/* NavHub — Design prototype (light-first) */

:root {
  --bg: #f6f7f9;
  --bg-elevated: #ffffff;
  --bg-card: #ffffff;
  --bg-card-hover: #f8fafc;
  --surface: #ffffff;
  --surface-2: #f1f5f9;
  --border: rgba(15, 23, 42, 0.08);
  --border-strong: rgba(15, 23, 42, 0.12);
  --text: #0f172a;
  --text-muted: #475569;
  --text-faint: #94a3b8;
  --accent: #059669;
  --accent-dim: rgba(5, 150, 105, 0.1);
  --sidebar-w: 240px;
  --radius: 12px;
  --radius-sm: 8px;
  --shadow: 0 4px 24px rgba(15, 23, 42, 0.06);
  --font: "DM Sans", "Noto Sans SC", system-ui, sans-serif;
  --transition: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
}

[data-theme="dark"] {
  --bg: #0a0b0f;
  --bg-elevated: #12141a;
  --bg-card: #161922;
  --bg-card-hover: #1c2030;
  --surface: #161922;
  --surface-2: #1c2030;
  --border: rgba(255, 255, 255, 0.06);
  --border-strong: rgba(255, 255, 255, 0.1);
  --text: #e8eaef;
  --text-muted: #8b92a8;
  --text-faint: #5c6378;
  --accent: #6ee7b7;
  --accent-dim: rgba(110, 231, 183, 0.12);
  --shadow: 0 8px 32px rgba(0, 0, 0, 0.4);
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.5;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
}

/* Background */
.bg-glow {
  position: fixed;
  border-radius: 50%;
  filter: blur(100px);
  pointer-events: none;
  z-index: 0;
}
.bg-glow--a {
  width: 520px;
  height: 520px;
  top: -140px;
  right: 5%;
  background: rgba(5, 150, 105, 0.12);
}
.bg-glow--b {
  width: 400px;
  height: 400px;
  bottom: -40px;
  left: 15%;
  background: rgba(99, 102, 241, 0.08);
}
[data-theme="dark"] .bg-glow--a {
  background: rgba(110, 231, 183, 0.08);
}
[data-theme="dark"] .bg-glow--b {
  background: rgba(124, 108, 255, 0.06);
}
.bg-grid {
  position: fixed;
  inset: 0;
  background-image:
    linear-gradient(rgba(15, 23, 42, 0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(15, 23, 42, 0.04) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: radial-gradient(ellipse 80% 60% at 50% 0%, black, transparent);
  pointer-events: none;
  z-index: 0;
}
[data-theme="dark"] .bg-grid {
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.02) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.02) 1px, transparent 1px);
}

.app {
  position: relative;
  z-index: 1;
  display: flex;
  min-height: 100vh;
}

/* Sidebar */
.sidebar {
  width: var(--sidebar-w);
  flex-shrink: 0;
  display: flex;
  flex-direction: column;
  padding: 1.5rem 1rem;
  border-right: 1px solid var(--border);
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(12px);
  position: sticky;
  top: 0;
  height: 100vh;
}
[data-theme="dark"] .sidebar {
  background: rgba(18, 20, 26, 0.6);
}

.sidebar__brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0 0.5rem 1.25rem;
  border-bottom: 1px solid var(--border);
  margin-bottom: 1rem;
  cursor: pointer;
  border-radius: var(--radius-sm);
  transition: var(--transition);
}
.sidebar__brand:hover {
  background: var(--bg-card);
}

.brand-mark {
  width: 40px;
  height: 40px;
  border-radius: 10px;
  background: linear-gradient(135deg, var(--accent) 0%, #7c6cff 100%);
  display: grid;
  grid-template-columns: repeat(2, 6px);
  gap: 4px;
  place-content: center;
  box-shadow: 0 4px 16px rgba(5, 150, 105, 0.2);
}
[data-theme="dark"] .brand-mark {
  box-shadow: 0 4px 16px rgba(110, 231, 183, 0.25);
}
.brand-mark span {
  width: 6px;
  height: 6px;
  border-radius: 2px;
  background: rgba(255, 255, 255, 0.85);
}
[data-theme="dark"] .brand-mark span {
  background: rgba(0, 0, 0, 0.35);
}
.brand-mark span:first-child { grid-column: span 2; justify-self: center; }

.brand-title {
  font-size: 1.125rem;
  font-weight: 700;
  letter-spacing: -0.02em;
}
.brand-sub {
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-top: 2px;
}

.sidebar__nav {
  flex: 1;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 0;
  padding-right: 4px;
}
.sidebar__nav::-webkit-scrollbar { width: 4px; }
.sidebar__nav::-webkit-scrollbar-thumb {
  background: var(--border-strong);
  border-radius: 4px;
}

