/* ==========================================================================
   Chronicle — vertical timeline layout theme
   Posts alternate left/right of a center spine with date bubbles
   ========================================================================== */

/* --- Design tokens -------------------------------------------------------- */

:root,
html[data-theme="light"] {
  --bg: #f4f7f9;
  --card-bg: #ffffff;
  --txt: #1e293b;
  --muted: #64748b;
  --line: #e2e8f0;
  --accent: #0ea5e9;
  --accent-2: #06b6d4;
  --accent-soft: rgba(14, 165, 233, 0.1);
  --spine: #cbd5e1;
  --dot-border: #ffffff;
  --bubble-bg: #0ea5e9;
  --bubble-fg: #ffffff;
  --shadow: 0 1px 3px rgba(0,0,0,0.07), 0 4px 12px rgba(0,0,0,0.05);
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #0f172a;
    --card-bg: #1e293b;
    --txt: #e2e8f0;
    --muted: #94a3b8;
    --line: #334155;
    --accent: #38bdf8;
    --accent-2: #22d3ee;
    --accent-soft: rgba(56, 189, 248, 0.12);
    --spine: #334155;
    --dot-border: #1e293b;
    --bubble-bg: #0284c7;
    --bubble-fg: #ffffff;
    --shadow: 0 1px 3px rgba(0,0,0,0.3), 0 4px 12px rgba(0,0,0,0.2);
  }
}

html[data-theme="dark"] {
  --bg: #0f172a;
  --card-bg: #1e293b;
  --txt: #e2e8f0;
  --muted: #94a3b8;
  --line: #334155;
  --accent: #38bdf8;
  --accent-2: #22d3ee;
  --accent-soft: rgba(56, 189, 248, 0.12);
  --spine: #334155;
  --dot-border: #1e293b;
  --bubble-bg: #0284c7;
  --bubble-fg: #ffffff;
  --shadow: 0 1px 3px rgba(0,0,0,0.3), 0 4px 12px rgba(0,0,0,0.2);
}

/* --- Reset & base --------------------------------------------------------- */

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--txt);
  font-family: "DM Sans", system-ui, -apple-system, sans-serif;
  font-size: 1rem;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--accent);
  text-decoration-thickness: 1px;
  text-underline-offset: 2px;
}

::selection { background: var(--accent-soft); }

/* --- Header --------------------------------------------------------------- */

.site-header {
  max-width: 860px;
  margin: 0 auto;
  padding: 2rem 1.5rem 1rem;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: 0.4rem;
}

.site-brand {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  text-decoration: none;
  color: var(--txt);
}

.site-prompt {
  font-size: 1.3rem;
  color: var(--accent);
}

.brand-name {
  font-size: 1.25rem;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.site-brand:hover .brand-name { color: var(--accent); }

.header-right {
  display: flex;
  align-items: center;
  gap: 1.25rem;
}

.header-right nav {
  display: flex;
  gap: 1.25rem;
  font-size: 0.9rem;
}

.header-right nav a {
  color: var(--muted);
  text-decoration: none;
  font-weight: 500;
  transition: color 0.15s ease;
}

.header-right nav a:hover { color: var(--accent); }
.header-right nav a[aria-current="true"] { color: var(--accent); font-weight: 700; }

.site-tagline {
  font-size: 0.83rem;
  color: var(--muted);
  margin: 0;
  font-style: italic;
  letter-spacing: 0.01em;
}

.theme-toggle {
  background: transparent;
  border: 1px solid var(--line);
  border-radius: 8px;
  width: 2.1rem;
  height: 2.1rem;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 0.95rem;
  color: var(--muted);
  cursor: pointer;
  transition: color 0.15s ease, border-color 0.15s ease;
}

.theme-toggle:hover { color: var(--accent); border-color: var(--accent); }

.theme-icon { display: none; }
.theme-icon-dark { display: inline; }

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .theme-icon-dark { display: none; }
  :root:not([data-theme="light"]) .theme-icon-light { display: inline; }
}

html[data-theme="dark"] .theme-icon-dark { display: none; }
html[data-theme="dark"] .theme-icon-light { display: inline; }
html[data-theme="light"] .theme-icon-dark { display: inline; }
html[data-theme="light"] .theme-icon-light { display: none; }

/* --- Main content --------------------------------------------------------- */

main {
  max-width: 860px;
  margin: 0 auto;
  padding: 1.5rem 1.5rem 4rem;
}

/* --- Timeline ------------------------------------------------------------- */

.timeline-wrap {
  padding: 2rem 0;
}

.timeline {
  list-style: none;
  margin: 0;
  padding: 0;
  position: relative;
}

/* Center vertical spine */
.timeline::before {
  content: "";
  position: absolute;
  left: 50%;
  top: 0;
  bottom: 0;
  width: 2px;
  background: var(--spine);
  transform: translateX(-50%);
}

/* Each item */
.timeline-item {
  position: relative;
  display: grid;
  grid-template-columns: 1fr 60px 1fr;
  align-items: center;
  margin-bottom: 2.5rem;
  min-height: 120px;
}

/* The card */
.timeline-card {
  background: var(--card-bg);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 1.25rem 1.5rem;
  box-shadow: var(--shadow);
  transition: border-color 0.15s ease, box-shadow 0.15s ease;
}

.timeline-card:hover {
  border-color: var(--accent);
  box-shadow: var(--shadow), 0 0 0 2px var(--accent-soft);
}

/* Left items: card in col 1, dot in col 2, date in col 3 */
.timeline-left .timeline-card { grid-column: 1; text-align: right; }
.timeline-left .timeline-dot { grid-column: 2; }
.timeline-left .timeline-date-bubble { grid-column: 3; justify-self: start; margin-left: 1.5rem; }

