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

:root {
  color-scheme: light;
  --bg: #f7f8fc;
  --surface: #ffffff;
  --surface-2: #f1f4fb;
  --text: #0f172a;
  --muted: #5b6476;
  --accent: #2563eb;
  --accent-soft: rgba(37, 99, 235, 0.12);
  --accent-red: #ef4444;
  --accent-yellow: #f59e0b;
  --accent-green: #22c55e;
  --accent-blue: #2563eb;
  --border: #e1e5ef;
  --shadow: 0 20px 45px rgba(15, 23, 42, 0.1);
}

body {
  font-family: "Segoe UI", "Inter", system-ui, -apple-system, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
}

a {
  color: inherit;
  text-decoration: none;
}

.container {
  width: min(1200px, 92vw);
  margin: 0 auto;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: rgba(245, 247, 251, 0.92);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
  padding: 1rem 0;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.7rem;
  font-weight: 700;
  font-size: 1.05rem;
}

.logo {
  width: 38px;
  height: 38px;
  display: grid;
  place-items: center;
  border-radius: 12px;
  background: linear-gradient(135deg, var(--accent-blue), var(--accent-green));
  color: white;
  font-size: 1.2rem;
}

.nav-links {
  display: flex;
  gap: 1.4rem;
  font-size: 0.95rem;
  color: var(--muted);
}

.nav-links a {
  padding: 0.35rem 0.4rem;
  border-radius: 10px;
}

.nav-links a:hover,
.nav-links a:focus {
  background: var(--surface-2);
  color: var(--text);
}

.cta {
  border: none;
  background: linear-gradient(135deg, var(--accent-blue), var(--accent-green));
  color: white;
  padding: 0.6rem 1.2rem;
  border-radius: 999px;
  font-weight: 600;
  cursor: pointer;
  box-shadow: var(--shadow);
}

.hero {
  padding: 4rem 0 2rem;
}

.hero-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 2rem;
  align-items: center;
}

.hero-copy h1 {
  font-size: clamp(2.4rem, 3vw, 3.2rem);
  margin: 0.8rem 0 1rem;
}

.eyebrow {
  color: var(--accent);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  font-size: 0.75rem;
}

.subhead {
  color: var(--muted);
  margin-bottom: 1.6rem;
}

.hero-actions {
  display: grid;
  gap: 1.4rem;
}

.search {
  background: var(--surface);
  padding: 0.8rem 1rem;
  border-radius: 16px;
  box-shadow: var(--shadow);
  display: grid;
  gap: 0.5rem;
  border: 1px solid var(--border);
}

.search span {
  font-size: 0.85rem;
  color: var(--muted);
}

.search input {
  border: none;
  font-size: 1rem;
  outline: none;
}

.stats {
  display: flex;
  gap: 1.5rem;
}

.stat-value {
  font-size: 1.6rem;
  font-weight: 700;
  display: block;
}

.stats > div:nth-child(1) .stat-value {
  color: var(--accent-blue);
}

.stats > div:nth-child(2) .stat-value {
  color: var(--accent-green);
}

.stat-label {
  font-size: 0.85rem;
  color: var(--muted);
}

.hero-card {
  background: var(--surface);
  padding: 2rem;
  border-radius: 24px;
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
}

.hero-card h2 {
  margin-bottom: 1rem;
}

.hero-card ul {
  display: grid;
  gap: 0.8rem;
  padding-left: 1.1rem;
  color: var(--muted);
}

.hero-card .note {
  margin-top: 1.4rem;
  font-size: 0.9rem;
  color: var(--muted);
}

.tool-page {
  background: var(--surface);
  padding: 2.5rem;
  border-radius: 24px;
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
  display: grid;
  gap: 1rem;
}

.tool-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  align-items: center;
}

.tool-cta {
  text-decoration: none;
}

.secondary-link {
  color: var(--muted);
  font-weight: 600;
}

.section {
  padding: 3rem 0 4rem;
}

.section-header {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 1rem;
  margin-bottom: 2rem;
}

.section-header p {
  color: var(--muted);
}

.tool-sections {
  display: grid;
  gap: 2.5rem;
}

.tool-section {
  background: var(--surface);
  border-radius: 22px;
  padding: 1.8rem;
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
}

.tool-section h3 {
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  gap: 0.7rem;
}

.pill {
  background: linear-gradient(135deg, rgba(37, 99, 235, 0.14), rgba(34, 197, 94, 0.14));
  color: var(--accent-blue);
  padding: 0.2rem 0.6rem;
  font-size: 0.75rem;
  border-radius: 999px;
  font-weight: 600;
}

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

.tool-card {
  border-radius: 16px;
  padding: 1rem;
  background: var(--surface-2);
  border: 1px solid transparent;
  transition: transform 0.2s ease, border 0.2s ease;
  display: grid;
  gap: 0.6rem;
}

.tool-card:hover {
  transform: translateY(-4px);
  border: 1px solid var(--accent-blue);
  box-shadow: 0 12px 24px rgba(37, 99, 235, 0.12);
}

.tool-card:nth-child(4n + 1) {
  border-left: 4px solid var(--accent-blue);
}

.tool-card:nth-child(4n + 2) {
  border-left: 4px solid var(--accent-red);
}

.tool-card:nth-child(4n + 3) {
  border-left: 4px solid var(--accent-yellow);
}

.tool-card:nth-child(4n) {
  border-left: 4px solid var(--accent-green);
}

.tool-card h4 {
  font-size: 1rem;
}

.tool-card p {
  color: var(--muted);
  font-size: 0.88rem;
}

.tool-card a {
  font-weight: 600;
  color: var(--accent-blue);
}

.page-content {
  display: grid;
  gap: 1rem;
}

.page-content h1 {
  font-size: clamp(2rem, 2.6vw, 2.6rem);
}

.rich-text {
  display: grid;
  gap: 1rem;
  color: var(--text);
}

.rich-text h2 {
  margin-top: 1rem;
  font-size: 1.4rem;
}

.rich-text h3 {
  margin-top: 0.8rem;
  font-size: 1.15rem;
}

.rich-text p,
.rich-text li {
  color: var(--muted);
}

.rich-text ul,
.rich-text ol {
  padding-left: 1.4rem;
}

.rich-text table {
  width: 100%;
  border-collapse: collapse;
  background: var(--surface-2);
  border-radius: 12px;
  overflow: hidden;
}