.nav-group + .nav-group {
  margin-top: 0.5rem;
  padding-top: 0.5rem;
  border-top: 1px solid var(--border);
}
.nav-group__head {
  display: flex;
  align-items: center;
  gap: 0.15rem;
  margin-bottom: 0.25rem;
}
.nav-group__toggle {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex: 1;
  min-width: 0;
  padding: 0.25rem 0.5rem 0.25rem 0.75rem;
  border: none;
  background: transparent;
  cursor: pointer;
  font-family: inherit;
  border-radius: var(--radius-sm);
  transition: var(--transition);
}
.nav-group__toggle:hover {
  background: var(--bg-card);
}
.nav-group__label {
  font-size: 0.7rem;
  font-weight: 600;
  color: var(--text-muted);
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
}
.nav-group__total {
  margin-left: auto;
  margin-right: 0.35rem;
  font-size: 0.65rem;
  color: var(--text-faint);
  font-variant-numeric: tabular-nums;
}
.nav-group__chevron {
  color: var(--text-faint);
  transition: transform var(--transition);
  flex-shrink: 0;
}
.nav-group.is-collapsed .nav-group__chevron {
  transform: rotate(-90deg);
}
.nav-group.is-collapsed .nav-group__items {
  display: none;
}
.nav-group__items {
  display: flex;
  flex-direction: column;
  gap: 1px;
}

.nav-item--child {
  padding-left: 1.1rem;
  font-size: 0.8125rem;
}
.nav-item--child .nav-item__icon {
  width: 18px;
  font-size: 0.7rem;
}

.nav-item {
  position: relative;
  display: flex;
  align-items: center;
  gap: 0.625rem;
  padding: 0.4rem 0.75rem 0.4rem calc(0.75rem + 4px);
  border-radius: var(--radius-sm);
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.875rem;
  font-weight: 500;
  transition: var(--transition);
  border: 1px solid transparent;
}
.nav-item::before {
  content: '';
  position: absolute;
  left: 0;
  top: 22%;
  bottom: 22%;
  width: 3px;
  border-radius: 0 3px 3px 0;
  background: transparent;
  transition: background var(--transition), height var(--transition);
}
.nav-item:hover {
  color: var(--text);
  background: var(--bg-card);
}
.nav-item.is-active {
  color: var(--text);
  background: color-mix(in srgb, var(--cat-color, var(--accent)) 10%, var(--bg-card));
  border-color: color-mix(in srgb, var(--cat-color, var(--accent)) 18%, transparent);
}
.nav-item.is-active::before {
  background: var(--cat-color, var(--accent));
}
[data-theme="dark"] .nav-item.is-active {
  background: color-mix(in srgb, var(--cat-color, var(--accent)) 14%, var(--bg-card));
}
.nav-item__icon {
  width: 22px;
  text-align: center;
  font-size: 0.75rem;
  opacity: 0.9;
  flex-shrink: 0;
}
.nav-item__label {
  flex: 1;
  min-width: 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.nav-item__count {
  flex-shrink: 0;
  font-size: 0.7rem;
  color: var(--text-faint);
  font-variant-numeric: tabular-nums;
  padding: 0.1rem 0.35rem;
  border-radius: 999px;
  background: var(--bg-elevated);
}
.nav-item.is-active .nav-item__count {
  color: var(--text-muted);
  background: color-mix(in srgb, var(--cat-color, var(--accent)) 12%, var(--bg-elevated));
}

.sidebar__favorites {
  margin-top: auto;
  padding-top: 0.75rem;
  border-top: 1px solid var(--border);
}
.sidebar__fav-hint {
  font-size: 0.625rem;
  color: var(--text-faint);
  padding: 0.35rem 0.75rem 0;
  line-height: 1.35;
}
.nav-item--favorites {
  width: 100%;
  border: none;
  cursor: pointer;
  font-family: inherit;
  text-align: left;
}
.nav-item--favorites.is-active {
  background: color-mix(in srgb, #f59e0b 12%, var(--bg-card));
  border-color: color-mix(in srgb, #f59e0b 25%, transparent);
}
.nav-item--favorites.is-active::before {
  background: #f59e0b;
}

.sidebar__footer {
  padding-top: 1rem;
  border-top: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}
.preview-badge {
  font-size: 0.65rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--accent);
  font-weight: 600;
}
.btn-ghost {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.5rem 0.75rem;
  border-radius: var(--radius-sm);
  border: 1px dashed var(--border-strong);
  background: transparent;
  color: var(--text-faint);
  font-size: 0.8rem;
  cursor: not-allowed;
  font-family: inherit;
}

