/* ============================================================
   styles.css — Mortgage / Home Loan Repayment Calculator
   ============================================================ */

/* ── Custom properties ─────────────────────────────────────── */
:root {
  --color-primary:       #1d4ed8;
  --color-primary-dark:  #1e3a8a;
  --color-primary-light: #dbeafe;
  --color-accent:        #0891b2;
  --color-success:       #059669;
  --color-success-light: #d1fae5;
  --color-warning:       #d97706;
  --color-danger:        #dc2626;
  --color-danger-light:  #fee2e2;

  --color-text:          #111827;
  --color-text-muted:    #6b7280;
  --color-border:        #e5e7eb;
  --color-bg:            #f3f4f6;
  --color-surface:       #ffffff;

  --radius:              0.5rem;
  --radius-sm:           0.25rem;
  --shadow-sm:           0 1px 3px 0 rgb(0 0 0 / 0.1), 0 1px 2px -1px rgb(0 0 0 / 0.1);
  --shadow:              0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);

  --font-sans:           system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --font-mono:           ui-monospace, "Cascadia Code", "Fira Code", monospace;

  --max-width:           680px;
  --spacing:             1.5rem;
}

/* ── Reset ─────────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { font-size: 16px; -webkit-text-size-adjust: 100%; }
body {
  font-family: var(--font-sans);
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.6;
  min-height: 100vh;
}
button, input, select, textarea { font: inherit; }
button { cursor: pointer; }
fieldset { border: none; }

/* ── Layout ─────────────────────────────────────────────────── */
.page-wrapper { min-height: 100vh; display: flex; flex-direction: column; }

.container {
  width: 100%;
  max-width: var(--max-width);
  margin-inline: auto;
  padding-inline: 1rem;
}

/* ── Header ─────────────────────────────────────────────────── */
.site-header {
  background: var(--color-primary-dark);
  color: #fff;
  padding: 2rem 0 1.75rem;
  margin-bottom: var(--spacing);
}
.site-title {
  font-size: clamp(1.4rem, 4vw, 2rem);
  font-weight: 700;
  letter-spacing: -0.01em;
}
.site-subtitle {
  color: #bfdbfe;
  font-size: 0.9rem;
  margin-top: 0.25rem;
}

/* ── Card ───────────────────────────────────────────────────── */
.card {
  background: var(--color-surface);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  padding: var(--spacing);
  margin-bottom: 1rem;
}
.card-title {
  font-size: 1rem;
  font-weight: 600;
  color: var(--color-primary-dark);
  margin-bottom: 1.25rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--color-border);
}
.card-title.section-title {
  font-size: 1.25rem;
  font-weight: 700;
}

/* ── Region tabs ────────────────────────────────────────────── */
.region-tabs {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0.25rem;
  background: var(--color-bg);
  border-radius: var(--radius-sm);
  padding: 0.25rem;
  margin-bottom: 1.25rem;
}

.region-tab {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.2rem;
  padding: 0.55rem 0.5rem 0.45rem;
  border: none;
  border-radius: calc(var(--radius-sm) - 1px);
  background: transparent;
  color: var(--color-text-muted);
  font-weight: 500;
  transition: background 0.15s, color 0.15s, box-shadow 0.15s;
  white-space: nowrap;
}
.tab-flag  { font-size: 1.4rem; line-height: 1; }
.tab-label { font-size: 0.72rem; }

.region-tab:hover {
  background: var(--color-surface);
  color: var(--color-text);
}
.region-tab[aria-selected="true"] {
  background: var(--color-surface);
  color: var(--color-primary-dark);
  font-weight: 600;
  box-shadow: var(--shadow-sm);
}

/* ── Form rows — horizontal label + input layout ────────────── */
.form-row {
  display: grid;
  grid-template-columns: 10rem 1fr;
  column-gap: 1rem;
  row-gap: 0.2rem;
  align-items: start;
  margin-bottom: 0.6rem;
}
.form-row:last-child { margin-bottom: 0; }

.form-label {
  grid-column: 1;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--color-text);
  text-align: right;
  /* nudge down so label baseline sits beside the input text */
  padding-top: 0.44rem;
  line-height: 1.3;
}

