:root {
  --bg: #f4f6fa;
  --surface: #ffffff;
  --text: #111827;
  --muted: #4b5563;
  --border: #cbd5e1;
  --accent: #1d4ed8;
  --accent-text: #ffffff;
  --danger: #b91c1c;
  --ok: #166534;
  --notice-bg: #eff6ff;
  --chip-bg: #e0e7ff;
  --chip-text: #1e3a8a;
  --tabbar-h: 56px;
  color-scheme: light dark;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0b1220;
    --surface: #131c2e;
    --text: #f3f4f6;
    --muted: #b6bfcc;
    --border: #334155;
    --accent: #60a5fa;
    --accent-text: #0b1220;
    --danger: #fca5a5;
    --ok: #86efac;
    --notice-bg: #172554;
    --chip-bg: #1e3a8a;
    --chip-text: #dbeafe;
  }
}

* { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 16px/1.6 -apple-system, BlinkMacSystemFont, "Hiragino Sans", "Hiragino Kaku Gothic ProN", "Yu Gothic", system-ui, sans-serif;
  padding: env(safe-area-inset-top) env(safe-area-inset-right) calc(var(--tabbar-h) + env(safe-area-inset-bottom) + 16px) env(safe-area-inset-left);
  overflow-wrap: anywhere;
}

h1, h2, h3 { line-height: 1.3; margin: 0 0 8px; }
h1 { font-size: 1.25rem; }
h2 { font-size: 1.1rem; }
h3 { font-size: 1rem; }
p { margin: 0 0 8px; }
ul { margin: 0 0 8px; padding-left: 1.2em; }

.app-header { padding: 12px 16px 4px; }
.app-sub { color: var(--muted); font-size: 0.85rem; margin: 0; }

main { padding: 8px 16px; max-width: 720px; margin: 0 auto; }
.view[hidden], [hidden] { display: none !important; }

.sr-status {
  position: absolute; width: 1px; height: 1px; overflow: hidden;
  clip: rect(0 0 0 0); white-space: nowrap;
}

.notice {
  background: var(--notice-bg);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 10px 12px;
  margin: 8px 0 12px;
  font-size: 0.92rem;
}
.notice-error { border-color: var(--danger); color: var(--danger); margin: 8px 16px; }

.card-group {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 14px;
  margin: 0 0 14px;
}

.service-block { margin-bottom: 14px; }
.service-block:last-child { margin-bottom: 0; }

.link-list, .btn-row { display: flex; flex-wrap: wrap; gap: 8px; }

.btn, button, select, input, textarea { font: inherit; color: inherit; }

.btn, button.btn {
  display: inline-flex; align-items: center; justify-content: center;
  min-height: 44px; min-width: 44px;
  padding: 8px 14px;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: var(--surface);
  color: var(--text);
  text-decoration: none;
  cursor: pointer;
  text-align: center;
  max-width: 100%;
}
.btn-primary { background: var(--accent); border-color: var(--accent); color: var(--accent-text); font-weight: 600; }
.btn-danger { color: var(--danger); border-color: var(--danger); }
.btn[aria-pressed="true"] { background: var(--chip-bg); color: var(--chip-text); border-color: var(--accent); font-weight: 600; }

.field { margin: 0 0 12px; border: 0; padding: 0; min-width: 0; }
.field > label, legend, .label { display: block; font-weight: 600; font-size: 0.9rem; margin-bottom: 4px; padding: 0; }

input[type="text"], input[type="search"], input[type="date"], input[type="file"], select, textarea {
  width: 100%;
  min-height: 44px;
  padding: 8px 10px;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: var(--surface);
  color: var(--text);
  font-size: 16px; /* iOSの自動ズーム防止 */
}
textarea { resize: vertical; }

.row { display: flex; gap: 8px; align-items: stretch; }
.row input { flex: 1; min-width: 0; }

.check { display: flex; align-items: center; gap: 10px; min-height: 44px; }
.check input { width: 22px; height: 22px; flex: none; }
.check-group { display: grid; grid-template-columns: 1fr; }

details.optional { margin: 0 0 12px; }
details.optional summary { min-height: 44px; display: flex; align-items: center; cursor: pointer; font-weight: 600; }

.form-msg { min-height: 1.4em; margin: 0 0 8px; font-size: 0.92rem; }
.form-msg.error { color: var(--danger); }
.form-msg.ok { color: var(--ok); }
.hint { color: var(--muted); font-size: 0.85rem; }
.count { color: var(--muted); font-size: 0.9rem; }

.post {
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 12px;
  margin: 0 0 12px;
  background: var(--surface);
}
.post.highlight { outline: 3px solid var(--accent); }
.post.is-read { opacity: 0.85; }
.post-head { display: flex; flex-wrap: wrap; gap: 4px 10px; align-items: baseline; margin-bottom: 6px; }
.post-author { font-weight: 700; }
.post-meta { color: var(--muted); font-size: 0.85rem; }
.badge {
  display: inline-block; padding: 1px 8px; border-radius: 999px;
  border: 1px solid var(--border); font-size: 0.78rem; color: var(--muted);
}
.post-text { white-space: pre-wrap; margin: 6px 0; }
.post-note { background: var(--notice-bg); border-radius: 8px; padding: 6px 10px; margin: 6px 0; white-space: pre-wrap; }
.chips { display: flex; flex-wrap: wrap; gap: 6px; margin: 6px 0; }
.chip { background: var(--chip-bg); color: var(--chip-text); padding: 2px 10px; border-radius: 999px; font-size: 0.82rem; }
.post-actions { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 8px; }
.post-url { font-size: 0.8rem; color: var(--muted); }

.tabbar {
  position: fixed; left: 0; right: 0; bottom: 0;
  display: flex;
  background: var(--surface);
  border-top: 1px solid var(--border);
  padding-bottom: env(safe-area-inset-bottom);
  padding-left: env(safe-area-inset-left);
  padding-right: env(safe-area-inset-right);
  z-index: 10;
}
.tabbar button {
  flex: 1; min-height: var(--tabbar-h);
  border: 0; background: transparent; color: var(--muted);
  font-size: 0.95rem; cursor: pointer;
}
.tabbar button[aria-selected="true"] { color: var(--accent); font-weight: 700; box-shadow: inset 0 3px 0 var(--accent); }

:focus-visible { outline: 3px solid var(--accent); outline-offset: 2px; }

@media (prefers-reduced-motion: no-preference) {
  .btn, .tabbar button { transition: background-color 0.15s; }
}
@media (prefers-reduced-motion: reduce) {
  * { animation: none !important; transition: none !important; scroll-behavior: auto !important; }
}

@media (min-width: 560px) {
  .check-group { grid-template-columns: 1fr 1fr; }
}