:root {
  --bg: #f6f6f3;
  --fg: #1c1e21;
  --muted: #5d646b;
  --card: #ffffff;
  --card2: #f0f1ee;
  --line: #d6d9dd;
  --accent: #1a5fd0;
  --accent-fg: #ffffff;
  --accent-soft: #e3edfc;
  --ok: #146c35;
  --ok-bg: #e2f4e8;
  --warn: #7a4e00;
  --warn-bg: #fff2d1;
  --err: #a8200f;
  --err-bg: #fde6e3;
  --radius: 8px;
  --shadow: 0 1px 2px rgba(0, 0, 0, 0.06);
  color-scheme: light dark;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #121416;
    --fg: #e6e8eb;
    --muted: #9aa3ac;
    --card: #1b1e22;
    --card2: #23272c;
    --line: #353a41;
    --accent: #6ea2f5;
    --accent-fg: #0b1220;
    --accent-soft: #1d2b44;
    --ok: #6fd18f;
    --ok-bg: #153322;
    --warn: #f0c668;
    --warn-bg: #3a2c0b;
    --err: #ff8f80;
    --err-bg: #3c1814;
    --shadow: none;
  }
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font: 16px/1.5 system-ui, -apple-system, "Segoe UI", Roboto, "Noto Sans", "Noto Sans SC", sans-serif;
}
a { color: var(--accent); }
code, pre { font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; font-size: 0.9em; }
code { background: var(--card2); padding: 0.1em 0.35em; border-radius: 4px; }
h1 { font-size: 1.5rem; margin: 0 0 0.5rem; }
h2 { font-size: 1.15rem; margin: 0 0 0.5rem; }
h3 { font-size: 1rem; margin: 1rem 0 0.35rem; }
.muted { color: var(--muted); }
.small { font-size: 0.85rem; }
.hint { color: var(--muted); font-size: 0.85rem; margin: 0.2rem 0 0.8rem; }
.wrap { max-width: 1500px; margin: 0 auto; padding: 12px 16px 48px; }
.narrow { max-width: 720px; margin: 0 auto; padding: 16px; }

/* navigation */
.topnav {
  display: flex; flex-wrap: wrap; align-items: center; gap: 8px 18px;
  padding: 10px 16px; background: var(--card); border-bottom: 1px solid var(--line);
}
.topnav .brand { font-weight: 700; color: var(--fg); text-decoration: none; }
.topnav .links { display: flex; flex-wrap: wrap; gap: 4px 14px; flex: 1; }
.topnav .links a { color: var(--fg); text-decoration: none; padding: 4px 2px; border-bottom: 2px solid transparent; }
.topnav .links a[aria-current="page"] { border-bottom-color: var(--accent); font-weight: 600; }
.topnav .who { font-size: 0.9rem; }
.banner { background: var(--warn-bg); color: var(--warn); padding: 8px 16px; font-size: 0.9rem; border-bottom: 1px solid var(--line); }

/* cards and forms */
.panel, .card {
  background: var(--card); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 14px; box-shadow: var(--shadow); min-width: 0;
}
.card + .card { margin-top: 12px; }
label { display: block; font-weight: 600; margin: 12px 0 2px; }
label .opt { font-weight: 400; color: var(--muted); }
input[type=text], input[type=password], input[type=number], input[type=search], select, textarea {
  width: 100%; font: inherit; color: var(--fg); background: var(--bg);
  border: 1px solid var(--line); border-radius: 6px; padding: 8px 10px;
}
textarea { min-height: 5.5em; resize: vertical; }
input:focus-visible, select:focus-visible, textarea:focus-visible, button:focus-visible, a:focus-visible, summary:focus-visible {
  outline: 2px solid var(--accent); outline-offset: 1px;
}
button {
  font: inherit; cursor: pointer; border-radius: 6px; padding: 8px 14px;
  border: 1px solid var(--line); background: var(--card2); color: var(--fg);
}
button:hover:not(:disabled) { border-color: var(--accent); }
button:disabled { opacity: 0.5; cursor: not-allowed; }
button.primary { background: var(--accent); color: var(--accent-fg); border-color: var(--accent); font-weight: 600; }
button.danger { color: var(--err); border-color: var(--err); background: transparent; }
button.link { background: none; border: none; color: var(--accent); padding: 0; text-decoration: underline; }
.row { display: flex; flex-wrap: wrap; gap: 8px; align-items: center; }
.row.end { justify-content: flex-end; }
.grow { flex: 1; min-width: 0; }
.two { display: grid; grid-template-columns: 1fr 1fr; gap: 0 12px; }
.three { display: grid; grid-template-columns: repeat(3, 1fr); gap: 0 12px; }
@media (max-width: 640px) { .two, .three { grid-template-columns: 1fr; } }

/* messages */
.msg { padding: 8px 12px; border-radius: 6px; margin: 8px 0; font-size: 0.95rem; }
.msg.err { background: var(--err-bg); color: var(--err); }
.msg.ok { background: var(--ok-bg); color: var(--ok); }
.msg.warn { background: var(--warn-bg); color: var(--warn); }
.badge { display: inline-block; padding: 1px 8px; border-radius: 999px; font-size: 0.8rem; background: var(--card2); border: 1px solid var(--line); }
.badge.ok { background: var(--ok-bg); color: var(--ok); border-color: transparent; }
.badge.off { color: var(--muted); }

