/**
 * BTU Calculator Stylesheet - Light Theme matching cheap-radiator.co.uk
 * Place at: catalog/view/theme/default/stylesheet/btu_calculator.css
 * UPDATED: Larger fonts, improved color contrast, fully readable on all backgrounds
 */

@import url('https://fonts.googleapis.com/css2?family=Rajdhani:wght@400;500;600;700&family=Exo+2:wght@300;400;500;600;700&display=swap');

/* ══ ROOT VARS — Light theme matching site ══ */
.btu-app {
  --bg: #f0f4f5;
  --panel: #ffffff;
  --panel2: #eaf3f3;
  --border: #b8d8d7;
  --border2: #89bfbe;
  --teal: #007a75;
  --teal2: #009d97;
  --teal-dim: #d4eeec;
  --teal-glow: rgba(0,122,117,.15);
  --teal-dark: #005a56;
  --text: #111e1e;
  --muted: #3a5a59;
  --light-text: #527170;
  --active-bg: rgba(0,122,117,.10);
  --active-border: #007a75;
  --r: 8px;
  --font-head: 'Rajdhani', sans-serif;
  --font-body: 'Exo 2', sans-serif;

  font-family: var(--font-body);
  background: var(--bg);
  color: var(--text);
  padding: 24px 16px 60px;
  border-radius: 12px;
}

/* ══ HEADER ══ */
.btu-header {
  text-align: center;
      max-width: 800px;
    margin: 0 auto;
  padding: 36px 24px 32px;
  border-bottom: 2px solid var(--border);
  margin-bottom: 24px;
  background: var(--panel);
  border-radius: var(--r);
  box-shadow: 0 2px 10px rgba(0,0,0,.08);
}
.btu-header-badge {
  display: inline-flex; align-items: center; gap: 8px;
  background: var(--teal); border: 1px solid var(--teal-dark);
  border-radius: 20px; padding: 5px 18px;
  font-size: 14px; font-family: var(--font-head); letter-spacing: 2px;
  color: #ffffff; text-transform: uppercase; margin-bottom: 16px;
  font-weight: 700;
}
.btu-header h1 {
  font-family: var(--font-head);
  font-size: clamp(1.9rem, 4.5vw, 2.6rem);
  font-weight: 700; letter-spacing: 1px;
  color: var(--text);
  margin: 0;
}
.btu-header h1 span { color: var(--teal); }
.btu-header p {
  font-size: 14px;
  color: var(--muted);
  margin-top: 10px;
  font-weight: 500;
}

/* ══ STEPS NAV ══ */
.btu-steps-nav {
      max-width: 800px;
    margin: 0 auto;

  display: flex; align-items: center;
  background: var(--panel); border: 1.5px solid var(--border);
  border-radius: var(--r); padding: 14px 18px;
  margin-bottom: 22px; gap: 0; overflow-x: auto;
  box-shadow: 0 1px 5px rgba(0,0,0,.06);
}
.btu-step-item {
  display: flex; align-items: center; gap: 8px;
  padding: 8px 16px; border-radius: 6px;
  font-family: var(--font-head); font-size: 14px; letter-spacing: .5px;
  font-weight: 700; cursor: pointer; white-space: nowrap;
  color: #7a9a99; transition: all .2s;
  border: 1.5px solid transparent;
}
.btu-step-item.active {
  background: var(--teal-dim);
  border-color: var(--teal);
  color: var(--teal-dark);
}
.btu-step-item.done { color: var(--teal2); }
.btu-step-sep { color: var(--border2); padding: 0 6px; font-size: .9rem; font-weight: 700; }

