/* Shared component contract. Colors belong to theme.css; layout belongs to pages. */
:root {
  --ui-space-1: 4px;
  --ui-space-2: 8px;
  --ui-space-3: 12px;
  --ui-space-4: 16px;
  --ui-space-6: 24px;
  --ui-space-8: 32px;
  --ui-control-sm: 32px;
  --ui-control-md: 40px;
  --ui-control-lg: 44px;
  --ui-radius-sm: 8px;
  --ui-radius-control: 12px;
  --ui-radius-panel: 16px;
  --ui-radius-pill: 999px;
  --ui-duration: 140ms;
  --ui-ease: cubic-bezier(.2, 0, 0, 1);
}

/* Existing .button consumers use the same foundation as new templates. */
:is(.ui-button, .button) {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--ui-space-2);
  min-height: var(--ui-control-md);
  max-width: 100%;
  padding: 8px 16px;
  border: 1px solid var(--line-strong);
  border-radius: var(--ui-radius-pill);
  background: var(--paper);
  color: var(--ink);
  font: inherit;
  font-size: 14px;
  font-weight: 550;
  line-height: 1.5;
  text-align: center;
  text-decoration: none;
  cursor: pointer;
  vertical-align: middle;
  transition: background-color var(--ui-duration) var(--ui-ease), border-color var(--ui-duration) var(--ui-ease), color var(--ui-duration) var(--ui-ease);
}
:is(.ui-button, .button):hover { background: var(--raised); border-color: var(--line-strong); color: var(--ink); }
:is(.ui-button--primary, .button.primary) { background: var(--accent-solid); color: var(--on-accent); border-color: var(--accent-solid); }
:is(.ui-button--primary, .button.primary):hover { background: var(--secondary); border-color: var(--secondary); color: var(--on-accent); filter: none; }
.ui-button--soft { background: var(--raised); border-color: transparent; }
.ui-button--soft:hover { background: var(--sidebar-hover); border-color: transparent; }
.ui-button--ghost { background: transparent; border-color: transparent; }
.ui-button--ghost:hover { background: var(--raised); border-color: transparent; }
:is(.ui-button--danger, .button.danger) { color: var(--danger-ink); border-color: var(--danger-line); background: transparent; }
:is(.ui-button--danger, .button.danger):hover { color: var(--danger-ink); background: var(--danger-bg); border-color: var(--danger-line); }
:is(.ui-button--sm, .button.small) { min-height: var(--ui-control-sm); padding: 5px 12px; font-size: 13px; }
.ui-button--lg { min-height: var(--ui-control-lg); padding: 10px 20px; }
.ui-button--icon { width: var(--ui-control-md); min-width: var(--ui-control-md); padding: 8px; flex-shrink: 0; }
.ui-button--icon.ui-button--sm { width: var(--ui-control-sm); min-width: var(--ui-control-sm); }
:is(.ui-button, .button) :is(svg, .lucide) { width: 18px; height: 18px; flex-shrink: 0; }
:is(.ui-button, .button):is(:disabled, [aria-disabled="true"]) { opacity: .45; cursor: not-allowed; pointer-events: none; }
:is(.ui-button, .button)[aria-busy="true"] { opacity: 1; cursor: progress; }
:is(.ui-button, .button):active:not(:disabled):not([aria-disabled="true"]) { filter: brightness(.94); }
:is(.ui-button, .button, .ui-chip, .ui-tab, .ui-menu summary, .ui-menu-item, .ui-input):focus-visible { outline: 2px solid var(--ink); outline-offset: 3px; }
.ui-spinner { display: inline-block; width: 16px; height: 16px; flex: 0 0 16px; border: 2px solid currentColor; border-right-color: transparent; border-radius: 50%; animation: ui-spin .8s linear infinite; }
.ui-button > .ui-spinner { width: 18px; height: 18px; flex-basis: 18px; }
@keyframes ui-spin { to { transform: rotate(360deg); } }

