:root {
  color-scheme: light;
  --surface: #ffffff;
  --surface-alt: #f5f7fb;
  --text: #152239;
  --muted: #5a6575;
  --accent: #f97316;
  --border: #d9deeb;
  --radius: 16px;
  --shadow: 0 18px 40px -24px rgba(15, 23, 42, 0.45);
  font-size: 16px;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: "Inter", "Segoe UI", "Helvetica Neue", Arial, sans-serif;
  line-height: 1.65;
  color: var(--text);
  background: var(--surface-alt);
  text-rendering: optimizeLegibility;
}

a {
  color: #0b62ff;
  text-decoration: none;
}

a:hover,
a:focus-visible {
  text-decoration: underline;
}

header {
  position: sticky;
  top: 0;
  z-index: 40;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border);
}

.header-inner {
  margin: 0 auto;
  max-width: 1200px;
  padding: 1rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.brand {
  font-weight: 700;
  font-size: 1.125rem;
  letter-spacing: 0.02em;
  color: var(--text);
}

nav {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}

nav a {
  padding: 0.35rem 0.85rem;
  border-radius: 999px;
  border: 1px solid transparent;
  transition: all 0.2s ease;
  font-weight: 500;
  color: var(--muted);
}

nav a:hover,
nav a:focus-visible,
nav a[aria-current="page"] {
  border-color: rgba(15, 118, 110, 0.25);
  background: rgba(15, 118, 110, 0.08);
  color: #0f766e;
}

main {
  margin: 0 auto;
  padding: 2.5rem 1.5rem 4rem;
  max-width: 1200px;
}

section {
  padding: 2.25rem clamp(1.2rem, 5vw, 3rem);
  margin-bottom: 2rem;
  border-radius: var(--radius);
  background: var(--surface);
  box-shadow: var(--shadow);
  border: 1px solid rgba(15, 23, 42, 0.05);
}

section h1,
section h2,
section h3 {
  margin-top: 0;
  font-weight: 700;
  line-height: 1.3;
  color: var(--text);
}

section h1 {
  font-size: clamp(2rem, 4vw, 2.75rem);
}

section h2 {
  font-size: clamp(1.45rem, 3vw, 2.1rem);
}

section h3 {
  font-size: clamp(1.25rem, 2.5vw, 1.6rem);
}

p {
  margin: 1rem 0;
  color: var(--muted);
}

.keyword {
  font-weight: 700;
  color: #0f4c81;
  background: rgba(15, 76, 129, 0.12);
  padding: 0.1em 0.35em;
  border-radius: 0.4em;
}

.cta {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.7rem 1.5rem;
  border-radius: 999px;
  font-weight: 600;
  background: linear-gradient(135deg, #2563eb, #0ea5e9);
  color: #ffffff;
  border: none;
  cursor: pointer;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.cta:hover,
.cta:focus-visible {
  transform: translateY(-1px);
  box-shadow: 0 15px 30px -20px rgba(14, 165, 233, 0.65);
}

.grid {
  display: grid;
  gap: 1.5rem;
}

.grid-2 {
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
}

.card {
  padding: 1.75rem;
  border-radius: var(--radius);
  background: var(--surface-alt);
  border: 1px solid rgba(15, 23, 42, 0.05);
}

.badge {
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
  padding: 0.25rem 0.65rem;
  border-radius: 999px;
  font-size: 0.8rem;
  font-weight: 600;
  background: rgba(14, 165, 233, 0.12);
  color: #0f4c81;
}

ul,
ol {
  padding-left: 1.1rem;
}

li + li {
  margin-top: 0.35rem;
}

footer {
  background: #0f172a;
  color: rgba(226, 232, 240, 0.8);
  padding: 2.5rem 1.5rem;
}

.footer-inner {
  margin: 0 auto;
  max-width: 1200px;
  display: grid;
  gap: 1.5rem;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
}

.footer-inner a {
  color: rgba(224, 231, 255, 0.85);
}

.footer-note {
  text-align: center;
  margin-top: 1.5rem;
  font-size: 0.85rem;
  color: rgba(226, 232, 240, 0.65);
}

@media (max-width: 960px) {
  header {
    position: static;
  }

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

  main {
    padding-top: 2rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}