/* ══ STEP PANELS ══ */
.btu-step-panel { max-width: 800px; margin: 0 auto; }

/* ══ CARD ══ */
.btu-card {
  background: var(--panel);
  border: 1.5px solid var(--border);
  border-radius: var(--r);
  overflow: hidden;
  margin-bottom: 16px;
  box-shadow: 0 2px 10px rgba(0,0,0,.06);
}
.btu-card-head {
  display: flex; align-items: center; gap: 12px;
  padding: 16px 22px;
  border-bottom: 1.5px solid var(--border);
  background: linear-gradient(90deg, var(--teal-dim) 0%, #ffffff 100%);
}
.btu-card-num {
  width: 32px; height: 32px; border-radius: 50%;
  background: var(--teal); color: #fff;
  font-family: var(--font-head); font-size: 1.05rem; font-weight: 700;
  display: flex; align-items: center; justify-content: center; flex-shrink: 0;
  box-shadow: 0 0 12px rgba(0,122,117,.35);
}
.btu-card-head h2 {
  font-family: var(--font-head); font-size: 1.15rem;
  font-weight: 700; letter-spacing: .8px; color: var(--text); margin: 0;
}
.btu-card-body { padding: 22px; }

/* ══ SLIDERS ══ */
.btu-slider-group { display: grid; gap: 18px; }
.btu-slider-row { display: grid; grid-template-columns: 100px 1fr 110px; align-items: center; gap: 16px; }
.btu-slider-label {
  font-family: var(--font-head); font-size: 14px;
  letter-spacing: .5px; color: var(--muted); font-weight: 700;
}
.btu-app input[type=range] {
  -webkit-appearance: none; appearance: none;
  width: 100%; height: 6px;
  background: var(--border); border-radius: 3px; cursor: pointer; outline: none;
}
.btu-app input[type=range]::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 22px; height: 22px; border-radius: 50%;
  background: var(--teal); border: 2.5px solid #fff;
  box-shadow: 0 2px 8px rgba(0,122,117,.45); cursor: pointer;
}
.btu-slider-val {
  display: flex; align-items: center; gap: 5px;
  background: var(--panel2); border: 2px solid var(--border2);
  border-radius: 6px; padding: 8px 12px;
}
.btu-slider-val input[type=number] {
  background: transparent; border: none; outline: none;
  color: var(--text); font-family: var(--font-head); font-size: 1.15rem; font-weight: 700;
  width: 52px; text-align: right;
  -moz-appearance: textfield;
}
.btu-slider-val input[type=number]::-webkit-inner-spin-button { -webkit-appearance: none; }
.btu-slider-val span { color: var(--muted); font-size: .9rem; font-family: var(--font-head); font-weight: 600; }

/* ══ ROOM VIZ ══ */
.btu-room-viz {
  display: flex; align-items: center; justify-content: center;
  min-height: 170px; background: var(--panel2);
  border-radius: var(--r); border: 1.5px solid var(--border);
}

/* ══ TILES ══ */
.btu-tiles { display: flex; gap: 10px; flex-wrap: wrap; }
.btu-tile {
  flex: 1; min-width: 75px;
  padding: 14px 10px;
  background: var(--panel2); border: 2px solid var(--border);
  border-radius: var(--r); cursor: pointer;
  text-align: center; transition: all .18s;
}
.btu-tile:hover { border-color: var(--teal2); background: var(--teal-dim); }
.btu-tile.selected {
  border-color: var(--teal);
  background: var(--teal-dim);
  box-shadow: 0 0 0 3px var(--teal-glow);
}
.btu-tile-icon  { font-size: 1.7rem; line-height: 1; margin-bottom: 7px; }
.btu-tile-label {
  font-family: var(--font-head); font-size: 14px;
  font-weight: 700; letter-spacing: .3px; color: var(--text); line-height: 1.3;
}
.btu-tile-sub { font-size: 10px; color: var(--muted); font-family: var(--font-head); margin-top: 3px; font-weight: 600; }
.btu-tile.selected .btu-tile-label { color: var(--teal-dark); }
.btu-tile.selected .btu-tile-sub   { color: var(--teal); }

