/* ============================================================
   calculator.css — Calculator page layout, cards, results, FAQ
   Dark mode via CSS variables defined in style.css
   ============================================================ */

/* ── Breadcrumb & Back ── */
.breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  color: var(--text-muted);
  padding: 14px 0;
}
.breadcrumb a { color: var(--blue); text-decoration: none; }
.breadcrumb a:hover { text-decoration: underline; }
.breadcrumb span { color: var(--text-light); }

.back-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: none;
  border: 1.5px solid var(--border);
  border-radius: 100px;
  padding: 7px 16px;
  font-size: 13px;
  font-weight: 500;
  cursor: pointer;
  color: var(--text-muted);
  transition: all .2s;
  margin-bottom: 8px;
}
.back-btn:hover { border-color: var(--blue); color: var(--blue); background: var(--blue-light); }

/* ── Tool Page Grid ── */
.tool-page-grid {
  display: grid;
  grid-template-columns: minmax(320px, 420px) 1fr;
  gap: 28px;
  align-items: start;
}

/* ── Calculator Card ── */
.calc-card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  overflow: hidden;
  position: sticky;
  top: 80px;
  transition: background .25s, border-color .25s;
}
.calc-card-header {
  background: linear-gradient(135deg, var(--blue), var(--blue-mid));
  padding: 20px 24px;
  display: flex;
  align-items: center;
  gap: 14px;
}
.calc-card-header .icon { display: flex; align-items: center; justify-content: center; }
.calc-card-header h2 {
  font-family: 'Sora', sans-serif;
  font-size: 18px;
  font-weight: 700;
  color: #fff;
}
.calc-card-header p { font-size: 12px; color: rgba(255,255,255,.75); }
.calc-card-body { padding: 24px; }

/* ── Inputs ── */
.input-group { margin-bottom: 18px; }
.input-group label {
  display: block;
  font-size: 13px;
  font-weight: 600;
  color: var(--text-muted);
  margin-bottom: 7px;
  letter-spacing: .3px;
}
.input-row {
  display: flex;
  align-items: center;
  gap: 0;
}
.input-prefix, .input-suffix {
  background: var(--bg);
  border: 1.5px solid var(--border);
  padding: 10px 13px;
  font-size: 14px;
  font-weight: 600;
  color: var(--text-muted);
  flex-shrink: 0;
  transition: background .25s, border-color .25s, color .25s;
}
.input-prefix { border-right: none; border-radius: var(--radius-sm) 0 0 var(--radius-sm); }
.input-suffix { border-left: none;  border-radius: 0 var(--radius-sm) var(--radius-sm) 0; }
.input-row input {
  flex: 1;
  padding: 10px 14px;
  border: 1.5px solid var(--border);
  font-size: 15px;
  font-family: 'DM Sans', sans-serif;
  color: var(--text);
  outline: none;
  transition: border-color .2s, background .25s, color .25s;
  background: var(--input-bg);
}
.input-row.only input { border-radius: var(--radius-sm); }
.input-row input:focus { border-color: var(--blue); z-index: 1; }

input[type="range"] {
  width: 100%;
  accent-color: var(--blue);
  margin-top: 6px;
  cursor: pointer;
}
.range-labels {
  display: flex;
  justify-content: space-between;
  font-size: 11px;
  color: var(--text-light);
  margin-top: 3px;
}

select {
  width: 100%;
  padding: 10px 14px;
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: 15px;
  font-family: 'DM Sans', sans-serif;
  color: var(--text);
  background: var(--input-bg);
  outline: none;
  cursor: pointer;
  transition: border-color .2s, background .25s, color .25s;
}
select:focus { border-color: var(--blue); }

.calc-btn {
  width: 100%;
  padding: 14px;
  background: var(--blue);
  border: none;
  border-radius: var(--radius-sm);
  color: #fff;
  font-size: 16px;
  font-weight: 700;
  font-family: 'DM Sans', sans-serif;
  cursor: pointer;
  transition: all .25s;
  margin-top: 4px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
}
.calc-btn:hover {
  background: var(--blue-dark);
  transform: translateY(-1px);
  box-shadow: 0 4px 20px rgba(26,86,219,.35);
}

