:root{
    --bg:#F2F7F3;
    --surface:#FFFFFF;
    --surface-2:#EAF2EC;
    --ink:#13241E;
    --muted:#5B7168;
    --line:#D9E5DC;
    --brand:#0E7A54;
    --brand-deep:#0A5C40;
    --brand-soft:#DFF0E6;
    --brand-ink:#FFFFFF;
    --accent:#FF7A45;
    --accent-ink:#3A1400;
    --key:#F3F7F4;
    --key-fn:#DCEAE0;
    --key-op:#CBE5D6;
    --display-bg:#10231C;
    --display-ink:#C9F5DF;
    --good:#0E7A54;
    --warn:#C77700;
    --bad:#C23A2B;
    --shadow:0 10px 30px rgba(16,35,28,.08);
    --radius:14px;
  }
  @media (prefers-color-scheme: dark){
    :root:not([data-theme="light"]){
      --bg:#0C1512;
      --surface:#131F1A;
      --surface-2:#182721;
      --ink:#E6F1EA;
      --muted:#94ABA0;
      --line:#243830;
      --brand:#2FBE87;
      --brand-deep:#0F3D2D;
      --brand-soft:#173327;
      --brand-ink:#06130E;
      --accent:#FF8A5C;
      --accent-ink:#2A0E00;
      --key:#1B2A24;
      --key-fn:#20332B;
      --key-op:#265242;
      --display-bg:#050B09;
      --display-ink:#7FE8BC;
      --good:#2FBE87;
      --warn:#E39A2D;
      --bad:#E06052;
      --shadow:0 10px 30px rgba(0,0,0,.35);
    }
  }
  :root[data-theme="dark"]{
    --bg:#0C1512;
    --surface:#131F1A;
    --surface-2:#182721;
    --ink:#E6F1EA;
    --muted:#94ABA0;
    --line:#243830;
    --brand:#2FBE87;
    --brand-deep:#0F3D2D;
    --brand-soft:#173327;
    --brand-ink:#06130E;
    --accent:#FF8A5C;
    --accent-ink:#2A0E00;
    --key:#1B2A24;
    --key-fn:#20332B;
    --key-op:#265242;
    --display-bg:#050B09;
    --display-ink:#7FE8BC;
    --good:#2FBE87;
    --warn:#E39A2D;
    --bad:#E06052;
    --shadow:0 10px 30px rgba(0,0,0,.35);
  }
  *{box-sizing:border-box}
  body{
    margin:0;
    background:var(--bg);
    color:var(--ink);
    font-family:"Instrument Sans",system-ui,-apple-system,"Segoe UI",sans-serif;
    font-size:16px;
    line-height:1.55;
  }
  a{color:var(--brand);text-decoration:none}
  a:hover{text-decoration:underline}
  button{font-family:inherit}
  input,select{font-family:inherit;font-size:1rem;color:var(--ink)}
  h1,h2,h3{font-family:"Bricolage Grotesque","Instrument Sans",system-ui,sans-serif;text-wrap:balance;line-height:1.15;margin:0 0 .5em}
  .mono{font-family:"Spline Sans Mono",ui-monospace,Menlo,Consolas,monospace;font-variant-numeric:tabular-nums}

  /* ---------- header ---------- */
  header.site{
    background:linear-gradient(120deg,var(--brand-deep),var(--brand));
    color:#fff;
    padding:0;
  }
  .site-inner{
    max-width:1120px;margin:0 auto;padding:16px 20px;
    display:flex;align-items:center;gap:18px;flex-wrap:wrap;
  }
  .logo{display:flex;align-items:center;gap:10px;cursor:pointer;user-select:none}
  .logo-mark{
    width:40px;height:40px;border-radius:10px;background:#fff;color:var(--brand-deep);
    display:grid;place-items:center;font-family:"Bricolage Grotesque",sans-serif;font-weight:800;font-size:22px;
    box-shadow:inset 0 0 0 3px var(--accent);
  }
  .logo-word{font-family:"Bricolage Grotesque",sans-serif;font-weight:800;font-size:26px;letter-spacing:-.02em;color:#fff}
  .logo-tag{font-size:12px;letter-spacing:.14em;text-transform:uppercase;opacity:.85;color:#fff;margin-top:-2px}
  .search{
    flex:1;min-width:230px;display:flex;gap:0;max-width:520px;margin-left:auto;
