:root {
  --indigo: #4F46E5;
  --blue: #3B82F6;
  --purple: #8B5CF6;
  --bg: #FFFFFF;
  --bg-soft: #F5F6FA;
  --text: #14162B;
  --text-dim: #5B5E76;
  --border: #E4E6F1;
  --card: #FFFFFF;
  --radius: 18px;
  --shadow: 0 10px 30px -12px rgba(79, 70, 229, 0.18);
}

[data-theme="dark"] {
  --bg: #0B0F19;
  --bg-soft: #10152A;
  --text: #EEF0FF;
  --text-dim: #9DA1C4;
  --border: #232945;
  --card: #131832;
  --shadow: 0 10px 30px -12px rgba(0, 0, 0, 0.5);
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Inter, Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
  transition: background 0.3s ease, color 0.3s ease;
}

.nav {
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: blur(12px);
  background: color-mix(in srgb, var(--bg) 80%, transparent);
  border-bottom: 1px solid var(--border);
}

.nav-inner {
  max-width: 1000px;
  margin: 0 auto;
  padding: 16px 24px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  font-weight: 800;
  font-size: 1.25rem;
  text-decoration: none;
  color: var(--text);
  letter-spacing: -0.02em;
}
.logo span {
  background: linear-gradient(135deg, var(--indigo), var(--purple));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.theme-toggle {
  border: 1px solid var(--border);
  background: var(--bg-soft);
  color: var(--text);
  width: 38px;
  height: 38px;
  border-radius: 50%;
  cursor: pointer;
  font-size: 1rem;
}

.hero {
  max-width: 780px;
  margin: 0 auto;
  padding: 72px 24px 40px;
  text-align: center;
}

.eyebrow {
  display: inline-block;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--indigo);
  background: color-mix(in srgb, var(--indigo) 12%, transparent);
  padding: 6px 14px;
  border-radius: 999px;
  margin-bottom: 20px;
}

.hero h1 {
  font-size: clamp(2.2rem, 5vw, 3.4rem);
  line-height: 1.08;
  letter-spacing: -0.03em;
  margin: 0 0 18px;
  background: linear-gradient(135deg, var(--text) 40%, var(--indigo) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.hero-sub {
  color: var(--text-dim);
  font-size: 1.05rem;
  line-height: 1.6;
  max-width: 560px;
  margin: 0 auto;
}

.tool-shell {
  max-width: 780px;
  margin: 0 auto 80px;
  padding: 0 24px;
}

.tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  justify-content: center;
  margin-bottom: 24px;
}

.tab {
  border: 1px solid var(--border);
  background: var(--bg-soft);
  color: var(--text-dim);
  padding: 10px 18px;
  border-radius: 999px;
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s ease;
}

.tab.active {
  background: linear-gradient(135deg, var(--indigo), var(--purple));
  color: white;
  border-color: transparent;
}

.panel {
  display: none;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 32px;
}

.panel.active { display: block; animation: fadeIn 0.3s ease; }

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(6px); }
  to { opacity: 1; transform: translateY(0); }
}

.panel h2 {
  margin-top: 0;
  font-size: 1.4rem;
  letter-spacing: -0.02em;
}

.mode-row {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 20px;
}

.mode-btn, .rate-btn {
  border: 1px solid var(--border);
  background: var(--bg-soft);
  color: var(--text-dim);
  padding: 8px 14px;
  border-radius: 10px;
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
}

.mode-btn.active, .rate-btn.active {
  background: var(--indigo);
  color: white;
  border-color: transparent;
}

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

.field-row, .field-grid {
  margin-bottom: 18px;
}

.field-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

@media (max-width: 560px) {
  .field-grid { grid-template-columns: 1fr; }
}

label {
  display: flex;
  flex-direction: column;
  gap: 8px;
  font-size: 0.9rem;
  color: var(--text-dim);
  font-weight: 500;
}

.field-row label {
  flex-direction: row;
  align-items: center;
  flex-wrap: wrap;
  gap: 10px;
}

input[type="number"], input[type="date"] {
  background: var(--bg-soft);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 10px 14px;
  font-size: 1rem;
  color: var(--text);
  width: 120px;
  min-width: 0;
}

.field-grid input[type="number"], .field-grid input[type="date"] {
  width: 100%;
}

input[type="range"] {
  width: 100%;
  accent-color: var(--indigo);
}

.checkbox-row {
  flex-direction: row;
  align-items: center;
  gap: 8px;
  margin-bottom: 12px;
}

.rate-select {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}

.result {
  font-size: 1.6rem;
  font-weight: 700;
  color: var(--indigo);
  margin-top: 8px;
}

.result-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 14px;
  margin: 20px 0;
}

.result-card {
  background: var(--bg-soft);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 16px;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.result-card span {
  font-size: 0.8rem;
  color: var(--text-dim);
}

.result-card strong {
  font-size: 1.3rem;
  letter-spacing: -0.02em;
  font-variant-numeric: tabular-nums;
  min-height: 1.6rem;
  display: block;
  word-break: break-word;
}

.result {
  font-variant-numeric: tabular-nums;
}

.panel {
  min-height: 420px;
}

input[type="number"], input[type="date"] {
  font-variant-numeric: tabular-nums;
}

.bar-viz {
  display: flex;
  height: 14px;
  border-radius: 999px;
  overflow: hidden;
  margin-bottom: 8px;
}

.bar.principal { background: var(--indigo); }
.bar.interest { background: var(--purple); }

.bar-legend {
  display: flex;
  gap: 16px;
  font-size: 0.8rem;
  color: var(--text-dim);
}

