:root {
  --bg: #fbfaf8; --panel: #f3f1ed; --ink: #1c1b19; --mute: #77736b; --rule: #dedad2;
  --accent: #b0206b; --accent-ink: #fff; --unread: #1c1b19;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #151412; --panel: #1d1c1a; --ink: #ece9e3; --mute: #8f8b82; --rule: #2e2c28;
    --accent: #e0509a; --accent-ink: #151412; --unread: #ece9e3;
  }
}
* { box-sizing: border-box; }
html, body { height: 100%; margin: 0; }
body { background: var(--bg); color: var(--ink); font: 15px/1.45 system-ui, -apple-system, "Segoe UI", sans-serif; }
[hidden] { display: none !important; }
h1 { font-size: 15px; margin: 0 0 14px; letter-spacing: .02em; display: flex; align-items: center; gap: 8px; }
h1 .logo { border-radius: 7px; }
button { font: inherit; color: inherit; background: none; border: 1px solid var(--rule); border-radius: 4px; padding: 6px 12px; cursor: pointer; }
button.primary { background: var(--accent); color: var(--accent-ink); border-color: var(--accent); }
button.quiet { border-color: transparent; color: var(--mute); }
input, select, textarea { font: inherit; color: inherit; background: var(--bg); border: 1px solid var(--rule); border-radius: 4px; padding: 7px 9px; width: 100%; }
.err { color: #c0392b; min-height: 1.2em; margin: 6px 0 0; font-size: 13px; }

#login { display: grid; place-items: center; height: 100%; padding: 16px; }
#loginForm { width: min(320px, 100%); display: grid; gap: 10px; }

#app { display: grid; grid-template-columns: 200px 340px 1fr; height: 100%; }
#boxes { background: var(--panel); border-right: 1px solid var(--rule); padding: 16px 12px; display: flex; flex-direction: column; gap: 4px; overflow: auto; }
#boxes #compose { margin-bottom: 12px; }
.spacer { flex: 1; }
.box { display: flex; justify-content: space-between; text-align: left; border: 0; border-radius: 4px; padding: 6px 8px; width: 100%; }
.box.on { background: var(--bg); font-weight: 600; }
.box .n { color: var(--accent); font-weight: 600; }

#list { border-right: 1px solid var(--rule); display: flex; flex-direction: column; min-width: 0; overflow: hidden; }
#list header { padding: 10px; border-bottom: 1px solid var(--rule); display: grid; gap: 8px; }
.tabs { display: flex; gap: 4px; }
.tabs button { border: 0; padding: 3px 8px; color: var(--mute); }
.tabs button.on { color: var(--ink); border-bottom: 2px solid var(--accent); border-radius: 0; }
#rows { list-style: none; margin: 0; padding: 0; overflow: auto; flex: 1; }
#rows li { padding: 10px 12px; border-bottom: 1px solid var(--rule); cursor: pointer; }
#rows li.on { background: var(--panel); }
#rows .top { display: flex; justify-content: space-between; gap: 8px; }
#rows .who { white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
#rows .when { color: var(--mute); font-size: 12px; white-space: nowrap; }
#rows .subj, #rows .prev { white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
#rows .prev { color: var(--mute); font-size: 13px; }
#rows li.unread .who, #rows li.unread .subj { font-weight: 700; color: var(--unread); }
#rows .to { color: var(--mute); font-size: 12px; }

#view { overflow: auto; padding: 18px 22px; min-width: 0; }
#view .empty { color: var(--mute); }
#view h2 { margin: 0 0 6px; font-size: 20px; font-weight: 600; }
#view .meta { color: var(--mute); font-size: 13px; margin-bottom: 12px; }
#view .actions { display: flex; gap: 6px; margin-bottom: 14px; flex-wrap: wrap; }
#view .text { white-space: pre-wrap; word-break: break-word; }
#view .text a { color: var(--accent); }
#view iframe { width: 100%; border: 1px solid var(--rule); border-radius: 4px; background: #fff; min-height: 420px; }

dialog { background: var(--bg); color: var(--ink); border: 1px solid var(--rule); border-radius: 6px; width: min(560px, calc(100% - 24px)); padding: 18px; }
dialog::backdrop { background: rgba(0,0,0,.4); }
dialog h2 { margin: 0 0 10px; font-size: 17px; }
dialog label { display: grid; gap: 3px; margin-bottom: 8px; font-size: 13px; color: var(--mute); }
dialog .row { display: flex; justify-content: flex-end; gap: 8px; margin-top: 8px; }

@media (max-width: 860px) {
  #app { grid-template-columns: 1fr; grid-template-rows: auto 1fr; }
  #boxes { flex-direction: row; align-items: center; padding: 8px; overflow-x: auto; border-right: 0; border-bottom: 1px solid var(--rule); }
  #boxes h1, #boxes .spacer { display: none; }
  #boxes #compose { margin: 0 8px 0 0; }
  #boxList { display: flex; gap: 4px; }
  .box { width: auto; white-space: nowrap; gap: 8px; }
  #list { border-right: 0; }
  #view { display: none; position: fixed; inset: 0; background: var(--bg); z-index: 5; padding: 14px 16px; }
  body.reading #view { display: block; }
}