flex-direction:column; overflow:hidden; min-width:0; }

/* ── Topbar ── */
#topbar {
  height:48px; flex-shrink:0;
  background:var(--bg2); border-bottom:1px solid var(--border);
  display:flex; align-items:center; padding:0 18px; gap:12px;
  position:sticky; top:0; z-index:5;
}
#toggle-sidebar { background:none; border:none; color:var(--text2); cursor:pointer; font-size:18px; padding:4px 7px; border-radius:4px; transition:all .15s; flex-shrink:0; }
#toggle-sidebar:hover { color:var(--text); background:var(--bg3); }
.topbar-title { font-family:'Syne',sans-serif; font-size:15px; font-weight:700; color:var(--text); white-space:nowrap; }
.topbar-crumb { font-size:11px; color:var(--text3); overflow:hidden; text-overflow:ellipsis; white-space:nowrap; }
.topbar-crumb span { color:var(--accent); }
.topbar-right { margin-left:auto; flex-shrink:0; }
.php-badge { font-size:10px; background:rgba(137,147,193,.1); border:1px solid rgba(137,147,193,.25); color:var(--php); padding:3px 10px; border-radius:12px; letter-spacing:.5px; white-space:nowrap; }

/* ── Content ── */
#content { flex:1; overflow-y:auto; overflow-x:hidden; }

/* ── Generic section ── */
.section { width:100%; max-width:1400px; padding:36px 40px; animation:fadeIn .2s ease; }
@keyframes fadeIn { from{opacity:0;transform:translateY(6px)} to{opacity:1;transform:translateY(0)} }

/* ══════════════════
   HERO
   ══════════════════ */
.hero { max-width:820px; margin:0 auto; text-align:center; padding:48px 0 28px; }
.hero-badge { display:inline-flex; align-items:center; gap:6px; background:rgba(79,195,247,.08); border:1px solid rgba(79,195,247,.22); padding:4px 16px; border-radius:20px; font-size:11px; color:var(--accent); margin-bottom:24px; letter-spacing:1px; }
.hero h1 { font-family:'Syne',sans-serif; font-size:46px; font-weight:800; line-height:1.12; margin-bottom:18px; color:#e8eef8; }
.hero h1 em { color:var(--accent); font-style:normal; }
.hero>p { color:var(--text2); font-size:14px; max-width:520px; margin:0 auto 36px; line-height:1.9; }
.hero-grid { display:grid; grid-template-columns:repeat(3,1fr); gap:14px; text-align:left; }
.hero-card { background:var(--bg3); border:1px solid var(--border); border-radius:12px; padding:20px 18px; display:block; transition:all .2s; }
.hero-card:hover { border-color:var(--accent); background:var(--bg4); transform:translateY(-2px); }
.hero-card-icon { font-size:22px; margin-bottom:12px; }
.hero-card h3 { font-size:13px; font-family:'Syne',sans-serif; color:var(--text); font-weight:700; margin-bottom:5px; }
.hero-card p { font-size:11.5px; color:var(--text3); line-height:1.6; }

/* ── Section header ── */
.section-header { margin-bottom:32px; }
.section-header h2 { font-family:'Syne',sans-serif; font-size:26px; font-weight:800; color:var(--text); margin-bottom:6px; }
.section-header p { color:var(--text3); font-size:13px; }

/* ══════════════════
   THEORY
   ══════════════════ */
.theory-section { padding:0; width:100%; max-width:100%; }
.theory-layout { display:grid; grid-template-columns:230px 1fr; height:calc(100vh - 48px); }

