/* =======================================================================
 * Domestic Bill Estimator — polished modern theme
 * Excel accent palette: blue #0F5AC8 / yellow #FFF073 / orange #FFC000
 *                       green #92D050 / grey #CDCDCF
 * ======================================================================= */

:root {
  --blue: #0F5AC8;
  --blue-d: #0c47a3;
  --yellow: #FFF073;
  --yellow-d: #e6db4a;
  --orange: #FFC000;
  --orange-d: #e6a800;
  --green: #92D050;
  --green-d: #76b034;
  --grey: #CDCDCF;
  --ink: #1b2330;
  --ink-2: #5a6473;
  --line: #e3e7ee;
  --bg: #f4f6fb;
  --card: #ffffff;
  --radius: 12px;
  --shadow: 0 1px 2px rgba(20,30,60,.06), 0 8px 24px rgba(20,30,60,.06);
  --font: "Inter", "Segoe UI", system-ui, -apple-system, Roboto, Arial, sans-serif;
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  font-family: var(--font);
  color: var(--ink);
  background: var(--bg);
  line-height: 1.4;
  -webkit-font-smoothing: antialiased;
}

/* ----------------------------- top bar ------------------------------- */
.topbar {
  position: sticky; top: 0; z-index: 20;
  display: flex; align-items: center; justify-content: space-between;
  gap: 16px; padding: 12px 20px;
  background: var(--blue);
  background: linear-gradient(135deg, var(--blue), var(--blue-d));
  color: #fff; box-shadow: 0 2px 12px rgba(12,40,90,.25);
}
.brand { display: flex; align-items: center; gap: 12px; }
.brand-logo { width: 40px; height: 40px; object-fit: contain; background: #fff; border-radius: 8px; padding: 4px; }
.topbar h1 { font-size: 1.05rem; margin: 0; font-weight: 700; letter-spacing: .2px; }
.subtitle { margin: 2px 0 0; font-size: .72rem; opacity: .85; }
.actions { display: flex; gap: 8px; }
.btn {
  font: inherit; font-weight: 600; font-size: .82rem;
  padding: 8px 14px; border-radius: 8px; border: 1px solid transparent;
  cursor: pointer; transition: transform .05s ease, background .15s ease;
}
.btn:active { transform: translateY(1px); }
.btn-ghost { background: rgba(255,255,255,.16); color: #fff; border-color: rgba(255,255,255,.35); }
.btn-ghost:hover { background: rgba(255,255,255,.28); }
.btn-primary { background: var(--yellow); color: #4a3b00; }
.btn-primary:hover { background: var(--yellow-d); }

/* ----------------------------- layout -------------------------------- */
.wrap { max-width: 1500px; margin: 0 auto; padding: 18px; }

.scenarios {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
}
@media (min-width: 1100px) {
  .scenarios { grid-template-columns: repeat(3, 1fr); }
}

/* ------------------------------ card --------------------------------- */
.card {
  background: var(--card);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  overflow: hidden;
  display: flex; flex-direction: column;
}
.card-head {
  background: linear-gradient(135deg, var(--blue), var(--blue-d));
  color: #fff; padding: 10px 16px; font-weight: 700; font-size: .95rem;
}
.card-body { padding: 14px 16px 16px; display: flex; flex-direction: column; gap: 10px; }

/* meta row (scheme + days) */
.meta { border: 0; margin: 0; padding: 0; display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
.field { display: flex; flex-direction: column; gap: 4px; font-size: .72rem; color: var(--ink-2); font-weight: 600; }
.field span { letter-spacing: .3px; text-transform: uppercase; }
.field input, .field select, input[type=number], select {
  font: inherit; font-size: .92rem; color: var(--ink);
  padding: 7px 9px; border: 1px solid var(--line); border-radius: 8px;
  background: #fff; width: 100%;
}
.field select { appearance: none; cursor: pointer; }
input[type=number]:focus, select:focus {
  outline: none; border-color: var(--blue); box-shadow: 0 0 0 3px rgba(15,90,200,.15);
}

/* section labels */
.section-label {
  display: flex; align-items: baseline; gap: 8px;
  font-size: .74rem; font-weight: 700; text-transform: uppercase; letter-spacing: .6px;
  margin-top: 4px; padding-bottom: 4px; border-bottom: 2px solid var(--line);
}
.inputs-label { color: var(--blue); border-color: rgba(15,90,200,.25); }
.outputs-label { color: var(--ink); }
.section-label .hint { font-weight: 500; text-transform: none; letter-spacing: 0; color: var(--ink-2); font-size: .68rem; }

