@import url('https://fonts.googleapis.com/css2?family=Lora:ital,wght@0,400;0,600;1,400&family=DM+Mono:wght@400;500&display=swap');

:root {
  --ink: #1a1a1a;
  --ink-soft: #4a4a4a;
  --ink-muted: #888;
  --paper: #faf8f4;
  --paper-warm: #f2ede4;
  --accent: #c0392b;
  --accent-soft: #e8c5c0;
  --green: #2d6a4f;
  --green-soft: #c8e6c9;
  --border: #d8d0c4;
  --mono: 'DM Mono', monospace;
  --serif: 'Lora', Georgia, serif;
}

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

body {
  background: var(--paper);
  color: var(--ink);
  font-family: var(--serif);
  font-size: 16px;
  line-height: 1.75;
  min-height: 100vh;
}

.tool-header {
  background: var(--ink);
  padding: 2.5rem 1.25rem 2rem;
  text-align: center;
}

.tool-header h1 {
  font-family: var(--mono);
  font-size: clamp(1.1rem, 3.5vw, 1.65rem);
  font-weight: 500;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--paper);
  line-height: 1.3;
  margin-bottom: 1.1rem;
}

.tool-logo {
  display: inline-block;
}

.tool-logo img {
  height: 32px;
  width: auto;
  display: block;
  margin: 0 auto;
  opacity: 0.92;
}

.tool-wrap {
  max-width: 1280px;
  margin: 0 auto;
  padding: 2rem 1.25rem 3rem;
}

.global-constraint {
  font-family: var(--mono);
  font-size: 0.78rem;
  color: var(--ink-muted);
  font-style: italic;
  line-height: 1.6;
  margin-bottom: 1.5rem;
  padding: 0.5rem 0.75rem;
  border-left: 2px solid var(--border);
}

.tab-switcher {
  display: flex;
  border: 1.5px solid var(--border);
  border-radius: 8px;
  overflow: hidden;
  margin-bottom: 2rem;
  background: var(--paper-warm);
}

.tab-btn {
  flex: 1;
  padding: 0.8rem 0.5rem;
  border: none;
  background: transparent;
  font-family: var(--mono);
  font-size: 0.78rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--ink-muted);
  cursor: pointer;
  transition: all 0.2s;
  border-right: 1.5px solid var(--border);
  line-height: 1.4;
}

.tab-btn:last-child { border-right: none; }
.tab-btn.active { background: var(--ink); color: var(--paper); }
.tab-btn:hover:not(.active) { background: var(--border); color: var(--ink); }

.tab-panel { display: none; }
.tab-panel.active { display: block; }

.input-group { margin-bottom: 1.25rem; }

.input-group label {
  display: block;
  font-family: var(--mono);
  font-size: 0.8rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--ink-muted);
  margin-bottom: 0.5rem;
}

.input-row {
  display: flex;
  align-items: stretch;
  border: 1.5px solid var(--border);
  border-radius: 6px;
  background: #fff;
  transition: border-color 0.2s;
}

.input-row:focus-within { border-color: var(--ink); }

.input-row input {
  flex: 1;
  border: none;
  outline: none;
  padding: 0.75rem 1rem;
  font-family: var(--mono);
  font-size: 1rem;
  color: var(--ink);
  background: transparent;
  min-width: 0;
  border-radius: 6px 0 0 6px;
}

.input-row .unit {
  padding: 0 1rem;
  font-family: var(--mono);
  font-size: 0.82rem;
  color: var(--ink-muted);
  white-space: nowrap;
  border-left: 1px solid var(--border);
  display: flex;
  align-items: center;
  background: var(--paper-warm);
  border-radius: 0 6px 6px 0;
}

.slider-wrap { margin-top: 0.5rem; }

input[type="range"] {
  width: 100%;
  -webkit-appearance: none;
  height: 4px;
  border-radius: 2px;
  background: var(--border);
  outline: none;
  cursor: pointer;
}

input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 18px; height: 18px;
  border-radius: 50%;
  background: var(--ink);
  cursor: pointer;
  border: 2px solid var(--paper);
  box-shadow: 0 0 0 1px var(--ink);
  transition: transform 0.15s;
}

input[type="range"]::-webkit-slider-thumb:hover { transform: scale(1.2); }

.slider-labels {
  display: flex;
  justify-content: space-between;
  font-family: var(--mono);
  font-size: 0.72rem;
  color: var(--ink-muted);
  margin-top: 0.35rem;
}

.input-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0 1rem;
}

@media (max-width: 400px) { .input-grid { grid-template-columns: 1fr; } }

.preset-note {
  font-family: var(--mono);
  font-size: 0.8rem;
  color: var(--ink-muted);
  margin-bottom: 1rem;
  line-height: 1.5;
}