/* ── Result Box ── */
.result-box {
  margin-top: 20px;
  background: linear-gradient(135deg, var(--blue-light), var(--card));
  border: 1.5px solid rgba(26,86,219,.2);
  border-radius: var(--radius);
  padding: 20px;
  display: none;
  transition: background .25s;
}
.result-box.show {
  display: block;
  animation: fadeSlide .3s ease;
}
.result-box h4 {
  font-size: 12px;
  font-weight: 600;
  color: var(--text-muted);
  letter-spacing: .5px;
  text-transform: uppercase;
  margin-bottom: 14px;
  display: flex;
  align-items: center;
  gap: 6px;
}
.result-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
}
.result-item { text-align: center; }
.result-item .r-label { font-size: 12px; color: var(--text-muted); margin-bottom: 4px; }
.result-item .r-value {
  font-family: 'Sora', sans-serif;
  font-size: 20px;
  font-weight: 700;
  color: var(--blue);
}
.result-item .r-value.highlight { color: var(--accent2); font-size: 24px; }
.result-divider { border: none; border-top: 1px solid rgba(26,86,219,.15); margin: 10px 0; }

/* ── Donut Chart ── */
.donut-wrap {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 20px;
  margin-top: 14px;
}
.donut { width: 100px; height: 100px; flex-shrink: 0; }
.donut-legend { display: flex; flex-direction: column; gap: 8px; }
.legend-item { display: flex; align-items: center; gap: 8px; font-size: 12px; color: var(--text-muted); }
.legend-dot { width: 10px; height: 10px; border-radius: 50%; flex-shrink: 0; }

/* ── Content Blocks ── */
.content-panel { display: flex; flex-direction: column; gap: 20px; }
.content-block {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  transition: background .25s, border-color .25s;
}
.content-block h3 {
  font-family: 'Sora', sans-serif;
  font-size: 17px;
  font-weight: 700;
  margin-bottom: 14px;
  color: var(--text);
  display: flex;
  align-items: center;
  gap: 8px;
}

/* ── Formula Box ── */
.formula-box {
  background: var(--formula-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 16px 20px;
  font-family: 'Courier New', monospace;
  font-size: 14px;
  line-height: 2;
  color: var(--text);
  white-space: pre-wrap;
  transition: background .25s, border-color .25s;
}
.formula-box .var { color: var(--blue); font-weight: 700; }

/* ── Example Steps ── */
.example-step {
  display: flex;
  gap: 14px;
  margin-bottom: 14px;
  padding: 14px;
  background: var(--example-bg);
  border-radius: var(--radius-sm);
  transition: background .25s;
}
.step-num {
  width: 28px; height: 28px;
  border-radius: 50%;
  background: var(--blue);
  color: #fff;
  font-size: 12px;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}
.step-text { font-size: 13px; line-height: 1.6; color: var(--text); }

/* ── FAQ ── */
.faq-item { border-bottom: 1px solid var(--border); padding: 14px 0; }
.faq-item:last-child { border-bottom: none; }
.faq-q {
  font-weight: 600;
  font-size: 14px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
  color: var(--text);
}
.faq-icon { display: flex; align-items: center; }
.faq-a {
  font-size: 13px;
  color: var(--text-muted);
  line-height: 1.7;
  margin-top: 10px;
  display: none;
}
.faq-a.open { display: block; animation: fadeSlide .2s ease; }

/* ── Related Calculators ── */
.related-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
.related-item {
  display: flex;
  align-items: center;
  gap: 10px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 10px 12px;
  cursor: pointer;
  transition: all .2s;
}
.related-item:hover { border-color: var(--blue); background: var(--blue-light); }
.related-item .ri-icon {
  width: 30px; height: 30px;
  border-radius: 6px;
  background: var(--blue-light);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--blue);
  flex-shrink: 0;
}
.related-item .ri-name { font-size: 13px; font-weight: 600; color: var(--text); }