:root{
    --paper:#faf7f1;
    --paper-2:#f3eee2;
    --paper-3:#ebe4d2;
    --ink:#171411;
    --ink-2:#3a3530;
    --ink-3:#6e655a;
    --line:#d6cfbe;
    --line-2:#bdb39c;
    /* terracotta default */
    --accent-deep:#9c3914;
    --accent-soft:#f6e3d6;
    --moss:#2a6f5a;
    --moss-soft:#dfeae3;
    --gold:#c8973a;
    --gold-soft:#f6ead0;
    --red:#a63227;

    --serif:'Source Serif 4','Source Serif Pro',Georgia,serif;
    --accent:#c84a1e;
    --density:1;
    --sans:'Inter',system-ui,-apple-system,sans-serif;
    --mono:'JetBrains Mono',ui-monospace,monospace;

    --r-sm:6px; --r:10px; --r-lg:14px;
    --shadow-sm: 0 1px 2px rgba(20,15,8,.05), 0 1px 1px rgba(20,15,8,.04);
    --shadow:    0 2px 4px rgba(20,15,8,.05), 0 6px 16px -6px rgba(20,15,8,.10);
    --shadow-lg: 0 4px 8px rgba(20,15,8,.06), 0 18px 36px -10px rgba(20,15,8,.16);
    --shadow-press: 0 1px 0 rgba(0,0,0,.10) inset;
  }

  *,*::before,*::after{box-sizing:border-box;margin:0;padding:0;}
  html,body{background:var(--paper);color:var(--ink);font-family:var(--sans);font-size:16px;line-height:1.6;-webkit-font-smoothing:antialiased;}
  body{
    /* subtle paper texture */
    background-image:
      radial-gradient(rgba(120,90,40,.022) 1px, transparent 1px),
      radial-gradient(rgba(120,90,40,.02) 1px, transparent 1px);
    background-size: 28px 28px, 17px 17px;
    background-position: 0 0, 14px 9px;
  }
  a{color:inherit;text-decoration:none;}
  button{font:inherit;color:inherit;background:none;border:none;cursor:pointer;}
  ::selection{background:var(--accent);color:var(--paper);}

  /* ============== TYPE ============== */
  h1,h2,h3,h4{font-family:var(--serif);font-weight:600;letter-spacing:-.02em;color:var(--ink);line-height:1.1;}
  .display{font-family:var(--serif);font-weight:600;letter-spacing:-.025em;line-height:1.02;}
  .display em{font-style:italic;font-weight:500;color:var(--accent);}
  .eyebrow{font-family:var(--sans);font-size:11px;font-weight:700;text-transform:uppercase;letter-spacing:.16em;color:var(--accent);}
  .muted{color:var(--ink-3);}
  .mono{font-family:var(--mono);font-size:.92em;}

  /* ============== APP CHROME ============== */
  .topbar{
    position:sticky;top:0;z-index:50;
    background:rgba(250,247,241,.85);
    backdrop-filter:saturate(140%) blur(10px);
    -webkit-backdrop-filter:saturate(140%) blur(10px);
    border-bottom:1px solid var(--line);
  }
  .topbar-inner{
    max-width:1240px;margin:0 auto;padding:0 28px;height:64px;
    display:flex;align-items:center;gap:28px;
  }
  .brand{display:flex;align-items:center;gap:10px;font-family:var(--serif);font-size:20px;font-weight:700;letter-spacing:-.02em;color:var(--ink);}
  .brand .mark{
    width:30px;height:30px;border-radius:7px;background:var(--ink);color:var(--paper);
    display:grid;place-items:center;font-family:var(--serif);font-style:italic;font-weight:600;font-size:18px;
    box-shadow:0 1px 0 rgba(255,255,255,.15) inset, 0 1px 2px rgba(0,0,0,.2);
  }
  .brand .mark::after{content:"";position:absolute;}
  .nav{display:flex;gap:4px;margin-left:8px;}
  .nav a{
    padding:8px 12px;border-radius:8px;font-size:14px;font-weight:500;color:var(--ink-2);
    transition:background .15s, color .15s;
  }
  .nav a:hover{background:var(--paper-2);color:var(--ink);}
  .nav a.on{background:var(--ink);color:var(--paper);}
  .nav a.on:hover{background:var(--ink);}
  .topbar-right{margin-left:auto;display:flex;align-items:center;gap:10px;}
  .streak-pill{
    display:inline-flex;align-items:center;gap:6px;padding:5px 11px;border-radius:999px;
    background:var(--accent-soft);color:var(--accent-deep);font-size:12px;font-weight:600;
    border:1px solid #f0c8a8;
  }
  .streak-pill .dot{width:6px;height:6px;border-radius:50%;background:var(--accent);}
  .avatar{
    width:32px;height:32px;border-radius:50%;background:var(--moss);color:var(--paper);
    display:grid;place-items:center;font-size:13px;font-weight:700;font-family:var(--sans);
    box-shadow:0 0 0 2px var(--paper), 0 0 0 3px var(--line);
    cursor:pointer;
  }
  .lang-toggle{
    display:inline-flex;border:1px solid var(--line);border-radius:999px;overflow:hidden;
    background:var(--paper-2);
  }
  .lang-btn{
    padding:4px 11px;font-size:11.5px;font-weight:700;letter-spacing:.05em;text-transform:uppercase;
    color:var(--ink-3);transition:background .15s,color .15s;cursor:pointer;
  }
  .lang-btn.on{background:var(--ink);color:var(--paper);}
  .lang-btn:hover:not(.on){background:var(--paper-3);color:var(--ink);}

  /* ============== BUTTONS ============== */
  .btn{
    display:inline-flex;align-items:center;gap:8px;
    padding:10px 18px;border-radius:8px;font-size:14px;font-weight:600;
    transition:transform .1s, box-shadow .15s, background .15s, color .15s, border-color .15s;
    cursor:pointer;border:1px solid transparent;white-space:nowrap;
  }
  .btn:active{transform:translateY(1px);}
  .btn-primary{background:var(--ink);color:var(--paper);box-shadow:var(--shadow-sm);}
  .btn-primary:hover{background:#000;box-shadow:var(--shadow);}
  .btn-accent{background:var(--accent);color:#fff;box-shadow:var(--shadow-sm);}
  .btn-accent:hover{background:var(--accent-deep);box-shadow:var(--shadow);}
  .btn-ghost{background:transparent;color:var(--ink);border-color:var(--line-2);}
  .btn-ghost:hover{background:var(--paper-2);border-color:var(--ink-2);}
  .btn-lg{padding:14px 24px;font-size:15px;border-radius:10px;}
  .btn-sm{padding:6px 12px;font-size:12.5px;border-radius:6px;}

