/* ============================================================
   TipReckon design system — matches the approved "Tip Calculator
   Site Strategy" reference design exactly.
   Warm-paper editorial system: vermilion accent, sharp corners,
   1px ink borders, graph-paper grid, Libre Franklin + IBM Plex Mono.
   MOBILE FIRST: base targets ~360px phones; min-width queries enhance.
   ============================================================ */
:root{
  --bg:#f2efe8; --paper:#fffdf8; --ink:#171918; --muted:#5d625e;
  --line:#c7c5bd; --soft:#e7e3da;
  --accent:#d9482f; --accent-ink:#8f2618;
  --green:#155f47; --green-soft:#e2efe8;
  --blue:#1b5f7c; --amber:#926316; --amber-soft:#f4ecd9;
  --shadow:0 14px 34px rgba(43,36,25,.08);
  --serif:"Libre Franklin",-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;
  --mono:"IBM Plex Mono",ui-monospace,SFMono-Regular,Menlo,monospace;
}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{
  margin:0; background:var(--bg); color:var(--ink);
  font-family:var(--serif); font-size:16px; line-height:1.55;
  background-image:
    linear-gradient(var(--line) 1px, transparent 1px),
    linear-gradient(90deg, var(--line) 1px, transparent 1px);
  background-size:28px 28px;
}
.wrap{max-width:760px;margin:0 auto;padding:0 18px}

/* ---------- header ---------- */
header.site{background:var(--paper);border-bottom:1px solid var(--ink)}
header.site .wrap{display:flex;align-items:center;justify-content:space-between;padding:14px 18px}
.brand{display:inline-flex;align-items:center;gap:10px;font-weight:800;font-size:1.25rem;letter-spacing:-.02em;color:var(--ink);text-decoration:none}
.brand span{color:var(--accent)}
.brand-mark{width:30px;height:30px;flex:none}
.brand-mark .bm-tile{fill:var(--accent);stroke:var(--ink);stroke-width:5}
.brand-mark .bm-glyph{fill:var(--paper)}
nav a{color:var(--muted);text-decoration:none;margin-left:16px;font-size:.85rem;
  font-family:var(--mono);text-transform:uppercase;letter-spacing:.06em}
nav a:hover{color:var(--accent-ink)}

/* ---------- hero / masthead ---------- */
.hero{padding:14px 0 0}
.card.masthead{text-align:center;padding:20px 16px}
.kicker{font-family:var(--mono);font-size:12px;font-weight:600;text-transform:uppercase;
  letter-spacing:.09em;color:var(--accent-ink);margin:0 0 12px}
.hero h1{font-size:clamp(34px,7vw,54px);line-height:.98;letter-spacing:-.04em;margin:0 0 12px}
.lede{font-size:clamp(16px,2.5vw,19px);color:var(--muted);margin:0 auto;max-width:560px}
.lede strong{color:var(--ink)}

/* ---------- cards ---------- */
.card{background:var(--paper);border:1px solid var(--ink);border-top:3px solid var(--ink);
  box-shadow:var(--shadow);padding:16px;margin:0 0 14px}
.card h2{font-family:var(--mono);font-size:12px;font-weight:600;margin:0 0 14px;
  text-transform:uppercase;letter-spacing:.09em;color:var(--accent-ink)}

/* ---------- form controls ---------- */
.field{margin:10px 0}
.field label{display:block;font-weight:600;margin-bottom:6px;font-size:.95rem}
.field .hint{font-weight:400;color:var(--muted);font-size:.85rem}
.input-row{display:flex;gap:10px;align-items:center}
.input-wrap{position:relative;flex:1}
.input-wrap .prefix{position:absolute;left:14px;top:50%;transform:translateY(-50%);color:var(--muted);font-weight:600}
.input-wrap .suffix{position:absolute;right:14px;top:50%;transform:translateY(-50%);color:var(--muted);font-weight:600}
input[type=text],input[type=number],select{width:100%;padding:13px 14px;font-size:16px;
  border:1px solid var(--line);border-radius:0;background:var(--paper);color:var(--ink);
  min-height:48px;font-family:var(--serif)}
input.has-prefix{padding-left:32px}
input.has-suffix{padding-right:34px}
.input-narrow{max-width:170px}
input:focus,select:focus,button:focus-visible{outline:2px solid var(--accent);outline-offset:1px}
button{min-height:44px;font-family:var(--serif)}
.is-hidden{display:none !important}