/* ══ PILLS ══ */
.btu-tier-pills { display: flex; gap: 10px; }
.btu-pill {
  flex: 1; padding: 14px 10px;
  background: var(--panel2); border: 2px solid var(--border);
  border-radius: 6px; cursor: pointer; text-align: center; transition: all .18s;
}
.btu-pill:hover { border-color: var(--teal2); background: var(--teal-dim); }
.btu-pill.selected {
  background: var(--teal-dim); border-color: var(--teal);
  box-shadow: 0 0 0 3px var(--teal-glow);
}
.btu-pill-label { font-family: var(--font-head); font-size: 14px; font-weight: 700; color: var(--text); }
.btu-pill.selected .btu-pill-label { color: var(--teal-dark); }
.btu-pill-val { font-size: .8rem; color: var(--muted); font-family: var(--font-head); margin-top: 4px; font-weight: 600; }

/* ══ SELECTS ══ */
.btu-row2 { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.btu-field-label {
  font-family: var(--font-head); font-size: 14px;
  letter-spacing: .5px; color: var(--text); font-weight: 700;
  margin-bottom: 8px; text-transform: uppercase;
}
.btu-field-note { font-size: 12px; color: var(--muted); margin-top: 7px; font-weight: 500; }
.btu-sel-wrap { position: relative; }
.btu-sel-wrap::after {
  content: '▾'; position: absolute; right: 13px; top: 50%;
  transform: translateY(-50%); pointer-events: none;
  color: var(--teal); font-size: 12px;
}
select.btu-sel {
  width: 100%; padding: 11px 36px 11px 14px;
  background: var(--panel2); border: 2px solid var(--border2);
  border-radius: 6px; color: var(--text);
  font-family: var(--font-body); font-size: 14px; font-weight: 500;
  cursor: pointer; appearance: none; -webkit-appearance: none; outline: none;
}
select.btu-sel:focus { border-color: var(--teal); box-shadow: 0 0 0 3px var(--teal-glow); }

/* ══ BUTTONS ══ */
.btu-next-btn {
  padding: 15px 30px;
  background: var(--teal);
  color: #ffffff; border: none; border-radius: var(--r);
  font-family: var(--font-head); font-size: 14px; font-weight: 700;
  letter-spacing: 1px; cursor: pointer;
  box-shadow: 0 4px 14px rgba(0,122,117,.35);
  transition: all .2s;
}
.btu-next-btn:hover {
  background: var(--teal-dark);
  transform: translateY(-1px);
  box-shadow: 0 6px 20px rgba(0,122,117,.45);
}
.btu-back-btn {
  padding: 15px 22px;
  background: transparent; color: var(--muted);
  border: 2px solid var(--border2); border-radius: var(--r);
  font-family: var(--font-head); font-size: 14px; letter-spacing: .5px;
  font-weight: 600; cursor: pointer; transition: all .2s;
}
.btu-back-btn:hover { color: var(--teal); border-color: var(--teal); }

/* ══ RESET LINK ══ */
.btu-reset-link {
  background: none; border: none; cursor: pointer;
  color: var(--muted); font-family: var(--font-head);
  font-size: .88rem; font-weight: 600; text-decoration: underline;
  padding: 0; margin-top: 6px;
}
.btu-reset-link:hover { color: var(--teal); }

/* ══ ERROR ══ */
.btu-error-msg {
  color: #9b1c1c; font-size: .9rem; font-family: var(--font-head); font-weight: 600;
  padding: 12px 16px; background: #fde8e8;
  border: 1.5px solid #f5c0c0; border-radius: 6px;
  display: none; margin-top: 10px;
}
.btu-error-msg.show { display: block; }

