:root {
  --font-body: "Noto Sans KR", sans-serif;
  --font-code: "Fira Code", "D2Coding", monospace;
  --color-bg: #f4f7fb;
  --color-surface: #ffffff;
  --bg-secondary: #f0f4fa;
  --color-text: #1f2937;
  --color-text-heading: #0f172a;
  --color-border: #d7dee8;
  --color-code-bg: #e9eff8;
  --color-code-text: #0f3a75;
  --accent-color: #1d4ed8;
  --accent-light-color: #e8f0ff;
  --shadow-md: 0 12px 26px rgba(15, 23, 42, 0.08);
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
}

body {
  font-family: var(--font-body);
  color: var(--color-text);
  background:
    radial-gradient(circle at 10% 0%, #e4ecff 0%, transparent 40%),
    radial-gradient(circle at 90% 0%, #e7fff8 0%, transparent 35%),
    var(--color-bg);
  line-height: 1.7;
}

main {
  padding-bottom: 3rem;
}

.container {
  width: min(1120px, calc(100% - 2rem));
  margin: 0 auto;
}

.page-header {
  background: linear-gradient(135deg, #0f172a 0%, #1e3a8a 55%, #0f766e 100%);
  color: #f8fafc;
  padding: 3.5rem 0 2.75rem;
  margin-bottom: 2rem;
  box-shadow: var(--shadow-md);
}

.page-header h1 {
  margin: 0;
  font-size: clamp(1.9rem, 3.8vw, 2.8rem);
  line-height: 1.2;
  font-weight: 800;
  letter-spacing: -0.02em;
}

.subtitle {
  margin: 0.95rem 0 0;
  max-width: 70ch;
  color: #d7e3ff;
  font-weight: 500;
}

.section-title {
  margin: 2.8rem 0 1rem;
  font-size: clamp(1.4rem, 2.4vw, 1.8rem);
  color: var(--color-text-heading);
  letter-spacing: -0.01em;
  border-left: 6px solid var(--accent-color);
  padding-left: 0.7rem;
}

.subsection-title {
  margin: 2rem 0 0.85rem;
  font-size: clamp(1.15rem, 2vw, 1.35rem);
  color: #1d3557;
}

.info-box {
  margin-top: 0.6rem;
}

.info-box p,
.info-box ul {
  margin: 0.5rem 0;
}

.info-box ul {
  padding-left: 1.1rem;
}

.mt-2 {
  margin-top: 1rem;
}

a {
  color: var(--accent-color);
  text-underline-offset: 2px;
}

a:hover {
  text-decoration-thickness: 2px;
}

.katex-table {
  width: 100%;
  table-layout: fixed;
}

.katex-table td,
.katex-table th {
  word-break: break-word;
}

.katex {
  color: #111827;
}

@media (max-width: 960px) {
  .container {
    width: min(1120px, calc(100% - 1.25rem));
  }

  .page-header {
    padding: 2.75rem 0 2.2rem;
  }

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

  .katex-table td,
  .katex-table th {
    min-width: 170px;
    white-space: normal;
  }
}

@media (prefers-reduced-motion: no-preference) {
  .page-header,
  .katex-table,
  .info-box {
    animation: fade-up 0.45s ease-out both;
  }

  .katex-table {
    animation-delay: 0.06s;
  }
}

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