/* inputs grid */
.grid-inputs { display: flex; flex-direction: column; gap: 6px; }
.grid-inputs label {
  display: grid; grid-template-columns: 1fr 92px 30px; align-items: center; gap: 8px;
  font-size: .82rem;
}
.grid-inputs label > span { color: var(--ink-2); }
.grid-inputs input { background: var(--yellow); border-color: var(--yellow-d); font-weight: 600; text-align: right; padding-right: 8px; }
.grid-inputs input::placeholder { color: #b3a73a; font-weight: 400; }
.grid-inputs i { font-style: normal; font-size: .72rem; color: var(--ink-2); }

/* outputs grid */
.grid-outputs { display: flex; flex-direction: column; gap: 1px; background: var(--line); border-radius: 8px; overflow: hidden; }
.out-row {
  display: grid; grid-template-columns: 88px 1fr 80px 30px; align-items: center; gap: 8px;
  padding: 6px 10px; background: #fff; font-size: .82rem;
}
.out-row .num { font-size: .66rem; color: var(--ink-2); font-family: ui-monospace, Menlo, monospace; }
.out-row .lbl { color: var(--ink); }
.out-row b { text-align: right; font-weight: 600; font-variant-numeric: tabular-nums; }
.out-row i { font-style: normal; font-size: .68rem; color: var(--ink-2); }
.out-row.sub { background: #fbfcfe; }
.out-row.sub .lbl { color: var(--ink-2); font-size: .78rem; }
.out-row.total-usage { background: var(--orange); }
.out-row.total-usage .num, .out-row.total-usage .lbl { color: #4a3500; font-weight: 700; }
.out-row.total-usage b { color: #4a3500; }

/* results */
.results {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 8px; margin-top: 6px;
}
.res {
  background: #f7f9fe; border: 1px solid var(--line); border-radius: 10px;
  padding: 10px 8px; text-align: center; display: flex; flex-direction: column; gap: 4px;
}
.res-lbl { font-size: .68rem; color: var(--ink-2); text-transform: uppercase; letter-spacing: .4px; font-weight: 600; }
.res-val { font-size: 1.15rem; font-weight: 700; font-variant-numeric: tabular-nums; }
.res i { font-style: normal; font-size: .65rem; color: var(--ink-2); }
.res-saving { background: var(--green); border-color: var(--green-d); }
.res-saving .res-lbl, .res-saving .res-val, .res-saving i { color: #1f3a06; }
.card.is-loss .res-saving { background: #ffb3b3; border-color: #e08080; }
.card.is-loss .res-saving .res-lbl, .card.is-loss .res-saving .res-val { color: #6b0f0f; }

/* =========================== diagram ================================= */
.diagram-wrap { margin-top: 20px; background: var(--card); border-radius: var(--radius); box-shadow: var(--shadow); overflow: hidden; }
.diagram-head {
  display: flex; align-items: center; justify-content: space-between; gap: 12px;
  padding: 12px 16px; border-bottom: 1px solid var(--line);
}
.diagram-head h2 { margin: 0; font-size: 1rem; }
.diagram-head .field { flex-direction: row; align-items: center; gap: 8px; }
.diagram-head .field select { width: auto; min-width: 70px; }

.diagram-scroll { overflow-x: auto; padding: 22px 16px; }
.diagram {
  display: grid;
  grid-template-columns: minmax(150px,1fr) minmax(320px,2.2fr) minmax(220px,1.5fr) minmax(200px,1.4fr);
  gap: 14px; align-items: start; min-width: 880px;
}

.node {
  border-radius: 10px; padding: 8px 10px; text-align: center;
  display: flex; flex-direction: column; gap: 2px; border: 2px solid transparent;
}
.node-cap { font-size: .68rem; font-weight: 700; line-height: 1.15; }
.node-cap small { font-weight: 500; opacity: .8; font-size: .6rem; }
.node-val { font-size: 1rem; font-weight: 800; font-variant-numeric: tabular-nums; }

.node-gen   { background: var(--yellow); border-color: var(--yellow-d); color: #4a3b00; }
.node-selco { background: var(--yellow); border-color: var(--yellow-d); color: #4a3b00; }
.node-imp   { background: var(--blue); border-color: var(--blue-d); color: #fff; }
.node-usage { background: var(--orange); border-color: var(--orange-d); color: #4a3500; }
.node.sum   { box-shadow: 0 2px 0 rgba(0,0,0,.08); }
.node-row { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; }

.branch { display: flex; flex-direction: column; gap: 8px; }
.branch-selco, .branch-export {
  border: 1px dashed var(--line); border-radius: 10px; padding: 10px; background: #fbfcfe;
}
.branch-export { margin-top: 10px; }
.flow-tag {
  font-size: .68rem; font-weight: 700; text-transform: uppercase; letter-spacing: .4px;
  color: var(--blue); text-align: center; padding: 3px 0;
}
.time-tags { display: grid; grid-template-columns: 1fr 1fr; gap: 6px; font-size: .62rem; color: var(--ink-2); text-align: center; margin-bottom: 4px; }
.time-tags span { background: #eef2fb; border-radius: 6px; padding: 3px 4px; }
.rule {
  font-size: .65rem; font-style: italic; text-align: center; color: var(--ink-2);
  background: #eef2fb; border-radius: 6px; padding: 4px; margin: 2px 0;
}
.gen-col, .usage-col { display: flex; flex-direction: column; gap: 8px; padding-top: 28px; }
.usage-col { align-items: stretch; }
.usage-col .node { width: 100%; }

