:root {
  --primary: #2f6f4f;
  --bg: #f7f8fa;
  --card-bg: #ffffff;
  --border: #e5e7eb;
  --text: #22262a;
  --muted: #8a8f98;
  --danger: #c0392b;
}

* { box-sizing: border-box; -webkit-tap-highlight-color: transparent; }

html, body {
  margin: 0;
  height: 100%;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
}

#app { max-width: 480px; margin: 0 auto; min-height: 100%; padding: 20px 16px 40px; }

.screen { animation: fade-in .15s ease-out; }
@keyframes fade-in { from { opacity: 0; transform: translateY(6px); } to { opacity: 1; transform: none; } }

.intro h1 { font-size: 19px; line-height: 1.5; margin-bottom: 14px; }
.intro p { font-size: 14px; line-height: 1.7; color: var(--muted); margin-bottom: 28px; }

.btn-primary {
  display: block;
  width: 100%;
  padding: 13px;
  background: var(--primary);
  color: #fff;
  border: none;
  border-radius: 8px;
  font-size: 15px;
  cursor: pointer;
}
.btn-primary:active { opacity: .85; }

.question .section-tag {
  display: inline-block;
  font-size: 11px;
  color: var(--primary);
  background: #e9f3ee;
  padding: 3px 8px;
  border-radius: 999px;
  margin-bottom: 10px;
}

.question h2 {
  font-size: 16px;
  line-height: 1.6;
  margin: 0 0 16px;
}
.question h2 small { display: block; font-size: 12px; color: var(--muted); font-weight: 400; margin-top: 4px; }

.options { margin-bottom: 16px; }

.option {
  display: block;
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 11px 12px;
  margin-bottom: 8px;
  font-size: 14px;
  line-height: 1.5;
}
.option input { margin-right: 8px; vertical-align: middle; }
.option .other-text {
  display: block;
  width: 100%;
  margin-top: 8px;
  padding: 7px 8px;
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 13px;
}

textarea#text-answer {
  width: 100%;
  min-height: 110px;
  padding: 10px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 14px;
  font-family: inherit;
}

.error { color: var(--danger); font-size: 13px; min-height: 18px; margin-bottom: 10px; }

.end { text-align: center; padding-top: 80px; }
.end h2 { font-size: 18px; margin-bottom: 10px; }
.end p { color: var(--muted); font-size: 14px; line-height: 1.7; }