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

:root {
  --sidebar-w: 240px;
  --bg: #fff;
  --text: #111;
  --muted: #888;
  --border: #e8e8e8;
  --hover-bg: #f5f5f5;
  --active-bg: #111;
  --active-text: #fff;
  --tab-h: 64px;
  --font: -apple-system, BlinkMacSystemFont, 'Segoe UI', system-ui, sans-serif;
}

html { height: 100%; }

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  font-size: 14px;
  line-height: 1.5;
  height: 100%;
}

/* ── App shell ───────────────────────────────────── */

#app {
  display: flex;
  height: 100vh;
}

/* ── Sidebar ─────────────────────────────────────── */

#sidebar {
  width: var(--sidebar-w);
  flex-shrink: 0;
  border-right: 1px solid var(--border);
  height: 100vh;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding-bottom: 24px;
}

#blog-name {
  padding: 18px 16px 10px;
  font-size: 14px;
  font-weight: 700;
  color: #3a7bd5;
  cursor: default;
}

/* ── Main nav (Home / Posts) ─────────────────────── */

#main-nav {
  display: flex;
  flex-direction: column;
  gap: 2px;
  padding: 0 8px;
}

.nav-item {
  display: flex;
  align-items: center;
  gap: 10px;
  width: 100%;
  padding: 7px 10px;
  border: none;
  border-radius: 6px;
  background: none;
  cursor: pointer;
  font-family: var(--font);
  font-size: 14px;
  font-weight: 500;
  color: var(--text);
  text-align: left;
  -webkit-tap-highlight-color: transparent;
}

.nav-item:hover {
  background: var(--hover-bg);
}

.nav-item.nav-active {
  background: var(--active-bg);
  color: var(--active-text);
}

.nav-icon {
  width: 20px;
  height: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.nav-icon img {
  display: block;
}

.nav-item.nav-active .nav-icon img {
  filter: brightness(0) invert(1);
}

/* ── Sidebar sections (Projects / Online) ────────── */

.sidebar-section {
  padding: 0 8px;
}

.section-label {
  font-size: 11px;
  font-weight: 600;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  padding: 10px 10px 4px;
}

.ext-link-item {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 6px 10px;
  border-radius: 6px;
  text-decoration: none;
  color: var(--text);
}

.ext-link-item:hover {
  background: var(--hover-bg);
}

.ext-icon {
  width: 24px;
  height: 24px;
  border-radius: 6px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 11px;
  font-weight: 700;
  color: #fff;
  flex-shrink: 0;
  overflow: hidden;
}

.ext-name {
  flex: 1;
  font-size: 13px;
}

.ext-arrow {
  color: var(--muted);
  font-size: 13px;
  flex-shrink: 0;
}

.ext-icon-img {
  background: none;
}

/* ── Content (right pane) ────────────────────────── */

#content {
  flex: 1;
  min-width: 0;
  height: 100vh;
  overflow-y: auto;
}

/* ── Posts pane ──────────────────────────────────── */

#posts-pane {
  min-height: 100%;
}

#article-pane[hidden],
#home-pane[hidden] {
  display: none;
}

.pane-header {
  padding: 18px 20px 14px;
  font-size: 14px;
  font-weight: 700;
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  background: var(--bg);
  z-index: 1;
}

#post-list {
  list-style: none;
}

.post-item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 14px 20px;
  cursor: pointer;
  border-bottom: 1px solid var(--border);
}

.post-item:hover {
  background: var(--hover-bg);
}

.post-item.active {
  background: var(--active-bg);
  color: var(--active-text);
}

.post-item-text {
  flex: 1;
  min-width: 0;
}

.post-item-title {
  display: block;
  font-size: 14px;
  font-weight: 600;
  line-height: 1.35;
}

.post-item-date {
  display: block;
  font-size: 12px;
  color: var(--muted);
  margin-top: 3px;
}

.post-item.active .post-item-date {
  color: #aaa;
}

.post-item-count {
  display: flex;
  align-items: center;
  gap: 4px;
  font-size: 13px;
  color: var(--muted);
  flex-shrink: 0;
}

