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

/* ── Tokens ── */
:root {
  --text:        #1a1a1a;
  --muted:       #666;
  --subtle:      #999;
  --border:      #e8e8e8;
  --accent:      #1a5eb8;
  --accent-bg:   #eef3fb;
  --accent-border: #b8cef0;
  --bg:          #fff;
  --max-width:   680px;
  --font-body:   "Open Sans", system-ui, sans-serif;
  --font-display: "Open Sans", system-ui, sans-serif;
}

/* ── Base ── */
body {
  font-family: var(--font-body);
  font-size: 1.0625rem;   /* 17px */
  line-height: 1.75;
  color: var(--text);
  background: var(--bg);
  margin: 0;
  padding: 0 1.25rem;
}

/* ── Breadcrumbs ── */
.breadcrumbs {
  max-width: var(--max-width);
  margin: 1.5rem auto 1.5rem;
  font-size: 0.8125rem;
  color: var(--muted);
  display: flex;
  align-items: center;
  gap: 0.4rem;
  flex-wrap: wrap;
}

.breadcrumbs a {
  color: var(--muted);
}

.breadcrumbs a:hover {
  color: var(--accent);
}

/* ── Site header ── */
header {
  max-width: var(--max-width);
  margin: 2rem auto 0.5rem;
  padding-bottom: 1rem;
  border-bottom: 2px solid var(--border);
}

header a {
  font-family: var(--font-display);
  font-size: 1.5rem;
  text-decoration: none;
  color: var(--text);
  letter-spacing: -0.01em;
}

header a:hover {
  color: var(--accent);
}

/* ── Main content ── */
main {
  max-width: var(--max-width);
  margin: 0 auto 4rem;
}

/* ── Typography ── */
h1 {
  font-family: var(--font-display);
  font-size: 2rem;
  line-height: 1.2;
  margin-top: 2rem;
  margin-bottom: 0.25rem;
  color: var(--text);
  letter-spacing: -0.02em;
}

h2 {
  font-family: var(--font-display);
  font-size: 1.4rem;
  line-height: 1.3;
  margin-top: 2rem;
  margin-bottom: 0.5rem;
}

p {
  margin: 0 0 1.25rem;
}

a {
  color: var(--accent);
}

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

/* ── Post meta (date + tags on post pages) ── */
.post-meta {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  flex-wrap: wrap;
  margin-bottom: 2rem;
}

time {
  display: block;
  color: var(--muted);
  font-size: 0.875rem;
  letter-spacing: 0.02em;
}

.post-meta time {
  display: inline;
  margin-bottom: 0;
}

/* ── Tags ── */
.tag {
  display: inline-block;
  background: var(--accent-bg);
  border: 1px solid var(--accent-border);
  border-radius: 3px;
  padding: 0.1em 0.55em;
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  text-decoration: none;
  color: var(--accent);
}

.tag:hover {
  background: #d8e6f8;
}

/* ── Images ── */
img {
  max-width: 100%;
  height: auto;
  display: block;
  margin: 2rem auto;
  border-radius: 4px;
}

/* ── Home page ── */
.site-description {
  font-size: 1.0625rem;
  color: var(--muted);
  margin: 1.25rem 0 1.75rem;
  line-height: 1.6;
}

.tag-nav {
  display: flex;
  gap: 0.75rem;
  margin-bottom: 2.5rem;
}

.tag-nav a {
  background: var(--accent-bg);
  border: 1px solid var(--accent-border);
  border-radius: 4px;
  padding: 0.35rem 0.9rem;
  text-decoration: none;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--accent);
}

.tag-nav a:hover {
  background: #d8e6f8;
}

/* ── Post list ── */
ul.post-list {
  list-style: none;
  padding: 0;
  margin: 0;
}

ul.post-list li {
  display: grid;
  grid-template-columns: 11rem 1fr auto;
  align-items: baseline;
  gap: 0.75rem;
  padding: 0.75rem 0;
  border-bottom: 1px solid var(--border);
}

.post-summary {
  grid-column: 1 / -1;
  margin: 0.1rem 0 0.25rem;
  font-size: 0.875rem;
  color: var(--muted);
  line-height: 1.5;
}

ul.post-list li time {
  display: block;
  font-size: 0.8125rem;
  color: var(--subtle);
  white-space: nowrap;
}

ul.post-list li a {
  font-weight: 600;
  font-size: 0.9375rem;
  text-decoration: none;
  color: var(--text);
}

ul.post-list li a:hover {
  color: var(--accent);
  text-decoration: underline;
}

/* ── Tag listing pages ── */
ul:not(.post-list) {
  list-style: none;
  padding: 0;
  margin: 0;
}

ul:not(.post-list) li {
  padding: 0.6rem 0;
  border-bottom: 1px solid var(--border);
  display: flex;
  gap: 1rem;
  align-items: baseline;
}

ul:not(.post-list) li time {
  display: inline;
  font-size: 0.8125rem;
  color: var(--subtle);
  white-space: nowrap;
}

/* ── Article body ── */
article {
  margin-top: 1.5rem;
}

article p {
  font-size: 1.0625rem;
  line-height: 1.8;
}

/* ── Photo gallery ── */
.gallery {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  gap: 0.5rem;
  margin: 2rem 0;
}

.gallery a {
  display: block;
  overflow: hidden;
  border-radius: 4px;
}

.gallery img {
  display: block;
  width: 100%;
  height: 160px;
  object-fit: cover;
  margin: 0;
  border-radius: 4px;
  transition: opacity 0.15s, transform 0.15s;
}

.gallery a:hover img {
  opacity: 0.85;
  transform: scale(1.03);
}

/* ── Back nav ── */
nav:not(.breadcrumbs):not(.tag-nav) {
  margin-top: 2.5rem;
  padding-top: 1.25rem;
  border-top: 1px solid var(--border);
  font-size: 0.9rem;
}

/* ── Post nav ── */
.post-nav {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
  align-items: start;
}

.post-nav-prev { text-align: left; }
.post-nav-next { text-align: right; }

.post-nav div + div { margin-top: 0.4rem; }

.post-nav a { text-decoration: none; }
.post-nav a:hover { text-decoration: underline; }

/* ── Responsive ── */
@media (max-width: 560px) {
  ul.post-list li {
    grid-template-columns: 1fr;
    gap: 0.2rem;
  }
}