  /* ============== PAGE ============== */
  .page{display:none;animation:fade .2s ease;}
  .page.on{display:block;}
  @keyframes fade{from{opacity:0;transform:translateY(4px);}to{opacity:1;transform:translateY(0);}}

  .container{max-width:1240px;margin:0 auto;padding:0 28px;}
  .narrow{max-width:760px;margin:0 auto;padding:0 28px;}

  /* ============== LANDING ============== */
  .hero{
    position:relative;padding:88px 0 72px;overflow:hidden;
  }
  .hero::before{
    content:"";position:absolute;inset:0;pointer-events:none;
    background:
      radial-gradient(60% 50% at 80% 0%, rgba(200,74,30,.08) 0%, transparent 60%),
      radial-gradient(50% 60% at 0% 100%, rgba(42,111,90,.07) 0%, transparent 60%);
  }
  .hero-grid{display:grid;grid-template-columns:1.05fr .95fr;gap:56px;align-items:center;position:relative;}
  .hero h1{font-size:clamp(40px,6vw,72px);margin:14px 0 22px;}
  .hero .lede{font-size:18px;line-height:1.55;color:var(--ink-2);max-width:520px;}
  .hero-cta{margin-top:32px;display:flex;gap:12px;align-items:center;flex-wrap:wrap;}
  .hero-stats{margin-top:44px;display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:16px;max-width:540px;}
  .hero-stat .n{font-family:var(--serif);font-size:30px;font-weight:600;line-height:1;color:var(--ink);}
  .hero-stat .l{font-size:11px;font-weight:600;text-transform:uppercase;letter-spacing:.1em;color:var(--ink-3);margin-top:6px;}

  .hero-card{
    position:relative;background:var(--paper);
    border:1px solid var(--line);border-radius:16px;
    box-shadow:var(--shadow-lg);
    padding:24px;
    transform:rotate(.4deg);
  }
  .hero-card::before{
    content:"";position:absolute;inset:-1px;border-radius:16px;
    background:linear-gradient(135deg, transparent 60%, rgba(200,74,30,.08));
    pointer-events:none;
  }
  .hero-card .label{font-size:11px;font-weight:700;text-transform:uppercase;letter-spacing:.12em;color:var(--ink-3);}
  .hero-card h3{font-family:var(--serif);font-size:22px;font-weight:600;margin:6px 0 4px;}
  .hero-card .meta{font-size:13px;color:var(--ink-3);}
  .hero-card .progress{margin-top:18px;}
  .progress-track{height:6px;background:var(--paper-3);border-radius:3px;overflow:hidden;}
  .progress-track > i{display:block;height:100%;background:linear-gradient(90deg,var(--moss),var(--accent));border-radius:3px;}
  .hero-card .modules{margin-top:18px;display:flex;flex-direction:column;gap:8px;}
  .hero-card .mod{display:flex;align-items:center;gap:10px;font-size:13.5px;}
  .hero-card .mod .check{width:18px;height:18px;border-radius:50%;border:1.5px solid var(--line-2);display:grid;place-items:center;font-size:10px;color:transparent;flex-shrink:0;}
  .hero-card .mod.done .check{background:var(--moss);border-color:var(--moss);color:#fff;}
  .hero-card .mod.cur .check{border-color:var(--accent);background:var(--accent);color:#fff;}
  .hero-card .mod.cur{font-weight:600;}
  .hero-card .mod .pct{margin-left:auto;font-size:11px;color:var(--ink-3);font-variant-numeric:tabular-nums;}

  .scribble{
    position:absolute;font-family:var(--serif);font-style:italic;font-weight:500;
    color:var(--accent);font-size:15px;
  }
  .scribble svg{display:block;}

  /* feature strip */
  .strip{
    background:var(--ink);color:var(--paper);
  }
  .strip-inner{
    max-width:1240px;margin:0 auto;padding:18px 28px;
    display:flex;justify-content:space-between;gap:32px;font-size:13px;flex-wrap:wrap;
    color:rgba(250,247,241,.85);
  }
  .strip-inner span{display:inline-flex;align-items:center;gap:8px;}
  .strip-inner b{color:var(--gold);font-weight:600;}

  .features{padding:88px 0;}
  .features h2{font-size:42px;max-width:640px;margin-bottom:14px;}
  .features .sub{font-size:17px;color:var(--ink-2);max-width:560px;margin-bottom:48px;}
  .feat-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:24px;}
  .feat{
    background:var(--paper);border:1px solid var(--line);border-radius:12px;padding:28px;
    transition:transform .2s, box-shadow .2s;
  }
  .feat:hover{transform:translateY(-2px);box-shadow:var(--shadow);}
  .feat .ico{
    width:40px;height:40px;border-radius:8px;background:var(--accent-soft);color:var(--accent);
    display:grid;place-items:center;font-family:var(--serif);font-weight:700;font-size:20px;font-style:italic;margin-bottom:18px;
  }
  .feat:nth-child(2) .ico{background:var(--moss-soft);color:var(--moss);}
  .feat:nth-child(3) .ico{background:var(--gold-soft);color:#7c5a14;}
  .feat h3{font-size:20px;margin-bottom:8px;font-weight:600;}
  .feat p{font-size:14.5px;color:var(--ink-2);}

  /* big quote */
  .quote{padding:80px 0;border-top:1px solid var(--line);border-bottom:1px solid var(--line);background:var(--paper-2);}
  .quote-inner{max-width:880px;margin:0 auto;padding:0 28px;text-align:center;}
  .quote q{
    font-family:var(--serif);font-size:34px;font-weight:500;line-height:1.25;color:var(--ink);
    quotes:"\201C" "\201D";
  }
  .quote q::before{content:open-quote;color:var(--accent);}
  .quote q::after{content:close-quote;color:var(--accent);}
  .quote .who{margin-top:24px;font-size:13px;color:var(--ink-3);font-weight:600;letter-spacing:.05em;text-transform:uppercase;}

