/* ============================================================
   PyMasters v3 - Complete Style Sheet
   Dark theme, modern, beginner-friendly
   Matches index.html + app.js class names
   ============================================================ */

/* ── 0. RESET & BASE ──────────────────────────────────────── */
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}
body{
  font-family:"Segoe UI","Hiragino Sans","Noto Sans JP",system-ui,sans-serif;
  background:#09090b;
  color:#e4e4e7;
  line-height:1.8;
  font-size:16px;
  min-height:100dvh;
  overflow-x:hidden;
  -webkit-font-smoothing:antialiased;
}
a{color:#60a5fa;text-decoration:none;transition:color .2s}
a:hover{color:#93bbfd}
img{max-width:100%;display:block}
ul,ol{list-style:none}
button,input,textarea,select{font:inherit;color:inherit;border:none;outline:none;background:none}
button{cursor:pointer}

/* ── 1. BUTTONS ──────────────────────────────────────────── */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:8px;
  padding:10px 22px;border-radius:10px;font-weight:600;font-size:.95rem;
  transition:all .2s ease;white-space:nowrap;
  border:2px solid transparent;
}
.btn:active{transform:scale(.97)}
.btn:disabled{opacity:.45;pointer-events:none}

.btn-p{background:#3b82f6;color:#fff}
.btn-p:hover{background:#2563eb;box-shadow:0 4px 20px #3b82f640}

.btn-g{background:#22c55e;color:#fff}
.btn-g:hover{background:#16a34a;box-shadow:0 4px 20px #22c55e40}

.btn-s{background:#27272a;color:#e4e4e7}
.btn-s:hover{background:#3f3f46}

.btn-o{background:transparent;border-color:#3f3f46;color:#e4e4e7}
.btn-o:hover{border-color:#60a5fa;color:#60a5fa;background:#3b82f610}

.btn-l{padding:14px 32px;font-size:1.1rem;border-radius:14px}
.btn-xs{padding:5px 12px;font-size:.78rem;border-radius:8px}

/* ── 2. PYODIDE LOADING (in-editor overlay) ──────────────── */
.pyodide-loading{
  position:absolute;inset:0;z-index:50;
  background:#0c0c0ef0;
  display:flex;align-items:center;justify-content:center;
  flex-direction:column;
}
.pyodide-loading-inner{
  text-align:center;
  padding:32px;
}
.pyodide-spinner{
  width:40px;height:40px;
  border:3px solid #27272a;
  border-top-color:#3b82f6;
  border-radius:50%;
  animation:spin .8s linear infinite;
  margin:0 auto 16px;
}
@keyframes spin{to{transform:rotate(360deg)}}
.pyodide-loading-text{
  color:#a1a1aa;font-size:.95rem;margin-bottom:12px;
}
.pyodide-progress-bar{
  width:200px;height:6px;border-radius:6px;
  background:#27272a;overflow:hidden;
  margin:0 auto 8px;
}
.pyodide-progress-fill{
  height:100%;border-radius:6px;
  background:linear-gradient(90deg,#3b82f6,#06b6d4);
  transition:width .3s ease;
  width:0%;
}
.pyodide-progress-text{
  font-size:.82rem;color:#3b82f6;font-weight:700;
}
.pyodide-cache-note{
  font-size:.72rem;color:#52525b;margin-top:8px;
}

/* ── 3. HEADER ───────────────────────────────────────────── */
.hdr{
  position:sticky;top:0;z-index:900;
  background:#09090bf0;
  backdrop-filter:blur(12px);-webkit-backdrop-filter:blur(12px);
  border-bottom:1px solid #27272a;
  padding:12px 20px;
  display:flex;align-items:center;justify-content:space-between;
  max-width:100%;
}
.logo{
  display:flex;align-items:center;gap:10px;
  cursor:pointer;
}
.logo-icon{
  background:linear-gradient(135deg,#3b82f6,#a855f7);
  color:#fff;font-weight:900;font-size:.85rem;
  width:34px;height:34px;border-radius:9px;
  display:flex;align-items:center;justify-content:center;
}
.logo h1{
  font-size:1.25rem;font-weight:800;
  background:linear-gradient(135deg,#3b82f6,#a855f7);
  -webkit-background-clip:text;-webkit-text-fill-color:transparent;
  background-clip:text;
  letter-spacing:-.02em;
}
.hdr-right{display:flex;align-items:center;gap:12px}
.search-btn{
  width:38px;height:38px;border-radius:10px;
  display:flex;align-items:center;justify-content:center;
  background:#18181b;border:1px solid #27272a;
  transition:all .2s;font-size:1.1rem;
}
.search-btn:hover{border-color:#3b82f6;background:#3b82f615}

.hdr-stats{display:flex;align-items:center;gap:8px}
.badge{
  display:inline-flex;align-items:center;gap:5px;
  padding:4px 12px;border-radius:20px;font-size:.8rem;font-weight:600;
  background:#18181b;border:1px solid #27272a;
  position:relative;
}
.xp-c{color:#3b82f6;border-color:#3b82f630}
.lv-c{color:#a855f7;border-color:#a855f730}
.st-c{color:#f59e0b;border-color:#f59e0b30}

.xpbar-m{
  width:40px;height:4px;border-radius:4px;
  background:#27272a;overflow:hidden;
  margin-left:4px;
}
.xpbar-f{
  height:100%;border-radius:4px;
  background:linear-gradient(90deg,#3b82f6,#06b6d4);
  transition:width .6s ease;
}

