@import url('https://fonts.googleapis.com/css2?family=DM+Mono:wght@400;500&family=DM+Sans:wght@400;500;600;700&family=Fraunces:opsz,wght@9..144,600;9..144,700&display=swap');

:root {
  --ink: #183138;
  --ink-soft: #4d6265;
  --paper: #f5f8f4;
  --paper-deep: #e7eee9;
  --card: #fbfcf8;
  --line: #d5e1dc;
  --line-strong: #b9ccc5;
  --teal: #0e6970;
  --teal-deep: #084a52;
  --teal-pale: #d9efeb;
  --coral: #e88b70;
  --coral-pale: #f9e5dc;
  --yellow: #efd987;
  --shadow: 0 15px 35px rgba(20, 57, 61, .08);
  --shadow-small: 0 5px 14px rgba(20, 57, 61, .07);
  --display: 'Fraunces', Georgia, serif;
  --sans: 'DM Sans', system-ui, sans-serif;
  --mono: 'DM Mono', monospace;
}

* { box-sizing: border-box; }
[x-cloak] { display: none !important; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background:
    radial-gradient(circle at 82% -10%, rgba(217,239,235,.8), transparent 35%),
    var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 15px;
  line-height: 1.5;
}
body::before {
  content: "";
  position: fixed; inset: 0; pointer-events: none; opacity: .3; z-index: -1;
  background-image: linear-gradient(rgba(14,105,112,.035) 1px, transparent 1px), linear-gradient(90deg, rgba(14,105,112,.035) 1px, transparent 1px);
  background-size: 36px 36px;
}
button, input, select { font: inherit; }
button { cursor: pointer; }
button:focus-visible, input:focus-visible, select:focus-visible, a:focus-visible {
  outline: 3px solid rgba(232,139,112,.65); outline-offset: 3px;
}
a { color: inherit; }
.app-shell { min-height: 100dvh; }
.topbar {
  min-height: 92px; padding: 14px clamp(18px, 4vw, 64px); display:flex; align-items:center; justify-content:space-between; gap:clamp(18px, 4vw, 54px);
  border-bottom: 1px solid var(--line); background: rgba(245,248,244,.86); backdrop-filter: blur(14px);
  position: sticky; top: 0; z-index: 10;
}
.header-identity { display:flex; align-items:flex-start; gap:14px; min-width:0; }
.brand-icon-link { display:block; width:32px; height:32px; flex:none; margin-top:7px; text-decoration:none; }
.brand-mark { width: 32px; height: 32px; border: 2px solid var(--teal); border-radius: 9px; position:relative; transform: rotate(-7deg); }
.brand-mark::before, .brand-mark::after { content:""; position:absolute; background:var(--teal); border-radius:2px; }
.brand-mark::before { width: 16px; height:2px; top:9px; left:6px; box-shadow: 0 6px 0 var(--coral); }
.brand-mark::after { width:2px; height:16px; left:14px; top:6px; opacity:.45; }
.header-copy { min-width:0; }
.eyebrow { margin:0 0 4px; color:var(--teal); font-family:var(--mono); font-size:10px; letter-spacing:.14em; text-transform:uppercase; }
h1, h2, h3, p { margin-top:0; }
h1 { font-family:var(--display); font-size: clamp(25px, 2.6vw, 35px); line-height:1; letter-spacing:-.055em; margin:0 0 5px; }
.header-lede { color:var(--ink-soft); font-size:12px; margin:0; white-space:nowrap; overflow:hidden; text-overflow:ellipsis; }
.page { max-width: 1440px; margin: 0 auto; padding: clamp(22px, 3vw, 40px) clamp(18px, 4vw, 64px) 68px; }
.tool-layout { display:grid; grid-template-columns: minmax(240px, 310px) minmax(0, 1fr); gap: 24px; align-items:start; }
.library, .workspace-card, .note-card, .ad-slot { border:1px solid var(--line); background:rgba(251,252,248,.87); box-shadow:var(--shadow-small); }
.library { border-radius: 18px; padding: 17px 12px 12px; position:sticky; top:106px; max-height: calc(100dvh - 125px); overflow:auto; }