.theory-toc { background:var(--bg2); border-right:1px solid var(--border); overflow-y:auto; padding:20px 0; }
.toc-title { font-size:9px; color:var(--text3); letter-spacing:2.5px; text-transform:uppercase; padding:0 16px 12px; font-weight:600; display:block; }
.toc-item { display:flex; align-items:center; gap:8px; padding:7px 16px; color:var(--text2); font-size:11.5px; border-left:2px solid transparent; transition:all .15s; }
.toc-item:hover { color:var(--text); background:var(--bg3); }
.toc-item.active { color:var(--accent); border-left-color:var(--accent); background:rgba(79,195,247,.06); }
.toc-num { font-size:10px; color:var(--text3); width:22px; flex-shrink:0; }

.theory-content-wrap { overflow-y:auto; padding:36px 44px; max-width:960px; }
.topic-header { margin-bottom:28px; padding-bottom:18px; border-bottom:1px solid var(--border); }
.topic-tag { font-size:10px; color:var(--php); letter-spacing:2px; text-transform:uppercase; margin-bottom:8px; display:block; }
.topic-title { font-family:'Syne',sans-serif; font-size:28px; font-weight:800; color:#e8eef8; margin-bottom:6px; }
.topic-num { font-size:11px; color:var(--text3); }
.theory-body { margin-bottom:32px; }
.topic-nav { display:flex; justify-content:space-between; align-items:center; padding-top:24px; border-top:1px solid var(--border); margin-top:32px; gap:12px; flex-wrap:wrap; }
.mobile-topic-select { display:none; padding:16px 16px 0; }
.mobile-topic-select select { width:100%; background:var(--bg3); border:1px solid var(--border2); color:var(--text); padding:10px 14px; border-radius:8px; font-family:'JetBrains Mono',monospace; font-size:13px; cursor:pointer; }

/* Info boxes */
.info-box { background:var(--bg3); border:1px solid var(--border); border-radius:8px; padding:14px 18px; margin:18px 0; font-size:13px; line-height:1.85; color:var(--text); }
.info-box.note { border-left:3px solid var(--accent); background:rgba(79,195,247,.03); }
.info-box.tip  { border-left:3px solid var(--green);  background:rgba(105,255,135,.03); }
.info-box.warn { border-left:3px solid var(--yellow); background:rgba(255,209,102,.03); }
.ib-label { font-size:10px; font-weight:600; letter-spacing:1.5px; text-transform:uppercase; margin-bottom:6px; display:block; color:var(--accent); }
.info-box.tip  .ib-label { color:var(--green); }
.info-box.warn .ib-label { color:var(--yellow); }
.theory-text { font-size:13px; color:var(--text2); line-height:1.95; margin:14px 0; }
.theory-text strong { color:var(--text); }
.theory-text code,.theory-body code { background:var(--bg4); color:var(--accent); padding:1px 6px; border-radius:3px; font-size:12px; font-family:'JetBrains Mono',monospace; }
h3.sub-heading { font-family:'Syne',sans-serif; font-size:16px; font-weight:700; color:var(--text); margin:26px 0 12px; }

/* Table */
.data-table { width:100%; border-collapse:collapse; margin:16px 0; font-size:12.5px; }
.data-table th { background:var(--bg4); color:var(--text2); padding:9px 14px; text-align:left; font-weight:600; font-size:10px; letter-spacing:1px; text-transform:uppercase; border-bottom:1px solid var(--border); }
.data-table td { padding:9px 14px; border-bottom:1px solid var(--border); color:var(--text); vertical-align:top; line-height:1.6; }
.data-table td code { color:var(--accent); background:var(--bg4); padding:1px 5px; border-radius:3px; }
.data-table td.type { color:var(--purple); font-size:11px; }
.data-table tr:last-child td { border-bottom:none; }