/* Main */
.main {
  flex: 1;
  min-width: 0;
  display: flex;
  flex-direction: column;
  padding: 1.5rem 2rem 2rem;
  max-width: 1200px;
}

.topbar {
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
  margin-bottom: 0.85rem;
  position: sticky;
  top: 0;
  z-index: 20;
  padding: 0.5rem 0 0.75rem;
  margin-top: -0.5rem;
  background: linear-gradient(to bottom, var(--bg) 70%, transparent);
  backdrop-filter: blur(8px);
}
.topbar__row {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  flex-wrap: wrap;
}
.topbar__context {
  display: flex;
  align-items: center;
  min-height: 1.5rem;
}
.topbar__stat {
  font-size: 0.75rem;
  color: var(--text-faint);
  white-space: nowrap;
  font-variant-numeric: tabular-nums;
}
.topbar__actions {
  display: flex;
  gap: 0.5rem;
  margin-left: auto;
}

.search {
  flex: 1;
  max-width: 420px;
  position: relative;
  display: flex;
  align-items: center;
}
.search__icon {
  position: absolute;
  left: 14px;
  color: var(--text-faint);
  pointer-events: none;
}
.search input {
  width: 100%;
  padding: 0.65rem 3rem 0.65rem 2.75rem;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--bg-elevated);
  color: var(--text);
  font-size: 0.9rem;
  font-family: inherit;
  transition: var(--transition);
}
.search input::placeholder { color: var(--text-faint); }
.search input:focus {
  outline: none;
  border-color: rgba(5, 150, 105, 0.45);
  box-shadow: 0 0 0 3px var(--accent-dim);
}
[data-theme="dark"] .search input:focus {
  border-color: rgba(110, 231, 183, 0.4);
}
.search__kbd {
  position: absolute;
  right: 10px;
  padding: 2px 6px;
  font-size: 0.65rem;
  border-radius: 4px;
  border: 1px solid var(--border);
  color: var(--text-faint);
  font-family: inherit;
  background: var(--bg-card);
}

.icon-btn {
  width: 40px;
  height: 40px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  background: var(--bg-elevated);
  color: var(--text-muted);
  cursor: pointer;
  display: grid;
  place-items: center;
  transition: var(--transition);
}
.icon-btn:hover {
  color: var(--text);
  border-color: var(--border-strong);
}
body:not([data-theme="dark"]) .icon-moon { display: none; }
body:not([data-theme="dark"]) .icon-sun { display: block; }
body[data-theme="dark"] .icon-sun { display: none; }
body[data-theme="dark"] .icon-moon { display: block; }
body[data-view="grid"] .icon-list { display: none; }
body[data-view="list"] .icon-grid { display: none; }

.current-cat {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.25rem 0.65rem;
  border-radius: 999px;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text);
  text-decoration: none;
  background: color-mix(in srgb, var(--cat-color, var(--accent)) 12%, var(--bg-card));
  border: 1px solid color-mix(in srgb, var(--cat-color, var(--accent)) 22%, transparent);
}
.current-cat__icon { font-size: 0.75rem; }

.search-results-bar {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 0.8rem;
  color: var(--text-muted);
}
.btn-text {
  border: none;
  background: none;
  color: var(--accent);
  font-size: 0.8rem;
  font-weight: 600;
  cursor: pointer;
  font-family: inherit;
  padding: 0.15rem 0;
}
.btn-text:hover { text-decoration: underline; }

.filter-chips {
  display: flex;
  gap: 0.5rem;
  overflow-x: auto;
  padding-bottom: 0.15rem;
  scrollbar-width: none;
}
.filter-chips::-webkit-scrollbar { display: none; }
.filter-chip {
  flex-shrink: 0;
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.35rem 0.75rem;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: var(--bg-card);
  color: var(--text-muted);
  font-size: 0.8rem;
  font-weight: 500;
  cursor: pointer;
  font-family: inherit;
  transition: var(--transition);
}
.filter-chip:hover {
  color: var(--text);
  border-color: var(--border-strong);
}
.filter-chip.is-active {
  color: var(--text);
  background: var(--accent-dim);
  border-color: rgba(5, 150, 105, 0.35);
  font-weight: 600;
}

.featured {
  margin-bottom: 1.5rem;
}
.featured__head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  margin-bottom: 0.65rem;
}
.featured__title {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-faint);
  letter-spacing: 0.04em;
}
.featured__more {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--accent);
  text-decoration: none;
}
.featured__more:hover {
  text-decoration: underline;
}
.featured__grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(148px, 1fr));
  gap: 0.5rem;
}
.featured .link-card-wrap .link-card {
  background: color-mix(in srgb, var(--accent) 4%, var(--bg-card));
}

