:root {
  --bg: #0f1320;
  --panel: #1a2032;
  --panel-2: #232b41;
  --ink: #eef2ff;
  --muted: #9aa6c4;
  --accent: #e0524f;      /* cinnabar red — Chinese seal colour */
  --accent-2: #f0a830;    /* warm gold */
  --good: #3fb98a;
  --line: #2c3550;
  --radius: 16px;
  font-family: "Inter", "Helvetica Neue", "PingFang SC", "Hiragino Sans GB",
    "Microsoft YaHei", system-ui, sans-serif;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: radial-gradient(1200px 600px at 50% -10%, #1b2236, var(--bg));
  color: var(--ink);
  min-height: 100vh;
}

.topbar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 14px 22px;
  background: rgba(16, 19, 32, 0.85);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(6px);
  position: sticky;
  top: 0;
  z-index: 10;
}

.brand {
  font-size: 22px;
  font-weight: 800;
  letter-spacing: 0.5px;
}
.brand-sub {
  font-size: 12px;
  font-weight: 500;
  color: var(--muted);
  margin-left: 6px;
}

.controls {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  align-items: center;
}
.ctl {
  display: flex;
  flex-direction: column;
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.6px;
  color: var(--muted);
  gap: 4px;
}
.ctl.checkbox {
  flex-direction: row;
  align-items: center;
  text-transform: none;
  letter-spacing: 0;
  font-size: 13px;
  color: var(--ink);
  gap: 6px;
}
.ctl select {
  background: var(--panel-2);
  color: var(--ink);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 6px 8px;
  font-size: 13px;
  min-width: 150px;
}
.types {
  display: flex;
  gap: 10px;
  text-transform: none;
  letter-spacing: 0;
  font-size: 13px;
  color: var(--ink);
}
.types label { display: flex; align-items: center; gap: 4px; }

main {
  max-width: 820px;
  margin: 0 auto;
  padding: 28px 20px 60px;
}

.progress {
  text-align: center;
  color: var(--muted);
  font-size: 13px;
  margin-bottom: 14px;
  letter-spacing: 0.4px;
}

.card {
  background: linear-gradient(180deg, var(--panel), var(--panel-2));
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 40px 36px;
  min-height: 320px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  box-shadow: 0 24px 60px rgba(0, 0, 0, 0.35);
}

.card-type {
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 1px;
  text-transform: uppercase;
  padding: 5px 12px;
  border-radius: 999px;
  margin-bottom: 18px;
}
.card-type.en2zh { background: rgba(224, 82, 79, 0.16); color: #ff9b88; }
.card-type.zh2en { background: rgba(240, 168, 48, 0.16); color: var(--accent-2); }
.card-type.respond { background: rgba(63, 185, 138, 0.16); color: var(--good); }

.prompt-label {
  font-size: 13px;
  color: var(--muted);
  margin-bottom: 12px;
}

.prompt {
  font-size: 44px;
  font-weight: 700;
  line-height: 1.3;
  word-break: break-word;
}
.prompt.zh { font-size: 56px; }

.prompt-pinyin {
  margin-top: 10px;
  font-size: 20px;
  color: var(--accent-2);
  letter-spacing: 0.4px;
}

.speak-btn {
  margin-top: 22px;
  background: var(--panel-2);
  color: var(--ink);
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 10px 18px;
  font-size: 15px;
  cursor: pointer;
  transition: transform 0.08s ease, border-color 0.15s ease;
}
.speak-btn:hover { border-color: var(--accent); }
.speak-btn:active { transform: scale(0.96); }
.speak-btn.playing { border-color: var(--accent); color: var(--accent); }
.speak-ico { font-size: 17px; }

.answer {
  margin-top: 28px;
  width: 100%;
  border-top: 1px dashed var(--line);
  padding-top: 22px;
}
.answer.hidden { display: none; }
.answer-label {
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--muted);
  margin-bottom: 10px;
}
.answer-main {
  font-size: 36px;
  font-weight: 700;
  line-height: 1.3;
}
.answer-main.zh { font-size: 46px; }
.answer-pinyin {
  margin-top: 8px;
  font-size: 18px;
  color: var(--accent-2);
}
.answer-extra {
  margin-top: 14px;
  font-size: 16px;
  color: var(--muted);
  line-height: 1.5;
}
.answer-extra .sample-zh { color: var(--ink); font-size: 20px; }

.actions {
  display: flex;
  gap: 12px;
  justify-content: center;
  margin-top: 26px;
}
.btn {
  background: var(--panel-2);
  color: var(--ink);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 14px 22px;
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  transition: transform 0.08s ease, background 0.15s ease, border-color 0.15s ease;
  min-width: 130px;
}
.btn:hover { border-color: var(--accent); }
.btn:active { transform: scale(0.97); }
.btn-primary {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}
.btn-primary:hover { background: #ef6562; }

.hint {
  text-align: center;
  color: var(--muted);
  font-size: 12px;
  margin-top: 22px;
}
kbd {
  background: var(--panel-2);
  border: 1px solid var(--line);
  border-bottom-width: 2px;
  border-radius: 6px;
  padding: 1px 6px;
  font-size: 11px;
  font-family: inherit;
}

.toast {
  position: fixed;
  bottom: 26px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--panel-2);
  border: 1px solid var(--accent);
  color: var(--ink);
  padding: 12px 18px;
  border-radius: 10px;
  font-size: 14px;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.4);
  z-index: 20;
}
.toast.hidden { display: none; }

@media (max-width: 600px) {
  .prompt { font-size: 32px; }
  .prompt.zh { font-size: 40px; }
  .answer-main { font-size: 28px; }
  .answer-main.zh { font-size: 34px; }
  .btn { min-width: 0; flex: 1; padding: 14px 10px; }
}