/* Code blocks */
.code-block { background:var(--bg3); border:1px solid var(--border); border-radius:10px; overflow:hidden; margin:16px 0; }
.code-header { display:flex; align-items:center; justify-content:space-between; padding:9px 14px; background:var(--bg4); border-bottom:1px solid var(--border); gap:8px; }
.code-lang { color:var(--php); font-size:10px; letter-spacing:1px; text-transform:uppercase; font-weight:600; }
.code-file { color:var(--text3); font-size:11px; flex:1; }
.copy-btn { background:none; border:1px solid var(--border); color:var(--text2); padding:3px 10px; border-radius:4px; cursor:pointer; font-size:10px; font-family:'JetBrains Mono',monospace; transition:all .15s; flex-shrink:0; }
.copy-btn:hover { color:var(--green); border-color:var(--green); }
pre { padding:18px 20px; overflow-x:auto; line-height:1.75; }
pre code { font-family:'JetBrains Mono',monospace; background:none; padding:0; font-size:12.5px; white-space:pre; }
.kw{color:#c084fc}.fn{color:#4fc3f7}.st{color:#ffd166}.cm{color:#4a5a70;font-style:italic}
.nm{color:#ff9f43}.va{color:#69ff87}.op{color:#c9d4e8}.cl{color:#ff9f43}

/* Buttons */
.btn { display:inline-flex; align-items:center; gap:6px; padding:8px 20px; border-radius:7px; font-family:'JetBrains Mono',monospace; font-size:12px; font-weight:600; cursor:pointer; border:none; transition:all .15s; white-space:nowrap; }
.btn-primary   { background:var(--accent); color:var(--bg); }
.btn-primary:hover { background:var(--accent2); }
.btn-secondary { background:var(--bg4); color:var(--text2); border:1px solid var(--border); }
.btn-secondary:hover { color:var(--text); border-color:var(--border2); }
.btn-purple { background:rgba(192,132,252,.12); color:var(--purple); border:1px solid rgba(192,132,252,.28); }
.btn-purple:hover { background:rgba(192,132,252,.22); }
.btn-green  { background:rgba(105,255,135,.1);  color:var(--green);  border:1px solid rgba(105,255,135,.25); }
.btn-green:hover { background:rgba(105,255,135,.2); }
.btn-sm { font-size:11px; padding:5px 12px; }

/* ══════════════════
   EXAMPLES
   ══════════════════ */
.examples-grid { display:grid; grid-template-columns:repeat(auto-fill,minmax(340px,1fr)); gap:18px; }
.example-card { background:var(--bg3); border:1px solid var(--border); border-radius:12px; overflow:hidden; transition:border-color .2s,transform .2s; display:flex; flex-direction:column; }
.example-card:hover { border-color:var(--border2); transform:translateY(-1px); }
.example-card-header { padding:14px 16px; border-bottom:1px solid var(--border); display:flex; align-items:center; justify-content:space-between; gap:8px; }
.example-card-title { font-size:13px; font-weight:700; color:var(--text); font-family:'Syne',sans-serif; }
.example-tag { font-size:10px; padding:2px 9px; border-radius:12px; background:rgba(79,195,247,.1); color:var(--accent); white-space:nowrap; }
.example-tag.inter { background:rgba(255,159,67,.1); color:var(--orange); }
.example-tag.adv   { background:rgba(192,132,252,.1); color:var(--purple); }
.example-desc { font-size:11.5px; color:var(--text3); padding:8px 16px; }
.example-preview { padding:12px 16px; font-size:11.5px; max-height:140px; overflow:hidden; line-height:1.65; flex:1; }
.example-full { padding:12px 16px; font-size:12px; overflow-x:auto; border-top:1px solid var(--border); line-height:1.65; }
.example-footer { padding:10px 16px; display:flex; justify-content:flex-end; gap:8px; border-top:1px solid var(--border); background:var(--bg4); }
.hidden { display:none !important; }