/* ── 4. PAGES & TRANSITIONS ─────────────────────────────── */
.pg{display:none;opacity:0}
.pg.on{display:block;animation:fadeIn .35s ease forwards}
@keyframes fadeIn{from{opacity:0;transform:translateY(8px)}to{opacity:1;transform:translateY(0)}}

/* ── 5. HOME ─────────────────────────────────────────────── */
.hero{
  text-align:center;
  padding:48px 20px 36px;
  max-width:800px;margin:0 auto;
}
.hero h2{
  font-size:2rem;font-weight:800;line-height:1.3;
  margin-bottom:12px;
}
.hero em{
  font-style:normal;
  background:linear-gradient(135deg,#3b82f6,#06b6d4);
  -webkit-background-clip:text;-webkit-text-fill-color:transparent;
  background-clip:text;
}
.hero p{
  color:#a1a1aa;font-size:1.05rem;max-width:640px;margin:0 auto 24px;
  line-height:1.7;
}

/* hero features */
.hero-feats{
  display:flex;flex-wrap:wrap;justify-content:center;gap:12px 20px;
  margin-bottom:28px;
}
.hf{
  display:flex;align-items:center;gap:8px;
  font-size:.88rem;color:#a1a1aa;
}
.dot{width:8px;height:8px;border-radius:50%;flex-shrink:0}
.dot-b{background:#3b82f6}
.dot-g{background:#22c55e}
.dot-p{background:#a855f7}
.dot-a{background:#f59e0b}

/* next recommend card */
.next-recommend{
  margin-bottom:16px;
}
.next-rec-inner{
  display:inline-flex;align-items:center;gap:8px;
  background:#18181b;border:1px solid #27272a;border-radius:12px;
  padding:10px 18px;font-size:.88rem;
}
.next-rec-label{color:#71717a;font-size:.82rem}
.next-rec-link{color:#60a5fa;font-weight:600;font-size:.88rem}
.next-rec-link:hover{color:#93bbfd}

/* progress card */
.progress-card{
  background:#18181b;border:1px solid #27272a;border-radius:16px;
  padding:22px 28px;max-width:480px;margin:0 auto 28px;
  text-align:left;
}
.progress-card h3{font-size:.95rem;font-weight:700;margin-bottom:14px;color:#e4e4e7}
.pbar{
  background:#27272a;border-radius:10px;height:10px;overflow:hidden;
  margin-bottom:6px;
}
.pbar-f{
  height:100%;border-radius:10px;
  background:linear-gradient(90deg,#3b82f6,#06b6d4);
  transition:width .6s ease;
}
.ptxt{font-size:.82rem;color:#a1a1aa}

/* course section */
.courses-sec{
  max-width:1100px;margin:0 auto;padding:0 20px 48px;
}
.courses-sec h3{
  font-size:1.3rem;font-weight:700;margin-bottom:16px;
}
.pro-label{
  background:linear-gradient(135deg,#f59e0b,#f97316);
  color:#fff;font-size:.65rem;font-weight:800;
  padding:2px 8px;border-radius:5px;
  margin-left:6px;vertical-align:middle;
}

/* course grid */
.course-grid{
  display:grid;
  grid-template-columns:repeat(auto-fill,minmax(280px,1fr));
  gap:16px;
}
.course-card{
  background:#18181b;border:1px solid #27272a;border-radius:16px;
  padding:24px;
  transition:all .25s ease;
  cursor:pointer;
  position:relative;overflow:hidden;
}
.course-card:hover{
  border-color:#3b82f650;
  transform:translateY(-3px) scale(1.03);
  box-shadow:0 8px 30px #3b82f618;
}
.course-card .cc-icon{font-size:3rem;margin-bottom:12px;display:block}
.course-card h4{font-size:1.05rem;font-weight:700;margin-bottom:6px}
.course-card p{font-size:.88rem;color:#a1a1aa;line-height:1.6;margin-bottom:14px}
.cc-meta{display:flex;align-items:center;gap:10px;font-size:.78rem;color:#71717a}
.cc-lv{
  padding:2px 8px;border-radius:6px;font-weight:700;font-size:.72rem;
}
.lv-b{background:#22c55e18;color:#22c55e}
.lv-i{background:#3b82f618;color:#3b82f6}
.lv-a{background:#f59e0b18;color:#f59e0b}
.lv-s{background:#a855f718;color:#a855f7}
.cc-cnt{color:#71717a}
.cc-pb{
  height:4px;border-radius:4px;background:#27272a;margin-top:14px;overflow:hidden;
}
.cc-pf{display:block;height:100%;border-radius:4px;background:#22c55e;transition:width .4s}
.cc-pct{
  font-size:.75rem;color:#a1a1aa;margin-top:6px;font-weight:600;
}

/* Course card gradient backgrounds */
.cc-grad-beginner{
  background:linear-gradient(135deg,#18181b 60%,#22c55e08 100%);
  border-color:#22c55e15;
}
.cc-grad-intermediate{
  background:linear-gradient(135deg,#18181b 60%,#3b82f608 100%);
  border-color:#3b82f615;
}
.cc-grad-advanced{
  background:linear-gradient(135deg,#18181b 60%,#f59e0b08 100%);
  border-color:#f59e0b15;
}
.cc-grad-skill{
  background:linear-gradient(135deg,#18181b 60%,#a855f708 100%);
  border-color:#a855f715;
}

/* Clear badge */
.cc-clear-badge{
  position:absolute;top:12px;right:12px;
  background:#22c55e18;color:#22c55e;
  font-size:.72rem;font-weight:700;
  padding:3px 10px;border-radius:8px;
  border:1px solid #22c55e30;
}

