/* Toolratio — global stylesheet
   Pure CSS, no framework, no build step. Mobile-first. */

:root {
  --color-bg: #ffffff;
  --color-bg-alt: #f7f9fb;
  --color-surface: #ffffff;
  --color-border: #e3e8ee;
  --color-text: #142433;
  --color-text-muted: #5c6b7a;
  --color-primary: #1e3a5f;
  --color-primary-dark: #142943;
  --color-primary-light: #eaf0f6;
  --gradient-primary: linear-gradient(135deg, #1e3a5f 0%, #2c5282 100%);
  --color-accent: #2ecc71;
  --color-accent-dark: #146c3d;
  --color-accent-light: #e6f9ee;
  --chart-1: #1e3a5f;
  --chart-2: #2ecc71;
  --chart-3: #f5a623;
  --chart-4: #9b59b6;
  --chart-5: #e74c3c;
  --chart-6: #16a2a2;
  --radius: 14px;
  --radius-sm: 8px;
  --shadow: 0 1px 2px rgba(20, 36, 51, 0.04), 0 6px 18px rgba(20, 36, 51, 0.06);
  --shadow-hover: 0 4px 10px rgba(20, 36, 51, 0.06), 0 18px 32px rgba(30, 58, 95, 0.12);
  --max-width: 1120px;
  --font-sans: "Inter", ui-sans-serif, system-ui, -apple-system, "Segoe UI", "Segoe UI Variable", Roboto, Helvetica, Arial, sans-serif;
}

* {
  box-sizing: border-box;
}

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font-sans);
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.6;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

img {
  max-width: 100%;
  display: block;
}

a {
  color: var(--color-primary);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

h1, h2, h3, h4 {
  line-height: 1.2;
  font-weight: 800;
  letter-spacing: -0.02em;
  margin: 0 0 0.5em;
  color: var(--color-primary-dark);
}

p {
  margin: 0 0 1em;
}

ul {
  margin: 0 0 1em;
  padding-left: 1.25em;
}

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 20px;
}

/* ============ Header & navigation ============ */
.site-header {
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  position: sticky;
  top: 0;
  z-index: 100;
}

.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.logo {
  font-size: 1.3rem;
  font-weight: 800;
  color: var(--color-primary-dark);
  letter-spacing: -0.03em;
  white-space: nowrap;
}

.logo span {
  color: var(--color-accent-dark);
}

.nav-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  background: var(--color-surface);
  cursor: pointer;
}

.nav-toggle svg {
  width: 20px;
  height: 20px;
}

.site-nav {
  position: fixed;
  top: 64px;
  left: 0;
  right: 0;
  bottom: 0;
  background: var(--color-surface);
  padding: 8px 20px 32px;
  overflow-y: auto;
  display: none;
  z-index: 90;
}

.site-nav.is-open {
  display: block;
}

.nav-list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-item {
  border-bottom: 1px solid var(--color-border);
}

.nav-item > a,
.nav-trigger {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  padding: 14px 4px;
  font-weight: 600;
  font-size: 1rem;
  color: var(--color-text);
  background: none;
  border: none;
  text-align: left;
  cursor: pointer;
  font-family: inherit;
}

.nav-trigger .chevron {
  width: 16px;
  height: 16px;
  transition: transform 0.2s ease;
  flex-shrink: 0;
}

.nav-item.is-open .nav-trigger .chevron {
  transform: rotate(180deg);
}

.nav-dropdown {
  display: none;
  padding: 0 0 12px 4px;
}

.nav-item.is-open .nav-dropdown {
  display: block;
}

.nav-group + .nav-group {
  margin-top: 14px;
}

.nav-group-title {
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--color-text-muted);
  margin: 0 0 6px;
}

.nav-dropdown a {
  display: block;
  padding: 8px 10px;
  border-radius: var(--radius-sm);
  color: var(--color-text-muted);
  font-size: 0.95rem;
}

.nav-dropdown a:hover {
  background: var(--color-primary-light);
  color: var(--color-primary);
  text-decoration: none;
}

@media (min-width: 900px) {
  .nav-toggle {
    display: none;
  }

  .site-nav {
    position: static;
    display: block;
    padding: 0;
    background: none;
    overflow: visible;
  }

