:root {
  --bg: #ffffff;
  --surface: #f8f9fb;
  --ink: #0f172a;
  --muted: #64748b;
  --border: #e2e5eb;
  --accent: #0f6e56;
  --accent-soft: #e1f5ee;
  --accent-text: #085041;
  --code-bg: #f4f5f7;
  --rail-bg: #111214;
  --rail-text: #ffffff;
  --rail-text-muted: #9a9da5;
  --rail-hover: rgba(255, 255, 255, 0.08);
  --rail-width: 220px;
  --font-mono: ui-monospace, "SF Mono", Consolas, Menlo, monospace;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Inter", "Segoe UI", Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--ink);
  line-height: 1.65;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
}

/* ---------- Portal layout ---------- */
.portal {
  display: flex;
  min-height: 100vh;
}

/* ---------- Rail (sidebar) ---------- */
.rail {
  width: var(--rail-width);
  flex-shrink: 0;
  background: var(--rail-bg);
  padding: 1.1rem 0.85rem;
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  transition: margin-left 0.2s ease, opacity 0.15s ease;
  overflow: hidden;
}

.rail.rail-collapsed {
  margin-left: calc(-1 * var(--rail-width));
  opacity: 0;
  pointer-events: none;
}

.rail-brand {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 0 6px;
}

.rail-mark {
  width: 28px;
  height: 28px;
  border-radius: 6px;
  background: var(--accent);
  color: #04342c;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 12px;
  flex-shrink: 0;
}

.rail-name {
  color: var(--rail-text);
  font-size: 14px;
  font-weight: 600;
  white-space: nowrap;
}

.rail-label {
  display: block;
  font-size: 11px;
  color: var(--rail-text-muted);
  letter-spacing: 0.05em;
  text-transform: uppercase;
  padding: 0 8px 6px;
}

.rail-link {
  display: block;
  padding: 7px 8px;
  border-radius: 6px;
  font-size: 13px;
  color: var(--rail-text-muted);
  text-decoration: none;
  white-space: nowrap;
  text-transform: capitalize;
}

.rail-link:hover {
  background: var(--rail-hover);
  color: var(--rail-text);
}

.rail-link-active {
  background: var(--rail-hover);
  color: var(--rail-text);
}

.rail-bottom {
  margin-top: auto;
}

/* ---------- Main column ---------- */
.portal-main {
  flex: 1;
  min-width: 0;
  display: flex;
  flex-direction: column;
}

/* ---------- Top bar ---------- */
.topbar {
  border-bottom: 1px solid var(--border);
  padding: 0.9rem 1.5rem;
  display: flex;
  align-items: center;
  gap: 1rem;
}

.rail-toggle {
  border: 1px solid var(--border);
  background: var(--bg);
  border-radius: 6px;
  width: 34px;
  height: 34px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--ink);
  cursor: pointer;
  flex-shrink: 0;
}

.rail-toggle:hover {
  background: var(--surface);
}

.search-wrap {
  position: relative;
  flex: 1;
  max-width: 420px;
}

.search-icon {
  position: absolute;
  left: 11px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--muted);
  pointer-events: none;
}

.search-input {
  width: 100%;
  padding: 0.55rem 0.8rem 0.55rem 2.1rem;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 0.88rem;
  background: var(--surface);
  color: var(--ink);
}

.search-input:focus {
  outline: none;
  border-color: var(--accent);
  background: var(--bg);
}

/* ---------- Content ---------- */
.site-content {
  max-width: 900px;
  width: 100%;
  margin: 0 auto;
  padding: 2.5rem 2rem 3rem;
  flex: 1;
}

.site-content h2 {
  font-size: 0.78rem;
  font-weight: 700;
  margin: 0 0 1.5rem;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.site-content h1 {
  font-size: 1.8rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 0.5rem;
}

.site-content p {
  margin: 0 0 1rem;
}

.site-content a {
  color: var(--accent-text);
  text-decoration: none;
  border-bottom: 1px solid transparent;
}

.site-content a:hover {
  border-bottom-color: var(--accent-text);
}

.site-content pre,
.site-content code {
  background: var(--code-bg);
  border-radius: 4px;
  font-family: var(--font-mono);
}

.site-content pre {
  padding: 1rem;
  overflow-x: auto;
  font-size: 0.85rem;
  border: 1px solid var(--border);
}

.site-content code {
  padding: 0.15rem 0.35rem;
  font-size: 0.85em;
}

.site-content pre code {
  padding: 0;
  background: none;
}

/* ---------- Notes list (homepage) ---------- */
.notes-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 1rem;
}

.notes-list-item {
  padding: 1.2rem 1.3rem;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: var(--bg);
  transition: border-color 0.15s ease, box-shadow 0.15s ease;
}

.notes-list-item:hover {
  border-color: var(--accent);
  box-shadow: 0 4px 14px rgba(15, 23, 42, 0.06);
}

.notes-list-item a {
  font-size: 1rem;
  font-weight: 600;
  text-decoration: none;
  color: var(--ink);
  display: block;
  border-bottom: none;
}

.notes-list-item a:hover {
  color: var(--accent-text);
}

.notes-list-item time {
  display: block;
  color: var(--muted);
  font-size: 0.78rem;
  margin-top: 0.4rem;
  font-family: var(--font-mono);
}

.tags {
  margin-top: 0.75rem;
}

.tag {
  display: inline-block;
  font-size: 0.68rem;
  font-weight: 600;
  color: var(--accent-text);
  background: var(--accent-soft);
  border-radius: 4px;
  padding: 0.15rem 0.5rem;
  margin-right: 0.35rem;
  text-transform: capitalize;
}

.notes-list-item.is-hidden {
  display: none;
}

.no-results {
  color: var(--muted);
  font-size: 0.9rem;
  padding: 1rem 0;
  display: none;
}

.no-results.is-visible {
  display: block;
}

/* ---------- Footer ---------- */
.site-footer {
  border-top: 1px solid var(--border);
  background: var(--surface);
}

.site-footer-inner {
  max-width: 900px;
  margin: 0 auto;
  padding: 1.5rem 2rem;
  color: var(--muted);
  font-size: 0.8rem;
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 0.5rem;
}

/* ---------- Responsive ---------- */
@media (max-width: 768px) {
  .rail {
    position: fixed;
    z-index: 20;
    height: 100vh;
  }
  .rail.rail-collapsed {
    margin-left: calc(-1 * var(--rail-width));
  }
  .site-content {
    padding: 1.75rem 1.25rem 2.5rem;
  }
  .topbar {
    padding: 0.75rem 1rem;
  }
  .notes-list {
    grid-template-columns: 1fr;
  }
}