/* Sections */
.sections {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 2rem;
}
.sections--search {
  gap: 0;
}

.section-group {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}
.section-group__head {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 4.25rem;
  z-index: 9;
  background: color-mix(in srgb, var(--bg) 94%, transparent);
  backdrop-filter: blur(8px);
}
.section-group__icon {
  font-size: 1rem;
  line-height: 1;
}
.section-group__title {
  font-size: 0.95rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--text);
}
.section-group__meta {
  margin-left: auto;
  font-size: 0.7rem;
  color: var(--text-faint);
}

.section {
  scroll-margin-top: 5.5rem;
}
.section--sub {
  scroll-margin-top: 5.5rem;
}
.section--sub .section__title {
  font-size: 0.9rem;
  font-weight: 600;
}
.section.is-hidden { display: none; }

.section__head {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: 0.75rem;
  padding: 0.5rem 0;
  position: sticky;
  top: 4.5rem;
  z-index: 10;
  background: color-mix(in srgb, var(--bg) 92%, transparent);
  backdrop-filter: blur(8px);
}
.section__toggle {
  width: 28px;
  height: 28px;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: var(--bg-card);
  color: var(--text-muted);
  cursor: pointer;
  display: grid;
  place-items: center;
  flex-shrink: 0;
  transition: var(--transition);
}
.section__toggle:hover {
  color: var(--text);
  border-color: var(--border-strong);
}
.section.is-collapsed .section__toggle svg {
  transform: rotate(-90deg);
}
.section.is-collapsed .section__body {
  display: none;
}
.section__toggle svg {
  transition: transform var(--transition);
}
.section__accent {
  width: 4px;
  height: 1.25rem;
  border-radius: 2px;
}
.section__title {
  font-size: 1rem;
  font-weight: 600;
  letter-spacing: -0.01em;
}
.section__meta {
  font-size: 0.75rem;
  color: var(--text-faint);
  margin-left: auto;
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
  gap: 0.5rem;
}
.card-grid > .link-card-wrap {
  min-width: 0;
}
.card-grid--flat {
  grid-template-columns: repeat(auto-fill, minmax(152px, 1fr));
  gap: 0.45rem;
}

body[data-view="list"] .card-grid:not(.featured__grid) {
  grid-template-columns: 1fr;
  gap: 0.35rem;
}
body[data-view="list"] .link-card-wrap {
  display: block;
}
body[data-view="list"] .link-card-wrap .link-card {
  align-items: center;
  padding: 0.5rem 0.65rem;
  padding-right: 2rem;
}
body[data-view="list"] .link-card__desc {
  -webkit-line-clamp: 1;
}
body[data-view="list"] .featured__grid {
  grid-template-columns: 1fr;
}

.link-card-wrap {
  position: relative;
  min-width: 0;
}
.link-card-wrap .link-card {
  height: 100%;
}
.link-card__fav {
  position: absolute;
  top: 6px;
  right: 6px;
  z-index: 2;
  width: 28px;
  height: 28px;
  border: none;
  border-radius: 6px;
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  color: var(--text-faint);
  cursor: pointer;
  display: grid;
  place-items: center;
  opacity: 0;
  transition: var(--transition);
  box-shadow: 0 1px 4px rgba(15, 23, 42, 0.06);
}
.link-card-wrap:hover .link-card__fav,
.link-card__fav:focus-visible,
.link-card__fav.is-active {
  opacity: 1;
}
.link-card__fav:hover {
  color: #f59e0b;
  border-color: rgba(245, 158, 11, 0.4);
}
.link-card__fav.is-active {
  color: #f59e0b;
  background: rgba(245, 158, 11, 0.12);
  border-color: rgba(245, 158, 11, 0.35);
}
.link-card__fav .icon-star-filled { display: none; }
.link-card__fav.is-active .icon-star-outline { display: none; }
.link-card__fav.is-active .icon-star-filled { display: block; }

.link-card {
  display: flex;
  align-items: flex-start;
  gap: 0.625rem;
  padding: 0.625rem 0.7rem;
  padding-right: 2rem;
  min-height: 0;
  border-radius: var(--radius-sm);
  background: var(--bg-card);
  border: 1px solid var(--border);
  text-decoration: none;
  color: inherit;
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}
.link-card::before {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, var(--card-glow, transparent), transparent 60%);
  opacity: 0;
  transition: var(--transition);
}
.link-card:hover {
  background: var(--bg-card-hover);
  border-color: var(--border-strong);
  transform: translateY(-2px);
  box-shadow: var(--shadow);
}
.link-card:hover::before { opacity: 1; }

