:root {
  color-scheme: light dark;
  --bg: #f6f5f2;
  --panel: #ffffff;
  --text: #1c1b19;
  --muted: #6b6860;
  --line: #e4e1da;
  --accent: #1f5f4a;
  --accent-text: #ffffff;
  --hover: #efede8;
  --selected: #e3efe9;
  --danger: #a3271f;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #171716;
    --panel: #1f1f1d;
    --text: #ecebe6;
    --muted: #9c998f;
    --line: #33322e;
    --accent: #6fc3a4;
    --accent-text: #10201a;
    --hover: #292926;
    --selected: #24362f;
    --danger: #f08a80;
  }
}

* { box-sizing: border-box; }
html, body { height: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 15px/1.45 system-ui, -apple-system, "Segoe UI", sans-serif;
}
[hidden] { display: none !important; }

button, input, select, textarea { font: inherit; color: inherit; }
button {
  border: 1px solid var(--line);
  background: var(--panel);
  border-radius: 8px;
  padding: 7px 12px;
  cursor: pointer;
}
button:hover { background: var(--hover); }
button:disabled { opacity: 0.6; cursor: default; }
button.primary { background: var(--accent); border-color: var(--accent); color: var(--accent-text); font-weight: 600; }
button.primary:hover { filter: brightness(1.08); background: var(--accent); }
button.danger { color: var(--danger); }
input, select, textarea {
  width: 100%;
  border: 1px solid var(--line);
  background: var(--panel);
  border-radius: 8px;
  padding: 8px 10px;
}
:focus-visible { outline: 2px solid var(--accent); outline-offset: 1px; }
a { color: var(--accent); }
.error { color: var(--danger); min-height: 1.4em; margin: 0; }

/* login */
#login { min-height: 100%; display: grid; place-items: center; padding: 16px; }
#login form { width: min(340px, 100%); display: grid; gap: 10px; }
#login h1 { margin: 0 0 8px; font-size: 26px; }

/* app shell */
#app { height: 100%; display: grid; grid-template-columns: 190px minmax(280px, 380px) 1fr; }
nav { display: flex; flex-direction: column; gap: 6px; padding: 16px 12px; border-right: 1px solid var(--line); }
nav .folder { text-align: left; border-color: transparent; background: none; display: flex; justify-content: space-between; }
nav .folder:hover { background: var(--hover); }
nav .folder.active { background: var(--selected); font-weight: 600; }
nav #compose-btn { margin-bottom: 10px; }
nav #logout { margin-top: auto; border-color: transparent; background: none; color: var(--muted); text-align: left; }
#unread { font-variant-numeric: tabular-nums; }

#list-pane { display: flex; flex-direction: column; min-height: 0; border-right: 1px solid var(--line); background: var(--panel); }
#search { margin: 12px; width: auto; }
#list { overflow-y: auto; flex: 1; }
.row {
  display: block;
  width: 100%;
  text-align: left;
  border: 0;
  border-bottom: 1px solid var(--line);
  border-radius: 0;
  padding: 10px 14px;
  background: none;
}
.row.selected { background: var(--selected); }
.row-top { display: flex; justify-content: space-between; gap: 8px; }
.row .who, .row .subject, .row .snippet { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.row time { color: var(--muted); font-size: 13px; flex: none; }
.row .snippet { color: var(--muted); font-size: 13px; }
.row.unread .who, .row.unread .subject { font-weight: 700; }
.empty { color: var(--muted); text-align: center; padding: 40px 16px; }
.more { display: block; margin: 12px auto; }

#reader { overflow-y: auto; padding: 16px 24px 40px; min-width: 0; }
#reader h2 { margin: 16px 0 8px; font-size: 21px; overflow-wrap: anywhere; }
#reader dl { display: grid; grid-template-columns: max-content 1fr; gap: 2px 12px; margin: 0 0 16px; font-size: 14px; }
#reader dt { color: var(--muted); }
#reader dd { margin: 0; overflow-wrap: anywhere; }
.actions { display: flex; flex-wrap: wrap; gap: 8px; }
.actions .back { display: none; }
.notice { background: var(--hover); border-radius: 8px; padding: 8px 12px; font-size: 14px; }
.attachments { list-style: none; padding: 0; margin: 0 0 16px; display: flex; flex-wrap: wrap; gap: 8px; font-size: 14px; color: var(--muted); }
.attachments li { border: 1px solid var(--line); border-radius: 8px; padding: 5px 10px; background: var(--panel); }
.body.text { white-space: pre-wrap; overflow-wrap: anywhere; }
.body iframe { width: 100%; border: 0; border-radius: 8px; background: #fff; min-height: 200px; }

/* compose */
dialog { border: 1px solid var(--line); border-radius: 12px; background: var(--bg); color: var(--text); padding: 20px; width: min(680px, calc(100% - 24px)); }
dialog::backdrop { background: rgb(0 0 0 / 0.45); }
#compose-form { display: grid; gap: 10px; }
#compose-form h2 { margin: 0; font-size: 18px; }
#compose-form label { display: grid; gap: 4px; font-size: 13px; color: var(--muted); }
#compose-form label > * { font-size: 15px; color: var(--text); }
#compose-form textarea { resize: vertical; }
#compose-form .actions { justify-content: flex-end; }

@media (max-width: 860px) {
  #app { grid-template-columns: 1fr; grid-template-rows: auto 1fr; }
  nav { flex-direction: row; flex-wrap: wrap; align-items: center; border-right: 0; border-bottom: 1px solid var(--line); padding: 10px 12px; }
  nav #compose-btn { margin: 0; }
  nav #logout { margin: 0 0 0 auto; }
  nav .folder { gap: 6px; }
  #list-pane { border-right: 0; }
  #reader { display: none; padding: 12px 16px 32px; }
  body.reading #list-pane { display: none; }
  body.reading #reader { display: block; }
  .actions .back { display: inline-block; }
}