.library-head { padding: 0 6px 14px; border-bottom:1px solid var(--line); margin-bottom:12px; }
.library-title { display:flex; justify-content:space-between; align-items:baseline; margin-bottom:11px; }
.library-title strong { font-family:var(--display); font-size:20px; }
.count { font-family:var(--mono); color:var(--ink-soft); font-size:11px; }
.search-wrap { position:relative; }
.search-wrap svg { position:absolute; left:11px; top:11px; color:var(--ink-soft); }
.search-wrap input { width:100%; border:1px solid var(--line-strong); background:var(--paper); border-radius:9px; padding:9px 10px 9px 34px; color:var(--ink); }
.search-wrap input::placeholder { color:#80918f; }
.filter-nav { display:flex; align-items:center; gap:5px; padding-top:13px; }
.filter-row { display:flex; flex-wrap:wrap; gap:6px; min-width:0; }
.filter-scroll { display:none; flex:none; width:26px; height:27px; place-items:center; border:1px solid var(--line); color:var(--teal-deep); background:var(--paper); border-radius:7px; font-size:20px; line-height:1; }
.filter-scroll:disabled { opacity:.35; cursor:default; }
.filter-btn { flex:none; border:1px solid var(--line); color:var(--ink-soft); background:transparent; border-radius:99px; padding:5px 9px; font-size:11px; }
.filter-btn.active { color:var(--teal-deep); background:var(--teal-pale); border-color:#acd7d0; font-weight:600; }
.group { margin-top: 15px; }
.group-label { margin: 0 7px 6px; color:#81918e; font-family:var(--mono); font-size:10px; letter-spacing:.12em; text-transform:uppercase; }
.calc-link { width:100%; display:flex; text-decoration:none; font:inherit; cursor:pointer; align-items:center; gap:9px; padding:8px 8px; border:0; background:transparent; border-radius:8px; color:var(--ink-soft); text-align:left; transition: background .18s, color .18s, transform .18s; }
.calc-link:hover { background:var(--teal-pale); color:var(--teal-deep); transform:translateX(2px); }
.calc-link.selected { color:var(--teal-deep); background:var(--teal-pale); font-weight:600; }
.calc-symbol { width:25px; height:25px; display:grid; place-items:center; border-radius:7px; color:var(--teal); background:#edf5f0; font-family:var(--mono); font-size:11px; flex:none; }
.calc-link.selected .calc-symbol { background:var(--teal); color:var(--paper); }
.workspace { min-width:0; }
.workspace-head { display:flex; justify-content:space-between; align-items:flex-start; gap:16px; margin-bottom:16px; }
.workspace-head h2 { margin:0 0 6px; font-family:var(--display); font-size:clamp(29px,4vw,45px); letter-spacing:-.05em; line-height:1; }
.workspace-desc { margin:0; color:var(--ink-soft); max-width:620px; }
.category-label { color:var(--teal); font-family:var(--mono); font-size:10px; text-transform:uppercase; letter-spacing:.1em; white-space:nowrap; padding-top:4px; }
.workspace-card { border-radius:18px; padding: clamp(18px, 3vw, 31px); box-shadow:var(--shadow); }
.form-grid { display:grid; grid-template-columns:repeat(2, minmax(0,1fr)); gap:18px 20px; }
.field.full { grid-column:1 / -1; }
.field label { display:block; color:var(--ink-soft); font-size:12px; font-weight:600; margin-bottom:7px; }
.input-shell { position:relative; }
.input-shell input, .input-shell select, .field > select { width:100%; border:1px solid var(--line-strong); background:var(--paper); color:var(--ink); border-radius:9px; padding:11px 12px; min-height:44px; }
.input-shell input { padding-right:50px; }
.input-unit { position:absolute; top:12px; right:12px; color:var(--ink-soft); font-family:var(--mono); font-size:11px; }