.link-card__icon {
  width: 32px;
  height: 32px;
  border-radius: 8px;
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  display: grid;
  place-items: center;
  flex-shrink: 0;
  overflow: hidden;
  margin-top: 1px;
  position: relative;
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--text-faint);
}
.link-card__icon::before {
  content: attr(data-initial);
}
.link-card__icon.has-img::before {
  display: none;
}
.link-card__icon img {
  width: 18px;
  height: 18px;
  object-fit: contain;
  position: relative;
  z-index: 1;
}
.link-card__cat {
  font-size: 0.625rem;
  font-weight: 600;
  color: var(--text-faint);
  letter-spacing: 0.02em;
}
body.is-searching .link-card__cat {
  color: var(--text-muted);
}
body.is-searching .filter-chips-wrap,
body.is-searching .featured,
body.is-searching .current-cat {
  display: none !important;
}

.favorites-panel__head {
  margin-bottom: 1rem;
}
.favorites-panel__title {
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: 0.35rem;
}
.favorites-panel__desc {
  font-size: 0.8rem;
  color: var(--text-muted);
  line-height: 1.45;
  max-width: 52ch;
}
.favorites-panel__actions {
  display: flex;
  gap: 1rem;
  margin-top: 0.65rem;
}
.btn-text--danger {
  color: #e11d48;
}
.btn-text--danger:hover {
  color: #be123c;
}
.btn-text:disabled {
  opacity: 0.4;
  cursor: not-allowed;
  text-decoration: none;
}
.sections--favorites {
  gap: 0;
}

.filter-chips-wrap {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  margin-bottom: 1rem;
}
.filter-chips--sub .filter-chip {
  font-size: 0.75rem;
  padding: 0.3rem 0.65rem;
}
.filter-chip--sub.is-active {
  background: var(--bg-card);
  border-color: var(--border-strong);
  color: var(--text);
}
.link-card__body {
  min-width: 0;
  flex: 1;
  position: relative;
  z-index: 1;
  display: flex;
  flex-direction: column;
  gap: 2px;
}
.link-card__name {
  font-size: 0.8125rem;
  font-weight: 600;
  line-height: 1.3;
  display: -webkit-box;
  -webkit-line-clamp: 1;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
.link-card__desc {
  font-size: 0.6875rem;
  line-height: 1.35;
  color: var(--text-muted);
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
.link-card__domain {
  display: none;
}
.link-card.is-hidden { display: none; }

.empty-hint {
  grid-column: 1 / -1;
  padding: 2rem;
  text-align: center;
  color: var(--text-faint);
  font-size: 0.9rem;
}

.footer {
  margin-top: 2.5rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border);
  text-align: center;
  font-size: 0.75rem;
  color: var(--text-faint);
}

.back-to-top {
  position: fixed;
  right: 1.5rem;
  bottom: 1.5rem;
  z-index: 50;
  width: 42px;
  height: 42px;
  border-radius: 50%;
  border: 1px solid var(--border);
  background: var(--bg-elevated);
  color: var(--text-muted);
  box-shadow: var(--shadow);
  cursor: pointer;
  display: grid;
  place-items: center;
  transition: var(--transition);
}
.back-to-top:hover {
  color: var(--text);
  border-color: var(--border-strong);
  transform: translateY(-2px);
}
.back-to-top[hidden] {
  display: none;
}

/* Mobile */
@media (max-width: 768px) {
  .app { flex-direction: column; }
  .sidebar {
    width: 100%;
    height: auto;
    position: relative;
    flex-direction: row;
    flex-wrap: wrap;
    align-items: center;
    padding: 1rem;
  }
  .sidebar__brand {
    border: none;
    margin: 0;
    padding: 0;
  }
  .sidebar__nav {
    flex-direction: row;
    flex-wrap: nowrap;
    overflow-x: auto;
    width: 100%;
    order: 3;
    padding-top: 0.75rem;
  }
  .nav-item { white-space: nowrap; }
  .nav-item__count { display: none; }
  .nav-group + .nav-group {
    margin-top: 0;
    padding-top: 0;
    border-top: none;
  }
  .nav-group__label { display: none; }
  .sidebar__footer { display: none; }
  .main { padding: 1rem; }
  .search__kbd { display: none; }
  .topbar__stat { display: none; }
  .card-grid { grid-template-columns: repeat(2, 1fr); }
  .card-grid--flat { grid-template-columns: 1fr; }
  .featured__grid { grid-template-columns: repeat(2, 1fr); }
  .section__head { top: 3.5rem; }
  .back-to-top { right: 1rem; bottom: 1rem; }
  .nav-group__toggle { display: none; }
  .nav-group.is-collapsed .nav-group__items { display: flex; }
}