/* locked card (PRO) */
.course-card.locked{opacity:.7;cursor:pointer}
.course-card.locked:hover{transform:none;box-shadow:none;border-color:#f59e0b40}
.course-card.locked::after{
  content:"PRO";
  position:absolute;top:14px;right:14px;
  background:linear-gradient(135deg,#f59e0b,#f97316);
  color:#fff;font-size:.68rem;font-weight:800;
  padding:3px 10px;border-radius:6px;
  letter-spacing:.04em;
}

/* premium banner */
.premium-banner{
  margin-top:24px;
  background:linear-gradient(135deg,#18181b,#1a1a2e);
  border:1px solid #3b82f630;border-radius:18px;
  padding:32px;text-align:center;
  position:relative;overflow:hidden;
}
.premium-banner::before{
  content:'';position:absolute;top:-50%;right:-30%;width:300px;height:300px;
  background:radial-gradient(circle,#3b82f610,transparent 70%);pointer-events:none;
}
.promo-badge{
  display:inline-block;background:linear-gradient(135deg,#f59e0b,#ef4444);
  color:#fff;font-size:.75rem;font-weight:700;padding:4px 14px;border-radius:20px;
  margin-bottom:14px;letter-spacing:.5px;animation:promoPulse 2s ease-in-out infinite;
}
@keyframes promoPulse{0%,100%{opacity:1;transform:scale(1)}50%{opacity:.85;transform:scale(1.03)}}
.promo-code-box{
  display:inline-flex;align-items:center;gap:8px;
  background:#1e1e2e;border:1px dashed #3b82f680;border-radius:12px;
  padding:10px 18px;margin:16px 0;
}
.promo-code-box-sm{margin:10px 0;padding:8px 14px}
.promo-label{color:#a1a1aa;font-size:.8rem}
.promo-code{
  font-family:monospace;font-size:1.1rem;font-weight:800;
  color:#60a5fa;background:#3b82f618;padding:3px 10px;border-radius:6px;
  letter-spacing:1px;
}
.promo-desc{color:#22c55e;font-size:.85rem;font-weight:600}
.premium-banner h4{font-size:1.15rem;font-weight:800;margin-bottom:8px}
.premium-banner p{color:#a1a1aa;font-size:.92rem;margin-bottom:20px;line-height:1.6}

/* ad slot */
.ad-slot{
  background:#18181b;border:1px solid #27272a;border-radius:14px;
  padding:16px;margin:24px auto;
  max-width:1100px;
  text-align:center;min-height:90px;
  display:flex;align-items:center;justify-content:center;
  color:#3f3f46;font-size:.85rem;
}

/* ── 6. SEARCH MODAL ─────────────────────────────────────── */
.modal-overlay{
  position:fixed;inset:0;z-index:1000;
  background:#09090be6;
  display:none;align-items:center;justify-content:center;
  padding:20px;
  backdrop-filter:blur(6px);-webkit-backdrop-filter:blur(6px);
}
.modal-overlay.on{display:flex}

/* search specific */
#searchModal.on{
  padding:80px 20px 40px;
  align-items:flex-start;
}
.search-modal{
  background:#18181b;border:1px solid #27272a;border-radius:18px;
  width:100%;max-width:560px;
  overflow:hidden;
  box-shadow:0 20px 60px #0009;
  animation:fadeIn .2s ease;
}
.search-modal-header{
  display:flex;align-items:center;gap:10px;
  padding:16px 22px;border-bottom:1px solid #27272a;
}
#searchInput{
  flex:1;background:none;border:none;font-size:1.05rem;
  color:#e4e4e7;padding:4px 0;
}
#searchInput::placeholder{color:#52525b}
.close-btn{
  color:#71717a;font-size:1.1rem;padding:4px 10px;border-radius:8px;
  transition:all .15s;background:none;border:none;cursor:pointer;
}
.close-btn:hover{color:#e4e4e7;background:#27272a}
.close-btn-sm{
  color:#71717a;font-size:.9rem;padding:2px 8px;border-radius:6px;
  transition:all .15s;background:none;border:none;cursor:pointer;
}
.close-btn-sm:hover{color:#e4e4e7;background:#27272a}

.search-results{max-height:400px;overflow-y:auto;padding:8px}
.search-placeholder{
  text-align:center;padding:32px 16px;color:#52525b;font-size:.9rem;
}
.search-result-item{
  padding:14px 18px;border-radius:12px;
  transition:background .15s;cursor:pointer;
}
.search-result-item:hover{background:#27272a}
.sr-term{font-size:.95rem;font-weight:600;color:#e4e4e7;margin-bottom:3px}
.sr-short{font-size:.85rem;color:#a1a1aa;line-height:1.5}

/* search term detail (inside search modal) */
.search-term-detail{padding:20px 22px}
.std-back{
  font-size:.85rem;color:#60a5fa;cursor:pointer;
  margin-bottom:14px;display:inline-block;
  transition:color .15s;
}
.std-back:hover{color:#93bbfd}
.std-title{font-size:1.15rem;font-weight:800;color:#e4e4e7;margin-bottom:4px}
.std-short{font-size:.9rem;color:#a1a1aa;margin-bottom:14px}
.std-detail{
  font-size:.9rem;color:#d4d4d8;line-height:1.8;margin-bottom:16px;
}
.std-detail code{
  background:#27272a;padding:1px 6px;border-radius:5px;
  font-family:'Fira Code',"Cascadia Code",monospace;font-size:.82rem;
}
.std-detail br{display:block;content:"";margin-bottom:6px}
.std-detail strong{color:#e4e4e7}