/* presets + segmented */
.presets{display:flex;flex-wrap:wrap;gap:8px;margin-bottom:6px}
.presets button{border:1px solid var(--line);background:var(--paper);border-radius:0;
  padding:8px 16px;font-size:.9rem;cursor:pointer;font-family:var(--mono);
  text-transform:uppercase;letter-spacing:.04em;font-size:.78rem}
.presets button:hover{border-color:var(--accent)}
.presets button.active{background:var(--soft);border-color:var(--accent);color:var(--accent-ink);font-weight:600}
.preset-note{font-size:.85rem;color:var(--muted);min-height:1.4em;margin:4px 0 0}
.segmented{display:flex;border:1px solid var(--ink);overflow:hidden}
.segmented button{flex:1;padding:12px;border:0;background:var(--paper);font-size:.85rem;
  cursor:pointer;color:var(--muted);font-family:var(--mono);text-transform:uppercase;letter-spacing:.05em}
.segmented button.active{background:var(--ink);color:var(--paper);font-weight:600}

/* tip grid */
.tipgrid{display:grid;grid-template-columns:repeat(3,1fr);gap:8px}
.tipgrid button{padding:12px 4px;border:1px solid var(--ink);background:var(--paper);
  border-radius:0;font-size:1rem;cursor:pointer;font-weight:700;font-family:var(--mono)}
.tipgrid button.active{background:var(--accent);border-color:var(--accent);color:#fff}

/* tabs */
.tabs{display:flex;gap:8px;margin-bottom:14px}
.tabs button{flex:1;padding:11px;border:1px solid var(--ink);background:var(--paper);
  border-radius:0;cursor:pointer;font-weight:600}
.tabs button.active{background:var(--ink);color:var(--paper);border-color:var(--ink)}

/* stepper */
.stepper{display:flex;align-items:center;gap:12px}
.stepper button{width:48px;height:48px;border-radius:0;border:1px solid var(--ink);
  background:var(--paper);font-size:1.3rem;cursor:pointer;min-height:48px;font-family:var(--mono)}
.stepper output{font-size:1.4rem;font-weight:700;min-width:2.5em;text-align:center;font-family:var(--mono)}

/* switch */
.switch-row{display:flex;align-items:center;justify-content:space-between;gap:12px;padding:10px 0}
.switch{position:relative;width:56px;height:32px;flex:none}
.switch input{opacity:0;width:100%;height:100%;position:absolute;margin:0;cursor:pointer;min-height:32px}
.knob{position:absolute;inset:0;background:var(--line);transition:.2s}
.knob:after{content:"";position:absolute;top:4px;left:4px;width:24px;height:24px;background:var(--paper);
  transition:.2s;box-shadow:0 1px 2px rgba(0,0,0,.25)}
.switch input:checked + .knob{background:var(--accent)}
.switch input:checked + .knob:after{left:28px}

/* item rows (by-item split) */
.item-row{display:grid;grid-template-columns:1fr 104px 118px 44px;gap:8px;margin-bottom:8px;align-items:center}
.item-row button.rm{border:1px solid var(--line);background:var(--paper);border-radius:0;height:48px;
  cursor:pointer;font-size:1.1rem;color:var(--muted);font-family:var(--mono)}
.add-item{border:1px dashed var(--ink);background:none;width:100%;padding:11px;border-radius:0;
  cursor:pointer;color:var(--accent-ink);font-weight:600;font-family:var(--mono);
  text-transform:uppercase;letter-spacing:.05em;font-size:.82rem}