/* ══════════════════
   QUIZ
   ══════════════════ */
.quiz-cat-tabs { display:flex; gap:8px; flex-wrap:wrap; margin-bottom:28px; }
.quiz-cat-btn { padding:7px 16px; border-radius:20px; font-size:12px; background:var(--bg4); border:1px solid var(--border); color:var(--text2); cursor:pointer; font-family:'JetBrains Mono',monospace; transition:all .15s; }
.quiz-cat-btn:hover { color:var(--text); border-color:var(--border2); }
.quiz-cat-btn.active { background:rgba(79,195,247,.1); border-color:var(--accent); color:var(--accent); }
.quiz-wrap { max-width:720px; }
.quiz-progress-bar-wrap { display:flex; align-items:center; gap:14px; margin-bottom:28px; }
.quiz-progress-bar { flex:1; height:4px; background:var(--bg4); border-radius:2px; overflow:hidden; }
.quiz-progress-bar>div { height:100%; background:linear-gradient(90deg,var(--accent),var(--purple)); transition:width .4s; border-radius:2px; }
.quiz-counter,.quiz-score-display { font-size:11px; color:var(--text3); white-space:nowrap; }
.quiz-score-display { color:var(--green); }
.quiz-card { background:var(--bg3); border:1px solid var(--border); border-radius:12px; padding:28px; margin-bottom:18px; }
.quiz-q-num { font-size:10px; color:var(--text3); letter-spacing:2px; text-transform:uppercase; margin-bottom:12px; }
.quiz-question { font-size:17px; color:var(--text); font-family:'Syne',sans-serif; font-weight:600; line-height:1.6; margin-bottom:8px; }
.quiz-question code { font-family:'JetBrains Mono',monospace; font-size:14px; background:var(--bg4); color:var(--accent); padding:2px 8px; border-radius:4px; }
.quiz-options { display:flex; flex-direction:column; gap:10px; margin-top:18px; }
.quiz-opt { padding:13px 18px; border-radius:9px; border:1px solid var(--border); background:var(--bg4); cursor:pointer; font-size:13px; color:var(--text2); transition:all .15s; display:flex; align-items:center; gap:14px; }
.quiz-opt:hover:not(.disabled) { border-color:var(--accent); color:var(--text); }
.quiz-opt.correct { border-color:var(--green);  background:rgba(105,255,135,.08); color:var(--green); }
.quiz-opt.wrong   { border-color:var(--red);    background:rgba(255,107,107,.08); color:var(--red); }
.quiz-opt.reveal  { border-color:var(--green);  background:rgba(105,255,135,.05); color:var(--green); }
.quiz-opt.disabled { cursor:default; }
.quiz-opt-letter { width:26px; height:26px; border-radius:6px; background:var(--bg3); display:flex; align-items:center; justify-content:center; font-size:10px; font-weight:700; color:var(--text3); flex-shrink:0; }
.quiz-feedback { margin-top:16px; padding:13px 16px; border-radius:9px; font-size:13px; line-height:1.75; display:none; }
.quiz-feedback.show { display:block; }
.quiz-feedback.correct { background:rgba(105,255,135,.06); border:1px solid rgba(105,255,135,.22); color:var(--text2); }
.quiz-feedback.wrong   { background:rgba(255,107,107,.06); border:1px solid rgba(255,107,107,.22); color:var(--text2); }
.quiz-feedback code { background:var(--bg4); color:var(--accent); padding:1px 6px; border-radius:3px; }
.quiz-result { background:var(--bg3); border:1px solid var(--border); border-radius:14px; padding:40px 32px; text-align:center; }
.result-emoji { font-size:52px; margin-bottom:18px; }
.result-score { font-family:'Syne',sans-serif; font-size:60px; font-weight:800; color:var(--accent); line-height:1; margin-bottom:6px; }
.result-label { color:var(--text3); font-size:12px; margin-bottom:28px; }
.result-stats,.review-stats { display:flex; gap:14px; justify-content:center; flex-wrap:wrap; margin-bottom:28px; }
.rs-item { background:var(--bg4); border:1px solid var(--border); border-radius:10px; padding:14px 24px; text-align:center; }
.rs-val { font-size:24px; font-weight:700; color:var(--text); font-family:'Syne',sans-serif; }
.rs-val.green{color:var(--green)}.rs-val.red{color:var(--red)}.rs-val.yellow{color:var(--yellow)}
.rs-lbl { font-size:10px; color:var(--text3); margin-top:3px; }