.preset-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0.5rem;
  margin-bottom: 1.5rem;
}

@media (max-width: 480px) { .preset-grid { grid-template-columns: repeat(3, 1fr); } }

.preset-btn {
  padding: 0.65rem 0.25rem;
  border: 1.5px solid var(--border);
  border-radius: 6px;
  background: #fff;
  font-family: var(--mono);
  font-size: 0.8rem;
  color: var(--ink-soft);
  cursor: pointer;
  text-align: center;
  transition: all 0.15s;
  line-height: 1.3;
}

.preset-btn:hover { border-color: var(--ink); color: var(--ink); }
.preset-btn.active { background: var(--green); color: #fff; border-color: var(--green); }

.calc-btn {
  width: 100%;
  padding: 1rem;
  background: var(--accent);
  color: #fff;
  border: none;
  border-radius: 6px;
  font-family: var(--mono);
  font-size: 0.82rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  cursor: pointer;
  margin-top: 1.5rem;
  transition: opacity 0.15s, transform 0.1s;
  font-weight: 500;
}

.calc-btn:hover { opacity: 0.88; }
.calc-btn:active { transform: scale(0.99); }

.results {
  display: none;
  margin-top: 2rem;
  animation: fadeUp 0.4s ease;
}

.results.visible { display: block; }

@keyframes fadeUp {
  from { opacity: 0; transform: translateY(10px); }
  to   { opacity: 1; transform: translateY(0); }
}

.chart-wrap {
  background: var(--paper-warm);
  border: 1.5px solid var(--border);
  border-radius: 8px;
  padding: 1.25rem;
  margin-bottom: 1rem;
}

.chart-wrap h3 {
  font-family: var(--mono);
  font-size: 0.72rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--ink-muted);
  margin-bottom: 1rem;
  font-weight: 400;
}

.css-chart {
  display: flex;
  align-items: flex-end;
  gap: 0.5rem;
  height: 260px;
  padding-bottom: 1.75rem;
  position: relative;
  border-bottom: 1.5px solid var(--border);
}

.css-chart::before {
  content: '';
  position: absolute;
  left: 0; right: 0; top: 0; bottom: 1.75rem;
  background: repeating-linear-gradient(
    to bottom,
    var(--border) 0px, var(--border) 1px,
    transparent 1px, transparent 25%
  );
  opacity: 0.4;
  pointer-events: none;
}

.css-bar-col {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  height: 100%;
  position: relative;
  justify-content: flex-end;
}

.css-bar-stack {
  width: 100%;
  max-width: 52px;
  display: flex;
  flex-direction: column-reverse;
  border-radius: 4px 4px 0 0;
  overflow: hidden;
  position: relative;
}

.css-bar-principal { background: #c8c0b4; flex-shrink: 0; }
.css-bar-interest  { background: var(--green); flex-shrink: 0; }

.css-bar-label {
  position: absolute;
  bottom: -1.6rem;
  left: 50%;
  transform: translateX(-50%);
  font-family: var(--mono);
  font-size: 0.65rem;
  color: var(--ink-muted);
  white-space: nowrap;
  text-align: center;
}

.css-bar-tooltip {
  position: absolute;
  bottom: 105%;
  left: 50%;
  transform: translateX(-50%);
  background: var(--ink);
  color: var(--paper);
  padding: 0.5rem 0.65rem;
  border-radius: 5px;
  font-family: var(--mono);
  font-size: 0.68rem;
  line-height: 1.5;
  white-space: nowrap;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.15s;
  z-index: 10;
  text-align: left;
}

.css-bar-tooltip::after {
  content: '';
  position: absolute;
  top: 100%; left: 50%;
  transform: translateX(-50%);
  border: 5px solid transparent;
  border-top-color: var(--ink);
}

.css-bar-col:hover .css-bar-tooltip { opacity: 1; }

.chart-legend {
  display: flex;
  gap: 1.25rem;
  margin-top: 0.75rem;
  font-family: var(--mono);
  font-size: 0.72rem;
  color: var(--ink-muted);
  flex-wrap: wrap;
}

.legend-item { display: flex; align-items: center; gap: 0.35rem; }
.legend-dot  { width: 10px; height: 10px; border-radius: 2px; flex-shrink: 0; }
.legend-dot-principal { background: #c8c0b4; }
.legend-dot-interest  { background: var(--green); }

.summary-cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0.5rem;
  margin-bottom: 1rem;
}

@media (max-width: 500px) { .summary-cards { grid-template-columns: 1fr 1fr; } }

.sum-card {
  background: var(--paper-warm);
  border: 1.5px solid var(--border);
  border-radius: 8px;
  padding: 0.85rem 0.75rem;
}