  /* CTA banner */
  .cta-band{padding:80px 0;text-align:center;}
  .cta-band h2{font-size:48px;max-width:680px;margin:0 auto 18px;}
  .cta-band p{font-size:17px;color:var(--ink-2);max-width:520px;margin:0 auto 32px;}

  footer.site-footer{
    border-top:1px solid var(--line);padding:32px 0;font-size:13px;color:var(--ink-3);
  }
  .footer-inner{max-width:1240px;margin:0 auto;padding:0 28px;display:flex;justify-content:space-between;align-items:center;flex-wrap:wrap;gap:16px;}

  /* ============== LOGIN ============== */
  .auth-shell{
    min-height:calc(100vh - 64px);display:grid;grid-template-columns:1.05fr .95fr;
  }
  .auth-aside{
    background:var(--ink);color:var(--paper);
    padding:64px 56px;display:flex;flex-direction:column;justify-content:space-between;
    position:relative;overflow:hidden;
  }
  .auth-aside::before{
    content:"";position:absolute;inset:0;pointer-events:none;
    background:
      radial-gradient(60% 50% at 100% 0%, rgba(200,74,30,.18) 0%, transparent 60%),
      radial-gradient(60% 50% at 0% 100%, rgba(42,111,90,.18) 0%, transparent 60%);
  }
  .auth-aside h2{font-size:54px;line-height:1.05;color:var(--paper);max-width:480px;position:relative;}
  .auth-aside h2 em{font-style:italic;color:var(--gold);font-weight:500;}
  .auth-aside .testimonial{position:relative;font-size:15px;color:rgba(250,247,241,.78);line-height:1.6;max-width:420px;}
  .auth-aside .testimonial b{color:var(--paper);}
  .auth-aside .testimonial cite{display:block;margin-top:14px;font-style:normal;font-size:12px;color:rgba(250,247,241,.55);text-transform:uppercase;letter-spacing:.12em;}
  .auth-aside .stamp{
    position:relative;display:inline-flex;align-items:center;gap:8px;
    border:1.5px solid rgba(250,247,241,.3);border-radius:999px;padding:6px 14px;
    font-size:11px;text-transform:uppercase;letter-spacing:.14em;color:var(--gold);
    align-self:flex-start;
  }
  .auth-form-wrap{
    display:flex;align-items:center;justify-content:center;padding:40px 28px;
  }
  .auth-form{width:100%;max-width:380px;}
  .auth-form .eyebrow{margin-bottom:8px;}
  .auth-form h3{font-size:32px;margin-bottom:8px;}
  .auth-form .lede{color:var(--ink-2);font-size:15px;margin-bottom:32px;}
  .field{display:flex;flex-direction:column;gap:6px;margin-bottom:16px;}
  .field label{font-size:12px;font-weight:600;color:var(--ink-2);letter-spacing:.02em;}
  .field input{
    font:inherit;font-size:15px;padding:12px 14px;border:1.5px solid var(--line);border-radius:8px;
    background:var(--paper);color:var(--ink);transition:border-color .15s, box-shadow .15s;
  }
  .field input:focus{outline:none;border-color:var(--ink);box-shadow:0 0 0 3px rgba(23,20,17,.08);}
  .field-row{display:flex;justify-content:space-between;align-items:center;font-size:13px;margin-top:-4px;margin-bottom:20px;}
  .field-row label{display:inline-flex;align-items:center;gap:6px;color:var(--ink-2);cursor:pointer;}
  .field-row a{color:var(--accent);font-weight:500;}
  .field-row a:hover{text-decoration:underline;}
  .auth-divider{display:flex;align-items:center;gap:12px;margin:24px 0;color:var(--ink-3);font-size:12px;text-transform:uppercase;letter-spacing:.14em;}
  .auth-divider::before,.auth-divider::after{content:"";flex:1;height:1px;background:var(--line);}
  .auth-alts{display:grid;grid-template-columns:1fr 1fr;gap:10px;}
  .auth-alts .btn-ghost{justify-content:center;}
  .auth-foot{margin-top:32px;text-align:center;font-size:13.5px;color:var(--ink-3);}
  .auth-foot a{color:var(--ink);font-weight:600;border-bottom:1px solid var(--accent);}

  /* ============== DASHBOARD ============== */
  .dash{padding:36px 0 64px;}
  .dash-greet{display:flex;justify-content:space-between;align-items:flex-end;gap:20px;margin-bottom:28px;flex-wrap:wrap;}
  .dash-greet h1{font-size:40px;}
  .dash-greet h1 em{font-style:italic;color:var(--accent);font-weight:500;}
  .dash-greet .when{font-size:13.5px;color:var(--ink-3);}

  .dash-grid{display:grid;grid-template-columns:1.5fr 1fr;gap:24px;}
  @media (max-width:880px){.dash-grid{grid-template-columns:1fr;}}

  .panel{
    background:var(--paper);border:1px solid var(--line);border-radius:14px;
    box-shadow:var(--shadow-sm);overflow:hidden;
  }
  .panel-head{
    padding:16px 22px;border-bottom:1px solid var(--line);
    display:flex;align-items:center;justify-content:space-between;gap:12px;
  }
  .panel-head h3{font-family:var(--sans);font-size:13px;font-weight:700;text-transform:uppercase;letter-spacing:.1em;color:var(--ink-2);}
  .panel-head .more{font-size:13px;color:var(--accent);font-weight:600;}
  .panel-body{padding:22px;}

  /* resume hero */
  .resume{
    position:relative;background:linear-gradient(135deg, var(--ink) 0%, #2a2520 100%);color:var(--paper);
    border-radius:14px;padding:32px;overflow:hidden;
    box-shadow:var(--shadow-lg);
  }
  .resume::before{
    content:"";position:absolute;right:-80px;top:-80px;width:280px;height:280px;border-radius:50%;
    background:radial-gradient(circle, rgba(200,74,30,.35), transparent 70%);
  }
  .resume::after{
    content:"";position:absolute;left:-60px;bottom:-60px;width:200px;height:200px;border-radius:50%;
    background:radial-gradient(circle, rgba(200,151,58,.18), transparent 70%);
  }
  .resume .label{font-size:11px;text-transform:uppercase;letter-spacing:.16em;color:var(--gold);font-weight:700;}
  .resume h2{font-family:var(--serif);font-size:34px;color:var(--paper);margin-top:8px;line-height:1.1;letter-spacing:-.02em;}
  .resume .submeta{margin-top:8px;font-size:14px;color:rgba(250,247,241,.7);}
  .resume .submeta b{color:var(--gold);font-weight:600;}
  .resume-bar{position:relative;margin-top:22px;height:8px;background:rgba(250,247,241,.12);border-radius:4px;overflow:hidden;}
  .resume-bar i{display:block;height:100%;width:48%;background:linear-gradient(90deg, var(--gold), var(--accent));border-radius:4px;}
  .resume-foot{position:relative;margin-top:24px;display:flex;justify-content:space-between;align-items:center;flex-wrap:wrap;gap:12px;}
  .resume-foot .next{font-size:14px;color:rgba(250,247,241,.85);}
  .resume-foot .next b{color:var(--paper);font-weight:600;}