  .nav-list {
    display: flex;
    align-items: center;
    gap: 4px;
  }

  .nav-item {
    position: relative;
    border-bottom: none;
  }

  .nav-item > a,
  .nav-trigger {
    padding: 10px 14px;
    border-radius: var(--radius-sm);
    font-size: 0.95rem;
    width: auto;
  }

  .nav-item > a:hover,
  .nav-trigger:hover {
    background: var(--color-primary-light);
  }

  .nav-dropdown {
    position: absolute;
    top: calc(100% + 6px);
    left: 0;
    min-width: 240px;
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    box-shadow: var(--shadow-hover);
    padding: 14px;
  }

  .nav-item:not(.is-open) .nav-dropdown {
    display: none;
  }
}

/* Breadcrumbs */
.breadcrumbs {
  font-size: 0.85rem;
  color: var(--color-text-muted);
  margin: 20px 0;
}

.breadcrumbs a {
  color: var(--color-text-muted);
}

.breadcrumbs a:hover {
  color: var(--color-primary);
}

/* ============ Hero ============ */
.hero {
  padding: 48px 0 36px;
  text-align: center;
}

.hero h1 {
  font-size: clamp(1.9rem, 4.5vw, 2.85rem);
  letter-spacing: -0.03em;
}

.hero p {
  color: var(--color-text-muted);
  font-size: 1.1rem;
  max-width: 620px;
  margin: 0 auto 1em;
}

/* ============ Category cards (homepage) ============ */
.category-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
  padding: 8px 0 8px;
}

@media (min-width: 700px) {
  .category-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.category-card {
  position: relative;
  background-color: var(--color-primary);
  background-image: var(--gradient-primary);
  color: #fff;
  border-radius: var(--radius);
  padding: 28px;
  box-shadow: var(--shadow);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
  overflow: hidden;
}

.category-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-hover);
}

.category-card .icon {
  font-size: 2rem;
  margin-bottom: 10px;
}

.category-card h2 {
  color: #fff;
  font-size: 1.3rem;
  margin-bottom: 6px;
}

.category-card p {
  color: rgba(255, 255, 255, 0.94);
  font-size: 0.92rem;
  margin-bottom: 0;
}

.category-card a.card-link {
  position: absolute;
  inset: 0;
}

/* ============ Calculator grid & cards ============ */
.section-heading {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
  padding: 40px 0 4px;
}

.section-heading h2 {
  font-size: 1.5rem;
  margin-bottom: 0;
}

.section-heading a {
  font-size: 0.9rem;
  font-weight: 600;
  white-space: nowrap;
}

.calc-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 18px;
  padding: 16px 0 40px;
}

@media (min-width: 640px) {
  .calc-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 980px) {
  .calc-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.calc-card {
  position: relative;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 24px;
  box-shadow: var(--shadow);
  overflow: hidden;
  transition: transform 0.2s ease, box-shadow 0.2s ease, border-color 0.2s ease;
}

.calc-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--color-accent);
  opacity: 0;
  transition: opacity 0.2s ease;
}

.calc-card:hover {
  transform: translateY(-4px);
  border-color: transparent;
  box-shadow: var(--shadow-hover);
}

.calc-card:hover::before {
  opacity: 1;
}

.calc-card .icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 46px;
  height: 46px;
  border-radius: var(--radius-sm);
  background: var(--color-primary-light);
  font-size: 1.4rem;
  margin-bottom: 14px;
}

.calc-card h3 {
  font-size: 1.08rem;
  margin-bottom: 6px;
}

.calc-card h3 a {
  color: var(--color-text);
}

.calc-card h3 a:hover {
  color: var(--color-primary);
  text-decoration: none;
}

.calc-card p {
  color: var(--color-text-muted);
  font-size: 0.92rem;
  margin-bottom: 0;
}

.badge {
  display: inline-block;
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  padding: 2px 8px;
  border-radius: 999px;
  background: var(--color-primary-light);
  color: var(--color-primary);
  margin-bottom: 10px;
}

/* ============ Calculator page layout ============ */
.calc-page-header {
  padding: 8px 0 24px;
}

.calc-page-header h1 {
  font-size: clamp(1.6rem, 3.5vw, 2.2rem);
}

.calc-page-header .subtitle {
  color: var(--color-text-muted);
  font-size: 1.05rem;
}

.calculator {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 22px;
  margin-bottom: 40px;
}