/* ---------- results (inverted panel, per strategy callout) ---------- */
.results{background:var(--ink);color:var(--paper);padding:16px;margin:0 0 14px;box-shadow:var(--shadow)}
.results h2{color:var(--muted);font-family:var(--mono);font-size:12px;font-weight:600;
  text-transform:uppercase;letter-spacing:.09em;margin:0 0 12px}
.rline{display:flex;justify-content:space-between;gap:10px;padding:7px 0;
  border-bottom:1px solid rgba(255,253,248,.14);font-size:.98rem}
.rline:last-child{border-bottom:0}
.rline .v{font-weight:700;font-variant-numeric:tabular-nums;white-space:nowrap;font-family:var(--mono)}
.rline.total .v{font-size:1.5rem;color:#ff8a74}
.rline .sub{font-size:.8rem;color:#a3a8a3;display:block;font-family:var(--serif);font-weight:400}
.savings{display:inline-block;background:var(--green-soft);color:var(--green);font-weight:700;
  padding:8px 14px;margin-top:12px;font-size:.92rem}
.warn{display:block;background:#3a1c12;color:#ff8a74;padding:8px 14px;margin-top:12px;font-size:.88rem}
.per-person{margin-top:14px;border-top:1px solid rgba(255,253,248,.14);padding-top:10px}
.per-person .rline{font-size:.93rem}
.share-row{display:flex;gap:10px;margin-top:14px}
.share-row button{flex:1;padding:12px;border:1px solid rgba(255,253,248,.3);
  background:transparent;color:var(--paper);cursor:pointer;font-weight:600;
  font-family:var(--mono);text-transform:uppercase;letter-spacing:.05em;font-size:.8rem}
.share-row button:hover{background:rgba(255,253,248,.08)}
.note{font-size:.85rem;color:var(--muted);background:var(--soft);padding:10px 14px;margin-top:12px}

/* ---------- flagship compact calculator card ---------- */
.calc-card{margin-top:14px}
.calc-card .kicker{text-align:center}
.calc-card h1{font-size:clamp(30px,6vw,44px);letter-spacing:-.03em;line-height:1;
  margin:0 0 8px;text-align:center}
.calc-card .lede{text-align:center;margin:0 0 16px;color:var(--muted);font-size:.95rem}
.calc-card .field > label{text-align:center}
.bill-field input{font-size:1.5rem;font-weight:700;text-align:center;
  font-family:var(--mono);min-height:64px}
.bill-field .prefix{font-size:1.25rem}
/* people stepper in the main card — compact, centered */
.people-field .stepper{justify-content:center;gap:18px}
.people-field .step-btn{width:48px;height:48px;min-height:48px;font-size:1.2rem}
.people-field .step-val{font-size:1.3rem;min-width:2em;text-align:center}
/* integrated light summary (replaces the dark results panel on flagship) */
.calc-summary{background:var(--soft);border:1px solid var(--ink);
  border-top:3px solid var(--accent);padding:12px 16px;margin:16px 0}
.calc-summary .rline{border-bottom:1px solid var(--line);color:var(--ink);padding:8px 0}
.calc-summary .rline .v{color:var(--ink)}
.calc-summary .rline .sub{color:var(--muted)}
.calc-summary .rline.total .v{color:var(--accent-ink);font-size:1.4rem}
.calc-summary .per-person{border-top:1px solid var(--line);margin-top:6px;padding-top:6px}
.calc-summary .per-person .rline{font-size:.9rem}
.calc-card .share-row{margin-top:4px}
.calc-card .share-row button{background:var(--paper);border:1px solid var(--ink);
  color:var(--ink);border-radius:0;font-family:var(--mono);text-transform:uppercase;
  letter-spacing:.05em;font-size:.78rem;font-weight:600}
.calc-card .share-row button:hover{background:var(--soft)}
.calc-card #copyLink{background:var(--accent);border-color:var(--accent);color:#fff}
.calc-card #copyLink:hover{background:var(--accent-ink)}
/* advanced options live behind a native expander */
details.advanced{margin-top:14px;border-top:1px solid var(--line);padding-top:4px}
details.advanced summary{cursor:pointer;font-family:var(--mono);font-size:.78rem;
  font-weight:600;text-transform:uppercase;letter-spacing:.06em;color:var(--accent-ink);
  text-align:center;list-style:none;min-height:44px;padding:10px 0}
details.advanced summary::-webkit-details-marker{display:none}
details.advanced summary .hint{font-family:var(--serif);text-transform:none;
  letter-spacing:0;color:var(--muted);font-weight:400}
.adv-body{padding-top:6px}