  }
  .search input{
    flex:1;border:none;border-radius:10px 0 0 10px;padding:11px 14px;outline:none;
    background:rgba(255,255,255,.95);color:#13241E;
  }
  .search input:focus{box-shadow:0 0 0 3px rgba(255,255,255,.45)}
  .search button{
    border:none;border-radius:0 10px 10px 0;padding:0 18px;background:var(--accent);color:var(--accent-ink);
    font-weight:700;cursor:pointer;font-size:15px;
  }
  .search button:hover{filter:brightness(1.05)}
  .search-results{
    position:relative;
  }
  .search-drop{
    position:absolute;top:calc(100% + 6px);left:0;right:0;background:var(--surface);
    border:1px solid var(--line);border-radius:12px;box-shadow:var(--shadow);z-index:30;overflow:hidden;
  }
  .search-drop button{
    display:block;width:100%;text-align:left;background:none;border:none;padding:10px 14px;cursor:pointer;color:var(--ink);font-size:15px;
  }
  .search-drop button:hover,.search-drop button:focus{background:var(--surface-2);outline:none}
  .search-drop .cat{color:var(--muted);font-size:12.5px;margin-left:6px}
  nav.crumbs{max-width:1120px;margin:0 auto;padding:10px 20px 0;font-size:14px;color:var(--muted)}
  nav.crumbs a{color:var(--brand);cursor:pointer}

  /* ---------- layout ---------- */
  main{max-width:1120px;margin:0 auto;padding:26px 20px 60px}
  .view{display:none}
  .view.active{display:block}
  .hero{
    display:grid;grid-template-columns:1.05fr 1fr;gap:34px;align-items:start;margin-bottom:44px;
  }
  @media (max-width:900px){.hero{grid-template-columns:1fr}}
  .hero h1{font-size:clamp(30px,4.5vw,44px);font-weight:800;letter-spacing:-.02em}
  .hero p.lede{font-size:17.5px;color:var(--muted);max-width:52ch;margin:0 0 22px}
  .linkrow{display:flex;flex-wrap:wrap;gap:6px 20px;margin-bottom:26px}
  .linkrow a{font-weight:600;font-size:15px}
  .stat-strip{display:flex;gap:26px;flex-wrap:wrap}
  .stat b{display:block;font-family:"Bricolage Grotesque",sans-serif;font-size:26px;color:var(--brand)}
  .stat span{font-size:13px;color:var(--muted);letter-spacing:.06em;text-transform:uppercase}

  /* ---------- scientific calculator ---------- */
  .sci{
    background:var(--surface);border:1px solid var(--line);border-radius:calc(var(--radius) + 4px);
    box-shadow:var(--shadow);padding:16px;max-width:430px;justify-self:end;width:100%;
  }
  @media (max-width:900px){.sci{justify-self:stretch;max-width:none}}
  .sci-top{display:flex;justify-content:space-between;align-items:center;margin-bottom:10px;padding:0 2px}
  .sci-top .label{font-size:12px;letter-spacing:.14em;text-transform:uppercase;color:var(--muted);font-weight:600}
  .degrad{display:flex;border:1px solid var(--line);border-radius:8px;overflow:hidden}
  .degrad button{border:none;background:var(--surface);color:var(--muted);padding:4px 12px;font-size:13px;font-weight:600;cursor:pointer}
  .degrad button.on{background:var(--brand);color:var(--brand-ink)}
  .display{
    background:var(--display-bg);border-radius:12px;padding:12px 16px 14px;margin-bottom:12px;min-height:78px;
    display:flex;flex-direction:column;justify-content:flex-end;align-items:flex-end;gap:2px;overflow:hidden;
  }
  .display .expr{color:var(--display-ink);font-size:27px;font-weight:500;min-height:36px;max-width:100%;overflow-x:auto;white-space:nowrap;scrollbar-width:none}