  .stat-row{display:grid;grid-template-columns:repeat(3,1fr);gap:16px;margin-top:24px;}
  .stat-card{
    background:var(--paper);border:1px solid var(--line);border-radius:10px;padding:18px 20px;
  }
  .stat-card .l{font-size:11px;text-transform:uppercase;letter-spacing:.1em;color:var(--ink-3);font-weight:600;}
  .stat-card .v{font-family:var(--serif);font-size:32px;font-weight:600;color:var(--ink);margin-top:4px;line-height:1;letter-spacing:-.02em;}
  .stat-card .v small{font-size:14px;color:var(--ink-3);font-weight:500;letter-spacing:0;}
  .stat-card .delta{font-size:12px;margin-top:6px;color:var(--moss);font-weight:600;}
  .stat-card .delta.down{color:var(--red);}

  /* weak areas */
  .weak{display:flex;flex-direction:column;gap:10px;}
  .weak-row{display:grid;grid-template-columns:1fr auto;align-items:center;gap:12px;padding:10px 0;border-bottom:1px dashed var(--line);}
  .weak-row:last-child{border-bottom:none;}
  .weak-row .t{font-size:14px;font-weight:500;color:var(--ink);}
  .weak-row .s{font-size:12px;color:var(--ink-3);margin-top:2px;}
  .weak-row .score{font-family:var(--serif);font-size:22px;font-weight:600;color:var(--accent);letter-spacing:-.02em;}

  /* schedule / streak */
  .week-grid{display:grid;grid-template-columns:repeat(7,1fr);gap:6px;margin-top:6px;}
  .week-cell{aspect-ratio:1;border-radius:6px;background:var(--paper-3);position:relative;}
  .week-cell.lvl-1{background:#e7d8b6;}
  .week-cell.lvl-2{background:#d8a877;}
  .week-cell.lvl-3{background:var(--accent);}
  .week-cell.today{box-shadow:0 0 0 2px var(--ink);}
  .week-labels{display:grid;grid-template-columns:repeat(7,1fr);gap:6px;margin-top:8px;font-size:10px;text-transform:uppercase;letter-spacing:.08em;color:var(--ink-3);text-align:center;font-weight:600;}

  /* recent activity */
  .activity-row{display:grid;grid-template-columns:auto 1fr auto;align-items:center;gap:14px;padding:12px 0;border-bottom:1px dashed var(--line);}
  .activity-row:last-child{border-bottom:none;}
  .activity-row .a-ic{
    width:34px;height:34px;border-radius:8px;background:var(--paper-2);color:var(--ink-2);
    display:grid;place-items:center;font-family:var(--serif);font-weight:600;font-size:14px;
  }
  .activity-row.q .a-ic{background:var(--accent-soft);color:var(--accent);}
  .activity-row.r .a-ic{background:var(--moss-soft);color:var(--moss);}
  .activity-row .a-t{font-size:14px;font-weight:500;color:var(--ink);}
  .activity-row .a-s{font-size:12px;color:var(--ink-3);margin-top:2px;}
  .activity-row .a-time{font-size:12px;color:var(--ink-3);font-variant-numeric:tabular-nums;}

  /* ============== CLASS BROWSER ============== */
  .browse-head{padding:44px 0 24px;}
  .browse-head h1{font-size:48px;}
  .browse-head h1 em{font-style:italic;color:var(--accent);font-weight:500;}
  .browse-head .lede{font-size:17px;color:var(--ink-2);max-width:580px;margin-top:10px;}

  .browse-tools{
    display:flex;gap:14px;align-items:center;padding:18px 0;border-bottom:1px solid var(--line);margin-bottom:32px;flex-wrap:wrap;
  }
  .search{
    flex:1;min-width:220px;display:flex;align-items:center;gap:8px;
    border:1.5px solid var(--line);border-radius:8px;padding:8px 12px;background:var(--paper);
  }
  .search input{flex:1;border:none;outline:none;background:none;font:inherit;font-size:14px;color:var(--ink);}
  .search .glass{color:var(--ink-3);font-size:14px;}
  .filters{display:flex;gap:6px;flex-wrap:wrap;}
  .chip{
    padding:7px 14px;border-radius:999px;font-size:13px;font-weight:500;
    border:1.5px solid var(--line);background:var(--paper);color:var(--ink-2);cursor:pointer;
    transition:all .15s;
  }
  .chip:hover{border-color:var(--ink-2);}
  .chip.on{background:var(--ink);color:var(--paper);border-color:var(--ink);}

  .course-section{margin-bottom:48px;}
  .course-section .sec-head{display:flex;align-items:baseline;justify-content:space-between;margin-bottom:18px;}
  .course-section .sec-head h2{font-family:var(--serif);font-size:26px;font-weight:600;}
  .course-section .sec-head .count{font-size:13px;color:var(--ink-3);}

