/* ===== Components ===== */

/* --- Sidebar --- */

.sidebar-header {
  padding: 2rem 1.5rem 1.5rem;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.75rem;
}

.sidebar-avatar {
  width: 72px;
  height: 72px;
  border-radius: var(--radius-full);
  background: var(--color-tag-bg);
  overflow: hidden;
  flex-shrink: 0;
}

.sidebar-avatar img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.sidebar-name {
  font-family: var(--font-display);
  font-size: 1.1rem;
  font-weight: 600;
  letter-spacing: -0.01em;
  color: var(--color-ink);
  text-align: center;
}

/* Navigation */
.sidebar-nav {
  flex: 1;
  padding: 0.5rem 0.75rem;
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.nav-item {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.625rem 1rem;
  border-radius: var(--radius-full);
  font-size: 0.9375rem;
  font-weight: 500;
  color: var(--color-ink-secondary);
  transition: background-color 0.15s ease, color 0.15s ease;
  text-decoration: none;
  cursor: pointer;
}

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

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

.nav-item svg {
  width: 20px;
  height: 20px;
  flex-shrink: 0;
  opacity: 0.8;
}

.nav-item.active svg {
  opacity: 1;
}

/* Sidebar footer — theme toggle */
.sidebar-footer {
  padding: 1rem 0.75rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  flex-shrink: 0;
}

.theme-toggle {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.5rem 1rem;
  border-radius: var(--radius-full);
  background: var(--color-glass);
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  border: 1px solid var(--color-glass-border);
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.04);
  font-size: 0.8125rem;
  font-weight: 500;
  color: var(--color-ink-secondary);
  transition: background-color 0.15s ease, color 0.15s ease;
  cursor: pointer;
  user-select: none;
}

.theme-toggle:hover {
  background: var(--color-divider);
  color: var(--color-ink);
}

.theme-toggle svg {
  width: 16px;
  height: 16px;
}

/* --- Top bar (fixed, transparent by default, blur on scroll) --- */

.top-bar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  padding: 0.75rem 1rem;
  background: transparent;
  transition: background-color 0.3s ease, backdrop-filter 0.3s ease, border-color 0.3s ease, left 0.35s cubic-bezier(0.32, 0.72, 0, 1);
}

/* Desktop: top bar starts after sidebar */
@media (min-width: 1024px) {
  .top-bar {
    left: var(--sidebar-width);
  }

  .app:not(.sidebar-open) .top-bar {
    left: 0;
  }
}

/* Blur state — appears when page is scrolled */
.top-bar.scrolled {
  background: var(--color-glass);
  backdrop-filter: blur(30px) saturate(200%);
  -webkit-backdrop-filter: blur(30px) saturate(200%);
  border-bottom: 1px solid var(--color-glass-border);
}

.top-bar-inner {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

/* --- Hamburger button (circular, glass, all screen sizes) --- */

.hamburger {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: var(--radius-full);
  background: var(--color-glass);
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  border: 1px solid var(--color-glass-border);
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.06);
  cursor: pointer;
  transition: background-color 0.15s ease, transform 0.1s ease;
  flex-shrink: 0;
}

.hamburger:hover {
  background: var(--color-divider);
}

.hamburger:active {
  transform: scale(0.93);
}

.hamburger svg {
  width: 20px;
  height: 20px;
  color: var(--color-ink);
}

/* --- Back button (same style as hamburger) --- */

.back-btn {
  display: flex;
  align-items: center;
  gap: 0.375rem;
  height: 40px;
  padding: 0 0.875rem 0 0.625rem;
  border-radius: var(--radius-full);
  background: var(--color-glass);
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  border: 1px solid var(--color-glass-border);
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.06);
  font-size: 0.8125rem;
  font-weight: 500;
  color: var(--color-ink);
  text-decoration: none;
  cursor: pointer;
  transition: background-color 0.15s ease, transform 0.1s ease;
  flex-shrink: 0;
}

.back-btn:hover {
  background: var(--color-divider);
  color: var(--color-ink);
}