/* Checkbox rows: collapse to single column so the checkbox+label
   spans full width without an empty label prefix column */
.form-row:has(.checkbox-label) {
  grid-template-columns: 1fr;
}

.checkbox-label {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  cursor: pointer;
  font-weight: 500;
  padding-top: 0;
}
.form-checkbox {
  width: 1rem;
  height: 1rem;
  accent-color: var(--color-primary);
  flex-shrink: 0;
  cursor: pointer;
}

.input-wrap { position: relative; }

/* ── Inputs ─────────────────────────────────────────────────── */
.form-input,
.form-select {
  display: block;
  width: 100%;
  padding: 0.55rem 0.75rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  background: var(--color-surface);
  color: var(--color-text);
  font-size: 0.95rem;
  transition: border-color 0.15s, box-shadow 0.15s;
  appearance: none;
  -webkit-appearance: none;
}
.form-select {
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' fill='none' viewBox='0 0 20 20'%3E%3Cpath stroke='%236b7280' stroke-linecap='round' stroke-linejoin='round' stroke-width='1.5' d='M6 8l4 4 4-4'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 0.6rem center;
  background-size: 1.2em;
  padding-right: 2.2rem;
}
.form-input:focus,
.form-select:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--color-primary) 20%, transparent);
}
.form-input.has-prefix { padding-left: 2.25rem; }
.form-input.has-suffix { padding-right: 3.25rem; }
.form-input[type="month"] { font-family: var(--font-sans); }

/* ── Input addons (prefix/suffix) ───────────────────────────── */
.input-group { position: relative; display: flex; }
.input-group .form-input { flex: 1; }
.input-addon {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  font-size: 0.875rem;
  color: var(--color-text-muted);
  pointer-events: none;
  user-select: none;
  z-index: 1;
}
.input-addon.prefix { left: 0.75rem; }
.input-addon.suffix { right: 0.75rem; }

/* ── Help icon ──────────────────────────────────────────────── */
.help-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 1rem;
  height: 1rem;
  border-radius: 50%;
  background: var(--color-text-muted);
  color: #fff;
  font-size: 0.65rem;
  font-weight: 700;
  cursor: help;
  margin-left: 0.3rem;
  vertical-align: middle;
  line-height: 1;
  text-decoration: none;
}

/* ── Field hints ────────────────────────────────────────────── */
.field-hint {
  grid-column: 2;
  font-size: 0.78rem;
  color: var(--color-text-muted);
  margin-top: 0.15rem;
  line-height: 1.4;
}
/* In checkbox rows (single-column grid), hint spans full width */
.form-row:has(.checkbox-label) .field-hint { grid-column: 1; }

/* ── Term presets ───────────────────────────────────────────── */
.term-presets {
  grid-column: 2;
  display: flex;
  gap: 0.4rem;
  margin-top: 0.3rem;
}
.preset-btn {
  padding: 0.25rem 0.65rem;
  font-size: 0.78rem;
  font-weight: 600;
  border: 1px solid var(--color-primary);
  border-radius: var(--radius-sm);
  background: transparent;
  color: var(--color-primary);
  transition: background 0.12s, color 0.12s;
}
.preset-btn:hover { background: var(--color-primary); color: #fff; }

/* ── Form fieldset ──────────────────────────────────────────── */
.form-fieldset {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 1rem;
  margin-bottom: 1rem;
}
.form-fieldset:last-child { margin-bottom: 0; }
.form-legend {
  font-size: 0.825rem;
  font-weight: 600;
  color: var(--color-text-muted);
  padding-inline: 0.3rem;
}

/* ── Inline form rows ───────────────────────────────────────── */
.form-row-inline {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 0.75rem;
  margin-bottom: 0.75rem;
}
/* Inline cells are too narrow for a side-by-side label — revert to stacked */
.form-row-inline .form-row {
  grid-template-columns: 1fr;
  margin-bottom: 0;
}
.form-row-inline .form-row .form-label {
  text-align: left;
  padding-top: 0;
  margin-bottom: 0.2rem;
}
.form-row-inline .form-row .field-hint { grid-column: 1; }