/* Owner edit mode */
.topbar-edit-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  font-size: 0.8rem;
  white-space: nowrap;
}
.topbar-edit-btn.is-active {
  border-color: var(--accent);
  color: var(--accent);
  background: color-mix(in srgb, var(--accent) 10%, var(--surface));
}
.btn-ghost--compact {
  padding: 0.35rem 0.6rem;
}
@media (max-width: 520px) {
  .topbar-edit-btn__label { display: none; }
}

.edit-hint {
  margin-bottom: 0.75rem;
  padding: 0.65rem 1rem;
  border-radius: var(--radius);
  background: color-mix(in srgb, var(--accent) 8%, var(--surface));
  border: 1px dashed color-mix(in srgb, var(--accent) 45%, var(--border));
  font-size: 0.875rem;
  line-height: 1.5;
  color: var(--text-muted);
}
.edit-hint em {
  font-style: normal;
  font-weight: 600;
  color: var(--accent);
}

.draft-banner {
  margin-bottom: 0.75rem;
  padding: 0.65rem 1rem;
  border-radius: var(--radius);
  background: color-mix(in srgb, var(--accent) 12%, var(--surface));
  border: 1px solid color-mix(in srgb, var(--accent) 35%, var(--border));
  font-size: 0.875rem;
  color: var(--text-muted);
}
.draft-banner code {
  font-size: 0.8em;
  padding: 0.1em 0.35em;
  border-radius: 4px;
  background: var(--surface-2);
}

.edit-toolbar[hidden],
.edit-hint[hidden],
.draft-banner[hidden] {
  display: none !important;
}
.edit-toolbar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: 1rem;
  padding: 0.65rem 0.85rem;
  border-radius: var(--radius);
  background: var(--surface-2);
  border: 1px solid var(--border);
}
.edit-toolbar__label {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--accent);
  margin-right: 0.25rem;
}
.edit-toolbar__btn {
  font: inherit;
  font-size: 0.8rem;
  padding: 0.35rem 0.65rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text);
  cursor: pointer;
}
.edit-toolbar__btn:hover {
  border-color: var(--accent);
  color: var(--accent);
}
.edit-toolbar__btn--muted {
  margin-left: auto;
  color: var(--text-muted);
}
.edit-toolbar__btn--accent {
  border-color: color-mix(in srgb, var(--accent) 45%, var(--border));
  background: color-mix(in srgb, var(--accent) 10%, var(--surface));
  color: var(--accent);
  font-weight: 600;
}
.section-group__edit-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
  margin-left: auto;
}
.section-group__head .section-group__edit-bar .edit-chip-btn--ghost {
  margin-left: 0;
}
.modal__panel--wide {
  max-width: 32rem;
}
.modal__field--checkbox {
  flex-direction: row;
  align-items: center;
  gap: 0.5rem;
}
.modal__field--checkbox input {
  width: auto;
  margin: 0;
}
.modal__actions--split {
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
}
.btn-danger-ghost {
  color: #dc2626;
}
.btn-danger-ghost:hover {
  color: #b91c1c;
  border-color: color-mix(in srgb, #dc2626 40%, var(--border));
}

body.is-edit-mode .link-card__fav {
  display: none;
}

body.is-edit-mode .link-card-wrap--editable {
  position: relative;
  cursor: grab;
}
body.is-edit-mode .link-card-wrap--editable:active {
  cursor: grabbing;
}
body.is-edit-mode .link-card-wrap--editable .link-card {
  pointer-events: none;
}
body.is-edit-mode .link-card-wrap--editable.is-dragging {
  opacity: 0.5;
}
body.is-edit-mode .link-card-wrap--editable.is-drag-over {
  outline: 2px dashed var(--accent);
  outline-offset: 2px;
}
body.is-edit-mode .section--sub.is-drop-target {
  outline: 2px dashed var(--accent);
  outline-offset: 3px;
  border-radius: var(--radius);
}
body.is-edit-mode .section--sub.is-drop-target .card-grid {
  min-height: 2.5rem;
}
body.is-edit-mode .card-grid--empty {
  min-height: 3rem;
  align-content: center;
}
.section-empty-bookmarks {
  grid-column: 1 / -1;
  margin: 0;
  padding: 0.75rem 0.5rem;
  font-size: 0.8rem;
  color: var(--text-faint);
  text-align: center;
}

