/* ============================================================
   Split — supper-club tip calculator
   Palette: warm ivory paper, espresso ink, dining green, amber
   Type: Fraunces (display / numerals) + Hanken Grotesk (UI)
   ============================================================ */

:root {
  --paper:      #f6f0e4;
  --paper-2:    #efe7d6;
  --card:       #fffdf8;
  --card-line:  #e7dcc6;
  --ink:        #241d16;
  --ink-2:      #5b5044;
  --ink-3:      #8b7d6b;
  --green:      #1f6b4a;
  --green-deep: #164e37;
  --green-soft: #e4efe6;
  --amber:      #d98a26;
  --amber-soft: #f6e6c6;
  --tomato:     #c0492f;
  --focus:      #1f6b4a;

  --shadow-sm: 0 1px 2px rgba(43,33,20,.06), 0 2px 6px rgba(43,33,20,.05);
  --shadow-md: 0 4px 14px rgba(43,33,20,.08), 0 14px 40px rgba(43,33,20,.10);
  --shadow-lg: 0 10px 30px rgba(43,33,20,.10), 0 30px 70px rgba(43,33,20,.14);

  --r-lg: 22px;
  --r-md: 14px;
  --r-sm: 10px;

  --sp: 8px;
  --maxw: 1080px;

  --sans: "Hanken Grotesk", ui-sans-serif, system-ui, sans-serif;
  --serif: "Fraunces", ui-serif, Georgia, serif;
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 17px;
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}

/* soft warm gradient wash + paper grain */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -2;
  background:
    radial-gradient(1100px 600px at 82% -8%, rgba(217,138,38,.13), transparent 60%),
    radial-gradient(900px 620px at 6% 108%, rgba(31,107,74,.10), transparent 62%),
    var(--paper);
}
.grain {
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  opacity: .5;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='140' height='140'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.9' numOctaves='2' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='.35'/%3E%3C/svg%3E");
  mix-blend-mode: multiply;
}

::selection { background: var(--amber-soft); color: var(--ink); }

/* ---------- header ---------- */
.site-head {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 26px clamp(20px, 5vw, 44px) 8px;
  display: flex;
  align-items: baseline;
  gap: 18px;
  flex-wrap: wrap;
}
.brand {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  text-decoration: none;
  color: var(--ink);
}
.brand-mark { color: var(--green); display: inline-flex; }
.brand-word {
  font-family: var(--serif);
  font-weight: 560;
  font-size: 27px;
  letter-spacing: -.01em;
}
.head-tag {
  margin: 0;
  color: var(--ink-3);
  font-size: 14.5px;
  letter-spacing: .01em;
}

/* ---------- hero ---------- */
main { max-width: var(--maxw); margin: 0 auto; padding: 0 clamp(20px, 5vw, 44px); }

.hero {
  padding: clamp(30px, 6vw, 60px) 0 clamp(20px, 4vw, 34px);
  max-width: 40ch;
}
.eyebrow {
  font-size: 12.5px;
  text-transform: uppercase;
  letter-spacing: .16em;
  font-weight: 600;
  color: var(--green);
  margin: 0 0 16px;
}
.hero h1 {
  font-family: var(--serif);
  font-weight: 460;
  font-size: clamp(2.5rem, 6.4vw, 4.3rem);
  line-height: 1.02;
  letter-spacing: -.022em;
  margin: 0 0 20px;
}
.lede {
  font-size: clamp(1.02rem, 1.8vw, 1.2rem);
  color: var(--ink-2);
  max-width: 46ch;
  margin: 0;
}
.lede em { font-style: italic; color: var(--ink); }

/* ---------- calc layout ---------- */
.calc {
  display: grid;
  grid-template-columns: 1.05fr .95fr;
  gap: clamp(18px, 2.4vw, 26px);
  align-items: start;
  padding-bottom: clamp(40px, 7vw, 80px);
}
.card {
  background: var(--card);
  border: 1px solid var(--card-line);
  border-radius: var(--r-lg);
  box-shadow: var(--shadow-md);
}
.ledger { padding: clamp(22px, 3vw, 30px); }