  .display .out{color:var(--display-ink);font-size:30px;font-weight:600;max-width:100%;overflow-x:auto;white-space:nowrap;scrollbar-width:none}
  .keys{display:grid;grid-template-columns:repeat(5,1fr);gap:8px}
  .keys button{
    border:none;border-radius:10px;padding:12px 0;font-size:16.5px;font-weight:600;cursor:pointer;
    background:var(--key);color:var(--ink);transition:transform .05s ease,filter .12s ease;
  }
  .keys button:hover{filter:brightness(.96)}
  .keys button:active{transform:scale(.96)}
  .keys button:focus-visible{outline:3px solid var(--brand);outline-offset:1px}
  .keys .fn{background:var(--key-fn);font-size:14.5px}
  .keys .op{background:var(--key-op)}
  .keys .danger{background:var(--bad);color:#fff}
  .keys .eq{background:var(--accent);color:var(--accent-ink);font-size:20px}
  .keys .mono{font-size:16.5px}

  /* ---------- category grid ---------- */
  .grid-title{font-size:24px;font-weight:800;letter-spacing:-.01em;margin-bottom:18px}
  .cats{display:grid;grid-template-columns:repeat(5,1fr);gap:28px}
  @media (max-width:1180px){.cats{grid-template-columns:repeat(3,1fr)}}
  @media (max-width:860px){.cats{grid-template-columns:repeat(2,1fr)}}
  @media (max-width:460px){.cats{grid-template-columns:1fr}}
  .cat-card h3{display:flex;align-items:center;gap:10px;font-size:17px;margin-bottom:12px}
  .cat-dot{width:12px;height:12px;border-radius:4px;background:var(--brand);flex:none}
  .cat-card.fin .cat-dot{background:#2E86DE}
  .cat-card.health .cat-dot{background:#E0533D}
  .cat-card.math .cat-dot{background:#8E5BD9}
  .cat-card.other .cat-dot{background:#C77700}
  .cat-card.trend .cat-dot{background:#E64980}
  .cat-card .guide-link{font-weight:700}
  .cat-card.fin .guide-link{color:#2E86DE}
  .cat-card.health .guide-link{color:#E0533D}
  .cat-card.math .guide-link{color:#8E5BD9}
  .cat-card.other .guide-link{color:#C77700}
  .cat-card.trend .guide-link{color:#E64980}
  .cat-card ul{list-style:none;margin:0;padding:0;display:flex;flex-direction:column;gap:9px}
  .cat-card li a{cursor:pointer;font-weight:500;font-size:15.5px}

  /* ---------- calculator pages ---------- */
  .calc-page{max-width:960px}
  .calc-page h1{font-size:clamp(26px,3.6vw,36px);font-weight:800;letter-spacing:-.02em}
  .calc-page p.desc{color:var(--muted);max-width:65ch;margin:0 0 24px}
  .panel{
    display:grid;grid-template-columns:minmax(300px,420px) 1fr;gap:24px;align-items:start;
  }
  @media (max-width:820px){.panel{grid-template-columns:1fr}}
  .card{
    background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);
    padding:22px;box-shadow:var(--shadow);
  }
  .card h3{font-size:16px;letter-spacing:.02em;margin-bottom:16px}
  .field{margin-bottom:14px}
  .field label{display:block;font-size:13.5px;font-weight:600;color:var(--muted);margin-bottom:6px}
  .field input,.field select,.field textarea{
    width:100%;border:1px solid var(--line);border-radius:10px;padding:10px 12px;background:var(--bg);
  }
  .field textarea{min-height:110px;resize:vertical;font-family:"Spline Sans Mono",ui-monospace,monospace;font-size:14.5px}
  .field input:focus,.field select:focus,.field textarea:focus{outline:none;border-color:var(--brand);box-shadow:0 0 0 3px var(--brand-soft)}
  .rand-out{display:flex;flex-wrap:wrap;gap:8px;margin-top:14px}
