:root {
  --bg: #0f1221;
  --panel: #1a1f36;
  --panel-2: #232a4a;
  --text: #e8ecf6;
  --muted: #95a0c0;
  --accent: #5b8cff;
  --accent-2: #7c5cff;
  --good: #2fbf71;
  --bad: #ff5c6c;
  --border: #2c3358;
  --radius: 14px;
  --shadow: 0 8px 30px rgba(0, 0, 0, .35);
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: radial-gradient(1200px 600px at 50% -10%, #1b2244 0%, var(--bg) 60%);
  color: var(--text);
  font-family: -apple-system, "PingFang SC", "Microsoft YaHei", "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  min-height: 100vh;
}

.app {
  max-width: 720px;
  margin: 0 auto;
  padding: 20px 16px 60px;
}

header.top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 16px;
}
.brand { font-weight: 800; font-size: 20px; letter-spacing: .5px; }
.brand small { color: var(--muted); font-weight: 500; font-size: 12px; margin-left: 8px; }

.tabs { display: flex; gap: 6px; }
.tab {
  background: var(--panel);
  border: 1px solid var(--border);
  color: var(--muted);
  padding: 8px 14px;
  border-radius: 999px;
  cursor: pointer;
  font-size: 14px;
  transition: .15s;
}
.tab.active { color: #fff; background: linear-gradient(135deg, var(--accent), var(--accent-2)); border-color: transparent; }
.tab:hover { color: #fff; }

.statbar {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 10px;
  margin-bottom: 18px;
}
.stat {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 12px;
  text-align: center;
}
.stat .num { font-size: 22px; font-weight: 800; }
.stat .lbl { font-size: 12px; color: var(--muted); margin-top: 2px; }

.filters { margin-bottom: 12px; display: flex; flex-direction: column; gap: 8px; }
.chips { display: flex; flex-wrap: wrap; gap: 6px; }
.chip {
  background: var(--panel);
  border: 1px solid var(--border);
  color: var(--muted);
  padding: 5px 11px;
  border-radius: 999px;
  font-size: 12px;
  cursor: pointer;
  transition: .12s;
}
.chip.on { color: #fff; background: var(--panel-2); border-color: var(--accent); }
.chip:hover { color: #fff; }

.card {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 26px 22px;
}

.qhead { display: flex; align-items: center; justify-content: space-between; margin-bottom: 18px; }
.badge {
  font-size: 12px; color: #fff; padding: 4px 10px; border-radius: 999px;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
}
.badge.rev { background: linear-gradient(135deg, #ff8a3d, #ff5c8a); }
.badge.cz { background: linear-gradient(135deg, #2fbf71, #19a3a3); }
.qmeta { color: var(--muted); font-size: 12px; }

.prompt {
  font-size: 34px;
  font-weight: 800;
  text-align: center;
  padding: 14px 6px 26px;
  word-break: break-word;
  line-height: 1.3;
}
.prompt.zh { font-size: 26px; font-weight: 700; }
.prompt.cloze { font-size: 20px; font-weight: 600; text-align: left; line-height: 1.7; }

.options { display: grid; gap: 10px; }
.opt {
  text-align: left;
  background: var(--panel-2);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 14px 16px;
  border-radius: 12px;
  font-size: 16px;
  cursor: pointer;
  transition: .12s;
  display: flex;
  gap: 12px;
  align-items: center;
}
.opt:hover:not(:disabled) { border-color: var(--accent); transform: translateY(-1px); }
.opt .key {
  flex: 0 0 24px; height: 24px; border-radius: 6px;
  display: grid; place-items: center; font-size: 12px;
  background: #0e1430; color: var(--muted); border: 1px solid var(--border);
}
.opt:disabled { cursor: default; }
.opt.correct { border-color: var(--good); background: rgba(47, 191, 113, .15); }
.opt.wrong { border-color: var(--bad); background: rgba(255, 92, 108, .15); }
.opt.correct .key { background: var(--good); color: #fff; border-color: transparent; }
.opt.wrong .key { background: var(--bad); color: #fff; border-color: transparent; }

.reveal {
  margin-top: 18px;
  border-top: 1px dashed var(--border);
  padding-top: 16px;
  display: none;
}
.reveal.show { display: block; }
.reveal .word { font-size: 22px; font-weight: 800; }
.reveal .speak { cursor: pointer; margin-left: 8px; opacity: .8; font-size: 18px; }
.reveal .zh { color: var(--muted); margin-top: 6px; font-size: 15px; }
.reveal .ex { margin-top: 10px; font-size: 15px; line-height: 1.6; color: var(--text); }
.reveal .ex mark { background: rgba(91, 140, 255, .25); color: #cfe0ff; padding: 0 3px; border-radius: 4px; }
.reveal .tr { margin-top: 4px; font-size: 14px; color: var(--muted); }
.reveal .note { margin-top: 10px; font-size: 13px; color: var(--muted); background: #0e1430; border: 1px solid var(--border); border-radius: 10px; padding: 8px 10px; line-height: 1.6; }
.reveal .note b { color: var(--text); }
.reveal .verdict { font-weight: 700; }
.reveal .verdict.good { color: var(--good); }
.reveal .verdict.bad { color: var(--bad); }

.row { display: flex; gap: 10px; margin-top: 16px; }
.btn {
  flex: 1;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  color: #fff; border: none; padding: 14px; border-radius: 12px;
  font-size: 16px; font-weight: 700; cursor: pointer;
}
.btn.ghost { background: var(--panel-2); border: 1px solid var(--border); color: var(--text); }
.btn:active { transform: translateY(1px); }

.list { display: flex; flex-direction: column; gap: 8px; }
.item {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 12px 14px;
  display: flex; align-items: center; justify-content: space-between; gap: 12px;
}
.item .w { font-weight: 700; }
.item .z { color: var(--muted); font-size: 14px; }
.item .tag { font-size: 12px; color: var(--bad); white-space: nowrap; }

.muted { color: var(--muted); }
.center { text-align: center; }
.hidden { display: none !important; }
.spacer { height: 14px; }

.bars { display: flex; flex-direction: column; gap: 8px; }
.barrow { display: flex; align-items: center; gap: 10px; font-size: 13px; }
.barrow .name { flex: 0 0 90px; color: var(--muted); }
.barrow .track { flex: 1; height: 10px; background: #0e1430; border-radius: 999px; overflow: hidden; }
.barrow .fill { height: 100%; background: linear-gradient(90deg, var(--accent), var(--accent-2)); }
.barrow .v { flex: 0 0 46px; text-align: right; }

textarea {
  width: 100%; min-height: 120px; background: #0e1430; color: var(--text);
  border: 1px solid var(--border); border-radius: 12px; padding: 12px; font-family: ui-monospace, monospace; font-size: 12px;
}

@media (max-width: 480px) {
  .statbar { grid-template-columns: repeat(2, 1fr); }
  .prompt { font-size: 28px; }
}