/* Link navigation keeps native navigation semantics; in-page tabs opt into JS. */
.ui-tabs { display: flex; align-items: center; gap: var(--ui-space-1); max-width: 100%; min-width: 0; overflow-x: auto; overscroll-behavior-x: contain; padding: 4px; scrollbar-width: thin; }
.ui-tabs--segmented { width: fit-content; border-radius: var(--ui-radius-pill); background: var(--raised); }
.ui-tab { display: inline-flex; align-items: center; justify-content: center; gap: 6px; flex: 0 0 auto; min-height: 36px; padding: 7px 16px; border: 1px solid transparent; border-radius: var(--ui-radius-pill); background: transparent; color: var(--secondary); font: inherit; font-size: 14px; font-weight: 500; line-height: 1.5; white-space: nowrap; cursor: pointer; }
.ui-tab:hover { color: var(--ink); background: var(--sidebar-hover); }
.ui-tab:is([aria-selected="true"], [aria-current="page"]) { background: var(--paper); color: var(--ink); border-color: var(--line-strong); font-weight: 650; }
.ui-tabs .ui-tab:focus-visible { outline-offset: -3px; }
.ui-tabs--pills { padding: 4px 0; gap: 8px; }
.ui-tabs--pills .ui-tab { border-color: var(--line-strong); }
.ui-tabs--pills .ui-tab:is([aria-selected="true"], [aria-current="page"]) { background: var(--raised); border-color: var(--ink); }
.ui-tab:disabled { opacity: .45; cursor: not-allowed; }
.ui-panel { padding-block: 16px; }

/* Shared feed tabs, including the existing separate edit action. */
.source-tabs { gap: 8px; padding-block: 4px; }
.source-tabs a { display: inline-flex; align-items: center; justify-content: center; gap: 6px; flex-shrink: 0; min-height: 36px; padding: 6px 14px; border: 1px solid var(--line-strong); border-radius: var(--ui-radius-pill); background: transparent; color: var(--secondary); font-size: 13px; line-height: 1.5; }
.source-tabs a:hover { background: var(--raised); border-color: var(--line-strong); color: var(--ink); }
.source-tabs a.active { background: var(--raised); border-color: var(--ink); color: var(--ink); font-weight: 650; }
.source-tabs a:focus-visible { outline: 2px solid var(--ink); outline-offset: -3px; }
.source-tabs .custom-channel-pill { border: 1px solid var(--line-strong); }
.source-tabs .custom-channel-pill.active { border-color: var(--ink); }
.source-tabs .custom-channel-tab-group { border: 1px solid var(--ink); border-radius: var(--ui-radius-pill); background: var(--raised); }
.source-tabs .custom-channel-tab-group > a { border: 0; background: transparent; }
.source-tabs .custom-channel-tab-group > .custom-channel-tab-edit { margin-inline-end: 3px; }
.channel-tag-modes { gap: 4px; padding: 4px; border: 0; border-radius: var(--ui-radius-pill); background: var(--raised); }
:is(.channel-tag-modes, .channel-create-dialog .channel-tag-modes) button { min-height: 36px; padding: 7px 14px; border: 1px solid transparent; border-radius: var(--ui-radius-pill); font-size: 13px; }
.channel-tag-modes button[aria-selected="true"] { background: var(--paper); border-color: var(--line-strong); color: var(--ink); }
.channel-tag-modes button:focus-visible { outline-offset: -3px; }
.feed-page:not(.people-feed) .custom-channel-add { border-radius: var(--ui-radius-pill); }

.ui-chip { display: inline-flex; align-items: center; gap: 6px; min-height: 32px; padding: 5px 12px; border: 1px solid var(--line-strong); border-radius: var(--ui-radius-pill); background: transparent; color: var(--secondary); font: inherit; font-size: 13px; line-height: 1.5; cursor: pointer; }
.ui-chip:hover { background: var(--raised); color: var(--ink); }
.ui-chip[aria-pressed="true"] { border-color: var(--ink); background: var(--raised); color: var(--ink); }
.ui-chip svg { width: 14px; height: 14px; }
.ui-chip .ui-chip-check { visibility: hidden; }
.ui-chip[aria-pressed="true"] .ui-chip-check { visibility: visible; }
.ui-badge { display: inline-flex; align-items: center; gap: 5px; padding: 3px 9px; border-radius: var(--ui-radius-pill); background: var(--raised); color: var(--secondary); font-size: 12px; font-weight: 500; line-height: 1.5; }
.ui-badge--success { background: var(--success-bg); color: var(--success-ink); }
.ui-badge--warning { background: var(--warning-bg); color: var(--warning-ink); }
.ui-badge--danger { background: var(--danger-bg); color: var(--danger-ink); }
.ui-badge svg { width: 13px; height: 13px; }

