/* ── Reset ── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
img { max-width: 100%; display: block; }

/* ── Tokens ── */
:root {
  --aqua: #00c4b4;
  --aqua-dark: #00a89a;
  --aqua-dim: rgba(0, 196, 180, 0.12);
  --bg: #ffffff;
  --bg-secondary: #f8f9fa;
  --bg-card: #ffffff;
  --text: #111111;
  --text-secondary: #555555;
  --text-tertiary: #999999;
  --border: rgba(0,0,0,0.08);
  --border-hover: rgba(0,0,0,0.18);
  --radius: 12px;
  --radius-sm: 6px;
  --font: 'Inter', -apple-system, sans-serif;
  --mono: 'SFMono-Regular', Consolas, monospace;
}

[data-theme="dark"] {
  --bg: #0f0f0f;
  --bg-secondary: #171717;
  --bg-card: #171717;
  --text: #f0f0f0;
  --text-secondary: #aaaaaa;
  --text-tertiary: #666666;
  --border: rgba(255,255,255,0.08);
  --border-hover: rgba(255,255,255,0.18);
}

/* ── Base ── */
body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  font-size: 16px;
  transition: background 0.2s, color 0.2s;
}

a { color: inherit; text-decoration: none; }

.container {
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ── Header ── */
.site-header {
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  background: var(--bg);
  z-index: 100;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 56px;
}

.logo {
  font-size: 17px;
  font-weight: 600;
  color: var(--aqua);
  letter-spacing: -0.3px;
}

.nav { display: flex; align-items: center; gap: 8px; }
.nav-links { display: flex; gap: 24px; }
.nav-links a {
  font-size: 14px;
  color: var(--text-secondary);
  transition: color 0.15s;
}
.nav-links a:hover { color: var(--text); }

/* ── Theme toggle ── */
.theme-toggle {
  background: none;
  border: none;
  cursor: pointer;
  padding: 6px;
  color: var(--text-secondary);
  display: flex;
  align-items: center;
}
.theme-toggle svg {
  width: 18px;
  height: 18px;
  stroke: currentColor;
  fill: none;
  stroke-width: 2;
  stroke-linecap: round;
}
[data-theme="dark"] .sun-icon { display: block; }
[data-theme="dark"] .moon-icon { display: none; }
.sun-icon { display: none; }
.moon-icon { display: block; }

/* ── Mobile nav ── */
.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 4px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 6px;
}
.nav-toggle span {
  display: block;
  width: 20px;
  height: 2px;
  background: var(--text);
  border-radius: 2px;
}

@media (max-width: 600px) {
  .nav-toggle { display: flex; }
  .nav-links {
    display: none;
    position: absolute;
    top: 56px;
    left: 0;
    right: 0;
    background: var(--bg);
    border-bottom: 1px solid var(--border);
    flex-direction: column;
    padding: 16px 24px;
    gap: 16px;
  }
  .nav-links.open { display: flex; }
}

/* ── Hero ── */
.hero {
  padding: 56px 0 32px;
  max-width: 600px;
}
.hero h1 {
  font-size: 28px;
  font-weight: 600;
  letter-spacing: -0.5px;
  margin-bottom: 10px;
}
.hero p {
  font-size: 15px;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* ── Filter pills ── */
.filter-row {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  margin-bottom: 28px;
}
.pill {
  font-size: 13px;
  padding: 5px 14px;
  border-radius: 99px;
  border: 1px solid var(--border);
  color: var(--text-secondary);
  background: transparent;
  cursor: pointer;
  transition: all 0.15s;
  font-family: var(--font);
}
.pill:hover { border-color: var(--border-hover); color: var(--text); }
.pill.active {
  background: var(--aqua);
  border-color: var(--aqua);
  color: #fff;
}

/* ── Card grid ── */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 20px;
  padding-bottom: 64px;
}

.post-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transition: border-color 0.15s, transform 0.15s;
}
.post-card:hover {
  border-color: var(--aqua);
  transform: translateY(-2px);
}

.card-img-link { display: block; }

.card-img {
  width: 100%;
  height: 180px;
  position: relative;
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
}
.card-img img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.card-img-label {
  position: absolute;
  bottom: 10px;
  right: 12px;
  font-size: 10px;
  font-weight: 600;
  letter-spacing: 1px;
  text-transform: uppercase;
  color: var(--aqua);
  font-family: var(--mono);
}