  .grid-courses{display:grid;grid-template-columns:repeat(auto-fill,minmax(300px,1fr));gap:20px;}
  .course-card{
    background:var(--paper);border:1px solid var(--line);border-radius:14px;
    overflow:hidden;display:flex;flex-direction:column;
    transition:transform .2s, box-shadow .2s, border-color .2s;
    cursor:pointer;position:relative;
  }
  .course-card:hover{transform:translateY(-3px);box-shadow:var(--shadow);border-color:var(--line-2);}
  .course-cover{
    height:140px;position:relative;overflow:hidden;
    background:linear-gradient(135deg, #2a2520, var(--ink));
  }
  .course-cover.c-cslb{background:linear-gradient(135deg, #1a3531 0%, #2a6f5a 100%);}
  .course-cover.c-elec{background:linear-gradient(135deg, #4a2a14 0%, #c84a1e 100%);}
  .course-cover.c-osha{background:linear-gradient(135deg, #2a2520 0%, #c8973a 100%);}
  .course-cover.c-plumb{background:linear-gradient(135deg, #1a2a3a 0%, #4a6f7a 100%);}
  .course-cover.c-real{background:linear-gradient(135deg, #2a1a3a 0%, #5a3a6a 100%);}
  .course-cover.c-hvac{background:linear-gradient(135deg, #2a3a14 0%, #5a7a2a 100%);}
  .course-cover.c-b{background:linear-gradient(135deg, #2a1e0f 0%, #8a5a2a 100%);}
  .course-cover .pat{
    position:absolute;inset:0;opacity:.18;
    background-image:repeating-linear-gradient(45deg, rgba(255,255,255,.4) 0 1px, transparent 1px 18px);
  }
  .course-cover .num{
    position:absolute;left:20px;bottom:14px;
    font-family:var(--serif);font-style:italic;font-size:54px;font-weight:600;color:rgba(255,255,255,.92);letter-spacing:-.02em;line-height:1;
  }
  .course-cover .badge{
    position:absolute;top:14px;right:14px;
    padding:4px 10px;border-radius:999px;background:rgba(0,0,0,.35);color:#fff;
    font-size:11px;font-weight:600;letter-spacing:.04em;backdrop-filter:blur(4px);
  }
  .course-cover .badge.new{background:var(--gold);color:#3a2a08;}
  .course-cover .badge.soon{background:rgba(0,0,0,.45);color:rgba(255,255,255,.7);}
  .course-card-body{padding:18px 20px 16px;flex:1;display:flex;flex-direction:column;}
  .course-card-body .cat{font-size:11px;font-weight:700;text-transform:uppercase;letter-spacing:.12em;color:var(--accent);}
  .course-card-body h3{font-family:var(--serif);font-size:19px;font-weight:600;margin:6px 0 4px;letter-spacing:-.01em;}
  .course-card-body .desc{font-size:13.5px;color:var(--ink-2);line-height:1.5;margin-bottom:14px;flex:1;}
  .course-meta{display:flex;align-items:center;gap:10px;font-size:12px;color:var(--ink-3);}
  .course-meta .dot{width:3px;height:3px;border-radius:50%;background:var(--ink-3);}
  .course-foot{
    padding:12px 20px;border-top:1px solid var(--line);background:var(--paper-2);
    display:flex;align-items:center;justify-content:space-between;font-size:13px;
  }
  .course-foot .pp{display:flex;align-items:center;gap:10px;color:var(--ink-3);font-weight:500;}
  .course-foot .pp .pb{width:80px;height:4px;background:var(--paper-3);border-radius:2px;overflow:hidden;}
  .course-foot .pp .pb i{display:block;height:100%;background:var(--accent);border-radius:2px;}
  .course-foot .arrow{color:var(--accent);font-weight:600;}
  .course-card.locked{opacity:.6;cursor:not-allowed;}
  .course-card.locked:hover{transform:none;box-shadow:var(--shadow-sm);}

  /* ============== CHAPTER VIEW ============== */
  .chap-shell{display:grid;grid-template-columns:280px 1fr;min-height:calc(100vh - 64px);}
  @media (max-width:880px){.chap-shell{grid-template-columns:1fr;}}
  .chap-side{
    border-right:1px solid var(--line);background:var(--paper);
    padding:28px 0;position:sticky;top:64px;height:calc(100vh - 64px);overflow-y:auto;
  }
  .chap-side .side-back{display:flex;align-items:center;gap:8px;padding:0 24px 16px;font-size:13px;color:var(--ink-3);}
  .chap-side .side-back:hover{color:var(--accent);}
  .chap-side .side-title{padding:0 24px 6px;font-size:11px;text-transform:uppercase;letter-spacing:.12em;color:var(--ink-3);font-weight:700;}
  .chap-side .side-h1{padding:0 24px 16px;font-family:var(--serif);font-size:18px;font-weight:600;line-height:1.2;letter-spacing:-.01em;}
  .side-nav{display:flex;flex-direction:column;}
  .side-link{
    display:flex;align-items:center;gap:10px;padding:9px 24px 9px 21px;
    border-left:3px solid transparent;font-size:14px;color:var(--ink-2);
    transition:background .15s, color .15s;cursor:pointer;
  }
  .side-link:hover{background:var(--paper-2);color:var(--ink);}
  .side-link.on{border-left-color:var(--accent);background:var(--paper-2);color:var(--ink);font-weight:600;}
  .side-link .check{
    width:18px;height:18px;border-radius:50%;border:1.5px solid var(--line-2);
    display:grid;place-items:center;font-size:10px;flex-shrink:0;color:transparent;
  }
  .side-link.done .check{background:var(--moss);border-color:var(--moss);color:#fff;}
  .side-link.on .check{border-color:var(--accent);}
  .side-mod{font-size:11px;color:var(--ink-3);font-weight:600;margin-right:2px;font-variant-numeric:tabular-nums;}
  .side-sep{border-top:1px solid var(--line);margin:12px 24px 4px;}
  .side-link.quiz-link{color:var(--accent);font-weight:600;margin-top:2px;}
  .side-link.quiz-link .check{border-color:var(--accent);color:var(--accent);font-size:11px;}
  .side-link.quiz-link:hover{color:var(--accent);}
  .side-link.hist-link{color:var(--ink-3);margin-top:2px;}
  .side-link.hist-link .check{border-color:var(--line-2);color:var(--ink-3);font-size:11px;}
  .side-link.hist-link:hover{color:var(--ink);}
  .side-progress{margin:18px 24px 8px;padding-top:18px;border-top:1px solid var(--line);}
  .side-progress .l{font-size:11px;text-transform:uppercase;letter-spacing:.1em;color:var(--ink-3);font-weight:700;display:flex;justify-content:space-between;}
  .side-progress .l b{color:var(--accent);font-family:var(--serif);font-size:14px;font-weight:600;}
  .side-progress .pb{margin-top:8px;height:5px;background:var(--paper-3);border-radius:3px;overflow:hidden;}
  .side-progress .pb i{display:block;height:100%;background:linear-gradient(90deg,var(--moss),var(--accent));border-radius:3px;}