.ui-field { display: grid; gap: 8px; min-width: 0; }
.ui-field label { font-size: 14px; font-weight: 550; }
.ui-field .ui-input, .ui-input { width: 100%; min-width: 0; min-height: var(--ui-control-lg); margin: 0; padding: 10px 14px; border: 1px solid var(--control-border); border-radius: var(--ui-radius-control); background: var(--paper); color: var(--ink); font: inherit; font-size: 14px; line-height: 1.5; }
.ui-input::placeholder { color: var(--muted); opacity: 1; }
.ui-input:hover { border-color: var(--secondary); }
.ui-input[aria-invalid="true"] { border-color: var(--danger-ink); }
.ui-input:disabled { background: var(--raised); color: var(--muted); cursor: not-allowed; }
.ui-field-help { margin: 0; color: var(--muted); font-size: 12px; line-height: 1.6; }
.ui-field-error { color: var(--danger-ink); }
.ui-check { display: flex; align-items: center; gap: 10px; min-height: 44px; font-size: 14px; font-weight: 400; cursor: pointer; }
.ui-check input[type="checkbox"] { width: 18px; height: 18px; margin: 0; accent-color: var(--ink); }
/* Named legacy fields consume control shape without changing checkbox/radio geometry. */
:is(.reader-login-modal, .channel-builder-form) :is(input:not([type="checkbox"]):not([type="radio"]):not([type="hidden"]), textarea, select) { border-radius: var(--ui-radius-control); }
.search-box { border-radius: var(--ui-radius-pill); }
.search-box:focus-within { outline: 2px solid var(--ink); outline-offset: 2px; }
.search-box input:focus-visible { outline: none; }

.ui-card { padding: 24px; border: 1px solid var(--line); border-radius: var(--ui-radius-panel); background: var(--paper); }
.ui-notice { display: flex; align-items: flex-start; gap: 10px; padding: 12px 16px; border-radius: var(--ui-radius-control); background: var(--raised); color: var(--secondary); font-size: 14px; line-height: 1.6; }
.ui-notice--success { background: var(--success-bg); color: var(--success-ink); }
.ui-notice--danger { background: var(--danger-bg); color: var(--danger-ink); }
.ui-notice > svg { width: 18px; height: 18px; flex-shrink: 0; margin-top: 2px; }
.ui-menu { position: relative; width: fit-content; margin: 0; }
.ui-menu > summary { list-style: none; }
.ui-menu > summary::-webkit-details-marker { display: none; }
.ui-menu-content { position: absolute; z-index: 20; inset-inline-start: 0; top: calc(100% + 8px); display: grid; width: 224px; max-width: calc(100vw - 48px); padding: 6px; border: 1px solid var(--line-strong); border-radius: var(--ui-radius-panel); background: var(--paper); box-shadow: var(--shadow); }
.ui-menu-item { display: flex; align-items: center; gap: 10px; min-height: 40px; padding: 8px 12px; border: 0; border-radius: var(--ui-radius-sm); color: var(--ink); background: transparent; font-size: 14px; text-align: start; cursor: pointer; }
.ui-menu-item:hover { background: var(--raised); }
.ui-menu-item svg { width: 18px; height: 18px; }
.ui-dialog { width: min(480px, calc(100% - 32px)); max-height: calc(100dvh - 32px); padding: 24px; border: 1px solid var(--line); border-radius: var(--ui-radius-panel); background: var(--paper); color: var(--ink); box-shadow: var(--shadow); overflow-y: auto; }
body:has(.ui-dialog[open]) { overflow: hidden; }
.ui-dialog::backdrop { background: var(--overlay); }
.ui-dialog-header { display: flex; align-items: center; justify-content: space-between; gap: 16px; margin-bottom: 12px; }
.ui-dialog-header h2 { font-size: 20px; }
.ui-dialog-actions { display: flex; justify-content: flex-end; flex-wrap: wrap; gap: 8px; margin-top: 24px; }

@media (max-width: 820px), (pointer: coarse) {
  :is(.ui-button, .button, .ui-tab, .ui-chip, .ui-menu-item) { min-height: 44px; }
  .ui-button--icon, .ui-button--icon.ui-button--sm { width: 44px; min-width: 44px; }
  .source-tabs a, :is(.channel-tag-modes, .channel-create-dialog .channel-tag-modes) button { min-height: 44px; }
  .ui-input, .ui-field .ui-input { font-size: 16px; }
}
@media (prefers-reduced-motion: reduce) {
  :is(.ui-button, .button, .ui-tab, .ui-chip) { transition: none; }
  .ui-spinner { animation: none; }
}
@media (forced-colors: active) {
  .ui-tab[aria-selected="true"], .ui-chip[aria-pressed="true"], .source-tabs a.active { outline: 2px solid Highlight; outline-offset: -3px; }
  :is(.ui-button, .button):disabled { opacity: 1; color: GrayText; border-color: GrayText; }
}