:root {
  --ink: #1a1816;
  --ink-soft: #3d3833;
  --ink-mute: #6b655e;
  --paper: #faf7f2;
  --paper-deep: #f3efe7;
  --accent: #8b6f47;
  --accent-soft: rgba(139, 111, 71, 0.12);
  --line: rgba(26, 24, 22, 0.08);
  --serif: "Noto Serif KR", "Apple SD Gothic Neo", serif;
  --mono: "JetBrains Mono", ui-monospace, "SF Mono", monospace;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: var(--serif);
  background: var(--paper);
  color: var(--ink);
  line-height: 1.85;
  letter-spacing: 0.01em;
  font-size: 17px;
  font-weight: 400;
  -webkit-font-smoothing: antialiased;
}

/* ─── 리포트 헤더 ─── */
.report-header {
  max-width: 720px;
  margin: 0 auto;
  padding: 64px 32px 48px;
  position: relative;
}

.back-link {
  display: inline-block;
  color: var(--ink-mute);
  text-decoration: none;
  font-size: 14px;
  letter-spacing: 0.05em;
  margin-bottom: 48px;
  transition: color 0.2s ease, transform 0.2s ease;
}

.back-link:hover {
  color: var(--accent);
  transform: translateX(-4px);
}

.header-meta { }

.date-badge {
  font-family: var(--mono);
  font-size: 13px;
  color: var(--accent);
  letter-spacing: 0.1em;
  margin-bottom: 16px;
}

.report-header h1 {
  font-size: 2.4rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.2;
  margin-bottom: 12px;
}

.subtitle {
  font-size: 15px;
  color: var(--ink-mute);
  letter-spacing: 0.02em;
}

/* ─── 본문 ─── */
.report-body {
  max-width: 720px;
  margin: 0 auto;
  padding: 0 32px 80px;
}

.report-body h1 {
  font-size: 2rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin: 64px 0 24px;
  padding-bottom: 12px;
  border-bottom: 2px solid var(--accent-soft);
}

.report-body h2 {
  font-size: 1.5rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  margin: 56px 0 20px;
  color: var(--ink);
}

.report-body h3 {
  font-size: 1.2rem;
  font-weight: 500;
  margin: 40px 0 16px;
  color: var(--ink-soft);
}

.report-body h4 {
  font-size: 1rem;
  font-weight: 500;
  margin: 28px 0 12px;
  color: var(--ink-soft);
  letter-spacing: 0.02em;
}

.report-body p {
  margin-bottom: 20px;
  color: var(--ink-soft);
}

.report-body strong {
  color: var(--ink);
  font-weight: 700;
}

.report-body em {
  font-style: italic;
  color: var(--accent);
}

.report-body ul, .report-body ol {
  margin: 0 0 20px 24px;
  color: var(--ink-soft);
}

.report-body li {
  margin-bottom: 8px;
}

.report-body li::marker {
  color: var(--accent);
}

.report-body blockquote {
  margin: 28px 0;
  padding: 4px 0 4px 24px;
  border-left: 3px solid var(--accent);
  color: var(--ink-soft);
  font-style: italic;
  background: var(--accent-soft);
  padding-top: 16px;
  padding-bottom: 16px;
  padding-right: 20px;
  border-radius: 0 6px 6px 0;
}

.report-body blockquote p { margin-bottom: 0; }

.report-body hr {
  border: none;
  border-top: 1px solid var(--line);
  margin: 56px 0;
}

/* ─── 코드 / 흐름도 ─── */
.report-body code {
  font-family: var(--mono);
  font-size: 0.88em;
  background: var(--paper-deep);
  padding: 2px 6px;
  border-radius: 4px;
  color: var(--accent);
}

.report-body pre {
  background: var(--paper-deep);
  padding: 20px 24px;
  border-radius: 8px;
  overflow-x: auto;
  margin: 28px 0;
  line-height: 1.7;
  border: 1px solid var(--line);
}

.report-body pre code {
  background: transparent;
  padding: 0;
  color: var(--ink-soft);
  font-size: 14px;
}

/* ─── 테이블 ─── */
.report-body table {
  width: 100%;
  border-collapse: collapse;
  margin: 28px 0;
  font-size: 15px;
}

.report-body th, .report-body td {
  padding: 12px 16px;
  text-align: left;
  border-bottom: 1px solid var(--line);
}

.report-body th {
  font-weight: 700;
  color: var(--ink);
  background: var(--paper-deep);
}

.report-body td {
  color: var(--ink-soft);
}

/* ─── 링크 ─── */
.report-body a {
  color: var(--accent);
  text-decoration: none;
  border-bottom: 1px solid var(--accent-soft);
  transition: border-color 0.2s ease;
}

.report-body a:hover {
  border-bottom-color: var(--accent);
}

/* ─── 풋터 ─── */
.report-footer {
  max-width: 720px;
  margin: 0 auto;
  padding: 32px;
  border-top: 1px solid var(--line);
  text-align: center;
  color: var(--ink-mute);
  font-size: 14px;
}

.report-footer a {
  color: var(--accent);
  text-decoration: none;
  margin-left: 8px;
}

/* ─── 아카이브 페이지 ─── */
body.archive .archive-header {
  max-width: 720px;
  margin: 0 auto;
  padding: 64px 32px 48px;
  text-align: center;
}

body.archive .archive-header .back-link {
  display: block;
  text-align: left;
  margin-bottom: 48px;
}

body.archive .archive-header h1 {
  font-size: 2.8rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 16px;
}

body.archive .archive-header .subtitle {
  font-size: 16px;
  color: var(--ink-mute);
  margin-bottom: 24px;
}

body.archive .archive-header .tagline {
  font-size: 14px;
  color: var(--accent);
  font-style: italic;
  letter-spacing: 0.02em;
}

.archive-list {
  max-width: 720px;
  margin: 0 auto;
  padding: 48px 32px;
}

.archive-entry {
  display: block;
  padding: 24px 20px;
  border-radius: 12px;
  text-decoration: none;
  color: inherit;
  transition: background 0.25s ease, transform 0.25s ease;
  margin-bottom: 4px;
}

.archive-entry:hover {
  background: var(--accent-soft);
  transform: translateX(6px);
}

.archive-entry .entry-date {
  font-family: var(--mono);
  font-size: 15px;
  color: var(--accent);
  letter-spacing: 0.06em;
  font-weight: 500;
}

.archive-entry .entry-label {
  font-size: 14px;
  color: var(--ink-mute);
  margin-left: 16px;
}

.archive-entry.latest .entry-label {
  color: var(--accent);
  font-weight: 500;
}

.archive-footer {
  max-width: 720px;
  margin: 0 auto;
  padding: 32px;
  text-align: center;
  color: var(--ink-mute);
  font-size: 14px;
  border-top: 1px solid var(--line);
}

.archive-footer strong {
  color: var(--ink);
}

/* ─── 모바일 ─── */
@media (max-width: 640px) {
  body { font-size: 16px; }
  .report-header { padding: 48px 20px 32px; }
  .report-body { padding: 0 20px 64px; }
  .report-header h1 { font-size: 1.9rem; }
  .report-body h1 { font-size: 1.6rem; }
  .report-body h2 { font-size: 1.3rem; }
  body.archive .archive-header { padding: 64px 20px 32px; }
  body.archive .archive-header h1 { font-size: 2.1rem; }
  .archive-list { padding: 32px 20px; }
  .archive-entry { padding: 20px 16px; }
}