.std-example{margin-bottom:16px}
.std-ex-header{
  display:flex;align-items:center;justify-content:space-between;
  margin-bottom:6px;
}
.std-ex-label{font-size:.78rem;color:#71717a;font-weight:600}
.std-run-btn{
  font-size:.75rem;color:#22c55e;background:#22c55e18;
  border:1px solid #22c55e40;border-radius:6px;
  padding:3px 12px;cursor:pointer;
  transition:all .15s;font-weight:600;
}
.std-run-btn:hover{background:#22c55e30;border-color:#22c55e}
.std-ex-code{
  background:#0c0c0e;border:1px solid #27272a;border-radius:8px;
  padding:12px 16px;margin:0;
  font-family:'Fira Code',"Cascadia Code",monospace;
  font-size:.82rem;line-height:1.6;color:#e4e4e7;
  overflow-x:auto;white-space:pre;
}
.std-output{
  margin-top:8px;border-radius:8px;
  background:#0a1a0e;border:1px solid #22c55e30;
  padding:10px 14px;min-height:32px;
  transition:all .2s;
}
.std-output-placeholder{font-size:.78rem;color:#4ade8060}
.std-output-running{font-size:.78rem;color:#fbbf24}
.std-output-label{font-size:.72rem;color:#4ade80;font-weight:600;margin-bottom:4px}
.std-output-code{
  background:transparent;border:none;
  padding:0;margin:0;
  font-family:'Fira Code',"Cascadia Code",monospace;
  font-size:.82rem;line-height:1.5;color:#d1fae5;
  white-space:pre-wrap;word-break:break-all;
}
.std-output-err{color:#fca5a5}

.std-related{margin-top:12px}
.std-rel-label{font-size:.78rem;color:#71717a}
.std-rel-link{
  display:inline-block;
  font-size:.8rem;color:#60a5fa;
  background:#3b82f610;border:1px solid #3b82f630;
  padding:3px 10px;border-radius:6px;
  margin:3px 4px 3px 0;cursor:pointer;
  transition:all .15s;
}
.std-rel-link:hover{background:#3b82f625;border-color:#3b82f6}

/* ── 7. GLOSSARY POPUP ───────────────────────────────────── */
.term{
  text-decoration:underline;text-decoration-color:#3b82f650;
  text-underline-offset:3px;
  cursor:pointer;color:#60a5fa;
  transition:text-decoration-color .2s;
}
.term:hover{text-decoration-color:#3b82f6}

.glossary-popup{
  position:fixed;z-index:950;
  background:#1e1e22;
  border:1px solid #3b82f640;
  border-radius:14px;
  padding:18px 20px;
  max-width:360px;width:max-content;
  box-shadow:0 12px 40px #0008;
  display:none;
}
.glossary-popup.on{display:block;animation:gpopIn .2s ease}
@keyframes gpopIn{from{opacity:0;transform:scale(.95)}to{opacity:1;transform:scale(1)}}

.glossary-popup-header{
  display:flex;align-items:center;justify-content:space-between;
  margin-bottom:8px;
}
.glossary-popup-title{
  font-size:.95rem;font-weight:700;color:#60a5fa;
}
.glossary-popup-short{
  font-size:.85rem;color:#a1a1aa;margin-bottom:10px;
}
.glossary-popup-detail{
  font-size:.85rem;color:#d4d4d8;line-height:1.7;margin-bottom:12px;
}
.glossary-popup-detail code{
  background:#27272a;padding:1px 6px;border-radius:5px;
  font-family:'Fira Code',"Cascadia Code",monospace;font-size:.82rem;
}
.glossary-popup-example{
  margin-top:10px;
}
.gp-ex-label{
  font-size:.78rem;color:#71717a;font-weight:600;margin-bottom:4px;
}
.gp-ex-code{
  background:#0c0c0e;border:1px solid #27272a;border-radius:8px;
  padding:10px 14px;
  font-family:'Fira Code',"Cascadia Code",monospace;
  font-size:.82rem;line-height:1.6;color:#e4e4e7;
  overflow-x:auto;white-space:pre;
}
.glossary-popup-related{margin-top:10px}
.gp-related-label{font-size:.75rem;color:#71717a;margin-bottom:4px}
.gp-related-link{
  display:inline-block;
  font-size:.78rem;color:#60a5fa;
  background:#3b82f610;border:1px solid #3b82f630;
  padding:2px 8px;border-radius:6px;
  margin:2px 4px 2px 0;cursor:pointer;
  transition:all .15s;
}
.gp-related-link:hover{background:#3b82f625;border-color:#3b82f6}

/* ── 8. COURSE DETAIL ────────────────────────────────────── */
.course-detail{
  max-width:700px;margin:0 auto;padding:32px 20px 60px;
}
.back-link{
  display:inline-flex;align-items:center;gap:6px;
  font-size:.9rem;color:#a1a1aa;margin-bottom:20px;
  padding:8px 14px;border-radius:10px;
  transition:all .2s;cursor:pointer;
}
.back-link:hover{color:#e4e4e7;background:#18181b}

.cd-icon{font-size:2.5rem;margin-bottom:12px;display:block}
#cdH h2{font-size:1.7rem;font-weight:800;margin-bottom:8px}
.cd-desc{color:#a1a1aa;font-size:1rem;line-height:1.6;margin-bottom:12px}