/* ══════════════════
   CHEATSHEET
   ══════════════════ */
.cheatsheet-grid { display:grid; grid-template-columns:repeat(auto-fill,minmax(310px,1fr)); gap:16px; }
.cs-card { background:var(--bg3); border:1px solid var(--border); border-radius:10px; overflow:hidden; }
.cs-header { display:flex; align-items:center; justify-content:space-between; padding:11px 16px; background:var(--bg4); border-bottom:1px solid var(--border); font-size:12px; font-family:'Syne',sans-serif; font-weight:700; color:var(--text); gap:8px; }
.cs-card pre { padding:14px 16px; font-size:11.5px; overflow-x:auto; line-height:1.7; }

/* ══════════════════
   PLAYGROUND
   ══════════════════ */
.playground-section { padding:28px 32px; max-width:100%; }
.playground-layout { display:grid; grid-template-columns:1fr 1fr; gap:18px; height:calc(100vh - 180px); min-height:500px; }
.pane { background:var(--bg3); border:1px solid var(--border); border-radius:12px; display:flex; flex-direction:column; overflow:hidden; min-height:0; }
.pane-header { padding:11px 16px; background:var(--bg4); border-bottom:1px solid var(--border); display:flex; align-items:center; justify-content:space-between; flex-shrink:0; gap:8px; flex-wrap:wrap; }
.pane-title { font-size:11px; color:var(--text2); display:flex; align-items:center; gap:8px; }
.dot { width:8px; height:8px; border-radius:50%; background:var(--accent); flex-shrink:0; }
.dot.explain { background:var(--purple); }
.pane-actions { display:flex; gap:8px; align-items:center; flex-wrap:wrap; }
.pane-actions select { background:var(--bg4); border:1px solid var(--border); color:var(--text2); padding:5px 10px; border-radius:6px; font-family:'JetBrains Mono',monospace; font-size:11px; cursor:pointer; }
#editor { flex:1; padding:18px; background:var(--bg3); border:none; resize:none; color:var(--text); font-family:'JetBrains Mono',monospace; font-size:13px; line-height:1.75; outline:none; min-height:0; }
.pane-toolbar { padding:10px 14px; border-top:1px solid var(--border); display:flex; gap:8px; flex-wrap:wrap; background:var(--bg4); flex-shrink:0; }
#explain-box { flex:1; padding:18px; overflow-y:auto; font-size:13px; line-height:1.75; min-height:0; }
.explain-text { color:var(--text2); }
.explain-text strong { color:var(--text); }
.explain-text code { background:var(--bg4); color:var(--accent); padding:1px 6px; border-radius:3px; }
.eb-line { margin-bottom:9px; padding:7px 12px; background:var(--bg4); border-radius:6px; border-left:2px solid var(--border); }
.eb-line.known { border-left-color:var(--accent); }
.eb-line code { color:var(--green); font-size:11.5px; }
.eb-desc { color:var(--text2); font-size:12px; display:block; margin-top:3px; }
.concept-tag { background:rgba(79,195,247,.1); border:1px solid rgba(79,195,247,.2); color:var(--accent); padding:2px 9px; border-radius:12px; font-size:11px; margin:3px 2px; display:inline-block; }
.review-issue { background:rgba(255,107,107,.06); border:1px solid rgba(255,107,107,.18); border-radius:7px; padding:9px 14px; margin:6px 0; font-size:12.5px; color:var(--text2); }
.review-tip   { background:rgba(255,209,102,.05); border:1px solid rgba(255,209,102,.15); border-radius:7px; padding:9px 14px; margin:6px 0; font-size:12.5px; color:var(--text2); }
.review-issue code,.review-tip code { background:var(--bg4); color:var(--accent); padding:1px 5px; border-radius:3px; }