/* tables */
.tablewrap { overflow-x: auto; }
table { border-collapse: collapse; width: 100%; font-size: 0.9rem; }
th, td { text-align: left; padding: 6px 10px; border-bottom: 1px solid var(--line); white-space: nowrap; }
th { color: var(--muted); font-weight: 600; }
td.num, th.num { text-align: right; font-variant-numeric: tabular-nums; }
td.wrap-ok { white-space: normal; }

/* login */
.login { max-width: 420px; margin: 10vh auto 0; padding: 0 16px; }

/* lessons layout */
.lessons { display: grid; gap: 14px; grid-template-columns: 1fr; align-items: start; }
@media (min-width: 760px) { .lessons { grid-template-columns: 250px minmax(0, 1fr); } .lessons .tryit { grid-column: 1 / -1; } }
@media (min-width: 1180px) { .lessons { grid-template-columns: 250px minmax(0, 1fr) 410px; } .lessons .tryit { grid-column: auto; position: sticky; top: 8px; } }
.tabs { display: flex; gap: 4px; margin-bottom: 8px; }
.tabs button { flex: 1; border-radius: 6px 6px 0 0; }
.tabs button[aria-selected="true"] { background: var(--accent-soft); border-color: var(--accent); font-weight: 600; }
.item-list { list-style: none; margin: 0 0 10px; padding: 0; max-height: 52vh; overflow: auto; }
.item-list li { display: flex; gap: 4px; align-items: stretch; margin-bottom: 4px; }
.item-list .pick {
  flex: 1; text-align: left; min-width: 0; padding: 7px 9px; background: var(--bg);
}
.item-list .pick[aria-current="true"] { border-color: var(--accent); background: var(--accent-soft); }
.item-list .pick .t { display: block; font-weight: 600; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.item-list .pick .s { display: block; font-size: 0.78rem; color: var(--muted); overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.item-list .mv { padding: 0 8px; }
.langtabs { display: flex; gap: 4px; margin: 14px 0 0; border-bottom: 1px solid var(--line); }
.langtabs button { border-radius: 6px 6px 0 0; border-bottom: none; }
.langtabs button[aria-selected="true"] { background: var(--accent-soft); border-color: var(--accent); font-weight: 600; }
.dirty-dot { color: var(--warn); font-weight: 700; }
.sticky-actions { position: sticky; bottom: 0; background: var(--card); padding: 10px 0 2px; margin-top: 14px; border-top: 1px solid var(--line); }
details > summary { cursor: pointer; font-weight: 600; margin: 6px 0; }
ul.history { list-style: none; margin: 4px 0; padding: 0; max-height: 240px; overflow: auto; font-size: 0.85rem; }
ul.history li { padding: 5px 0; border-bottom: 1px solid var(--line); }

/* try it */
.chat { background: var(--bg); border: 1px solid var(--line); border-radius: 6px; padding: 8px; min-height: 160px; max-height: 42vh; overflow: auto; }
.bubble { max-width: 92%; margin: 6px 0; padding: 7px 10px; border-radius: 10px; background: var(--card2); overflow-wrap: anywhere; }
.bubble.you { margin-left: auto; background: var(--accent-soft); }
.bubble .who { display: block; font-size: 0.75rem; color: var(--muted); }
.bubble .hid { color: var(--muted); font-style: italic; }
.opened { background: var(--ok-bg); color: var(--ok); border: 1px solid var(--ok); border-radius: 6px; padding: 8px 12px; font-weight: 700; margin: 8px 0; }
.mic {
  touch-action: none; user-select: none; -webkit-user-select: none; min-width: 150px;
}
.mic.rec { background: var(--err); color: #fff; border-color: var(--err); }
.stats { display: flex; flex-wrap: wrap; gap: 4px 14px; font-size: 0.85rem; color: var(--muted); margin: 8px 0; }
ul.plain { margin: 4px 0; padding-left: 1.2rem; }

/* assets */
.gallery { display: grid; grid-template-columns: repeat(auto-fill, minmax(190px, 1fr)); gap: 12px; }
.gallery figure { margin: 0; background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden; }
.gallery img { display: block; width: 100%; height: 150px; object-fit: cover; background: var(--card2); }
.gallery figcaption { padding: 6px 9px; font-size: 0.85rem; overflow-wrap: anywhere; }
.empty { text-align: center; color: var(--muted); padding: 32px 12px; border: 1px dashed var(--line); border-radius: var(--radius); }

/* home */
.cards { display: grid; gap: 12px; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); margin: 14px 0; }
.cards a.card { text-decoration: none; color: var(--fg); display: block; }
.cards a.card:hover { border-color: var(--accent); }
.cards .card + .card { margin-top: 0; }
.sr { position: absolute; left: -9999px; }

/* refinements */
.row select, .row input[type=text].shrink { width: auto; }
@media (max-width: 700px) {
  .topnav .links { order: 3; flex-basis: 100%; }
  .item-list { max-height: 34vh; }
}
@media (min-width: 1180px) {
  .lessons .tryit { max-height: calc(100vh - 16px); overflow: auto; }
  .lessons .tryit .chat { max-height: 30vh; }
}