  .chap-main{padding:48px 56px 80px;max-width:860px;}
  @media (max-width:1100px){.chap-main{padding:40px 32px 64px;}}
  .chap-eyebrow{font-size:11px;text-transform:uppercase;letter-spacing:.16em;font-weight:700;color:var(--accent);}
  .chap-h1{font-size:42px;margin:8px 0 14px;}
  .chap-h1 em{font-style:italic;font-weight:500;color:var(--accent);}
  .chap-meta{display:flex;gap:8px;flex-wrap:wrap;margin-bottom:24px;}
  .meta-chip{
    display:inline-flex;align-items:center;gap:6px;padding:5px 12px;border-radius:999px;
    background:var(--paper-2);border:1px solid var(--line);font-size:12.5px;color:var(--ink-2);font-weight:500;
  }
  .meta-chip.weight{background:var(--accent);color:#fff;border-color:var(--accent);font-weight:600;}
  .meta-chip.weight b{color:#fff;}

  .chap-rule{height:1px;background:var(--line);margin:8px 0 32px;}

  .prose p{font-size:16px;line-height:1.75;color:var(--ink-2);margin:0 0 16px;}
  .prose strong{color:var(--ink);font-weight:600;}
  .prose h3{font-family:var(--serif);font-size:24px;margin:36px 0 12px;font-weight:600;letter-spacing:-.01em;}
  .prose ul,.prose ol{padding-left:22px;margin:0 0 18px;color:var(--ink-2);font-size:15.5px;line-height:1.7;}
  .prose li{margin-bottom:6px;}
  .prose li::marker{color:var(--accent);}

  .callout{
    border-radius:10px;padding:18px 22px;margin:22px 0;
    background:var(--moss-soft);border-left:3px solid var(--moss);
    font-size:14.5px;line-height:1.65;color:var(--ink-2);
  }
  .callout-title{font-family:var(--sans);font-size:11px;font-weight:700;text-transform:uppercase;letter-spacing:.12em;color:var(--moss);margin-bottom:6px;}
  .callout.tip{background:var(--gold-soft);border-left-color:var(--gold);}
  .callout.tip .callout-title{color:#7c5a14;}
  .callout.warn{background:var(--accent-soft);border-left-color:var(--accent);}
  .callout.warn .callout-title{color:var(--accent-deep);}

  /* knowledge check */
  .kc{
    margin:28px 0;border:1px solid var(--ink);border-radius:14px;overflow:hidden;
    background:var(--paper);box-shadow:var(--shadow);
  }
  .kc-head{
    padding:14px 20px;background:var(--ink);color:var(--paper);
    display:flex;justify-content:space-between;align-items:center;
    font-size:11px;font-weight:700;text-transform:uppercase;letter-spacing:.14em;
  }
  .kc-head .pts{background:var(--accent);color:#fff;padding:2px 10px;border-radius:999px;font-size:10.5px;letter-spacing:.08em;}
  .kc-body{padding:22px;}
  .kc-q{font-family:var(--serif);font-size:18px;font-weight:500;color:var(--ink);line-height:1.4;margin-bottom:16px;letter-spacing:-.01em;}
  .kc-opts{display:flex;flex-direction:column;gap:8px;}
  .kc-opt{
    display:flex;align-items:flex-start;gap:12px;padding:12px 14px;
    border:1.5px solid var(--line);border-radius:8px;cursor:pointer;
    transition:all .15s;font-size:14.5px;color:var(--ink-2);background:var(--paper);
  }
  .kc-opt:hover:not(.disabled){border-color:var(--ink-2);background:var(--paper-2);}
  .kc-opt .key{
    width:24px;height:24px;border-radius:6px;border:1.5px solid var(--line);background:var(--paper-2);
    display:grid;place-items:center;font-family:var(--sans);font-weight:700;font-size:12px;color:var(--ink-3);
    flex-shrink:0;transition:all .15s;
  }
  .kc-opt.sel{border-color:var(--ink);background:var(--paper-2);}
  .kc-opt.sel .key{background:var(--ink);color:var(--paper);border-color:var(--ink);}
  .kc-opt.correct{border-color:var(--moss);background:var(--moss-soft);color:var(--ink);}
  .kc-opt.correct .key{background:var(--moss);color:#fff;border-color:var(--moss);}
  .kc-opt.wrong{border-color:var(--accent);background:var(--accent-soft);}
  .kc-opt.wrong .key{background:var(--accent);color:#fff;border-color:var(--accent);}
  .kc-foot{
    padding:14px 22px;border-top:1px dashed var(--line);
    display:flex;justify-content:space-between;align-items:center;gap:12px;flex-wrap:wrap;
  }
  .kc-foot .why{font-size:13px;color:var(--ink-3);}
  .kc-foot .why b{color:var(--moss);}
  .kc-explain{
    padding:16px 22px;border-top:1px dashed var(--line);background:var(--paper-2);
    font-size:14px;line-height:1.6;color:var(--ink-2);
  }
  .kc-explain.hidden{display:none;}

  .chap-footer{
    margin-top:48px;padding-top:24px;border-top:1px solid var(--line);
    display:flex;justify-content:space-between;gap:16px;flex-wrap:wrap;
  }
  .chap-foot-link{
    flex:1;min-width:240px;border:1px solid var(--line);border-radius:10px;padding:16px 20px;background:var(--paper);
    transition:all .15s;cursor:pointer;
  }
  .chap-foot-link:hover{border-color:var(--ink);box-shadow:var(--shadow);}
  .chap-foot-link .l{font-size:11px;text-transform:uppercase;letter-spacing:.1em;color:var(--ink-3);font-weight:600;}
  .chap-foot-link .t{font-family:var(--serif);font-size:18px;font-weight:600;margin-top:4px;}
  .chap-foot-link .t::before{content:"← ";color:var(--accent);}
  .chap-foot-link.next{text-align:right;}
  .chap-foot-link.next .t::before{content:"";}
  .chap-foot-link.next .t::after{content:" →";color:var(--accent);}