/* lesson list */
.lesson-list{display:flex;flex-direction:column;gap:6px;margin-top:24px}
.lesson-item{
  display:flex;align-items:center;gap:14px;
  padding:16px 20px;border-radius:14px;
  background:#18181b;border:1px solid #27272a;
  transition:all .2s;cursor:pointer;
}
.lesson-item:hover{border-color:#3b82f640;background:#1c1c20}
.li-num{
  width:36px;height:36px;border-radius:10px;
  display:flex;align-items:center;justify-content:center;
  background:#27272a;font-size:.85rem;font-weight:700;color:#a1a1aa;
  flex-shrink:0;
}
.lesson-item.done .li-num{background:#22c55e25;color:#22c55e}
.li-info{flex:1}
.li-info h4{font-size:.95rem;font-weight:600;margin-bottom:2px}
.li-info span{font-size:.78rem;color:#71717a}
.li-xp{
  font-size:.8rem;font-weight:700;color:#3b82f6;
  background:#3b82f615;padding:4px 10px;border-radius:8px;
  flex-shrink:0;
}

/* ── 9. LESSON PAGE ──────────────────────────────────────── */
.lesson-page{
  display:flex;
  height:calc(100dvh - 61px);
  overflow:hidden;
}

/* content side */
.lesson-content{
  flex:0 0 50%;max-width:50%;
  overflow-y:auto;
  padding:28px 32px 80px;
}
.lesson-breadcrumb{
  font-size:.78rem;color:#71717a;margin-bottom:4px;
}
.lesson-title{
  font-size:1.5rem;font-weight:800;margin-bottom:8px;
}
.lesson-time{
  font-size:.82rem;color:#a1a1aa;margin-bottom:20px;
}
.content-block{margin-bottom:18px}

/* Scroll to editor CTA */
.scroll-to-editor-cta{
  text-align:center;
  padding:16px;margin:24px 0 0;
  background:#3b82f608;border:1px solid #3b82f630;border-radius:12px;
  color:#60a5fa;font-weight:600;font-size:.95rem;
  cursor:pointer;
  transition:all .2s;
}
.scroll-to-editor-cta:hover{
  background:#3b82f615;border-color:#3b82f6;
}

/* text block */
.text-block{font-size:.93rem;color:#d4d4d8;line-height:1.9}
.text-block h2{font-size:1.2rem;font-weight:700;margin-top:24px;margin-bottom:10px;color:#e4e4e7}
.text-block h3{font-size:1.05rem;font-weight:700;margin-top:18px;margin-bottom:8px;color:#d4d4d8}
.text-block p{margin-bottom:12px}
.text-block code{
  background:#27272a;padding:1px 6px;border-radius:5px;
  font-family:'Fira Code',"Cascadia Code",monospace;font-size:.85rem;
}
.text-block pre{
  background:#0c0c0e;border:1px solid #27272a;border-radius:10px;
  padding:14px 18px;margin:12px 0;overflow-x:auto;
  font-family:'Fira Code',"Cascadia Code",monospace;
  font-size:.85rem;line-height:1.7;color:#e4e4e7;
}
.text-block pre code{background:none;padding:0;border-radius:0;font-size:inherit}
.text-block ul,.text-block ol{margin-bottom:12px;padding-left:20px}
.text-block li{margin-bottom:6px;line-height:1.8;position:relative}
.text-block ul li::before{
  content:"";position:absolute;left:-14px;top:11px;
  width:5px;height:5px;border-radius:50%;background:#3b82f6;
}
.text-block table{
  width:100%;border-collapse:collapse;margin:12px 0;
  font-size:.88rem;
}
.text-block table td{
  padding:8px 12px;border:1px solid #27272a;color:#d4d4d8;
}
.text-block table tr:first-child td{
  background:#18181b;font-weight:600;color:#e4e4e7;
}
.text-block strong{color:#e4e4e7}

/* code example */
.code-example{
  background:#0c0c0e;border:1px solid #27272a;border-radius:12px;
  overflow:hidden;
}
.cex-header{
  display:flex;align-items:center;justify-content:space-between;
  padding:8px 14px;background:#18181b;border-bottom:1px solid #27272a;
  font-size:.8rem;color:#71717a;
}
.cex-body{
  padding:14px 18px;
  font-family:'Fira Code',"Cascadia Code","Source Code Pro",monospace;
  font-size:.85rem;line-height:1.7;color:#e4e4e7;
  white-space:pre;overflow-x:auto;
}
.cex-desc{
  padding:8px 14px;border-top:1px solid #27272a;
  font-size:.82rem;color:#a1a1aa;line-height:1.6;
  background:#18181b08;
}

/* tip block */
.tip-block{
  background:#22c55e0c;border:1px solid #22c55e30;border-radius:12px;
  padding:16px 20px;
  font-size:.9rem;color:#d4d4d8;line-height:1.7;
}
.tip-block strong{color:#22c55e}
.tip-block code{
  background:#27272a;padding:1px 6px;border-radius:5px;
  font-family:'Fira Code',"Cascadia Code",monospace;font-size:.82rem;
}

/* copyable inline */
.copyable{
  display:inline-flex;align-items:center;gap:4px;
  background:#18181b;border:1px solid #27272a;border-radius:8px;
  padding:2px 10px;font-family:'Fira Code',"Cascadia Code",monospace;
  font-size:.85rem;cursor:pointer;
  transition:all .2s;
}
.copyable:hover{border-color:#3b82f650;background:#3b82f610}
.copyable.copied{border-color:#22c55e50;color:#22c55e}

