:root {
  --bg: #f0f2f5;
  --panel: #fff;
  --border: #d5dae0;
  --accent: #8B5E3C;
  --accent2: #6B3F1F;
  --accent-light: #f5ece4;
  --text: #2d3436;
  --muted: #636e72;
  --input-bg: #f7f9fb;
  --success: #1a7a52;
  --danger: #b93030;
  --header-bg: #2d3436;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

body {
  background: var(--bg);
  color: var(--text);
  font-family: 'Barlow', sans-serif;
  min-height: 100vh;
  -webkit-user-select: none;
  user-select: none;
}

/* ─── HEADER ─── */
header {
  background: var(--header-bg);
  border-bottom: 3px solid var(--accent);
  padding: 0 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 62px;
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 2px 12px rgba(0,0,0,.25);
}
.logo {
  font-family: 'Barlow Condensed', sans-serif;
  font-weight: 900;
  font-size: 24px;
  letter-spacing: 2px;
  color: #f5a623;
  text-transform: uppercase;
}
.logo span { color: #fff; }
.logo-plus { font-size: 18px; color: #dfe6e9; font-weight: 700; }
.logo-sub {
  font-size: 10px;
  letter-spacing: 4px;
  color: #8899aa;
  text-transform: uppercase;
  margin-top: 1px;
}
.badge {
  background: var(--accent2);
  color: #fff;
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 2px;
  padding: 4px 10px;
  text-transform: uppercase;
  border-radius: 2px;
}
.header-controls { display: flex; align-items: center; gap: 10px; }
.country-toggle { display: flex; gap: 5px; }
.country-btn {
  padding: 6px 12px;
  background: transparent;
  border: 1px solid #444;
  color: #888;
  font-family: 'Barlow Condensed', sans-serif;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 1px;
  cursor: pointer;
  border-radius: 4px;
  transition: all .15s;
}
.country-btn.active { background: var(--accent); border-color: var(--accent); color: #fff; }
.country-btn:hover:not(.active) { border-color: var(--accent); color: var(--accent); }

/* ─── LAYOUT ─── */
.wrap {
  max-width: 700px;
  margin: 0 auto;
  padding: 16px 12px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

/* ─── TABS ─── */
.tab-row { display: flex; gap: 8px; }
.tab-btn {
  flex: 1;
  padding: 14px;
  background: var(--panel);
  border: 2px solid var(--accent);
  color: var(--accent);
  font-family: 'Barlow Condensed', sans-serif;
  font-size: 16px;
  font-weight: 700;
  letter-spacing: 2px;
  text-transform: uppercase;
  cursor: pointer;
  border-radius: 8px;
  transition: all .15s;
}
.tab-btn.active {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
  box-shadow: 0 2px 8px rgba(139,94,60,.3);
}
.tab-content { display: none; }
.tab-content.active { display: block; }

/* ─── CARDS ─── */
.card {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 20px;
  position: relative;
  overflow: hidden;
  box-shadow: 0 1px 6px rgba(0,0,0,.06);
  margin-bottom: 14px;
}
.card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--accent), var(--accent2));
}
.card-title {
  font-family: 'Barlow Condensed', sans-serif;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 3px;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 16px;
  display: flex;
  align-items: center;
  gap: 7px;
}

/* ─── SHAPE PICKER ─── */
.shape-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 8px;
}
@media(max-width:500px) { .shape-grid { grid-template-columns: repeat(2, 1fr); } }

.shape-btn {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  padding: 12px 6px;
  background: var(--input-bg);
  border: 2px solid var(--border);
  border-radius: 8px;
  cursor: pointer;
  transition: all .15s;
  color: var(--muted);
}
.shape-btn svg {
  width: 48px;
  height: 36px;
}
.shape-btn span {
  font-family: 'Barlow Condensed', sans-serif;
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 1px;
  text-transform: uppercase;
}
.shape-btn.active {
  border-color: var(--accent);
  background: var(--accent-light);
  color: var(--accent);
}
.shape-btn:hover:not(.active) {
  border-color: var(--accent);
}

/* ─── SHAPE DIAGRAM ─── */
.shape-diagram {
  background: #f7f9fb;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 16px;
  margin-bottom: 16px;
  display: flex;
  justify-content: center;
  min-height: 200px;
}
.shape-diagram svg {
  max-width: 100%;
  max-height: 220px;
}

/* ─── DIMENSION INPUTS ─── */
.dim-inputs {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
}
.section-name-row {
  display: flex;
  flex-direction: column;
  gap: 5px;
  margin-bottom: 14px;
}
.section-name-row input {
  background: var(--input-bg);
  border: 1.5px solid var(--border);
  color: var(--text);
  font-family: 'Barlow Condensed', sans-serif;
  font-size: 17px;
  font-weight: 600;
  padding: 9px 12px;
  border-radius: 6px;
  width: 100%;
  outline: none;
  transition: border-color .2s, box-shadow .2s;
}
.section-name-row input:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(139,94,60,.1);
}