  /* ============== QUIZ ============== */
  .quiz-shell{min-height:calc(100vh - 64px);display:grid;place-items:start center;padding:48px 24px 80px;}
  .quiz-card{
    width:100%;max-width:720px;background:var(--paper);border:1px solid var(--line);
    border-radius:14px;box-shadow:var(--shadow);overflow:hidden;
  }
  .quiz-progress{
    display:flex;align-items:center;gap:14px;padding:16px 24px;border-bottom:1px solid var(--line);background:var(--paper-2);
  }
  .quiz-progress .num{font-family:var(--serif);font-size:14px;font-weight:600;color:var(--ink);}
  .quiz-progress .num em{color:var(--ink-3);font-style:normal;}
  .quiz-progress .pb{flex:1;height:6px;background:var(--paper-3);border-radius:3px;overflow:hidden;}
  .quiz-progress .pb i{display:block;height:100%;background:linear-gradient(90deg,var(--moss),var(--accent));border-radius:3px;transition:width .4s ease;}
  .quiz-progress .live{font-size:12px;color:var(--moss);font-weight:600;font-variant-numeric:tabular-nums;}

  .quiz-body{padding:36px 40px;}
  .quiz-stem{font-family:var(--serif);font-size:22px;font-weight:500;line-height:1.4;color:var(--ink);margin-bottom:24px;letter-spacing:-.01em;}
  .quiz-opts{display:flex;flex-direction:column;gap:10px;margin-bottom:24px;}
  .quiz-opt{
    display:flex;align-items:flex-start;gap:14px;padding:14px 18px;
    border:1.5px solid var(--line);border-radius:10px;cursor:pointer;
    transition:all .15s;font-size:15px;color:var(--ink-2);background:var(--paper);
    text-align:left;line-height:1.5;
  }
  .quiz-opt:hover:not(.disabled){border-color:var(--ink-2);background:var(--paper-2);}
  .quiz-opt.sel{border-color:var(--ink);background:var(--paper-2);}
  .quiz-opt.sel .key{background:var(--ink);color:var(--paper);border-color:var(--ink);}
  .quiz-opt.correct{border-color:var(--moss);background:var(--moss-soft);color:var(--ink);}
  .quiz-opt.correct .key{background:var(--moss);color:#fff;border-color:var(--moss);}
  .quiz-opt.wrong{border-color:var(--accent);background:var(--accent-soft);}
  .quiz-opt.wrong .key{background:var(--accent);color:#fff;border-color:var(--accent);}
  .quiz-opt .key{
    width:28px;height:28px;border-radius:8px;background:var(--paper-2);border:1.5px solid var(--line);
    color:var(--ink-3);font-weight:700;font-size:13px;display:grid;place-items:center;flex-shrink:0;
    transition:all .15s;
  }
  .quiz-explain{
    margin-top:8px;padding:18px 22px;background:var(--paper-2);border-left:3px solid var(--moss);border-radius:0 10px 10px 0;
    font-size:14px;line-height:1.65;color:var(--ink-2);
  }
  .quiz-explain.hidden{display:none;}
  .quiz-explain b{color:var(--moss);font-weight:600;}
  .quiz-foot{
    padding:18px 40px;background:var(--paper-2);border-top:1px solid var(--line);
    display:flex;justify-content:space-between;align-items:center;gap:14px;
  }
  .quiz-foot .left{font-size:13px;color:var(--ink-3);}
  .quiz-start-card{padding:48px 56px;}
  .quiz-start-card .eyebrow{margin-bottom:8px;}
  .quiz-start-card h2{font-size:36px;margin-bottom:8px;}
  .quiz-start-card .lede{font-size:16px;color:var(--ink-2);margin-bottom:32px;}
  .quiz-counts{display:grid;grid-template-columns:repeat(3,1fr);gap:12px;margin-bottom:24px;}
  .quiz-count{
    border:1.5px solid var(--line);border-radius:12px;padding:20px;text-align:center;
    cursor:pointer;transition:all .15s;background:var(--paper);
  }
  .quiz-count:hover{border-color:var(--ink);background:var(--paper-2);}
  .quiz-count .n{font-family:var(--serif);font-size:36px;font-weight:600;color:var(--ink);line-height:1;letter-spacing:-.02em;}
  .quiz-count .l{font-size:12px;color:var(--ink-3);text-transform:uppercase;letter-spacing:.1em;font-weight:600;margin-top:6px;}
  .quiz-count.rec{border-color:var(--ink);background:var(--ink);color:var(--paper);}
  .quiz-count.rec .n{color:var(--paper);}
  .quiz-count.rec .l{color:rgba(250,247,241,.7);}

  .quiz-results{padding:48px 56px;text-align:center;}
  .quiz-results .ring{
    width:140px;height:140px;border-radius:50%;margin:0 auto 24px;
    display:grid;place-items:center;position:relative;
    background:conic-gradient(var(--moss) calc(var(--p,0)*1%), var(--paper-3) 0);
  }
  .quiz-results .ring::before{
    content:"";position:absolute;inset:10px;border-radius:50%;background:var(--paper);
  }
  .quiz-results .ring .v{position:relative;font-family:var(--serif);font-size:40px;font-weight:600;color:var(--ink);letter-spacing:-.02em;}
  .quiz-results .ring .v small{font-size:18px;color:var(--ink-3);}
  .quiz-results h2{font-size:32px;margin-bottom:8px;}
  .quiz-results .msg{font-size:16px;color:var(--ink-2);margin-bottom:32px;max-width:440px;margin-left:auto;margin-right:auto;}
  .quiz-results .actions{display:flex;gap:12px;justify-content:center;flex-wrap:wrap;}
  .quiz-history-link{display:block;margin-top:18px;font-size:13px;color:var(--ink-3);text-align:center;}
  .quiz-history-link:hover{color:var(--accent);}

  /* ============== RESULTS / EXAM HISTORY ============== */
  .res-container{max-width:900px;padding:48px 0 80px;}
  .res-back{display:inline-flex;align-items:center;gap:6px;font-size:13px;color:var(--ink-3);margin-bottom:28px;}
  .res-back:hover{color:var(--accent);}
  .res-container .display{margin-bottom:32px;}

  .res-stats{display:flex;gap:16px;flex-wrap:wrap;margin-bottom:32px;}
  .res-stat{
    flex:1;min-width:120px;background:var(--paper);border:1px solid var(--line);
    border-radius:10px;padding:18px 20px;
  }
  .res-stat .n{font-family:var(--serif);font-size:32px;font-weight:600;color:var(--ink);letter-spacing:-.02em;line-height:1;}
  .res-stat .l{font-size:12px;text-transform:uppercase;letter-spacing:.1em;color:var(--ink-3);font-weight:700;margin-top:6px;}