@media (min-width: 700px) {
  .calculator {
    padding: 30px;
  }
}

.calc-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: 28px;
}

@media (min-width: 800px) {
  .calc-layout {
    grid-template-columns: 1.1fr 1fr;
  }
}

.field-group {
  margin-bottom: 18px;
}

.field-group label {
  display: block;
  font-weight: 600;
  font-size: 0.9rem;
  margin-bottom: 6px;
}

.field-group .hint {
  font-size: 0.8rem;
  color: var(--color-text-muted);
  margin-top: 4px;
}

.field-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
}

input[type="number"],
input[type="text"],
select {
  width: 100%;
  padding: 10px 12px;
  font-size: 1rem;
  border: 1px solid var(--color-border);
  border-radius: 8px;
  background: var(--color-bg-alt);
  color: var(--color-text);
  font-family: inherit;
}

input[type="number"]:focus,
input[type="text"]:focus,
select:focus {
  outline: none;
  border-color: var(--color-primary);
  background: var(--color-surface);
  box-shadow: 0 0 0 3px var(--color-primary-light);
}

/* ============ Results panel (green accent) ============ */
.results {
  background: var(--color-accent-light);
  border-radius: var(--radius);
  padding: 22px;
  align-self: start;
}

.results h2 {
  font-size: 1rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--color-accent-dark);
  margin-bottom: 16px;
}

.result-main {
  font-size: 2.3rem;
  font-weight: 800;
  color: var(--color-accent-dark);
  letter-spacing: -0.02em;
  line-height: 1.1;
}

.result-main .unit {
  font-size: 1rem;
  font-weight: 600;
  color: var(--color-text-muted);
  margin-left: 4px;
}

.result-list {
  list-style: none;
  padding: 0;
  margin: 20px 0 0;
  border-top: 1px solid rgba(31, 156, 86, 0.18);
}

.result-list li {
  display: flex;
  justify-content: space-between;
  padding: 10px 0;
  border-bottom: 1px solid rgba(31, 156, 86, 0.18);
  font-size: 0.92rem;
}

.result-list li span:first-child {
  color: var(--color-text-muted);
}

.result-list li span:last-child {
  font-weight: 700;
  color: var(--color-primary-dark);
}

.result-note {
  margin-top: 14px;
  font-size: 0.82rem;
  color: var(--color-text-muted);
}

.chart-wrap {
  margin-top: 20px;
  background: var(--color-surface);
  border-radius: var(--radius-sm);
  padding: 14px;
  height: 200px;
  position: relative;
}

/* ============ SEO / article content ============ */
.content-section {
  padding: 8px 0 40px;
}

.content-section h2 {
  font-size: 1.4rem;
  margin-top: 1.4em;
}

.content-section h3 {
  font-size: 1.1rem;
}

/* ============ FAQ ============ */
.faq {
  padding: 8px 0 56px;
}

.faq h2 {
  font-size: 1.4rem;
}

.faq-item {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 16px 18px;
  margin-bottom: 10px;
}

.faq-item h3 {
  font-size: 1rem;
  margin-bottom: 8px;
}

.faq-item p {
  margin: 0;
  color: var(--color-text-muted);
}

/* ============ Category page ============ */
.subcategory-block {
  padding: 8px 0 24px;
}

.subcategory-block h2 {
  font-size: 1.25rem;
  padding-bottom: 4px;
  border-bottom: 2px solid var(--color-accent-light);
}

/* ============ Footer ============ */
.site-footer {
  border-top: 1px solid var(--color-border);
  padding: 32px 0;
  color: var(--color-text-muted);
  font-size: 0.85rem;
  background: var(--color-bg-alt);
}

.footer-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
  padding-bottom: 20px;
}

@media (min-width: 700px) {
  .footer-grid {
    grid-template-columns: 1.2fr 1fr 1fr 1fr 1fr;
  }
}

.footer-grid h3 {
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-text-muted);
  margin-bottom: 10px;
}

.footer-grid ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

.footer-grid li {
  margin-bottom: 6px;
}

.footer-grid a {
  color: var(--color-text-muted);
  font-size: 0.9rem;
}

.footer-grid a:hover {
  color: var(--color-primary);
}

.footer-bottom {
  border-top: 1px solid var(--color-border);
  padding-top: 16px;
}

.disclaimer {
  font-size: 0.78rem;
  color: var(--color-text-muted);
  margin-top: 20px;
}