  .rand-out span{background:var(--surface-2);border:1px solid var(--line);border-radius:8px;padding:6px 12px;font-family:"Spline Sans Mono",ui-monospace,monospace;font-variant-numeric:tabular-nums;font-size:15px}
  .sched{max-height:340px;overflow:auto;margin-top:16px;border:1px solid var(--line);border-radius:10px}
  .sched table{width:100%;border-collapse:collapse;font-size:14px;font-variant-numeric:tabular-nums}
  .sched th{position:sticky;top:0;background:var(--surface-2);text-align:right;padding:8px 12px;font-size:12.5px;letter-spacing:.04em;text-transform:uppercase;color:var(--muted)}
  .sched th:first-child,.sched td:first-child{text-align:left}
  .sched td{text-align:right;padding:7px 12px;border-top:1px solid var(--line)}
  .fine{font-size:13px;color:var(--muted);margin-top:12px}
  .pw-box{
    font-family:"Spline Sans Mono",ui-monospace,monospace;font-size:19px;letter-spacing:.02em;
    background:var(--surface-2);border:1px solid var(--line);border-radius:10px;
    padding:14px 16px;word-break:break-all;user-select:all;margin-bottom:10px;
  }
  .an-grid{display:grid;grid-template-columns:1fr 1fr;gap:24px;align-items:start;margin-top:22px}
  @media (max-width:820px){.an-grid{grid-template-columns:1fr}}
  .an-item{padding:8px 0;border-top:1px solid var(--line)}
  .an-item:first-of-type{border-top:none;padding-top:0}
  .an-line{display:flex;justify-content:space-between;gap:12px;font-size:15px;margin-bottom:5px}
  .an-line b{font-variant-numeric:tabular-nums}
  .an-meter{height:8px;border-radius:4px;background:var(--surface-2);overflow:hidden}
  .an-meter i{display:block;height:100%;background:var(--brand);border-radius:4px}
  .prose{max-width:70ch}
  .prose h2{font-size:20px;margin-top:30px}
  .prose h2:first-child{margin-top:0}
  .prose p{color:var(--ink);font-size:15.5px;margin:0 0 14px}
  .prose ul{margin:0 0 14px;padding-left:22px;color:var(--ink);font-size:15.5px}
  .prose li{margin-bottom:6px}
  .prose .muted{color:var(--muted)}
  .cat-tiles{display:grid;grid-template-columns:repeat(5,1fr);gap:16px;margin:18px 0 22px}
  @media (max-width:980px){.cat-tiles{grid-template-columns:repeat(3,1fr)}}
  @media (max-width:760px){.cat-tiles{grid-template-columns:repeat(2,1fr)}}
  .cat-tile{background:var(--surface);border:1px solid var(--line);border-radius:12px;padding:16px 18px;box-shadow:var(--shadow)}
  .cat-tile b{display:block;font-family:"Bricolage Grotesque",sans-serif;font-size:22px;color:var(--brand)}
  .cat-tile span{font-size:13.5px;color:var(--muted)}
  .contact-card{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:22px;box-shadow:var(--shadow);max-width:520px}
  .contact-email{display:inline-block;font-size:20px;font-weight:700;color:var(--brand);margin:6px 0 4px}
  .contact-routes{list-style:none;margin:18px 0 0;padding:0;display:flex;flex-direction:column;gap:10px}
  .contact-routes li{display:flex;gap:10px;font-size:14.5px;color:var(--ink)}
  .contact-routes b{color:var(--brand);flex:none}
  .legal-updated{font-size:13px;color:var(--muted);margin:-8px 0 20px}
  .field-row{display:flex;gap:12px}
  .field-row .field{flex:1}
  .btn{
    display:inline-block;border:none;border-radius:10px;padding:12px 22px;cursor:pointer;
    background:var(--brand);color:var(--brand-ink);font-weight:700;font-size:15.5px;