/* ══ RESULT BOX (Step 4) ══ */
.btu-result-box {
  background: var(--panel);
  border: 2px solid var(--teal);
  border-radius: var(--r);
  overflow: hidden;
  box-shadow: 0 4px 20px rgba(0,122,117,.15);
}
.btu-result-header {
  background: var(--teal);
  padding: 16px 22px;
  display: flex; align-items: center; gap: 12px;
}
.btu-result-header h3 {
  font-family: var(--font-head); font-size: 14px;
  font-weight: 700; letter-spacing: 1px; color: #ffffff; margin: 0;
}
.btu-result-body {
  padding: 26px 22px;
  display: grid; grid-template-columns: 1fr 1fr; gap: 0;
  background: var(--teal-dim);
}
.btu-result-metric {
  padding: 18px 22px; border-right: 1.5px solid var(--border);
}
.btu-result-metric:last-child { border-right: none; }
.btu-metric-label {
  font-family: var(--font-head); font-size: 12px;
  letter-spacing: 1px; color: var(--muted); font-weight: 700;
  text-transform: uppercase; margin-bottom: 8px;
}
.btu-metric-value {
  font-family: var(--font-head);
  font-size: clamp(1.7rem, 3.5vw, 2.3rem);
  font-weight: 700; color: var(--teal-dark); line-height: 1;
}
.btu-metric-unit {
  font-size: .85rem; color: var(--muted); font-weight: 600;
  font-family: var(--font-head); margin-top: 5px;
}

/* ══ REDIRECT LINK BUTTON ══ */
.btu-redirect-section {
  padding: 22px;
  background: #ffffff;
  border-top: 1.5px solid var(--border);
  text-align: center;
}
.btu-redirect-section p {
  font-size: 12px; color: var(--muted); font-weight: 600;
  font-family: var(--font-head); margin-bottom: 16px;
}
.btu-match-btn {
  display: inline-flex; align-items: center; gap: 10px;
  padding: 17px 34px;
  background: var(--teal);
  color: #ffffff;
  border: none; border-radius: var(--r);
  font-family: var(--font-head); font-size: 14px; font-weight: 700;
  letter-spacing: 1px; cursor: pointer; text-decoration: none;
  box-shadow: 0 4px 16px rgba(0,122,117,.38);
  transition: all .2s;
}
.btu-match-btn:hover {
  background: var(--teal-dark); color: #ffffff;
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(0,122,117,.48);
  text-decoration: none;
}
.btu-match-btn svg { width: 20px; height: 20px; flex-shrink: 0; }
.btu-match-btn-url {
  font-size: 12px; color: var(--muted); font-weight: 600;
  font-family: monospace; margin-top: 10px;
  word-break: break-all;
}

/* ══ BREAKDOWN ══ */
.btu-breakdown {
  background: var(--panel); border: 1.5px solid var(--border);
  border-radius: var(--r); overflow: hidden; margin-top: 14px;
}
.btu-breakdown summary {
  padding: 12px 18px; cursor: pointer;
  font-family: var(--font-head); font-size: 14px;
  letter-spacing: .8px; color: var(--teal); font-weight: 700;
  user-select: none;
}
.btu-breakdown-table { width: 100%; border-collapse: collapse; font-size: 14px; }
.btu-breakdown-table td {
  padding: 10px 18px; border-top: 1.5px solid var(--border);
  font-family: var(--font-head); color: var(--muted); font-weight: 600;
}
.btu-breakdown-table td:last-child { text-align: right; color: var(--teal-dark); font-weight: 700; }

/* ══ RESPONSIVE ══ */
@media(max-width:600px) {
  .btu-slider-row  { grid-template-columns: 80px 1fr 90px; }
  .btu-row2        { grid-template-columns: 1fr; }
  .btu-result-body { grid-template-columns: 1fr; }
  .btu-result-metric { border-right: none; border-bottom: 1.5px solid var(--border); }
  .btu-steps-nav   { padding: 8px; }
  .btu-step-item   { padding: 6px 10px; font-size: .8rem; }
  .btu-tier-pills  { flex-direction: column; }
}