/* key visual */
.key{
  display:inline-block;
  background:linear-gradient(180deg,#27272a,#1c1c1f);
  border:1px solid #3f3f46;border-bottom-width:3px;
  border-radius:6px;padding:2px 8px;
  font-family:'Fira Code',"Cascadia Code",monospace;
  font-size:.78rem;font-weight:600;color:#d4d4d8;
  white-space:nowrap;line-height:1.5;
}

/* ── 10. EDITOR PANEL ────────────────────────────────────── */
.editor-panel{
  flex:0 0 50%;max-width:50%;
  display:flex;flex-direction:column;
  background:#0c0c0e;
  border-left:1px solid #27272a;
  position:relative;
}

/* File tab header */
.ep-header{
  display:flex;align-items:center;justify-content:space-between;
  padding:0 18px 0 0;
  background:#18181b;border-bottom:1px solid #27272a;
}
.ep-file-tab{display:flex;align-items:stretch}
.ep-tab{
  padding:10px 18px;
  font-size:.82rem;font-weight:600;color:#a1a1aa;
  border-bottom:2px solid transparent;
  display:flex;align-items:center;gap:6px;
}
.ep-tab.active{
  color:#e4e4e7;
  border-bottom-color:#3b82f6;
  background:#0c0c0e;
}
.ep-actions{display:flex;gap:6px;margin-left:auto}

.exercise-inst{
  padding:14px 20px;
  background:#18181b80;
  border-bottom:1px solid #27272a;
  font-size:.9rem;line-height:1.7;color:#d4d4d8;
}
.exercise-inst strong{color:#3b82f6}

.editor-wrapper{
  flex:1;position:relative;
  overflow:hidden;
}

/* Line numbers */
.editor-line-numbers{
  position:absolute;top:0;left:0;
  width:40px;
  padding:16px 0;
  text-align:right;
  font-family:'Fira Code',"Cascadia Code","Source Code Pro",monospace;
  font-size:.82rem;line-height:1.7;
  color:#3f3f46;
  user-select:none;pointer-events:none;
  overflow:hidden;
}
.editor-line-numbers .ln{
  padding-right:8px;
}

/* Syntax highlight overlay */
.editor-highlight-layer{
  position:absolute;top:0;left:0;right:0;bottom:0;
  padding:16px 20px 16px 48px;
  font-family:'Fira Code',"Cascadia Code","Source Code Pro",monospace;
  font-size:.88rem;line-height:1.7;
  color:#e4e4e7;
  white-space:pre-wrap;
  word-wrap:break-word;
  overflow:hidden;
  pointer-events:none;
  tab-size:4;-moz-tab-size:4;
  letter-spacing:normal;word-spacing:normal;
}
.hl-kw{color:#c084fc}
.hl-str{color:#86efac}
.hl-cmt{color:#6b7280;font-style:italic}
.hl-fn{color:#93c5fd}
.hl-num{color:#fbbf24}

.code-editor{
  width:100%;height:100%;
  padding:16px 20px 16px 48px;
  font-family:'Fira Code',"Cascadia Code","Source Code Pro",monospace;
  font-size:.88rem;line-height:1.7;
  color:transparent;
  -webkit-text-fill-color:transparent;
  background:transparent;
  resize:none;border:none;outline:none;
  tab-size:4;-moz-tab-size:4;
  min-height:150px;
  caret-color:#e4e4e7;
  position:relative;
  z-index:1;
  white-space:pre-wrap;
  word-wrap:break-word;
  letter-spacing:normal;word-spacing:normal;
}
.code-editor::placeholder{color:#3f3f46}

.editor-status{
  padding:6px 18px;
  background:#18181b;border-top:1px solid #27272a;border-bottom:1px solid #27272a;
  font-size:.72rem;color:#52525b;
  display:flex;align-items:center;gap:16px;flex-wrap:wrap;
}

/* Editor action buttons (below editor) */
.editor-actions{
  display:flex;gap:8px;
  padding:8px 12px;
  background:#18181b;border-top:1px solid #27272a;
}
.editor-actions .btn{flex:1;padding:8px 16px;font-size:.85rem;}

/* hint */
.hint-toggle{
  padding:10px 18px;cursor:pointer;
  font-size:.85rem;font-weight:600;color:#f59e0b;
  transition:background .15s;
  border-bottom:1px solid #27272a;
}
.hint-toggle:hover{background:#f59e0b0a}

.hint-panel{
  padding:12px 18px;
  background:#f59e0b08;border-bottom:1px solid #f59e0b25;
  font-size:.88rem;color:#d4d4d8;line-height:1.7;
}
.hint-panel p{margin-bottom:6px}
.hint-panel code{
  background:#27272a;padding:1px 6px;border-radius:5px;
  font-family:'Fira Code',"Cascadia Code",monospace;font-size:.82rem;
}

/* output panel */
.output-panel{
  border-bottom:1px solid #27272a;
}
.output-header{
  padding:6px 18px;
  background:#18181b;border-bottom:1px solid #27272a;
  font-size:.75rem;font-weight:600;color:#71717a;
  text-transform:uppercase;letter-spacing:.04em;
}
.output-content{
  min-height:60px;max-height:160px;
  overflow-y:auto;
  padding:12px 18px;
  font-family:'Fira Code',"Cascadia Code",monospace;
  font-size:.85rem;line-height:1.6;
  color:#a1a1aa;
  white-space:pre-wrap;
  background:#09090b;
}
.output-content.err{color:#ef4444}
.output-content.ok{color:#22c55e}
.output-err-icon,.output-ok-icon{
  font-style:normal;
}