.card-body {
  padding: 16px 18px 18px;
  display: flex;
  flex-direction: column;
  flex: 1;
}

.card-tag {
  font-size: 11px;
  font-weight: 600;
  color: var(--aqua);
  text-transform: uppercase;
  letter-spacing: 0.6px;
  margin-bottom: 6px;
}

.card-title {
  font-size: 15px;
  font-weight: 500;
  line-height: 1.4;
  margin-bottom: 8px;
}
.card-title a { color: var(--text); }
.card-title a:hover { color: var(--aqua); }

.card-excerpt {
  font-size: 13px;
  color: var(--text-secondary);
  line-height: 1.6;
  flex: 1;
  margin-bottom: 14px;
}

.card-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 12px;
  border-top: 1px solid var(--border);
}

.card-date { font-size: 12px; color: var(--text-tertiary); }

.read-link {
  font-size: 12px;
  color: var(--aqua);
  font-weight: 500;
}

/* ── Empty state ── */
.posts-empty {
  text-align: center;
  padding: 64px 0;
  color: var(--text-secondary);
  font-size: 14px;
}

/* ── Post page ── */
.post-container {
  max-width: 720px;
  margin: 0 auto;
  padding: 48px 0 80px;
}

.post-header {
  margin-bottom: 40px;
  padding-bottom: 24px;
  border-bottom: 1px solid var(--border);
}

.post-header h1 {
  font-size: 28px;
  font-weight: 600;
  letter-spacing: -0.4px;
  line-height: 1.25;
  margin-bottom: 14px;
}

.meta { font-size: 14px; color: var(--text-secondary); }

.meta .tag {
  display: inline-block;
  background: var(--aqua-dim);
  color: var(--aqua);
  font-size: 12px;
  font-weight: 500;
  padding: 2px 8px;
  border-radius: var(--radius-sm);
}

/* ── Post article ── */
.post-article { font-size: 16px; line-height: 1.75; }
.post-article p { margin-bottom: 1.25em; }
.post-article h2 {
  font-size: 20px;
  font-weight: 600;
  margin: 2em 0 0.75em;
  letter-spacing: -0.3px;
}
.post-article h3 {
  font-size: 17px;
  font-weight: 600;
  margin: 1.75em 0 0.6em;
}
.post-article a { color: var(--aqua); }
.post-article a:hover { text-decoration: underline; }

.post-article code {
  font-family: var(--mono);
  font-size: 0.875em;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  padding: 1px 5px;
  border-radius: 4px;
}

.post-article pre {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 18px 20px;
  overflow-x: auto;
  margin: 1.5em 0;
}
.post-article pre code {
  background: none;
  border: none;
  padding: 0;
  font-size: 13px;
  line-height: 1.6;
}

.post-article ul, .post-article ol {
  padding-left: 1.5em;
  margin-bottom: 1.25em;
}
.post-article li { margin-bottom: 0.4em; }
.post-article strong { font-weight: 600; }
.post-article figure { margin: 1.5em 0; }
.post-article img { border-radius: var(--radius-sm); }

.post-article figcaption,
.post-article .img-caption {
  font-size: 13px;
  color: var(--text-tertiary);
  margin-top: 8px;
  text-align: center;
}

.post-article table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.5em 0;
  font-size: 14px;
}
.post-article th {
  text-align: left;
  padding: 8px 12px;
  border-bottom: 2px solid var(--border-hover);
  font-weight: 600;
  font-size: 13px;
}
.post-article td {
  padding: 8px 12px;
  border-bottom: 1px solid var(--border);
}

.post-back {
  margin-top: 3em;
  padding-top: 1.5em;
  border-top: 1px solid var(--border);
  font-size: 14px;
}
.post-back a { color: var(--aqua); }

/* ── About ── */
.about-container {
  max-width: 640px;
  margin: 0 auto;
  padding: 56px 0 80px;
}
.about-container h1 {
  font-size: 26px;
  font-weight: 600;
  margin-bottom: 24px;
  letter-spacing: -0.3px;
}
.about-container p {
  font-size: 15px;
  color: var(--text-secondary);
  line-height: 1.75;
  margin-bottom: 1.25em;
}
.about-container a { color: var(--aqua); }

/* ── Footer ── */
.site-footer {
  border-top: 1px solid var(--border);
  padding: 24px 0;
}
.site-footer p { font-size: 13px; color: var(--text-tertiary); }
.site-footer a { color: var(--aqua); }