  .res-filters{display:flex;gap:8px;flex-wrap:wrap;margin-bottom:24px;}
  .res-filter{
    padding:6px 14px;border-radius:999px;font-size:13px;font-weight:500;
    background:var(--paper-2);border:1px solid var(--line);color:var(--ink-2);cursor:pointer;
    transition:background .15s,color .15s,border-color .15s;
  }
  .res-filter:hover{background:var(--paper-3);color:var(--ink);}
  .res-filter.on{background:var(--accent);border-color:var(--accent);color:#fff;}

  .res-thead{
    display:grid;
    grid-template-columns:1fr 2fr 72px 84px 88px 72px;
    gap:0 12px;padding:8px 16px;
    font-size:11px;text-transform:uppercase;letter-spacing:.1em;font-weight:700;color:var(--ink-3);
    border-bottom:2px solid var(--line);
  }
  .res-list{display:flex;flex-direction:column;}
  .res-row{
    display:grid;
    grid-template-columns:1fr 2fr 72px 84px 88px 72px;
    gap:0 12px;padding:14px 16px;
    border-bottom:1px solid var(--line);align-items:center;
    font-size:14px;color:var(--ink-2);
    transition:background .12s;
  }
  .res-row:hover{background:var(--paper-2);}
  .res-col-date{font-size:13px;color:var(--ink-2);}
  .res-time{display:block;font-size:11px;color:var(--ink-3);margin-top:2px;}
  .res-col-chap{display:flex;align-items:baseline;gap:6px;color:var(--ink);font-weight:500;}
  .res-chap-num{font-size:11px;font-weight:700;color:var(--ink-3);flex-shrink:0;}
  .res-col-score{font-family:var(--serif);font-size:16px;font-weight:600;}
  .res-col-score.pass{color:var(--moss);}
  .res-col-score.fail{color:var(--accent);}
  .res-col-qs{font-size:13px;color:var(--ink-3);}
  .res-badge{display:inline-flex;align-items:center;padding:3px 10px;border-radius:999px;font-size:12px;font-weight:600;}
  .res-badge.pass{background:color-mix(in srgb,var(--moss) 15%,transparent);color:var(--moss);}
  .res-badge.fail{background:color-mix(in srgb,var(--accent) 12%,transparent);color:var(--accent);}

  .res-empty{
    display:flex;flex-direction:column;align-items:center;justify-content:center;
    padding:72px 24px;text-align:center;color:var(--ink-3);font-size:15px;gap:6px;
  }
  .res-empty-icon{font-size:40px;opacity:.3;margin-bottom:8px;}

  @media (max-width:720px){
    .res-thead{display:none;}
    .res-row{grid-template-columns:1fr 1fr;gap:6px 12px;padding:14px 12px;}
    .res-col-date{grid-column:1;}
    .res-col-chap{grid-column:2;}
    .res-col-score{font-size:14px;}
    .res-col-qs{display:none;}
    .res-col-action{display:none;}
  }

  /* ============== UTIL ============== */
  .row{display:flex;align-items:center;gap:8px;}
  .spacer{flex:1;}

  @media (max-width:880px){
    .hero-grid{grid-template-columns:1fr;gap:40px;}
    .feat-grid{grid-template-columns:1fr;}
    .auth-shell{grid-template-columns:1fr;}
    .auth-aside{padding:48px 32px;}
    .nav{display:none;}
    .stat-row{grid-template-columns:1fr 1fr;}
    .quiz-counts{grid-template-columns:1fr;}
  }

/* ============== TWEAKS PANEL ============== */
  #tweaks{
    position:fixed;right:20px;bottom:20px;z-index:200;width:280px;
    background:var(--paper);border:1px solid var(--ink);border-radius:14px;
    box-shadow:0 10px 30px rgba(0,0,0,.18);font-family:var(--sans);
    overflow:hidden;
  }
  #tweaks .h{background:var(--ink);color:var(--paper);padding:10px 14px;display:flex;align-items:center;justify-content:space-between;}
  #tweaks .h .ttl{font-family:var(--serif);font-size:16px;font-weight:600;letter-spacing:-.01em;}
  #tweaks .h button{color:var(--paper);font-size:18px;line-height:1;padding:2px 6px;border-radius:4px;}
  #tweaks .h button:hover{background:rgba(255,255,255,.12);}
  #tweaks .body{padding:14px 16px 16px;max-height:60vh;overflow-y:auto;}
  #tweaks .grp{margin-bottom:14px;}
  #tweaks .grp:last-child{margin-bottom:0;}
  #tweaks .lbl{font-size:10.5px;text-transform:uppercase;letter-spacing:.12em;color:var(--ink-3);font-weight:700;margin-bottom:6px;}
  #tweaks .seg{display:flex;border:1px solid var(--line-2);border-radius:7px;overflow:hidden;}
  #tweaks .seg button{flex:1;padding:7px 6px;font-size:12px;font-weight:600;color:var(--ink-2);background:var(--paper);border-right:1px solid var(--line);}
  #tweaks .seg button:last-child{border-right:none;}
  #tweaks .seg button.on{background:var(--ink);color:var(--paper);}
  #tweaks .swatches{display:flex;gap:8px;}
  #tweaks .sw{width:34px;height:34px;border-radius:8px;border:2px solid var(--line);cursor:pointer;position:relative;}
  #tweaks .sw.on{border-color:var(--ink);box-shadow:0 0 0 2px var(--paper) inset;}
  body.density-tight{--density:.85;}
  body.density-tight .hero{padding:64px 0 56px;}
  body.density-tight .features{padding:64px 0;}
  body.density-tight .panel-body{padding:16px;}
  body.density-tight .resume{padding:24px;}
  body.density-tight .chap-main{padding:36px 44px 64px;}
  body.density-tight .quiz-body{padding:28px 32px;}
  body.serif-newsreader{--serif:'Newsreader','Source Serif 4',Georgia,serif;}
  body.serif-crimson{--serif:'Crimson Pro','Source Serif 4',Georgia,serif;}
  body.serif-source{--serif:'Source Serif 4','Source Serif Pro',Georgia,serif;}