/* ---------- fields ---------- */
.field { margin-bottom: 26px; }
.field:last-child { margin-bottom: 0; }
.field > label:not(.toggle-line),
.field-head label {
  display: block;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: .04em;
  text-transform: uppercase;
  color: var(--ink-2);
  margin-bottom: 10px;
}
.field-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  margin-bottom: 10px;
}
.field-head label { margin-bottom: 0; }
.tip-readout {
  font-family: var(--serif);
  font-weight: 500;
  font-size: 18px;
  color: var(--green);
  font-variant-numeric: tabular-nums;
}

/* money input */
.money-input {
  display: flex;
  align-items: center;
  background: var(--paper);
  border: 1.5px solid var(--card-line);
  border-radius: var(--r-md);
  padding: 4px 18px;
  transition: border-color .18s, box-shadow .18s, background .18s;
}
.money-input:focus-within {
  border-color: var(--green);
  background: #fff;
  box-shadow: 0 0 0 4px rgba(31,107,74,.12);
}
.money-input .cur {
  font-family: var(--serif);
  font-size: clamp(1.9rem, 4vw, 2.4rem);
  font-weight: 460;
  color: var(--ink-3);
  padding-right: 6px;
}
.money-input input {
  border: 0;
  background: none;
  outline: none;
  width: 100%;
  font-family: var(--serif);
  font-weight: 460;
  font-size: clamp(2rem, 5vw, 2.7rem);
  color: var(--ink);
  padding: 10px 0;
  font-variant-numeric: tabular-nums;
  letter-spacing: -.01em;
}
.money-input input::placeholder { color: #c9bda6; }
.hint { margin: 9px 2px 0; font-size: 13.5px; color: var(--ink-3); }

/* ---------- tip chips ---------- */
.chips {
  display: grid;
  grid-template-columns: repeat(4, 1fr) 1.15fr;
  gap: 9px;
}
.chip {
  font-family: var(--sans);
  font-size: 15.5px;
  font-weight: 600;
  color: var(--ink-2);
  background: var(--paper);
  border: 1.5px solid var(--card-line);
  border-radius: var(--r-md);
  padding: 13px 4px;
  cursor: pointer;
  transition: transform .12s, border-color .16s, background .16s, color .16s, box-shadow .16s;
  text-align: center;
}
.chip:hover { border-color: var(--green); color: var(--green); transform: translateY(-1px); }
.chip:active { transform: translateY(0); }
.chip.is-on {
  background: var(--green);
  border-color: var(--green);
  color: #fff;
  box-shadow: 0 6px 16px rgba(31,107,74,.24);
}
.chip-custom {
  display: flex;
  align-items: center;
  gap: 1px;
  padding: 0 12px;
  cursor: text;
}
.chip-custom:hover { transform: none; }
.chip-custom input {
  border: 0; background: none; outline: none;
  width: 100%;
  min-width: 0;
  font-family: var(--sans);
  font-size: 15.5px;
  font-weight: 600;
  color: var(--ink);
  text-align: center;
  padding: 13px 0;
}
.chip-custom input::placeholder { color: var(--ink-3); }
.chip-custom span { color: var(--ink-3); font-weight: 600; }
.chip-custom.is-on { background: var(--amber-soft); border-color: var(--amber); }
.chip-custom.is-on span,
.chip-custom.is-on input { color: var(--green-deep); }

/* ---------- toggle ---------- */
.toggle-line {
  display: flex;
  align-items: center;
  gap: 11px;
  margin-top: 16px;
  cursor: pointer;
  font-size: 14.5px;
  color: var(--ink-2);
  user-select: none;
}
.toggle-line input { position: absolute; opacity: 0; width: 0; height: 0; }
.switch {
  flex: none;
  width: 42px; height: 24px;
  border-radius: 20px;
  background: #ddd0b8;
  position: relative;
  transition: background .2s;
}
.switch::after {
  content: "";
  position: absolute;
  top: 3px; left: 3px;
  width: 18px; height: 18px;
  border-radius: 50%;
  background: #fff;
  box-shadow: 0 1px 3px rgba(0,0,0,.25);
  transition: transform .2s;
}
.toggle-line input:checked + .switch { background: var(--green); }
.toggle-line input:checked + .switch::after { transform: translateX(18px); }
.toggle-line input:focus-visible + .switch { box-shadow: 0 0 0 4px rgba(31,107,74,.22); }