/* ---------- why strip ---------- */
.why-grid{display:grid;grid-template-columns:1fr;gap:14px}
.why-grid b{display:block;margin-bottom:4px;font-size:1rem}
.why-grid small{color:var(--muted);font-size:.9rem}

/* ---------- FAQ ---------- */
details.faq{border:1px solid var(--ink);background:var(--paper);margin-bottom:10px;
  padding:0 16px;box-shadow:var(--shadow)}
details.faq summary{cursor:pointer;font-weight:600;padding:14px 0;list-style:none;min-height:48px}
details.faq summary::-webkit-details-marker{display:none}
details.faq summary:after{content:"+";float:right;color:var(--accent);font-weight:700;font-family:var(--mono)}
details.faq[open] summary:after{content:"–"}
details.faq p{margin:0 0 14px;color:var(--muted)}
details.faq p strong{color:var(--ink)}

/* ---------- category directory ---------- */
.cat-grid{display:grid;grid-template-columns:1fr;gap:14px}
.cat-card{border:1px solid var(--ink);border-top:3px solid var(--ink);background:var(--paper);
  padding:18px;box-shadow:var(--shadow)}
.cat-card h3{margin:0 0 4px;font-size:1.15rem;letter-spacing:-.01em}
.cat-card > p{margin:0 0 12px;color:var(--muted);font-size:.9rem}
.calc-list{list-style:none;margin:0;padding:0}
.calc-list li{display:flex;align-items:center;justify-content:space-between;gap:10px;
  padding:10px 0;border-top:1px solid var(--line)}
.calc-list a{font-weight:600;color:var(--accent-ink);text-decoration:none}
.calc-list a:hover{text-decoration:underline}
.calc-list small{display:block;color:var(--muted);font-weight:400}
.badge{font-size:.72rem;font-weight:600;text-transform:uppercase;letter-spacing:.05em;
  padding:4px 10px;white-space:nowrap;font-family:var(--mono);border:1px solid var(--ink)}
.badge.live{background:var(--green-soft);color:var(--green);border-color:var(--green)}
.badge.soon{background:var(--paper);color:var(--muted)}
.badge.guide{background:var(--amber-soft);color:var(--amber)}

/* ---------- guides teaser ---------- */
.guides-grid{display:grid;grid-template-columns:1fr;gap:12px}
.guides-grid a{display:block;border:1px solid var(--ink);border-top:3px solid var(--ink);
  padding:14px;background:var(--paper);text-decoration:none;color:var(--ink);box-shadow:var(--shadow)}
.guides-grid a:hover{border-top-color:var(--accent)}
.guides-grid b{display:block;margin-bottom:4px}
.guides-grid small{color:var(--muted)}