/* ─── FORM FIELDS ─── */
.field-row { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; margin-bottom: 12px; }
.field-row-3 { display: grid; grid-template-columns: 1fr 1fr 1fr; gap: 10px; margin-bottom: 12px; }
.field { display: flex; flex-direction: column; gap: 5px; }

label {
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 1.5px;
  text-transform: uppercase;
  color: var(--muted);
}
label em { font-style: normal; color: var(--accent); }

input[type=number], select {
  background: var(--input-bg);
  border: 1.5px solid var(--border);
  color: var(--text);
  font-family: 'Barlow Condensed', sans-serif;
  font-size: 18px;
  font-weight: 600;
  padding: 10px 12px;
  border-radius: 6px;
  width: 100%;
  outline: none;
  transition: border-color .2s, box-shadow .2s;
  -moz-appearance: textfield;
}
input[type=number]::-webkit-inner-spin-button,
input[type=number]::-webkit-outer-spin-button { -webkit-appearance: none; }
input[type=number]:focus, select:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(139,94,60,.1);
  background: #fff;
}

.divider {
  display: flex;
  align-items: center;
  gap: 8px;
  margin: 10px 0;
  color: var(--muted);
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 2px;
  text-transform: uppercase;
}
.divider::before, .divider::after {
  content: '';
  flex: 1;
  height: 1px;
  background: var(--border);
}

/* ─── BUTTONS ─── */
.go {
  width: 100%;
  padding: 14px;
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  border: none;
  color: #fff;
  font-family: 'Barlow Condensed', sans-serif;
  font-size: 16px;
  font-weight: 900;
  letter-spacing: 3px;
  text-transform: uppercase;
  cursor: pointer;
  border-radius: 6px;
  margin-top: 8px;
  box-shadow: 0 2px 10px rgba(139,94,60,.25);
  transition: opacity .2s;
}
.go:hover { opacity: .9; }

.rst {
  width: 100%;
  padding: 8px;
  margin-top: 7px;
  background: transparent;
  border: 1px solid var(--border);
  color: var(--muted);
  font-family: 'Barlow Condensed', sans-serif;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 2px;
  text-transform: uppercase;
  cursor: pointer;
  border-radius: 6px;
  transition: all .15s;
}
.rst:hover { border-color: var(--accent); color: var(--accent); }

.save-btn {
  width: 100%;
  padding: 12px;
  margin-top: 14px;
  background: linear-gradient(135deg, #1a7a52, #145a3c);
  border: none;
  color: #fff;
  font-family: 'Barlow Condensed', sans-serif;
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 2px;
  text-transform: uppercase;
  cursor: pointer;
  border-radius: 6px;
  box-shadow: 0 2px 8px rgba(26,122,82,.25);
  transition: opacity .2s;
}
.save-btn:hover { opacity: .9; }

/* ─── RESULTS / SUMMARY ─── */
.row2 { display: grid; grid-template-columns: 340px 1fr; gap: 16px; }
@media(max-width:760px) { .row2 { grid-template-columns: 1fr; } }

#stairResultsPanel { display: none; }
#stairResultsPanel.show { display: block; }

.sum-grid { display: grid; grid-template-columns: repeat(4,1fr); gap: 8px; margin-bottom: 14px; }
@media(max-width:700px) {
  .sum-grid { grid-template-columns: repeat(2,1fr); }
  .slabel { font-size: 8px; letter-spacing: 1px; }
  .sval { font-size: 18px; }
}

.scard {
  background: var(--input-bg);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 10px 12px;
  position: relative;
}
.scard.hi { border-color: var(--accent); background: var(--accent-light); }

.slabel { font-size: 9px; font-weight: 700; letter-spacing: 2px; text-transform: uppercase; color: var(--muted); margin-bottom: 4px; }
.sval { font-family: 'Barlow Condensed', sans-serif; font-size: 22px; font-weight: 700; color: var(--text); line-height: 1; }
.sval.ac { color: var(--accent); }
.smm { font-family: 'Barlow Condensed', sans-serif; font-size: 11px; color: var(--muted); margin-top: 2px; }
.ssub { font-size: 10px; color: var(--muted); margin-top: 3px; }

.ctag {
  position: absolute;
  top: 8px; right: 8px;
  font-size: 8px;
  letter-spacing: 1.5px;
  text-transform: uppercase;
  font-weight: 700;
  padding: 2px 5px;
  border-radius: 2px;
  background: rgba(26,122,82,.1);
  color: var(--success);
  border: 1px solid rgba(26,122,82,.25);
}
.ctag.w { background: rgba(185,48,48,.08); color: var(--danger); border-color: rgba(185,48,48,.25); }