/* ---------- segmented tabs ---------- */
.seg {
  display: flex;
  background: var(--paper);
  border: 1.5px solid var(--card-line);
  border-radius: var(--r-md);
  padding: 4px;
  gap: 4px;
  margin-bottom: 18px;
}
.seg-btn {
  flex: 1;
  font-family: var(--sans);
  font-size: 14.5px;
  font-weight: 600;
  color: var(--ink-2);
  background: none;
  border: 0;
  border-radius: 10px;
  padding: 11px 8px;
  cursor: pointer;
  transition: background .18s, color .18s, box-shadow .18s;
}
.seg-btn:hover { color: var(--ink); }
.seg-btn.is-on {
  background: var(--card);
  color: var(--green-deep);
  box-shadow: var(--shadow-sm);
}

.panel.is-hidden { display: none; }

/* stepper */
.stepper-row {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 6px 0 2px;
}
.stepper-label { font-size: 15px; color: var(--ink-2); }
.stepper-unit { font-size: 15px; color: var(--ink-3); }
.stepper {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  background: var(--paper);
  border: 1.5px solid var(--card-line);
  border-radius: 40px;
  padding: 4px;
}
.step-btn {
  width: 38px; height: 38px;
  border-radius: 50%;
  border: 0;
  background: var(--card);
  box-shadow: var(--shadow-sm);
  font-size: 22px;
  font-weight: 500;
  color: var(--green);
  cursor: pointer;
  display: grid;
  place-items: center;
  transition: transform .12s, background .16s, color .16s;
  line-height: 1;
}
.step-btn:hover { background: var(--green); color: #fff; }
.step-btn:active { transform: scale(.92); }
.step-btn:disabled { opacity: .35; cursor: not-allowed; background: var(--card); color: var(--ink-3); }
.count {
  font-family: var(--serif);
  font-size: 26px;
  font-weight: 500;
  min-width: 40px;
  text-align: center;
  font-variant-numeric: tabular-nums;
}

/* ---------- people list ---------- */
.panel-note { font-size: 14px; color: var(--ink-2); margin: 0 0 16px; max-width: 52ch; }
.people { display: flex; flex-direction: column; gap: 10px; }
.person {
  display: flex;
  align-items: center;
  gap: 10px;
  animation: slideIn .22s ease;
}
@keyframes slideIn { from { opacity: 0; transform: translateY(-4px); } to { opacity: 1; transform: none; } }
.person .p-name {
  flex: 1 1 auto;
  min-width: 0;
  font-family: var(--sans);
  font-size: 15.5px;
  font-weight: 500;
  color: var(--ink);
  background: var(--paper);
  border: 1.5px solid var(--card-line);
  border-radius: var(--r-sm);
  padding: 12px 14px;
  outline: none;
  transition: border-color .16s, box-shadow .16s, background .16s;
}
.person .p-amt-wrap {
  flex: 0 0 128px;
  display: flex;
  align-items: center;
  background: var(--paper);
  border: 1.5px solid var(--card-line);
  border-radius: var(--r-sm);
  padding: 0 12px;
  transition: border-color .16s, box-shadow .16s, background .16s;
}
.person .p-amt-wrap .cur { color: var(--ink-3); font-family: var(--serif); font-size: 17px; padding-right: 4px; }
.person .p-amt {
  width: 100%;
  min-width: 0;
  border: 0; background: none; outline: none;
  font-family: var(--serif);
  font-weight: 460;
  font-size: 17px;
  color: var(--ink);
  padding: 12px 0;
  text-align: right;
  font-variant-numeric: tabular-nums;
}
.person .p-name:focus,
.person .p-amt-wrap:focus-within {
  border-color: var(--green);
  background: #fff;
  box-shadow: 0 0 0 3px rgba(31,107,74,.12);
}
.p-remove {
  flex: none;
  width: 34px; height: 34px;
  border-radius: 50%;
  border: 1.5px solid transparent;
  background: none;
  color: var(--ink-3);
  cursor: pointer;
  font-size: 18px;
  display: grid; place-items: center;
  transition: background .16s, color .16s;
}
.p-remove:hover { background: #f2dcd4; color: var(--tomato); }
.p-remove:disabled { opacity: .25; cursor: not-allowed; }