.dot {
  display: inline-block;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  margin-right: 6px;
}
.dot.principal { background: var(--indigo); }
.dot.interest { background: var(--purple); }

.disclaimer {
  font-size: 0.8rem;
  color: var(--text-dim);
  background: var(--bg-soft);
  border-radius: 10px;
  padding: 10px 14px;
  margin: 0 0 18px;
}

.copy-btn {
  margin-top: 8px;
  border: none;
  background: linear-gradient(135deg, var(--indigo), var(--purple));
  color: white;
  padding: 10px 20px;
  border-radius: 10px;
  font-weight: 600;
  cursor: pointer;
  font-size: 0.9rem;
}

.copy-btn:active { transform: scale(0.98); }

.site-footer {
  text-align: center;
  padding: 30px 24px 50px;
  color: var(--text-dim);
  font-size: 0.85rem;
  border-top: 1px solid var(--border);
}

/* ---------- Multi-page additions ---------- */
.tool-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  justify-content: center;
  margin-bottom: 24px;
}

.tool-nav a {
  border: 1px solid var(--border);
  background: var(--bg-soft);
  color: var(--text-dim);
  padding: 10px 18px;
  border-radius: 999px;
  font-size: 0.9rem;
  font-weight: 600;
  text-decoration: none;
  transition: all 0.2s ease;
}

.tool-nav a.current {
  background: linear-gradient(135deg, var(--indigo), var(--purple));
  color: white;
  border-color: transparent;
}

.tool-nav a:hover:not(.current) {
  border-color: var(--indigo);
  color: var(--indigo);
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 18px;
}

.tool-card {
  display: block;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  text-decoration: none;
  color: var(--text);
  box-shadow: var(--shadow);
  transition: transform 0.2s ease;
}

.tool-card:hover {
  transform: translateY(-4px);
}

.tool-card .icon {
  font-size: 1.6rem;
  margin-bottom: 10px;
  display: block;
}

.tool-card h3 {
  margin: 0 0 6px;
  font-size: 1.1rem;
}

.tool-card p {
  margin: 0;
  color: var(--text-dim);
  font-size: 0.88rem;
  line-height: 1.5;
}

.seo-content {
  max-width: 780px;
  margin: 40px auto 0;
  padding: 0 24px;
  color: var(--text-dim);
  line-height: 1.7;
}

.seo-content h2 {
  color: var(--text);
  font-size: 1.3rem;
  margin: 28px 0 12px;
}

.faq-section {
  max-width: 780px;
  margin: 20px auto 0;
  padding: 0 24px;
}

.faq-item {
  border-bottom: 1px solid var(--border);
  padding: 16px 0;
}

.faq-item h3 {
  font-size: 1rem;
  margin: 0 0 6px;
}

.faq-item p {
  margin: 0;
  color: var(--text-dim);
  font-size: 0.92rem;
  line-height: 1.6;
}

.related-tools {
  max-width: 780px;
  margin: 30px auto 60px;
  padding: 0 24px;
}

.related-tools h2 {
  font-size: 1.1rem;
  margin-bottom: 12px;
}

.related-tools ul {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.related-tools a {
  color: var(--indigo);
  text-decoration: none;
  font-weight: 600;
  font-size: 0.9rem;
  border: 1px solid var(--border);
  padding: 8px 14px;
  border-radius: 10px;
}

.related-tools a:hover {
  border-color: var(--indigo);
}

.breadcrumb {
  max-width: 780px;
  margin: 0 auto;
  padding: 16px 24px 0;
  font-size: 0.85rem;
  color: var(--text-dim);
}

.breadcrumb a {
  color: var(--text-dim);
  text-decoration: none;
}

.breadcrumb a:hover {
  color: var(--indigo);
}

.mini-hero {
  padding: 40px 24px 24px;
}

.mini-hero h1 {
  font-size: clamp(1.8rem, 4vw, 2.6rem);
}

/* ---------- Blog & nav-links additions ---------- */
.nav-links {
  display: flex;
  align-items: center;
  gap: 20px;
}

.nav-links a {
  color: var(--text-dim);
  text-decoration: none;
  font-weight: 600;
  font-size: 0.95rem;
}

.nav-links a:hover {
  color: var(--indigo);
}

.blog-list {
  max-width: 780px;
  margin: 0 auto 60px;
  padding: 0 24px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.blog-card {
  display: block;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  text-decoration: none;
  color: var(--text);
  box-shadow: var(--shadow);
  transition: transform 0.2s ease;
}

.blog-card:hover {
  transform: translateY(-3px);
}

.blog-card .blog-date {
  font-size: 0.78rem;
  color: var(--text-dim);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.blog-card h3 {
  margin: 6px 0 8px;
  font-size: 1.15rem;
}

.blog-card p {
  margin: 0;
  color: var(--text-dim);
  font-size: 0.92rem;
  line-height: 1.6;
}

.blog-article {
  max-width: 720px;
  margin: 0 auto;
  padding: 40px 24px 60px;
  line-height: 1.75;
  color: var(--text-dim);
}

.blog-article h1 {
  color: var(--text);
  font-size: clamp(1.7rem, 4vw, 2.2rem);
  line-height: 1.15;
  margin-bottom: 8px;
}

.blog-article .blog-meta {
  font-size: 0.85rem;
  color: var(--text-dim);
  margin-bottom: 28px;
}

.blog-article h2 {
  color: var(--text);
  font-size: 1.3rem;
  margin: 30px 0 12px;
}

.blog-article a {
  color: var(--indigo);
  font-weight: 600;
}

.blog-cta {
  margin-top: 30px;
  padding: 20px;
  background: var(--bg-soft);
  border: 1px solid var(--border);
  border-radius: 14px;
}