/* Sidebar structure edit (knowledge-base style) */
.sidebar-nav-edit {
  padding: 0 0.5rem 0.65rem;
  margin-bottom: 0.35rem;
  border-bottom: 1px dashed var(--border);
}
.sidebar-nav-edit__btn {
  display: flex;
  align-items: center;
  gap: 0.45rem;
  width: 100%;
  padding: 0.45rem 0.65rem;
  border: 1px dashed color-mix(in srgb, var(--accent) 35%, var(--border));
  border-radius: var(--radius-sm);
  background: color-mix(in srgb, var(--accent) 6%, var(--surface));
  color: var(--accent);
  font: inherit;
  font-size: 0.78rem;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
}
.sidebar-nav-edit__btn:hover {
  background: color-mix(in srgb, var(--accent) 12%, var(--surface));
  border-color: var(--accent);
}
.sidebar-nav-edit__icon {
  display: inline-flex;
  width: 1.1rem;
  height: 1.1rem;
  align-items: center;
  justify-content: center;
  border-radius: 4px;
  background: color-mix(in srgb, var(--accent) 18%, transparent);
  font-size: 0.85rem;
  line-height: 1;
}
.nav-group__actions {
  display: flex;
  align-items: center;
  gap: 0.1rem;
  flex-shrink: 0;
  padding-right: 0.25rem;
}
@media (hover: hover) {
  body.is-edit-mode .nav-group__actions {
    opacity: 0;
    pointer-events: none;
  }
  body.is-edit-mode .nav-group__head:hover .nav-group__actions,
  body.is-edit-mode .nav-group__head:focus-within .nav-group__actions {
    opacity: 1;
    pointer-events: auto;
  }
}
.nav-mini-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 1.5rem;
  height: 1.5rem;
  padding: 0;
  border: none;
  border-radius: 4px;
  background: transparent;
  color: var(--text-faint);
  font-size: 0.72rem;
  line-height: 1;
  cursor: pointer;
  transition: var(--transition);
}
.nav-mini-btn:hover {
  background: var(--bg-card);
  color: var(--text);
}
.nav-mini-btn--accent:hover {
  color: var(--accent);
  background: color-mix(in srgb, var(--accent) 12%, var(--bg-card));
}
.nav-item-wrap {
  display: flex;
  align-items: center;
  gap: 0.1rem;
  padding-right: 0.2rem;
}
.nav-item-wrap .nav-item {
  flex: 1;
  min-width: 0;
}
body.is-edit-mode .nav-item-wrap .nav-mini-btn {
  opacity: 0;
  pointer-events: none;
}
body.is-edit-mode .nav-item-wrap:hover .nav-mini-btn,
body.is-edit-mode .nav-item-wrap:focus-within .nav-mini-btn {
  opacity: 1;
  pointer-events: auto;
}
.nav-add-child {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  width: calc(100% - 0.5rem);
  margin: 0.15rem 0.25rem 0.35rem 1rem;
  padding: 0.35rem 0.55rem;
  border: none;
  border-radius: var(--radius-sm);
  background: transparent;
  color: var(--text-faint);
  font: inherit;
  font-size: 0.75rem;
  cursor: pointer;
  transition: var(--transition);
}
.nav-add-child:hover {
  color: var(--accent);
  background: color-mix(in srgb, var(--accent) 8%, var(--bg-card));
}
.nav-add-child__icon {
  display: inline-flex;
  width: 1rem;
  height: 1rem;
  align-items: center;
  justify-content: center;
  font-size: 0.85rem;
  line-height: 1;
}

/* Sidebar nav drag (edit mode) */
body.is-edit-mode .nav-item--editable {
  cursor: grab;
}
body.is-edit-mode .nav-item--editable.is-dragging {
  opacity: 0.45;
}
body.is-edit-mode .nav-item--editable.is-drag-over {
  background: var(--accent-dim);
  outline: 1px dashed var(--accent);
}
body.is-edit-mode .nav-group--editable .nav-group__toggle[draggable] {
  cursor: grab;
}
body.is-edit-mode .nav-group.is-nav-drop-target {
  outline: 1px dashed var(--accent);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}
body.is-edit-mode .nav-group.is-nav-drop-target .nav-group__items {
  min-height: 1.5rem;
}