  }
  .btn:hover{filter:brightness(1.07)}
  .btn:focus-visible{outline:3px solid var(--accent);outline-offset:2px}
  .btn.ghost{background:var(--surface-2);color:var(--ink);margin-left:8px}
  .seg{display:inline-flex;border:1px solid var(--line);border-radius:10px;overflow:hidden;margin-bottom:16px}
  .seg button{border:none;background:var(--surface);color:var(--muted);padding:8px 16px;font-size:14px;font-weight:600;cursor:pointer}
  .seg button.on{background:var(--brand);color:var(--brand-ink)}
  .result-big{
    font-family:"Bricolage Grotesque",sans-serif;font-weight:800;font-size:clamp(30px,4vw,42px);
    color:var(--brand);letter-spacing:-.02em;font-variant-numeric:tabular-nums;
  }
  .result-sub{color:var(--muted);font-size:14px;margin-top:2px}
  .kv{width:100%;border-collapse:collapse;margin-top:14px;font-size:15px}
  .kv td{padding:9px 0;border-top:1px solid var(--line)}
  .kv td:last-child{text-align:right;font-weight:600;font-variant-numeric:tabular-nums}
  .kv tr.total td{font-weight:700;color:var(--brand)}
  .bar{
    height:14px;border-radius:7px;background:var(--surface-2);overflow:hidden;display:flex;margin-top:16px;
  }
  .bar i{display:block;height:100%}
  .bar .p{background:var(--brand)}
  .bar .i{background:var(--accent)}
  .legend{display:flex;gap:18px;margin-top:8px;font-size:13px;color:var(--muted)}
  .legend b{display:inline-block;width:10px;height:10px;border-radius:3px;margin-right:5px}
  .legend .lp b{background:var(--brand)}
  .legend .li b{background:var(--accent)}
  .badge{
    display:inline-block;border-radius:999px;padding:4px 14px;font-size:14px;font-weight:700;margin-top:8px;
  }
  .badge.good{background:var(--brand-soft);color:var(--good)}
  .badge.warn{background:color-mix(in srgb,var(--warn) 16%,transparent);color:var(--warn)}
  .badge.bad{background:color-mix(in srgb,var(--bad) 14%,transparent);color:var(--bad)}
  .gauge{margin-top:18px}
  .gauge-track{position:relative;height:12px;border-radius:6px;background:linear-gradient(90deg,#4aa3df 0 18.5%,var(--good) 18.5% 50%,var(--warn) 50% 70%,var(--bad) 70% 100%)}
  .gauge-pin{position:absolute;top:-6px;width:4px;height:24px;border-radius:2px;background:var(--ink);transform:translateX(-2px)}
  .gauge-labels{display:flex;justify-content:space-between;font-size:12px;color:var(--muted);margin-top:6px}
  .placeholder{color:var(--muted);font-size:15px}
  .error-msg{color:var(--bad);font-size:14px;font-weight:600;margin-top:10px}
  .explain{margin-top:34px;max-width:68ch}
  .explain h2{font-size:20px}
  .explain p{color:var(--muted);font-size:15.5px}

  .faq{margin-top:48px;max-width:760px}
  .faq h2{font-size:22px;margin-bottom:10px}
  .faq-item{border-bottom:1px solid var(--line);padding:14px 0}
  .faq-item summary{
    cursor:pointer;font-weight:700;font-size:16px;color:var(--ink);list-style:none;
    display:flex;justify-content:space-between;align-items:center;gap:12px;
  }
  .faq-item summary::-webkit-details-marker{display:none}
  .faq-item summary::after{content:"+";font-size:20px;color:var(--brand);font-weight:800;flex:none}
  .faq-item[open] summary::after{content:"\2212"}
  .faq-item p{color:var(--muted);font-size:15px;margin:10px 0 0;line-height:1.55}