.helper { color:#7b8c89; font-size:11px; margin-top:5px; }
.actions { display:flex; align-items:center; gap:10px; margin-top:25px; padding-top:18px; border-top:1px solid var(--line); }
.btn-primary, .btn-ghost { min-height:41px; border-radius:8px; padding:9px 16px; border:1px solid transparent; font-weight:600; transition:transform .18s, background .18s; }
.btn-primary { color:#f5f8f4; background:var(--teal); box-shadow:0 4px 0 var(--teal-deep); }
.btn-primary:hover { background:var(--teal-deep); transform:translateY(-1px); }
.btn-ghost { color:var(--ink-soft); border-color:var(--line-strong); background:transparent; }
.btn-ghost:hover { color:var(--teal-deep); background:var(--teal-pale); }
.result-panel { margin-top:22px; border-radius:12px; background:var(--teal-deep); color:#edf6f2; padding:20px; position:relative; overflow:hidden; }
.result-panel::after { content:""; position:absolute; width:145px; height:145px; right:-34px; top:-48px; border:1px solid rgba(239,217,135,.35); border-radius:50%; box-shadow:0 0 0 18px rgba(239,217,135,.06), 0 0 0 36px rgba(239,217,135,.05); }
.result-kicker { color:#a9d8d1; font-family:var(--mono); font-size:10px; text-transform:uppercase; letter-spacing:.12em; margin-bottom:7px; }
.result-value { font-family:var(--display); font-size:clamp(29px,4vw,43px); line-height:1.05; letter-spacing:-.04em; margin:0; position:relative; z-index:1; }
.result-detail { margin:10px 0 0; color:#c8e1dc; font-size:13px; position:relative; z-index:1; max-width: 700px; }
.note-card { margin-top:18px; border-radius:14px; padding:22px 24px; }
.note-card h3 { font-family:var(--display); font-size:21px; margin-bottom:11px; }
.note-card h4 { color:var(--teal); font-size:12px; text-transform:uppercase; letter-spacing:.1em; margin:18px 0 5px; }
.note-card p { color:var(--ink-soft); margin-bottom:10px; font-size:13px; }
.note-card ul { color:var(--ink-soft); margin:7px 0 0; padding-left:18px; font-size:13px; }
.note-card code, .formula { font-family:var(--mono); color:var(--teal-deep); background:var(--teal-pale); border-radius:4px; padding:2px 5px; font-size:12px; }
.formula { display:block; padding:10px 12px; margin:10px 0; overflow:auto; }
.ad-slot { min-height:78px; display:flex; align-items:center; justify-content:center; border-style:dashed; border-radius:12px; margin:25px 0 0; color:#8b9c98; font-family:var(--mono); font-size:10px; letter-spacing:.12em; text-transform:uppercase; }
.empty { padding:30px 8px; text-align:center; color:var(--ink-soft); }
.empty strong { display:block; color:var(--ink); font-family:var(--display); font-size:20px; margin-bottom:5px; }
.footer { max-width:1440px; margin:0 auto; padding:0 clamp(18px,4vw,64px) 30px; color:#7b8c89; font-size:12px; display:flex; justify-content:space-between; gap:15px; }
.footer a { color:var(--teal); text-decoration:none; }
.fade-in { animation: rise .45s both; }
@keyframes rise { from { opacity:0; transform:translateY(8px); } to { opacity:1; transform:translateY(0); } }
@media (max-width: 820px) {
  .topbar { align-items:flex-start; }
  .header-identity { gap:10px; }
  .brand-icon-link { margin-top:4px; }
  .header-lede { display:none; }
  .tool-layout { grid-template-columns:1fr; }
  .library { position:static; max-height:none; }
  .library-head { display:grid; grid-template-columns:1fr; }
  .filter-nav { min-width:0; }
  .filter-scroll { display:grid; }