.post-item.active .post-item-count {
  color: #aaa;
}

/* ── Article ─────────────────────────────────────── */

#post-view,
#home-content {
  max-width: 680px;
  margin: 0 auto;
  padding: 56px 40px 80px;
}

#post-title {
  font-size: 2rem;
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.02em;
  margin-bottom: 8px;
}

#post-meta {
  font-size: 13px;
  color: var(--muted);
  margin-bottom: 36px;
}

#post-body {
  font-size: 16px;
  line-height: 1.75;
  color: #222;
}

#post-body p            { margin-bottom: 1.25em; }
#post-body p:last-child  { margin-bottom: 0; }

#post-body h2 {
  font-size: 1.2rem;
  font-weight: 700;
  margin: 2em 0 0.6em;
  letter-spacing: -0.01em;
  color: var(--text);
}

#post-body h3 {
  font-size: 1rem;
  font-weight: 700;
  margin: 1.6em 0 0.4em;
  color: var(--text);
}

#post-body a {
  color: inherit;
  text-decoration: underline;
  text-underline-offset: 2px;
}

#post-body a:hover { opacity: 0.7; }

#post-body code {
  font-family: 'SF Mono', 'Fira Code', Consolas, monospace;
  font-size: 0.88em;
  background: #f3f3f3;
  padding: 2px 6px;
  border-radius: 4px;
}

#post-body pre {
  background: #f3f3f3;
  padding: 18px 20px;
  border-radius: 8px;
  overflow-x: auto;
  margin-bottom: 1.25em;
  font-size: 14px;
  line-height: 1.6;
}

#post-body pre code { background: none; padding: 0; font-size: inherit; }

#post-body blockquote {
  border-left: 3px solid #ddd;
  padding-left: 16px;
  color: #555;
  margin-bottom: 1.25em;
}

#post-body ul,
#post-body ol { padding-left: 1.4em; margin-bottom: 1.25em; }
#post-body li  { margin-bottom: 0.3em; }

#post-body img { max-width: 100%; border-radius: 6px; margin: 0.5em 0; }

/* Home/about page */
#home-content h1 {
  font-size: 2rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 24px;
}

#home-content p,
#home-content li {
  font-size: 16px;
  line-height: 1.75;
  color: #222;
  margin-bottom: 1.25em;
}

/* ── Tab bar (mobile only) ───────────────────────── */

#tab-bar { display: none; }

/* ── Mobile ──────────────────────────────────────── */

@media (max-width: 768px) {
  #app {
    display: block;
    height: auto;
    min-height: 100vh;
    padding-bottom: var(--tab-h);
  }

  #sidebar { display: none; }

  #content {
    height: auto;
    overflow-y: visible;
  }

  /* View state classes control which pane is visible on mobile */
  #app.view-home   #posts-pane   { display: none; }
  #app.view-home   #article-pane { display: none !important; }
  #app.view-home   #home-pane    { display: block !important; }

  #app.view-posts  #posts-pane   { display: block; }
  #app.view-posts  #article-pane { display: none !important; }
  #app.view-posts  #home-pane    { display: none !important; }

  #app.view-article #posts-pane   { display: none; }
  #app.view-article #article-pane { display: block !important; }
  #app.view-article #home-pane    { display: none !important; }

  /* Bigger touch targets in post list */
  .post-item { padding: 16px 16px; }
  .post-item-title { font-size: 15px; }
  .post-item-date  { font-size: 13px; margin-top: 4px; }

  /* Article */
  #post-view,
  #home-content { padding: 28px 18px 60px; margin: 0; }
  #post-title   { font-size: 1.6rem; }
  #post-body    { font-size: 15px; }

  /* Tab bar */
  #tab-bar {
    display: flex;
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    height: var(--tab-h);
    background: var(--bg);
    border-top: 1px solid var(--border);
    z-index: 100;
  }

  .tab {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 3px;
    border: none;
    background: none;
    cursor: pointer;
    font-family: var(--font);
    font-size: 11px;
    color: var(--muted);
    -webkit-tap-highlight-color: transparent;
  }

  .tab.tab-active { color: var(--text); }
}