  .gpa-row{display:grid;grid-template-columns:1fr 130px 90px 36px;gap:8px;margin-bottom:8px;align-items:center}
  .gpa-row input,.gpa-row select{width:100%;border:1px solid var(--line);border-radius:10px;padding:9px 10px;background:var(--bg)}
  .gpa-row input:focus,.gpa-row select:focus{outline:none;border-color:var(--brand);box-shadow:0 0 0 3px var(--brand-soft)}
  .gpa-head{display:grid;grid-template-columns:1fr 130px 90px 36px;gap:8px;font-size:12.5px;font-weight:600;color:var(--muted);margin-bottom:6px}
  .gpa-del{border:none;background:var(--surface-2);color:var(--muted);border-radius:8px;height:36px;cursor:pointer;font-size:16px;line-height:1}

  .sub-row{display:grid;grid-template-columns:1fr 110px 36px;gap:8px;margin-bottom:8px;align-items:center}
  .sub-row input{width:100%;border:1px solid var(--line);border-radius:10px;padding:9px 10px;background:var(--bg)}
  .sub-row input:focus{outline:none;border-color:var(--brand);box-shadow:0 0 0 3px var(--brand-soft)}
  .sub-head{display:grid;grid-template-columns:1fr 110px 36px;gap:8px;font-size:12.5px;font-weight:600;color:var(--muted);margin-bottom:6px}
  @media (max-width:480px){.sub-row,.sub-head{grid-template-columns:1fr 84px 32px}}
  .chiprow{display:flex;flex-wrap:wrap;gap:8px;margin:10px 0 16px}
  .chip{border:1px solid var(--line);background:var(--surface-2);color:var(--ink);border-radius:999px;padding:6px 13px;font-size:13px;font-weight:600;cursor:pointer}
  .chip:hover{border-color:var(--brand)}

  .share-btn{
    display:block;width:100%;margin-top:20px;border:none;border-radius:14px;padding:18px 20px;
    background:linear-gradient(135deg,#E64980,#C2255C);color:#fff;font-weight:800;font-size:17px;
    cursor:pointer;box-shadow:0 8px 20px rgba(230,73,128,.35);letter-spacing:-.01em;
  }
  .share-btn:hover{filter:brightness(1.05)}
  .share-btn:focus-visible{outline:3px solid var(--accent);outline-offset:2px}
  .share-btn[hidden]{display:none}
  .share-overlay{position:fixed;inset:0;background:rgba(10,10,12,.55);display:flex;align-items:center;justify-content:center;padding:20px;z-index:200}
  .share-overlay[hidden]{display:none}
  .share-modal{background:var(--surface);border-radius:18px;padding:26px;max-width:440px;width:100%;box-shadow:0 24px 70px rgba(0,0,0,.35)}
  .share-modal h3{margin:0 0 4px;font-family:"Bricolage Grotesque",sans-serif}
  .share-modal p{color:var(--muted);font-size:14px;margin:0 0 14px}
  .share-modal textarea{
    width:100%;min-height:96px;border:1px solid var(--line);border-radius:12px;padding:12px;
    background:var(--bg);color:var(--ink);font:inherit;font-size:14.5px;resize:vertical;box-sizing:border-box;
  }
  .share-modal-actions{display:flex;gap:10px;margin-top:14px;justify-content:flex-end;flex-wrap:wrap}
  .gpa-del:hover{background:color-mix(in srgb,var(--bad) 14%,transparent);color:var(--bad)}
  @media (max-width:480px){.gpa-row,.gpa-head{grid-template-columns:1fr 104px 70px 32px}}
  footer.site{
    border-top:1px solid var(--line);margin-top:20px;
  }
  .foot-inner{max-width:1120px;margin:0 auto;padding:26px 20px;display:flex;justify-content:space-between;gap:16px;flex-wrap:wrap;color:var(--muted);font-size:14px}
  .foot-inner a{cursor:pointer}
  @media (prefers-reduced-motion: reduce){
    *{transition:none !important;animation:none !important}
  }