.add-person {
  margin-top: 14px;
  width: 100%;
  font-family: var(--sans);
  font-size: 14.5px;
  font-weight: 600;
  color: var(--green);
  background: none;
  border: 1.5px dashed var(--card-line);
  border-radius: var(--r-md);
  padding: 12px;
  cursor: pointer;
  transition: border-color .16s, background .16s;
}
.add-person:hover { border-color: var(--green); background: var(--green-soft); }
.add-person span { font-size: 17px; }

.reconcile {
  margin: 14px 2px 0;
  font-size: 13.5px;
  min-height: 1.2em;
  color: var(--ink-3);
}
.reconcile.warn { color: var(--tomato); }
.reconcile.ok { color: var(--green); }

/* ============================================================
   RESULT RECEIPT
   ============================================================ */
.receipt {
  position: sticky;
  top: 20px;
  padding: 0;
  overflow: hidden;
  background:
    linear-gradient(180deg, var(--green-deep), var(--green));
  color: #f4efe2;
  border-color: var(--green-deep);
  box-shadow: var(--shadow-lg);
}
.receipt-perf {
  height: 12px;
  background:
    radial-gradient(circle at 10px -3px, transparent 6px, var(--card) 6.5px) repeat-x;
  background-size: 20px 12px;
  opacity: 0;
}
.receipt-top {
  padding: 30px clamp(22px, 3vw, 30px) 22px;
  text-align: center;
}
.receipt-kicker {
  margin: 0 0 6px;
  font-size: 12.5px;
  text-transform: uppercase;
  letter-spacing: .16em;
  font-weight: 600;
  color: rgba(244,239,226,.72);
}
.receipt-hero {
  margin: 0;
  font-family: var(--serif);
  font-weight: 460;
  font-size: clamp(3rem, 8vw, 4.4rem);
  line-height: 1;
  letter-spacing: -.02em;
  font-variant-numeric: tabular-nums;
  color: #fff;
}
.receipt-sub {
  margin: 10px 0 0;
  font-size: 14.5px;
  color: rgba(244,239,226,.82);
}

.tape {
  background: var(--card);
  color: var(--ink);
  margin: 0 clamp(14px, 2vw, 18px);
  border-radius: var(--r-md) var(--r-md) 0 0;
  padding: 18px clamp(16px, 2.4vw, 22px) 6px;
  position: relative;
}
.tape-row {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  font-size: 15px;
  padding: 7px 0;
  color: var(--ink-2);
}
.tape-row span:last-child { font-variant-numeric: tabular-nums; font-weight: 500; color: var(--ink); }
.tape-row.rule { padding: 0; border-top: 1.5px dashed var(--card-line); margin: 4px 0; }
.tape-row.total { padding-top: 12px; padding-bottom: 14px; }
.tape-row.total span { font-family: var(--serif); font-size: 21px; font-weight: 560; color: var(--ink); }

.breakdown {
  background: var(--card);
  color: var(--ink);
  margin: 0 clamp(14px, 2vw, 18px);
  padding: 0 clamp(16px, 2.4vw, 22px);
}
.breakdown:empty { display: none; }
.bd-row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 10px;
  padding: 11px 0;
  border-top: 1px solid var(--card-line);
  font-size: 15px;
}
.bd-row:first-child { border-top: 1.5px dashed var(--card-line); }
.bd-name { font-weight: 600; color: var(--ink); overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.bd-detail { font-size: 12.5px; color: var(--ink-3); font-weight: 500; }
.bd-amt { font-family: var(--serif); font-size: 18px; font-weight: 500; color: var(--green-deep); font-variant-numeric: tabular-nums; flex: none; }