/* ── Advanced options ───────────────────────────────────────── */
.advanced-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-top: 1px solid var(--color-border);
  margin-top: 1.25rem;
  padding-top: 1.25rem;
}
.advanced-header .card-title { margin-bottom: 0; padding-bottom: 0; border-bottom: none; }
.toggle-switch {
  position: relative;
  flex-shrink: 0;
  width: 2.5rem;
  height: 1.375rem;
  background: var(--color-border);
  border: none;
  border-radius: 999px;
  padding: 0;
  transition: background 0.2s;
}
.toggle-switch::after {
  content: '';
  position: absolute;
  top: 0.1875rem;
  left: 0.1875rem;
  width: 1rem;
  height: 1rem;
  background: #fff;
  border-radius: 50%;
  box-shadow: 0 1px 3px rgb(0 0 0 / 0.25);
  transition: transform 0.2s;
}
.toggle-switch[aria-expanded="true"] { background: var(--color-primary); }
.toggle-switch[aria-expanded="true"]::after { transform: translateX(1.125rem); }

#advanced-content { margin-top: 1.25rem; border-top: 1px solid var(--color-border); padding-top: 1.25rem; padding-bottom: 1.5rem; border-bottom: 1px solid var(--color-border); }

/* ── Region dividers ────────────────────────────────────────── */
.region-divider {
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  margin: 1.25rem 0 0.75rem;
}
.region-section + .region-section .region-divider { margin-top: 1.5rem; }

.sub-section {
  background: var(--color-bg);
  border-radius: var(--radius-sm);
  padding: 0.875rem;
  margin-top: 0.5rem;
}

/* ── Buttons ────────────────────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.65rem 1.5rem;
  font-size: 0.95rem;
  font-weight: 600;
  border-radius: var(--radius-sm);
  border: 1px solid transparent;
  transition: background 0.15s, box-shadow 0.15s, border-color 0.15s;
  white-space: nowrap;
}
.btn-primary {
  background: var(--color-primary);
  color: #fff;
  border-color: var(--color-primary);
}
.btn-primary:hover { background: var(--color-primary-dark); border-color: var(--color-primary-dark); }
.btn-secondary {
  background: var(--color-surface);
  color: var(--color-text);
  border-color: var(--color-border);
}
.btn-secondary:hover { background: var(--color-bg); }
.btn-sm { padding: 0.35rem 0.9rem; font-size: 0.825rem; }
.btn-calculate {
  display: block;
  width: 100%;
  margin-top: 1.75rem;
  padding-top: 0.8rem;
  padding-bottom: 0.8rem;
  font-size: 1rem;
  letter-spacing: 0.01em;
}

/* ── Close button (Results header) ──────────────────────────── */
.results-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 1.25rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--color-border);
}
.results-header .card-title { margin-bottom: 0; padding-bottom: 0; border-bottom: none; }

.btn-close {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 2.25rem;
  height: 2.25rem;
  flex-shrink: 0;
  border: 1.5px solid var(--color-border);
  border-radius: 50%;
  background: var(--color-bg);
  color: var(--color-text);
  transition: background 0.15s, color 0.15s, border-color 0.15s;
}
.btn-close:hover { background: var(--color-danger-light); color: var(--color-danger); border-color: var(--color-danger); }

/* ── Errors ─────────────────────────────────────────────────── */
.errors-box {
  background: var(--color-danger-light);
  border: 1px solid #fca5a5;
  border-radius: var(--radius-sm);
  padding: 0.75rem 1rem;
  margin-bottom: 1rem;
  color: #991b1b;
  font-size: 0.875rem;
}
.errors-box ul { padding-left: 1.25rem; }
.errors-box li + li { margin-top: 0.25rem; }