.rich-text th,
.rich-text td {
  padding: 0.85rem;
  border-bottom: 1px solid var(--border);
  text-align: left;
}

.rich-text blockquote {
  border-left: 4px solid var(--accent);
  padding: 0.8rem 1rem;
  background: var(--surface-2);
  border-radius: 12px;
  color: var(--muted);
}

.rich-text form {
  display: grid;
  gap: 0.8rem;
}

.rich-text input,
.rich-text textarea,
.rich-text select {
  width: 100%;
  padding: 0.7rem 0.9rem;
  border-radius: 10px;
  border: 1px solid var(--border);
  font-size: 1rem;
}

.rich-text button,
.rich-text input[type="submit"] {
  border: none;
  background: var(--accent);
  color: #fff;
  padding: 0.7rem 1.4rem;
  border-radius: 999px;
  font-weight: 600;
  cursor: pointer;
  width: fit-content;
}

.bmi-layout {
  display: grid;
  gap: 1.5rem;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
}

.bmi-card {
  background: var(--surface);
  padding: 1.6rem;
  border-radius: 18px;
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
  display: grid;
  gap: 1rem;
}

.bmi-card .input-group {
  display: grid;
  gap: 0.4rem;
}

.bmi-card label {
  font-weight: 600;
}

.bmi-card input,
.bmi-card select {
  width: 100%;
  padding: 0.7rem 0.9rem;
  border-radius: 10px;
  border: 1px solid var(--border);
  font-size: 1rem;
}

.bmi-card .result {
  padding: 0.8rem 1rem;
  border-radius: 10px;
  font-weight: 600;
  color: #fff;
  text-align: center;
}

.bmi-card .ideal-weight {
  color: var(--muted);
  font-size: 0.95rem;
  text-align: center;
}

.bmi-card .normal {
  background-color: var(--accent-green);
}

.bmi-card .underweight {
  background-color: var(--accent-yellow);
}

.bmi-card .overweight {
  background-color: #f97316;
}

.bmi-card .obese {
  background-color: var(--accent-red);
}

.bmi-card.chart {
  background: var(--surface-2);
}

.bmi-card.chart h3 {
  margin-bottom: 0.5rem;
}

.bmi-card.chart .category {
  display: flex;
  justify-content: space-between;
  padding: 0.4rem 0;
  color: var(--muted);
  font-weight: 600;
}

.calc-layout {
  display: grid;
  gap: 1.6rem;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  margin-top: 1.5rem;
}

.calc-card {
  background: var(--surface);
  padding: 1.6rem;
  border-radius: 18px;
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
  display: grid;
  gap: 1rem;
}

.calc-card .input-group {
  display: grid;
  gap: 0.4rem;
}

.calc-card label {
  font-weight: 600;
}

.calc-card input,
.calc-card select {
  width: 100%;
  padding: 0.7rem 0.9rem;
  border-radius: 10px;
  border: 1px solid var(--border);
  font-size: 1rem;
}

.calc-results {
  display: grid;
  gap: 0.8rem;
}

.calc-results .result-item {
  background: var(--surface-2);
  border-radius: 14px;
  padding: 0.9rem 1rem;
  border: 1px solid var(--border);
}

.calc-results .result-item strong {
  display: block;
  font-size: 1.2rem;
  margin-top: 0.3rem;
}

.calc-results .result-item:nth-child(4n + 1) strong {
  color: var(--accent-blue);
}

.calc-results .result-item:nth-child(4n + 2) strong {
  color: var(--accent-red);
}

.calc-results .result-item:nth-child(4n + 3) strong {
  color: var(--accent-yellow);
}

.calc-results .result-item:nth-child(4n) strong {
  color: var(--accent-green);
}

.site-footer {
  border-top: 1px solid var(--border);
  padding: 3rem 0;
  background: var(--surface);
}

.footer-grid {
  display: grid;
  gap: 2rem;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
}

.footer-links {
  display: grid;
  gap: 0.5rem;
  color: var(--muted);
}

.footer-meta {
  margin-top: 2rem;
  color: var(--muted);
  font-size: 0.9rem;
}

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

  .cta {
    display: none;
  }
}

@media (max-width: 768px) {
  .container {
    width: min(1200px, 94vw);
  }

  .hero {
    padding: 3rem 0 1.5rem;
  }

  .hero-grid {
    grid-template-columns: 1fr;
  }

  .hero-copy h1 {
    font-size: clamp(2rem, 6vw, 2.6rem);
  }

  .stats {
    flex-direction: column;
  }

  .section-header {
    flex-direction: column;
    align-items: flex-start;
  }

  .tool-grid {
    grid-template-columns: 1fr;
  }

  .tool-section {
    padding: 1.2rem;
  }

  .tool-page {
    padding: 1.5rem;
  }

  .calc-layout,
  .bmi-layout {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 640px) {
  .nav {
    flex-direction: column;
    align-items: flex-start;
  }

  .hero-card,
  .calc-card,
  .bmi-card {
    padding: 1.2rem;
  }

  .rich-text table {
    display: block;
    overflow-x: auto;
    white-space: nowrap;
  }
}