.copy-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 9px;
  width: calc(100% - 2 * clamp(14px, 2vw, 18px));
  margin: clamp(16px, 2.4vw, 20px) clamp(14px, 2vw, 18px) clamp(18px, 2.6vw, 22px);
  padding: 15px;
  font-family: var(--sans);
  font-size: 15px;
  font-weight: 600;
  color: var(--green-deep);
  background: #fff;
  border: 0;
  border-radius: var(--r-md);
  cursor: pointer;
  box-shadow: var(--shadow-sm);
  transition: transform .12s, box-shadow .16s, background .16s;
}
.copy-btn:hover { transform: translateY(-1px); box-shadow: var(--shadow-md); background: #fffef9; }
.copy-btn:active { transform: translateY(0); }
.copy-btn.done { background: var(--amber-soft); color: var(--green-deep); }

/* ============================================================
   HOW section
   ============================================================ */
.how {
  padding: clamp(30px, 6vw, 72px) 0 clamp(20px, 5vw, 40px);
  border-top: 1px solid var(--card-line);
}
.how h2 {
  font-family: var(--serif);
  font-weight: 460;
  font-size: clamp(1.7rem, 4vw, 2.6rem);
  letter-spacing: -.02em;
  margin: 0 0 clamp(24px, 4vw, 40px);
  max-width: 22ch;
}
.how-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: clamp(16px, 2.4vw, 30px);
}
.how article {
  border-top: 2px solid var(--ink);
  padding-top: 18px;
}
.how-num {
  font-family: var(--serif);
  font-size: 15px;
  color: var(--amber);
  font-weight: 560;
  letter-spacing: .05em;
}
.how h3 {
  font-family: var(--serif);
  font-weight: 500;
  font-size: 1.32rem;
  margin: 10px 0 8px;
  letter-spacing: -.01em;
}
.how p { margin: 0; color: var(--ink-2); font-size: 15.5px; }

/* ============================================================
   Footer
   ============================================================ */
.site-foot {
  border-top: 1px solid var(--card-line);
  margin-top: clamp(20px, 4vw, 40px);
}
.foot-inner {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 32px clamp(20px, 5vw, 44px) 44px;
  display: flex;
  flex-direction: column;
  gap: 6px;
}
.foot-brand {
  font-family: var(--serif);
  font-weight: 560;
  font-size: 21px;
}
.foot-note { color: var(--ink-2); font-size: 15px; }
.foot-cred { color: var(--ink-3); font-size: 13.5px; }

/* ============================================================
   Toast
   ============================================================ */
.toast {
  position: fixed;
  left: 50%;
  bottom: 28px;
  transform: translate(-50%, 20px);
  background: var(--ink);
  color: var(--paper);
  padding: 12px 20px;
  border-radius: 40px;
  font-size: 14.5px;
  font-weight: 500;
  box-shadow: var(--shadow-lg);
  opacity: 0;
  pointer-events: none;
  transition: opacity .22s, transform .22s;
  z-index: 50;
}
.toast.show { opacity: 1; transform: translate(-50%, 0); }

/* ============================================================
   Responsive
   ============================================================ */
@media (max-width: 860px) {
  .calc { grid-template-columns: 1fr; }
  .receipt { position: static; }
  .hero { max-width: none; }
}

@media (max-width: 520px) {
  body { font-size: 16px; }
  .site-head { gap: 8px 14px; padding-top: 20px; }
  .head-tag { font-size: 13.5px; }
  .chips { grid-template-columns: repeat(3, 1fr); }
  .chip-custom { grid-column: span 3; }
  .how-grid { grid-template-columns: 1fr; gap: 4px; }
  .how article { border-top: none; padding-top: 0; padding-bottom: 20px; border-bottom: 1px solid var(--card-line); }
  .how article:last-child { border-bottom: none; }
  .person .p-amt-wrap { flex-basis: 108px; }
  .stepper-row { flex-wrap: wrap; gap: 10px 14px; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: .001ms !important;
    transition-duration: .001ms !important;
  }
}