.sum-card-label { font-family: var(--mono); font-size: 0.7rem; letter-spacing: 0.1em; text-transform: uppercase; color: var(--ink-muted); margin-bottom: 0.3rem; }
.sum-card-value { font-family: var(--mono); font-size: 1rem; font-weight: 500; color: var(--green); line-height: 1.2; }
.sum-card-sub   { font-family: var(--mono); font-size: 0.65rem; color: var(--ink-muted); margin-top: 0.2rem; }

.result-table-wrap {
  overflow-x: auto;
  border-radius: 6px;
  border: 1.5px solid var(--border);
  margin-bottom: 1rem;
}

.result-table {
  width: 100%;
  border-collapse: collapse;
  font-family: var(--mono);
  font-size: 0.85rem;
}

.result-table thead tr { background: var(--ink); color: var(--paper); }

.result-table thead th {
  padding: 0.65rem 1rem;
  text-align: left;
  font-weight: 400;
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.result-table tbody td {
  padding: 0.6rem 1rem;
  color: var(--ink-soft);
  border-bottom: 1px solid var(--border);
  vertical-align: middle;
}

.result-table tbody tr:last-child td { border-bottom: none; }
.result-table tbody td:first-child { color: var(--ink); }
.result-table .td-green  { color: var(--green); font-weight: 500; }
.result-table .td-accent { color: var(--accent); font-weight: 500; }

.insight-note {
  background: var(--paper-warm);
  border-left: 3px solid var(--accent);
  padding: 1rem 1.25rem;
  border-radius: 0 6px 6px 0;
  font-size: 0.92rem;
  line-height: 1.65;
  color: var(--ink-soft);
  font-style: italic;
  margin-bottom: 1rem;
}

.insight-note strong { color: var(--accent); font-style: normal; }

.pmt-result { display: none; margin-top: 2rem; animation: fadeUp 0.4s ease; }
.pmt-result.visible { display: block; }

.pmt-highlight {
  background: var(--green);
  color: #fff;
  border-radius: 8px;
  padding: 1.5rem 1.25rem;
  margin-bottom: 1rem;
  text-align: center;
}

.pmt-tag { font-family: var(--mono); font-size: 0.68rem; letter-spacing: 0.16em; text-transform: uppercase; opacity: 0.75; margin-bottom: 0.5rem; }
.pmt-amount { font-family: var(--mono); font-size: clamp(1.5rem, 6vw, 2.2rem); font-weight: 500; color: #fff; line-height: 1.1; margin-bottom: 0.4rem; }
.pmt-desc   { font-size: 0.85rem; opacity: 0.82; font-family: var(--mono); }

.val-error {
  display: none;
  font-family: var(--mono);
  font-size: 0.75rem;
  color: var(--accent);
  margin-top: 0.4rem;
  line-height: 1.5;
  padding: 0.4rem 0.6rem;
  background: #fdf0ee;
  border-left: 2px solid var(--accent);
  border-radius: 0 4px 4px 0;
}

.formula-box {
  background: var(--ink);
  color: var(--paper);
  padding: 1.25rem 1.5rem;
  border-radius: 6px;
  margin: 2rem 0 0;
  font-family: var(--mono);
  font-size: 0.85rem;
  line-height: 1.9;
}

.formula-title { font-size: 0.62rem; letter-spacing: 0.18em; text-transform: uppercase; color: rgba(255,255,255,0.4); margin-bottom: 0.75rem; }
.formula-main  { color: var(--accent-soft); font-size: 0.95rem; font-weight: 500; }
.formula-vars  { margin-top: 0.75rem; color: rgba(255,255,255,0.6); font-size: 0.78rem; border-top: 1px solid rgba(255,255,255,0.1); padding-top: 0.75rem; }
.formula-vars span { display: block; margin-bottom: 0.2rem; }

.tool-footer {
  border-top: 1px solid var(--border);
  padding: 1.25rem 0 2rem;
  margin-top: 2rem;
  font-family: var(--mono);
  font-size: 0.65rem;
  color: var(--ink-muted);
  line-height: 1.7;
}

@media (max-width: 768px) {
  .tab-btn { font-size: 0.68rem; padding: 0.65rem 0.25rem; }
  .preset-grid { grid-template-columns: repeat(3, 1fr); }
  .chart-wrap {
    border: none;
    border-top: 1px solid var(--border);
    border-bottom: 1px solid var(--border);
    border-radius: 0;
    background: transparent;
    padding: 1.25rem 0;
  }
  .result-table-wrap {
    border: none;
    border-top: 1px solid var(--border);
    border-bottom: 1px solid var(--border);
    border-radius: 0;
  }
}