.edit-card-actions {
  position: absolute;
  right: 0.35rem;
  bottom: 0.35rem;
  z-index: 3;
  display: flex;
  gap: 0.2rem;
  pointer-events: auto;
}
.edit-mini-btn {
  width: 1.5rem;
  height: 1.5rem;
  padding: 0;
  border: 1px solid var(--border);
  border-radius: 5px;
  background: var(--bg-elevated);
  color: var(--text-muted);
  font-size: 0.7rem;
  line-height: 1;
  cursor: pointer;
  box-shadow: 0 1px 4px rgba(15, 23, 42, 0.08);
}
.edit-mini-btn:hover {
  color: var(--accent);
  border-color: var(--accent);
}
.edit-mini-btn--danger:hover {
  color: #dc2626;
  border-color: #dc2626;
}

.section__edit-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
  padding: 0 0 0.5rem 2.25rem;
}
.edit-chip-btn {
  font: inherit;
  font-size: 0.75rem;
  padding: 0.2rem 0.5rem;
  border-radius: 999px;
  border: 1px dashed var(--border);
  background: transparent;
  color: var(--text-muted);
  cursor: pointer;
}
.edit-chip-btn:hover {
  border-color: var(--accent);
  color: var(--accent);
}
.edit-chip-btn--primary {
  border-style: solid;
  border-color: color-mix(in srgb, var(--accent) 50%, var(--border));
  background: color-mix(in srgb, var(--accent) 12%, var(--surface));
  color: var(--accent);
  font-weight: 600;
}
body.is-edit-mode .section__edit-bar {
  padding: 0.35rem 0 0.65rem 2.25rem;
  margin-bottom: 0.25rem;
}
.edit-chip-btn--ghost {
  margin-left: auto;
}
.section-group__head .edit-chip-btn--ghost {
  margin-left: auto;
}

.modal {
  position: fixed;
  inset: 0;
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1rem;
  isolation: isolate;
}
.modal[hidden] {
  display: none !important;
}
.modal__backdrop {
  position: fixed;
  inset: 0;
  z-index: 0;
  background: rgba(15, 23, 42, 0.55);
  backdrop-filter: blur(4px);
}
[data-theme="dark"] .modal__backdrop {
  background: rgba(0, 0, 0, 0.65);
}
.modal__panel {
  position: relative;
  z-index: 1;
  width: min(100%, 420px);
  max-height: min(90vh, 640px);
  overflow: auto;
  padding: 1.25rem;
  border-radius: var(--radius);
  background: var(--bg-elevated);
  border: 1px solid var(--border-strong);
  box-shadow: 0 24px 64px rgba(15, 23, 42, 0.22);
}
.modal__panel,
.modal__panel input,
.modal__panel select,
.modal__panel button {
  position: relative;
  z-index: 1;
}
.modal__title {
  margin: 0 0 1rem;
  font-size: 1.1rem;
}
.modal__hint {
  margin: -0.5rem 0 0.75rem;
  font-size: 0.85rem;
  color: var(--text-muted);
  line-height: 1.5;
}
.modal__form {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}
.modal__row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.75rem;
}
.modal__field {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
  font-size: 0.8rem;
  color: var(--text-muted);
}
.modal__field input,
.modal__field select {
  font: inherit;
  padding: 0.5rem 0.65rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  background: var(--bg-card);
  color: var(--text);
}
.modal__actions {
  display: flex;
  justify-content: flex-end;
  gap: 0.5rem;
  margin-top: 0.25rem;
}
.btn-primary {
  font: inherit;
  padding: 0.45rem 1rem;
  border-radius: var(--radius-sm);
  border: none;
  background: var(--accent);
  color: #fff;
  cursor: pointer;
}
.btn-primary:hover {
  filter: brightness(1.05);
}

.edit-link-icon-preview {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  margin: -0.15rem 0 0.35rem;
  padding: 0.5rem 0.65rem;
  border-radius: var(--radius-sm);
  background: var(--surface-2, rgba(0, 0, 0, 0.04));
}
.edit-link-icon-preview img {
  flex-shrink: 0;
  border-radius: 6px;
  object-fit: contain;
  background: #fff;
}
.edit-link-icon-preview__status {
  margin: 0;
  font-size: 0.8rem;
  color: var(--text-muted);
  line-height: 1.35;
}

.edit-toast {
  position: fixed;
  bottom: 1.5rem;
  left: 50%;
  transform: translateX(-50%);
  z-index: 300;
  padding: 0.55rem 1rem;
  border-radius: 999px;
  background: var(--text);
  color: var(--surface);
  font-size: 0.85rem;
  box-shadow: 0 8px 24px rgba(15, 23, 42, 0.2);
  pointer-events: none;
}
.edit-toast[hidden] {
  display: none !important;
}

body.has-modal {
  overflow: hidden;
}
body.has-modal .app {
  pointer-events: none;
  user-select: none;
}
body.has-modal .modal {
  pointer-events: auto;
}
body.has-modal .link-card:hover {
  transform: none;
}