/* lesson nav */
.lesson-nav{
  display:flex;align-items:center;justify-content:space-between;
  padding:8px 12px;
  background:#18181b;border-top:1px solid #27272a;
  gap:6px;
  margin-top:auto;
}
.lesson-nav .btn{padding:6px 14px;font-size:.82rem;border-radius:8px}
.lesson-nav-center{display:flex;gap:6px}
.lesson-nav-sub{
  text-align:center;padding:8px;
  background:#18181b;border-top:1px solid #27272a;
  font-size:.82rem;
}
.lesson-nav-sub a{color:#71717a;transition:color .2s}
.lesson-nav-sub a:hover{color:#60a5fa}

/* Modal sub link */
.modal-sub-link{
  color:#71717a;font-size:.88rem;
  transition:color .2s;
}
.modal-sub-link:hover{color:#60a5fa}

/* Mobile fixed action buttons */
.mobile-fixed-actions{
  display:none;
  position:fixed;bottom:0;left:0;right:0;
  z-index:800;
  padding:8px 12px;
  background:#18181bf5;
  border-top:1px solid #27272a;
  backdrop-filter:blur(12px);
  gap:8px;
  justify-content:center;
}
.mobile-action-btn{
  flex:1;
  padding:10px 12px;
  font-size:.85rem;
  font-weight:700;
  border-radius:10px;
  min-height:40px;
}

/* ── 11. MODALS (shared) ────────────────────────────────── */
/* Overlay already defined as .modal-overlay */

/* generic modal inner */
.modal{
  background:#18181b;border:1px solid #27272a;border-radius:24px;
  padding:40px 36px;max-width:460px;width:100%;
  position:relative;overflow:hidden;
  text-align:center;
  animation:fadeIn .25s ease;
  margin:auto;
}
.modal-icon{font-size:3rem;margin-bottom:14px;display:block}
.modal-icon.big-icon{font-size:4rem}
.modal-icon.huge-icon{font-size:4.5rem}
.modal h3{font-size:1.4rem;font-weight:800;margin-bottom:8px}
.modal p{color:#a1a1aa;font-size:1rem;margin-bottom:8px;line-height:1.6}

/* success modal specifics */
.success-modal .confetti{position:absolute;top:0;left:0;width:100%;height:100%;pointer-events:none;overflow:hidden}
.confetti-piece{
  position:absolute;top:-10px;
  width:8px;height:8px;border-radius:2px;
  animation:confettiFall 1.2s ease forwards;
}
@keyframes confettiFall{
  0%{transform:translateY(0) rotate(0);opacity:1}
  100%{transform:translateY(350px) rotate(720deg);opacity:0}
}
.xp-gain{
  font-size:1.2rem;font-weight:800;color:#3b82f6;
  margin:12px 0 20px;
}

/* course clear modal */
.clear-modal{
  background:linear-gradient(180deg,#1a1a2e,#18181b);
  border-color:#3b82f630;border-radius:28px;
  padding:48px 40px;max-width:500px;
  box-shadow:0 0 80px #3b82f615;
}
.clear-praise{
  font-size:.95rem;color:#f59e0b;font-weight:600;
  margin:14px 0 24px;
  line-height:1.7;white-space:pre-line;
}

/* level up modal */
#luO.on{display:flex;align-items:center;justify-content:center}
.levelup-content{
  text-align:center;
  animation:lvupPop .5s ease;
}
@keyframes lvupPop{
  0%{transform:scale(.5);opacity:0}
  70%{transform:scale(1.08)}
  100%{transform:scale(1);opacity:1}
}
.levelup-title{
  font-size:1.3rem;font-weight:900;color:#a855f7;
  text-transform:uppercase;letter-spacing:.08em;
  margin-bottom:8px;
}
#luO .modal-icon{
  animation:lvupGlow 1.5s ease infinite alternate;
}
@keyframes lvupGlow{
  0%{filter:drop-shadow(0 0 10px #a855f740)}
  100%{filter:drop-shadow(0 0 25px #a855f770)}
}
#luO p{color:#d4d4d8;font-size:1.1rem}
#luO span{font-weight:900;color:#a855f7;font-size:1.3rem}

/* premium preview modal */
.premium-modal{
  padding:0;max-width:600px;overflow:hidden;text-align:left;
}
.premium-preview-content{
  padding:28px 32px;
  max-height:260px;overflow:hidden;
  position:relative;
}
.premium-preview-content h2{font-size:1.3rem;font-weight:800;margin-bottom:8px}
.premium-preview-content h3{font-size:1rem;font-weight:700;margin-bottom:12px;color:#d4d4d8}
.premium-blur-overlay{
  position:relative;
  background:linear-gradient(transparent 0%,#18181b 30%);
  margin-top:-60px;
  padding:60px 32px 28px;
  text-align:center;
}
.premium-cta h3{font-size:1.15rem;font-weight:800;margin-bottom:8px}
.premium-cta p{color:#a1a1aa;font-size:.9rem;margin-bottom:18px;line-height:1.6}

/* ── 12. FOOTER ──────────────────────────────────────────── */
.ftr{
  border-top:1px solid #27272a;
  padding:28px 20px;margin-top:40px;
  max-width:1100px;margin-left:auto;margin-right:auto;
  display:flex;align-items:center;justify-content:space-between;
  flex-wrap:wrap;gap:16px;
}
.ftr-links{display:flex;gap:20px;flex-wrap:wrap}
.ftr-links a{font-size:.82rem;color:#71717a;transition:color .2s;cursor:pointer}
.ftr-links a:hover{color:#e4e4e7}
.ftr small{font-size:.78rem;color:#52525b}