.back-btn:active {
  transform: scale(0.93);
}

.back-btn svg {
  width: 18px;
  height: 18px;
}

/* --- Article List --- */

.article-list {
  display: flex;
  flex-direction: column;
}

.article-item {
  display: block;
  padding: 1.25rem 0;
  border-bottom: 1px solid var(--color-divider);
  text-decoration: none;
  color: inherit;
  transition: background-color 0.15s ease;
  cursor: pointer;
}

.article-item:first-child {
  padding-top: 0;
}

.article-item:last-child {
  border-bottom: none;
}

.article-item-header {
  display: flex;
  align-items: baseline;
  gap: 0.75rem;
  margin-bottom: 0.375rem;
}

.article-item-date {
  font-size: 0.8125rem;
  color: var(--color-ink-tertiary);
  font-variant-numeric: tabular-nums;
  flex-shrink: 0;
}

.article-item-title {
  font-family: var(--font-display);
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--color-ink);
  letter-spacing: -0.01em;
  transition: color 0.15s ease;
}

.article-item:hover .article-item-title {
  color: var(--color-accent);
}

.article-item-summary {
  font-size: 0.875rem;
  line-height: 1.6;
  color: var(--color-ink-secondary);
  margin-bottom: 0.5rem;
}

.article-item-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.375rem;
}

.tag {
  display: inline-block;
  padding: 0.125rem 0.5rem;
  border-radius: var(--radius-full);
  background: var(--color-tag-bg);
  font-size: 0.75rem;
  font-weight: 500;
  color: var(--color-tag-ink);
}

/* --- Home Hero --- */

.hero {
  text-align: center;
  padding: 2rem 0 3rem;
  border-bottom: 1px solid var(--color-divider);
  margin-bottom: 2rem;
}

.hero-avatar {
  width: 96px;
  height: 96px;
  border-radius: var(--radius-full);
  background: var(--color-tag-bg);
  overflow: hidden;
  margin: 0 auto 1.25rem;
}

.hero-avatar img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.hero-name {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
}

.hero-bio {
  font-size: 0.9375rem;
  color: var(--color-ink-secondary);
  max-width: 480px;
  margin: 0 auto;
  line-height: 1.7;
}

/* --- Section headers --- */

.section-header {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  margin-bottom: 1rem;
}

.section-title {
  font-size: 1.25rem;
  font-weight: 600;
  letter-spacing: -0.015em;
}

.section-link {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--color-accent);
}

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

/* --- Article page --- */

.article-header {
  margin-bottom: 2rem;
  padding-bottom: 1.5rem;
  border-bottom: 1px solid var(--color-divider);
}

.article-meta {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-top: 0.75rem;
  font-size: 0.875rem;
  color: var(--color-ink-secondary);
}

.article-cover {
  width: calc(100% + 2 * var(--content-padding));
  margin-left: calc(-1 * var(--content-padding));
  margin-bottom: 2rem;
  border-radius: 0;
  overflow: hidden;
}

.article-cover img {
  width: 100%;
  height: auto;
  object-fit: cover;
}

/* --- About page --- */

.about-content {
  text-align: center;
  padding: 2rem 0;
}

.about-avatar {
  width: 120px;
  height: 120px;
  border-radius: var(--radius-full);
  background: var(--color-tag-bg);
  overflow: hidden;
  margin: 0 auto 1.5rem;
}

.about-avatar img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* --- Back link --- */

.back-link {
  display: inline-flex;
  align-items: center;
  gap: 0.375rem;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--color-accent);
  margin-bottom: 1.5rem;
}

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

.back-link svg {
  width: 16px;
  height: 16px;
}

/* --- Empty state --- */

.empty-state {
  text-align: center;
  padding: 4rem 1rem;
  color: var(--color-ink-secondary);
}

.empty-state svg {
  width: 48px;
  height: 48px;
  margin-bottom: 1rem;
  opacity: 0.5;
}

.empty-state p {
  font-size: 0.9375rem;
}

/* --- Page title --- */

.page-title {
  font-size: 1.75rem;
  font-weight: 700;
  margin-bottom: 1.5rem;
  letter-spacing: -0.02em;
}

/* --- Loading state --- */

.loading {
  text-align: center;
  padding: 4rem 1rem;
  color: var(--color-ink-secondary);
  font-size: 0.9375rem;
}

/* --- Smooth page transitions --- */

#app {
  animation: fadeIn 0.2s ease;
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}