/* ── Results ────────────────────────────────────────────────── */
.results-section { margin-top: 0.5rem; }
.results-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 0.75rem;
}
.result-card {
  background: var(--color-bg);
  border-radius: var(--radius-sm);
  padding: 1rem;
  border: 1px solid var(--color-border);
}
.result-card.primary {
  background: var(--color-primary-dark);
  border-color: var(--color-primary-dark);
  color: #fff;
  grid-column: 1 / -1;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
}
.result-card.highlight {
  background: var(--color-success-light);
  border-color: #a7f3d0;
}
.result-label {
  font-size: 0.78rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--color-text-muted);
  margin-bottom: 0.3rem;
}
.result-card.primary .result-label { color: #bfdbfe; margin-bottom: 0; }
.result-card.highlight .result-label { color: #065f46; }
.result-value {
  font-size: 1.35rem;
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  line-height: 1.2;
  color: var(--color-text);
}
.result-card.primary .result-value { font-size: 2rem; color: #fff; }
.result-card.highlight .result-value { color: var(--color-success); }
.result-period {
  font-size: 0.75rem;
  font-weight: 500;
  color: #93c5fd;
  margin-left: 0.25rem;
}
.result-date { font-size: 1.05rem; }

/* ── Assumptions (footer inside results card) ───────────────── */
.assumptions-footer {
  margin-top: 1.25rem;
  border-top: 1px solid var(--color-border);
  background: #fefce8;
  border-radius: var(--radius-sm);
  padding: 0.75rem 0.875rem;
}
.assumptions-label {
  display: block;
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  margin-bottom: 0.35rem;
}
.assumptions { font-size: 0.78rem; color: var(--color-text-muted); line-height: 1.5; }
.assumptions-list { list-style: none; padding: 0; display: flex; flex-wrap: wrap; gap: 0 1.5rem; }
.assumptions-list li {
  padding: 0.1rem 0 0.1rem 0.9rem;
  position: relative;
}
.assumptions-list li::before {
  content: "–";
  position: absolute;
  left: 0;
  color: var(--color-border);
}

/* ── Schedule ───────────────────────────────────────────────── */
.schedule-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-top: 1px solid var(--color-border);
  margin-top: 1.25rem;
  padding-top: 1.25rem;
}
.schedule-header .card-title { margin-bottom: 0; padding-bottom: 0; border-bottom: none; }

.table-wrapper { overflow-x: auto; margin-top: 1rem; }
.schedule-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.85rem;
  font-variant-numeric: tabular-nums;
}
.schedule-table th {
  background: var(--color-bg);
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--color-text-muted);
  padding: 0.6rem 0.75rem;
  text-align: right;
  white-space: nowrap;
  border-bottom: 2px solid var(--color-border);
}
.schedule-table th:first-child { text-align: left; }
.schedule-table td {
  padding: 0.5rem 0.75rem;
  text-align: right;
  border-bottom: 1px solid var(--color-border);
  color: var(--color-text);
}
.schedule-table td:first-child { text-align: left; font-weight: 600; }
.schedule-table tbody tr:last-child td { border-bottom: none; }
.schedule-table tbody tr:hover { background: var(--color-bg); }
.schedule-table tbody tr:nth-child(even) { background: color-mix(in srgb, var(--color-bg) 50%, white); }

/* ── Disclaimer ─────────────────────────────────────────────── */
.disclaimer {
  font-size: 0.78rem;
  color: var(--color-text-muted);
  line-height: 1.5;
  margin: 1.5rem 0 2rem;
  padding: 0.75rem;
  background: var(--color-surface);
  border-radius: var(--radius-sm);
  border-left: 3px solid var(--color-border);
}

/* ── Responsive ─────────────────────────────────────────────── */
@media (max-width: 400px) {
  .tab-label { display: none; }
  .region-tab { padding: 0.6rem 0.25rem; }
}

@media (max-width: 540px) {
  /* Revert form rows to stacked layout on small screens */
  .form-row {
    grid-template-columns: 1fr;
    row-gap: 0.25rem;
  }
  .form-label {
    text-align: left;
    padding-top: 0;
  }
  .field-hint,
  .term-presets {
    grid-column: 1;
  }
}

@media (max-width: 480px) {
  .results-grid { grid-template-columns: 1fr 1fr; }
  .result-card.primary { grid-column: 1 / -1; }
  .form-row-inline { grid-template-columns: 1fr; }
}

@media (min-width: 640px) {
  .container { padding-inline: 1.5rem; }
  .card { padding: 1.75rem; }
}