/* ---------- article (guide) pages ---------- */
.article{font-size:1.02rem}
.article h2{font-size:1.4rem;margin:1.8em 0 .6em;letter-spacing:-.02em;text-transform:none;color:var(--ink);font-family:var(--serif)}
.article h3{font-size:1.12rem;margin:1.4em 0 .5em;color:var(--ink)}
.article p{margin:0 0 1em;color:var(--muted)}
.article p strong,.article li strong{color:var(--ink)}
.article ul,.article ol{margin:0 0 1em;padding-left:1.4em;color:var(--muted)}
.article li{margin-bottom:.4em}
.answer-box{background:var(--paper);border:1px solid var(--ink);border-left:4px solid var(--accent);
  box-shadow:var(--shadow);padding:18px 20px;margin:0 0 8px;font-size:1.05rem}
.answer-box strong{color:var(--accent-ink)}
.calc-cta{display:flex;align-items:center;justify-content:space-between;gap:12px;
  background:var(--ink);color:var(--paper);padding:18px 20px;margin:20px 0;text-decoration:none}
.calc-cta b{font-size:1.05rem}
.calc-cta span{color:#ff8a74;font-weight:700;white-space:nowrap;font-family:var(--mono)}
.calc-cta small{display:block;color:#a3a8a3;font-weight:400}
.breadcrumb{font-size:.85rem;color:var(--muted);margin:18px 0 0;font-family:var(--mono)}
.breadcrumb a{color:var(--accent-ink);text-decoration:none}
/* data table — sharp, ink header, fits the system */
.data-table{width:100%;border-collapse:collapse;margin:14px 0;font-size:.93rem}
.data-table th{font-family:var(--mono);font-size:.7rem;text-transform:uppercase;letter-spacing:.06em;
  text-align:left;padding:10px 12px;background:var(--ink);color:var(--paper);border:1px solid var(--ink)}
.data-table td{padding:10px 12px;border:1px solid var(--line);vertical-align:top;color:var(--ink)}
.data-table td:last-child{font-family:var(--mono);font-weight:600;white-space:nowrap}
.subtle{margin:0;color:var(--muted)}
.more-link{margin:14px 0 0;font-size:.95rem}
.more-link a{color:var(--accent-ink);font-weight:600;text-decoration:none}

/* ---------- footer ---------- */
footer{border-top:1px solid var(--ink);margin-top:34px;padding:22px 0 40px;
  color:var(--muted);font-size:.88rem;text-align:center;background:var(--paper)}
.foot-nav{margin-bottom:12px}
.foot-nav a{color:var(--muted);text-decoration:none;margin:0 10px;font-size:.78rem;
  font-family:var(--mono);text-transform:uppercase;letter-spacing:.06em}
.foot-nav a:hover{color:var(--accent-ink)}
footer p{margin:0}

/* ---------- larger screens: gentle enhancements only ---------- */
@media(min-width:640px){
  .hero{padding:28px 0 4px}
  .card.masthead{padding:36px 24px}
  .hero h1{font-size:clamp(40px,6vw,58px)}
  .card{padding:22px;margin:22px 0}
  .field{margin:14px 0}
  .results{padding:22px;margin:22px 0}
  .tipgrid{grid-template-columns:repeat(6,1fr)}
  .cat-grid{grid-template-columns:1fr 1fr}
  .guides-grid{grid-template-columns:1fr 1fr}
  .why-grid{grid-template-columns:1fr 1fr}
  .item-row{grid-template-columns:1fr 110px 130px 44px}
}

/* ---------- dark mode (per strategy reference) ---------- */
@media (prefers-color-scheme: dark){
  :root{
    --bg:#111312; --paper:#181b19; --ink:#f2f0e9; --muted:#9aa09a;
    --line:#2b302c; --soft:#222724;
    --accent:#ff6b4f; --accent-ink:#ff8a74;
    --green:#5fce9d; --green-soft:#1c2f27;
    --blue:#6fb3d6; --amber:#d9a441; --amber-soft:#2c2517;
    --shadow:0 14px 34px rgba(0,0,0,.45);
  }
  header.site,footer{border-color:var(--line)}
  .card,.cat-card,.guides-grid a,details.faq{border-color:var(--line)}
  .card,.cat-card{border-top:3px solid var(--line)}
  .guides-grid a{border-top:3px solid var(--line)}
  .results{background:var(--soft)}
  .answer-box{background:var(--soft);border-color:var(--line)}
  .calc-cta{background:var(--soft)}
  .badge{border-color:var(--line)}
  input[type=text],input[type=number],select{background:var(--paper)}
}