/* ─── NOTES / WARNINGS ─── */
.note {
  font-size: 11px;
  color: var(--muted);
  line-height: 1.6;
  padding: 10px 14px;
  background: var(--input-bg);
  border-radius: 6px;
  border: 1px solid var(--border);
}
.warn-box {
  background: #fff5f5;
  border: 1px solid rgba(185,48,48,.3);
  border-radius: 6px;
  padding: 10px 14px;
  font-size: 12px;
  color: var(--danger);
  display: none;
  line-height: 1.6;
  margin-bottom: 12px;
}
.warn-box.show { display: block; }

/* ─── PARTS TABLE ─── */
.parts-table { width: 100%; border-collapse: collapse; font-size: 13px; }
.parts-table th {
  font-family: 'Barlow Condensed', sans-serif;
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: var(--muted);
  text-align: left;
  padding: 6px 10px;
  border-bottom: 2px solid var(--border);
}
.parts-table td { padding: 8px 10px; border-bottom: 1px solid var(--border); vertical-align: top; }
.parts-table tr:last-child td { border-bottom: none; }
.parts-table tr:nth-child(even) td { background: var(--input-bg); }
.part-name { font-family: 'Barlow Condensed', sans-serif; font-size: 14px; font-weight: 700; color: var(--text); }
.part-dim { font-family: 'Barlow Condensed', sans-serif; font-size: 13px; font-weight: 600; color: var(--accent); }

/* ─── DIAGRAM ─── */
.diag-wrap {
  background: #f0f3f8;
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 10px;
  overflow-x: auto;
}
svg#stairSvg { display: block; width: 100%; max-width: 900px; margin: 0 auto; height: auto; }

/* ─── DECK SECTIONS LIST ─── */
.deck-section-item {
  background: var(--input-bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 14px;
  margin-bottom: 10px;
  position: relative;
}
.deck-section-item .section-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 8px;
}
.deck-section-item .section-title {
  font-family: 'Barlow Condensed', sans-serif;
  font-size: 16px;
  font-weight: 700;
  color: var(--accent);
  letter-spacing: 1px;
  text-transform: uppercase;
}
.deck-section-item .section-shape {
  font-size: 11px;
  color: var(--muted);
  letter-spacing: 1px;
  text-transform: uppercase;
}
.deck-section-item .section-dims {
  font-size: 13px;
  color: var(--text);
  line-height: 1.6;
}
.deck-section-item .section-area {
  font-family: 'Barlow Condensed', sans-serif;
  font-size: 18px;
  font-weight: 700;
  color: var(--success);
  margin-top: 6px;
}
.section-delete {
  background: var(--danger);
  color: #fff;
  border: none;
  padding: 4px 10px;
  border-radius: 4px;
  cursor: pointer;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 1px;
}
.section-delete:hover { opacity: .8; }

/* ─── MATERIALS LIST ─── */
.mat-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 8px 0;
  border-bottom: 1px solid var(--border);
  font-size: 14px;
}
.mat-row:last-child { border-bottom: none; }
.mat-label {
  font-family: 'Barlow Condensed', sans-serif;
  font-weight: 600;
  color: var(--text);
  letter-spacing: 0.5px;
}
.mat-val {
  font-family: 'Barlow Condensed', sans-serif;
  font-weight: 700;
  color: var(--accent);
  font-size: 16px;
}

/* ─── ADS ─── */
.ad-banner {
  background: linear-gradient(135deg, #2a2a2a, #1a1a1a);
  border: 1px dashed #444;
  color: #888;
  text-align: center;
  padding: 12px;
  font-size: 11px;
  letter-spacing: 2px;
  text-transform: uppercase;
}
.ad-top { margin-bottom: 0; }
.ad-bottom {
  margin-top: 20px;
  padding: 16px;
  background: linear-gradient(135deg, #2d3436, #1a1a1a);
  border-color: var(--accent);
}

/* ─── FOOTER ─── */
.app-footer {
  background: var(--header-bg);
  border-top: 2px solid var(--accent);
  padding: 16px 24px;
  text-align: center;
  margin-top: 20px;
}
.footer-brand {
  font-family: 'Barlow Condensed', sans-serif;
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: #f5a623;
  margin-bottom: 8px;
}
.footer-links {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
}
.footer-links a {
  color: #8899aa;
  text-decoration: none;
  font-size: 12px;
  letter-spacing: 1px;
  transition: color .2s;
}
.footer-links a:hover { color: #f5a623; }
.footer-divider { color: #444; font-size: 12px; }