  .filter-row { flex:1; flex-wrap:nowrap; overflow-x:auto; padding:0 1px 2px; scrollbar-width:thin; scrollbar-color:var(--line-strong) transparent; }
  .filter-row::-webkit-scrollbar { display:block; height:4px; }
  .filter-row::-webkit-scrollbar-thumb { background:var(--line-strong); border-radius:99px; }
  .group { display:inline; }
  .calc-link { width:auto; display:inline-flex; margin:2px; }
  .group-label { margin-top:12px; }
  .calc-link span:last-child { display:none; }
  .calc-symbol { width:28px; height:28px; }
}
@media (max-width: 540px) {
  .page { padding-top:20px; }
  .topbar { padding-top:12px; padding-bottom:12px; }
  .brand-mark { width:28px; height:28px; }
  .brand-mark::before { width:13px; top:8px; left:5px; }
  .brand-mark::after { height:13px; left:12px; top:5px; }
  h1 { font-size:27px; }
  .form-grid { grid-template-columns:1fr; gap:15px; }
  .field.full { grid-column:auto; }
  .workspace-head { display:block; }
  .category-label { display:block; margin-bottom:9px; }
  .workspace-card { padding:18px; }
  .actions { flex-wrap:wrap; }
}

/* Theme selector */
.theme-switcher { display:flex; align-items:center; gap:8px; flex:none; }
.theme-switcher label { color:var(--ink-soft); font-family:var(--mono); font-size:10px; text-transform:uppercase; letter-spacing:.1em; }
.theme-switcher select { border:1px solid var(--line-strong); background:var(--card); color:var(--ink); border-radius:8px; padding:8px 28px 8px 10px; min-height:38px; cursor:pointer; }

/* Dark theme */
html.dark {
  --ink: #edf5f2;
  --ink-soft: #a9bab6;
  --paper: #101918;
  --paper-deep: #172321;
  --card: #1a2927;
  --line: #30433f;
  --line-strong: #47605a;
  --teal: #69c5c0;
  --teal-deep: #3aa6a4;
  --teal-pale: #183d3b;
  --coral: #ef9b82;
  --coral-pale: #452d28;
  --yellow: #efd987;
  --shadow: 0 15px 35px rgba(0,0,0,.28);
  --shadow-small: 0 5px 14px rgba(0,0,0,.22);
}
html.dark body {
  background: radial-gradient(circle at 82% -10%, rgba(24,61,59,.75), transparent 35%), var(--paper);
}
html.dark body::before {
  background-image: linear-gradient(rgba(105,197,192,.035) 1px, transparent 1px), linear-gradient(90deg, rgba(105,197,192,.035) 1px, transparent 1px);
}
html.dark .topbar { background:rgba(16,25,24,.88); }
html.dark .library,
html.dark .workspace-card,
html.dark .note-card,
html.dark .ad-slot { background:rgba(26,41,39,.9); }
html.dark .search-wrap input,
html.dark .input-shell input,
html.dark .input-shell select,
html.dark .field > select,
html.dark .theme-switcher select { background:#14211f; color:var(--ink); }
html.dark .calc-symbol { background:#203632; }
html.dark .btn-ghost { color:var(--ink-soft); }
html.dark .btn-ghost:hover,
html.dark .calc-link:hover,
html.dark .calc-link.selected { background:var(--teal-pale); color:var(--ink); }
html.dark .filter-btn.active { color:#bce8e3; background:var(--teal-pale); border-color:#376b66; }
html.dark .note-card code,
html.dark .note-card .formula { color:#bce8e3; background:var(--teal-pale); }
html.dark .helper,
html.dark .empty,
html.dark .footer { color:#879b96; }
html.dark .empty strong { color:var(--ink); }
html.dark .search-wrap input::placeholder { color:#71837f; }

@media (max-width: 820px) {
  .theme-switcher { position:absolute; right:18px; top:14px; }
  .topbar { position:sticky; }
  .header-copy { padding-right:105px; }
}
@media (max-width: 540px) {
  .theme-switcher label { display:none; }
  .theme-switcher select { min-height:34px; padding-top:6px; padding-bottom:6px; }
}