/* simple arrow cues between columns (decorative) */
.diagram-scroll::before { content: ""; }

footer.note {
  margin-top: 16px; padding: 10px 14px; font-size: .7rem; color: var(--ink-2);
  background: #eef2fb; border-radius: 8px; text-align: center;
}

/* =========================== rates panel ============================= */
.rates {
  background: var(--card); border-radius: var(--radius); box-shadow: var(--shadow);
  margin-bottom: 16px; overflow: hidden;
}
.rates > summary {
  list-style: none; cursor: pointer; padding: 12px 16px; font-weight: 700; font-size: .9rem;
  color: var(--blue); display: flex; align-items: center; gap: 8px; user-select: none;
  border-bottom: 1px solid transparent;
}
.rates > summary::-webkit-details-marker { display: none; }
.rates > summary::before {
  content: "▸"; transition: transform .15s ease; font-size: .8rem; color: var(--ink-2);
}
.rates[open] > summary::before { transform: rotate(90deg); }
.rates[open] > summary { border-bottom-color: var(--line); }
.rates-body {
  padding: 14px 16px 16px; display: grid; gap: 16px;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); align-items: start;
}
.rate-group { border: 1px solid var(--line); border-radius: 10px; padding: 10px 12px 12px; margin: 0; }
.rate-group > legend {
  font-size: .72rem; font-weight: 700; text-transform: uppercase; letter-spacing: .4px;
  color: var(--ink-2); padding: 0 6px;
}
.rate-group label {
  display: flex; align-items: center; justify-content: space-between; gap: 8px;
  font-size: .8rem; padding: 4px 0; color: var(--ink);
}
.rate-group label input {
  width: 90px; text-align: right; font-weight: 600; background: var(--yellow); border-color: var(--yellow-d);
}
.rate-tbl { width: 100%; border-collapse: collapse; font-size: .8rem; }
.rate-tbl th, .rate-tbl td { padding: 5px 6px; text-align: center; }
.rate-tbl thead th { font-size: .68rem; color: var(--ink-2); font-weight: 600; border-bottom: 1px solid var(--line); }
.rate-tbl tbody td:first-child { text-align: left; color: var(--ink-2); }
.rate-tbl input {
  width: 72px; text-align: right; font-weight: 600; background: var(--yellow); border-color: var(--yellow-d);
  padding: 5px 6px;
}
.eei-head, .eei-row { display: grid; grid-template-columns: 1fr 70px 70px; gap: 6px; align-items: center; }
.eei-head { font-size: .66rem; color: var(--ink-2); text-transform: uppercase; letter-spacing: .3px; padding: 0 2px 4px; border-bottom: 1px solid var(--line); margin-bottom: 2px; }
.eei-row { padding: 2px 0; }
.eei-band { font-size: .72rem; color: var(--ink-2); font-variant-numeric: tabular-nums; }
.eei-row input { width: 100%; text-align: right; font-weight: 600; background: var(--yellow); border-color: var(--yellow-d); padding: 4px 5px; font-size: .8rem; }
.rates-actions { grid-column: 1 / -1; display: flex; justify-content: flex-end; }

/* ============================ print ================================== */
@page { size: A4 landscape; margin: 12mm; }
@media print {
  body { background: #fff; }
  .no-print { display: none !important; }
  .wrap { max-width: none; padding: 0; }
  .scenarios { grid-template-columns: repeat(3, 1fr); gap: 8px; }
  .card, .diagram-wrap { box-shadow: none; border: 1px solid var(--line); break-inside: avoid; }
  .card-body { padding: 8px 10px; }
  .grid-inputs input { background: var(--yellow) !important; -webkit-print-color-adjust: exact; print-color-adjust: exact; }
  * { -webkit-print-color-adjust: exact; print-color-adjust: exact; }
}

/* ---------- small screens: tighten ------------------------------- */
@media (max-width: 560px) {
  .topbar { flex-wrap: wrap; padding: 10px 12px; }
  .topbar h1 { font-size: .92rem; }
  .wrap { padding: 12px; }
  .out-row { grid-template-columns: 70px 1fr 70px 26px; font-size: .78rem; gap: 6px; padding: 5px 8px; }
  .grid-inputs label { grid-template-columns: 1fr 78px 28px; }
  .res-val { font-size: 1rem; }
}