/* ── 13. LEGAL PAGES ─────────────────────────────────────── */
.legal-page{
  max-width:720px;margin:0 auto;padding:32px 20px 80px;
}
.legal-page h2{font-size:1.5rem;font-weight:800;margin-bottom:8px}
.legal-page h3{font-size:1.1rem;font-weight:700;margin-top:28px;margin-bottom:10px;color:#e4e4e7}
.legal-page p{font-size:.92rem;color:#a1a1aa;line-height:1.9;margin-bottom:12px}
.legal-page ul{padding-left:20px;margin-bottom:12px}
.legal-page li{font-size:.92rem;color:#a1a1aa;line-height:1.8;margin-bottom:4px}

.law-table{
  width:100%;border-collapse:collapse;margin-top:16px;
}
.law-table td{
  padding:12px 16px;border:1px solid #27272a;font-size:.92rem;color:#d4d4d8;
}
.law-th{
  background:#18181b;font-weight:600;color:#e4e4e7;
  width:140px;white-space:nowrap;
}

/* ── 14. SCROLLBAR ───────────────────────────────────────── */
::-webkit-scrollbar{width:6px;height:6px}
::-webkit-scrollbar-track{background:transparent}
::-webkit-scrollbar-thumb{background:#27272a;border-radius:10px}
::-webkit-scrollbar-thumb:hover{background:#3f3f46}
*{scrollbar-width:thin;scrollbar-color:#27272a transparent}

/* ── 15. RESPONSIVE ──────────────────────────────────────── */

/* tablet */
@media(max-width:1024px){
  .lesson-page{flex-direction:column;height:auto}
  .lesson-content{
    flex:none;max-width:100%;
    padding:24px 20px 28px;
  }
  .editor-panel{
    flex:none;max-width:100%;
    border-left:none;border-top:1px solid #27272a;
    min-height:460px;
  }
  .scroll-to-editor-cta{display:block}
}

/* mobile */
@media(max-width:768px){
  body{font-size:15px}

  .hdr{padding:10px 14px}
  .logo h1{font-size:1.1rem}
  .hdr-stats{gap:5px}
  .badge{padding:3px 8px;font-size:.72rem}

  .hero{padding:32px 16px 24px}
  .hero h2{font-size:1.45rem}
  .hero p{font-size:.92rem}
  .hero-feats{gap:8px 14px}

  .progress-card{padding:18px}

  .courses-sec{padding:0 14px 40px}
  .course-grid{grid-template-columns:1fr;gap:12px}
  .course-card{padding:20px}
  .course-card:hover{transform:none;box-shadow:0 4px 20px #3b82f610}

  .search-modal{border-radius:14px}
  .search-modal-header{padding:12px 16px}

  .glossary-popup{max-width:300px;padding:14px 16px}

  .course-detail{padding:24px 14px 40px}
  #cdH h2{font-size:1.4rem}
  .lesson-item{padding:14px 16px;gap:10px}

  .lesson-content{padding:18px 14px 24px}
  .lesson-title{font-size:1.25rem}

  /* Editor: 16px minimum to prevent iOS zoom */
  .code-editor{
    font-size:16px;
    padding:12px 16px 12px 44px;
  }
  .editor-highlight-layer{
    font-size:16px;
    padding:12px 16px 12px 44px;
  }
  .editor-line-numbers{
    font-size:13px;
    width:36px;
  }

  /* Hide keyboard shortcuts info on mobile */
  .editor-status-pc{display:none}

  /* Mobile fixed buttons visible */
  .mobile-fixed-actions{display:flex}

  /* Editor and lesson adjustments */
  .editor-panel{padding-bottom:0}
  .lesson-page{padding-bottom:0}

  .lesson-nav{padding:10px 12px;gap:6px;flex-wrap:wrap;justify-content:center}
  .lesson-nav .btn{font-size:.8rem;padding:8px 12px}
  .lesson-nav-center{order:3;width:100%;justify-content:center}

  .modal{padding:32px 24px;border-radius:20px}
  .clear-modal{padding:36px 24px;border-radius:22px}

  .premium-modal{border-radius:18px;margin:16px}
  .premium-preview-content{padding:20px 22px}
  .premium-cta{padding-bottom:22px}

  .ftr{flex-direction:column;align-items:flex-start;gap:12px}
  .ftr-links{gap:14px}

  .legal-page{padding:24px 14px 60px}
  .legal-page h2{font-size:1.3rem}

  /* Prevent horizontal scroll */
  .lesson-page,.editor-panel,.lesson-content{
    max-width:100vw;
    overflow-x:hidden;
  }
}

/* very small screens */
@media(max-width:380px){
  .hero h2{font-size:1.25rem}
  .badge{padding:2px 6px;font-size:.68rem}
  .editor-status{flex-wrap:wrap;gap:8px}
}

/* PC: hide scroll-to-editor CTA (only useful on mobile/tablet) */
@media(min-width:1025px){
  .scroll-to-editor-cta{display:none}
}

/* print */
@media print{
  .hdr,.ftr,.ad-slot,.modal-overlay,.glossary-popup,.mobile-fixed-actions{display:none!important}
  body{background:#fff;color:#111}
  .lesson-page{display:block}
  .lesson-content{max-width:100%;padding:20px}
  .editor-panel{display:none}
}