/* ══════════════════
   RESPONSIVE
   ══════════════════ */

/* Wide desktop */
@media(min-width:1400px){
  .section { padding:40px 60px; }
  .theory-content-wrap { padding:40px 60px; max-width:1100px; }
  .hero h1 { font-size:52px; }
}

/* Tablet landscape */
@media(max-width:1200px){
  .hero-grid { grid-template-columns:repeat(2,1fr); }
  .playground-layout { grid-template-columns:1fr; height:auto; min-height:unset; }
  #editor { min-height:260px; }
  #explain-box { min-height:220px; }
}

/* Tablet portrait */
@media(max-width:1024px){
  :root { --sw:230px; }
  .section { padding:28px; }
  .theory-content-wrap { padding:28px; }
  .hero h1 { font-size:36px; }
  .examples-grid { grid-template-columns:repeat(auto-fill,minmax(280px,1fr)); }
  .playground-layout { grid-template-columns:1fr; height:auto; }
  #editor { min-height:240px; }
}

/* ── MOBILE ≤ 768px ── */
@media(max-width:768px){

  /* Unlock viewport — content scrolls normally */
  #app { flex-direction:column; height:auto; min-height:100vh; overflow:visible; }
  #main { width:100%; overflow:visible; }
  #content { overflow:visible; height:auto; }

  /* Sidebar = slide-over drawer */
  #sidebar {
    position:fixed; top:0; left:0;
    height:100dvh;
    width:var(--sw) !important; min-width:var(--sw) !important;
    z-index:200;
    transform:translateX(-100%);
    transition:transform .28s cubic-bezier(.4,0,.2,1);
    box-shadow:4px 0 32px rgba(0,0,0,.65);
  }
  #sidebar.mobile-open  { transform:translateX(0); }
  #sidebar.collapsed    { transform:translateX(-100%); }

  /* Topbar sticks at top */
  #topbar { position:sticky; top:0; z-index:10; }

  /* Sections */
  .section { padding:20px 16px; }
  .hero { padding:28px 0 16px; }
  .hero h1 { font-size:28px; }
  .hero>p { font-size:13px; }
  .hero-grid { grid-template-columns:1fr; gap:10px; }
  .hero-badge { font-size:10px; }

  /* Theory */
  .theory-layout { grid-template-columns:1fr; height:auto; }
  .theory-toc { display:none; }
  .mobile-topic-select { display:block; }
  .theory-content-wrap { padding:20px 16px; overflow-y:visible; }
  .topic-nav { flex-direction:column; }
  .topic-nav .btn { width:100%; justify-content:center; }

  /* Examples / cheatsheet */
  .examples-grid { grid-template-columns:1fr; }
  .cheatsheet-grid { grid-template-columns:1fr; }

  /* Quiz */
  .quiz-wrap { max-width:100%; }
  .quiz-card { padding:18px 16px; }
  .quiz-question { font-size:15px; }
  .quiz-cat-tabs { gap:5px; }
  .quiz-cat-btn { font-size:11px; padding:6px 12px; }

  /* Playground */
  .playground-section { padding:18px 16px; }
  .playground-layout { gap:14px; }
  #editor { min-height:200px; font-size:12px; }
  #explain-box { min-height:180px; }
  .pane-actions select { max-width:130px; font-size:10px; }

  /* Tables */
  .data-table { font-size:11.5px; }
  .data-table th,.data-table td { padding:7px 10px; }

  /* Misc */
  .php-badge { display:none; }
}

/* Small phones */
@media(max-width:400px){
  .hero h1 { font-size:23px; }
  .section { padding:16px 12px; }
  .quiz-card { padding:14px 12px; }
  .quiz-opt { font-size:12px; padding:10px 12px; }
  .result-score { font-size:48px; }
  pre { padding:12px 14px; }
  pre code { font-size:11.5px; }
  .btn { font-size:11px; padding:6px 14px; }
}