/* Right items: date in col 1, dot in col 2, card in col 3 */
.timeline-right .timeline-date-bubble { grid-column: 1; justify-self: end; margin-right: 1.5rem; }
.timeline-right .timeline-dot { grid-column: 2; }
.timeline-right .timeline-card { grid-column: 3; text-align: left; }

/* Dot on spine */
.timeline-dot {
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 2;
  grid-row: 1;
}

.dot-inner {
  display: block;
  width: 14px;
  height: 14px;
  background: var(--accent);
  border: 3px solid var(--dot-border);
  border-radius: 50%;
  box-shadow: 0 0 0 2px var(--accent);
}

/* Date bubble */
.timeline-date-bubble {
  display: flex;
  flex-direction: column;
  align-items: center;
  background: var(--bubble-bg);
  color: var(--bubble-fg);
  border-radius: 8px;
  padding: 0.5rem 0.75rem;
  min-width: 52px;
  font-family: "DM Mono", ui-monospace, monospace;
  grid-row: 1;
}

.bubble-month {
  font-size: 0.62rem;
  font-weight: 500;
  letter-spacing: 0.1em;
  opacity: 0.85;
}

.bubble-day {
  font-size: 1.4rem;
  font-weight: 500;
  line-height: 1;
}

.bubble-year {
  font-size: 0.6rem;
  opacity: 0.7;
  margin-top: 0.1rem;
}

/* Card content */
.timeline-link {
  text-decoration: none;
  color: var(--txt);
}

.timeline-link:hover .timeline-title { color: var(--accent); }

.timeline-title {
  font-size: 1.05rem;
  font-weight: 700;
  margin: 0 0 0.4rem;
  line-height: 1.3;
  transition: color 0.15s ease;
}

.timeline-desc {
  font-size: 0.87rem;
  color: var(--muted);
  margin: 0 0 0.5rem;
  line-height: 1.5;
}

.timeline-meta {
  font-family: "DM Mono", ui-monospace, monospace;
  font-size: 0.72rem;
  color: var(--muted);
  margin-bottom: 0.4rem;
}

.timeline-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  justify-content: inherit;
}

.tag {
  font-size: 0.72rem;
  color: var(--accent);
  background: var(--accent-soft);
  padding: 0.1em 0.5em;
  border-radius: 4px;
}

.draft-badge {
  font-size: 0.65rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  padding: 0.1em 0.4em;
  border-radius: 3px;
  color: #d97706;
  border: 1px solid #d97706;
}

/* --- Post page ------------------------------------------------------------ */

.post-back {
  display: inline-block;
  font-family: "DM Mono", ui-monospace, monospace;
  font-size: 0.82rem;
  color: var(--muted);
  text-decoration: none;
  margin-bottom: 2rem;
  transition: color 0.15s ease;
}

.post-back:hover { color: var(--accent); }

.post-head {
  margin-bottom: 2.5rem;
  padding-bottom: 1.5rem;
  border-bottom: 1px solid var(--line);
}

.post-head h1 {
  margin: 0 0 0.75rem;
  font-size: 2rem;
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.02em;
}

.post-meta-line {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.5rem;
  font-family: "DM Mono", ui-monospace, monospace;
  font-size: 0.8rem;
  color: var(--muted);
}

.post-meta-sep { opacity: 0.5; }
.post-tags { display: inline-flex; gap: 0.5rem; margin-left: 0.25rem; }
.post-tag { color: var(--accent); }

.post p, .post li { line-height: 1.8; }
.post h2, .post h3 { margin-top: 2.5rem; letter-spacing: -0.01em; }
.post img { border-radius: 8px; border: 1px solid var(--line); max-width: 100%; }
.post blockquote { border-left: 3px solid var(--accent); color: var(--muted); padding-left: 1.25rem; margin-left: 0; }

/* --- Code ----------------------------------------------------------------- */

pre {
  background: #0f172a;
  color: #e2e8f0;
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 1.25rem;
  overflow-x: auto;
  font-size: 0.85rem;
  line-height: 1.6;
}

code { font-family: "DM Mono", ui-monospace, Menlo, monospace; font-size: 0.875em; }

:not(pre) > code {
  background: var(--accent-soft);
  color: var(--accent-2);
  border-radius: 5px;
  padding: 0.12em 0.4em;
}

/* --- Footer --------------------------------------------------------------- */

.site-footer {
  max-width: 860px;
  margin: 0 auto;
  padding: 1.5rem 1.5rem;
  border-top: 1px solid var(--line);
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 0.75rem;
  font-family: "DM Mono", ui-monospace, monospace;
  font-size: 0.78rem;
  color: var(--muted);
}

.footer-links { display: flex; gap: 1.25rem; }
.footer-links a { color: var(--muted); text-decoration: none; transition: color 0.15s ease; }
.footer-links a:hover { color: var(--accent); }

/* --- Responsive ----------------------------------------------------------- */

@media (max-width: 640px) {
  .timeline::before { left: 16px; }
  .timeline-item {
    grid-template-columns: 32px 1fr;
    grid-template-rows: auto auto;
    align-items: start;
    gap: 0.5rem;
    padding-left: 0.5rem;
  }
  .timeline-left .timeline-dot,
  .timeline-right .timeline-dot { grid-column: 1; grid-row: 1; margin-top: 1rem; }
  .timeline-left .timeline-card,
  .timeline-right .timeline-card { grid-column: 2; grid-row: 1; text-align: left; }
  .timeline-left .timeline-date-bubble,
  .timeline-right .timeline-date-bubble { grid-column: 2; grid-row: 2; justify-self: start; margin: 0 0 0 0; }
  .timeline-date-bubble { flex-direction: row; gap: 0.4rem; padding: 0.25rem 0.6rem; }
  .bubble-day { font-size: 1rem; }
}