/* =============================================
   CSS Variables
   ============================================= */
:root {
  --color-bg: #faf9f7;
  --color-text: #1f1e1c;
  --color-text-muted: #7a7570;
  --color-heading: #141312;
  --color-accent: #1a1a2e;
  --color-border: #e3dfd9;
  --color-surface: #f3f1ee;
  --color-link: #2a4a8a;
  --color-link-hover: #1a3060;

  --font-serif: Georgia, 'Times New Roman', serif;
  --font-sans: 'Helvetica Neue', Arial, sans-serif;

  --container-width: 720px;
  --container-padding: 1.5rem;

  --header-height: 56px;
}

/* =============================================
   Reset & Base
   ============================================= */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  background-color: var(--color-bg);
  color: var(--color-text);
  font-family: var(--font-serif);
  font-size: 1rem;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
}

/* =============================================
   Layout Container
   ============================================= */
.container {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 var(--container-padding);
}

/* =============================================
   Header
   ============================================= */
header {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: var(--color-bg);
  border-bottom: 1px solid transparent;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

header.scrolled {
  border-bottom-color: var(--color-border);
  box-shadow: 0 1px 6px rgba(0,0,0,0.05);
}

.header-inner {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 var(--container-padding);
  height: var(--header-height);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  text-decoration: none;
  color: var(--color-accent);
  font-family: var(--font-sans);
  font-weight: 600;
  font-size: 0.95rem;
  letter-spacing: 0.01em;
}

.logo svg {
  flex-shrink: 0;
}

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

/* =============================================
   Main & Spacing
   ============================================= */
main {
  padding-top: 3rem;
  padding-bottom: 4rem;
}

/* =============================================
   H1
   ============================================= */
h1 {
  font-family: var(--font-serif);
  font-size: clamp(1.55rem, 4vw, 2.1rem);
  font-weight: 700;
  line-height: 1.25;
  color: var(--color-heading);
  margin-bottom: 1.5rem;
  letter-spacing: -0.01em;
}

/* =============================================
   Intro Section
   ============================================= */
.intro {
  margin-bottom: 2rem;
  border-bottom: 1px solid var(--color-border);
  padding-bottom: 2rem;
}

.intro p {
  font-size: 1.05rem;
  color: var(--color-text);
  margin-bottom: 0.9rem;
}

.intro p:last-child {
  margin-bottom: 0;
}

/* =============================================
   Author Box
   ============================================= */
.author-box {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 1.25rem 0;
  border-bottom: 1px solid var(--color-border);
  margin-bottom: 2.5rem;
}

.author-photo {
  width: 52px;
  height: 52px;
  border-radius: 50%;
  object-fit: cover;
  flex-shrink: 0;
  border: 2px solid var(--color-border);
}

.author-info {
  display: flex;
  flex-direction: column;
  gap: 0.2rem;
}

.author-name {
  font-family: var(--font-sans);
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--color-heading);
}

.author-updated {
  font-family: var(--font-sans);
  font-size: 0.78rem;
  color: var(--color-text-muted);
}

/* =============================================
   Content Headings
   ============================================= */
.content h2 {
  font-family: var(--font-serif);
  font-size: clamp(1.2rem, 3vw, 1.5rem);
  font-weight: 700;
  line-height: 1.3;
  color: var(--color-heading);
  margin-top: 2.8rem;
  margin-bottom: 0.9rem;
  letter-spacing: -0.01em;
}

.content h3 {
  font-family: var(--font-serif);
  font-size: 1.1rem;
  font-weight: 700;
  line-height: 1.35;
  color: var(--color-heading);
  margin-top: 2rem;
  margin-bottom: 0.6rem;
}

.content h4 {
  font-family: var(--font-sans);
  font-size: 0.88rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--color-text-muted);
  margin-top: 1.4rem;
  margin-bottom: 0.4rem;
}

/* =============================================
   Content Paragraphs
   ============================================= */
.content p {
  margin-bottom: 1rem;
  color: var(--color-text);
}

.content p:last-child {
  margin-bottom: 0;
}

/* =============================================
   Links
   ============================================= */
a {
  color: var(--color-link);
  text-decoration: underline;
  text-underline-offset: 2px;
  text-decoration-thickness: 1px;
  transition: color 0.15s ease;
}

a:hover {
  color: var(--color-link-hover);
}

/* =============================================
   Lists
   ============================================= */
.content ul,
.content ol {
  padding-left: 1.5rem;
  margin-bottom: 1rem;
}

.content li {
  margin-bottom: 0.3rem;
}

.content li:last-child {
  margin-bottom: 0;
}

/* =============================================
   Blockquotes
   ============================================= */
.content blockquote {
  border-left: 3px solid var(--color-border);
  padding: 0.5rem 0 0.5rem 1.25rem;
  margin: 1.5rem 0;
  color: var(--color-text-muted);
  font-style: italic;
}

/* =============================================
   Tables
   ============================================= */
.table-wrap {
  overflow-x: auto;
  margin: 1.5rem 0;
  border: 1px solid var(--color-border);
  border-radius: 4px;
}

table {
  width: 100%;
  border-collapse: collapse;
  font-family: var(--font-sans);
  font-size: 0.82rem;
  min-width: 480px;
}

thead {
  background-color: var(--color-surface);
}

th {
  text-align: left;
  padding: 0.6rem 0.75rem;
  font-weight: 600;
  color: var(--color-heading);
  border-bottom: 1px solid var(--color-border);
  white-space: nowrap;
}

td {
  padding: 0.55rem 0.75rem;
  border-bottom: 1px solid var(--color-border);
  vertical-align: top;
  color: var(--color-text);
}

tbody tr:last-child td {
  border-bottom: none;
}

tbody tr:hover {
  background-color: var(--color-surface);
}

/* =============================================
   Footer
   ============================================= */
footer {
  border-top: 1px solid var(--color-border);
  padding: 1.5rem 0;
}

footer p {
  font-family: var(--font-sans);
  font-size: 0.8rem;
  color: var(--color-text-muted);
  text-align: center;
}

/* =============================================
   Responsive – Mobile
   ============================================= */
@media (max-width: 600px) {
  :root {
    --container-padding: 1rem;
  }

  main {
    padding-top: 2rem;
    padding-bottom: 3rem;
  }

  .author-photo {
    width: 44px;
    height: 44px;
  }

  .author-box {
    gap: 0.75rem;
  }

  table {
    font-size: 0.78rem;
  }

  th, td {
    padding: 0.45rem 0.6rem;
  }
}