:root{
  --bg: #f3fbf7;
  --card: #ffffff;
  --text: #143a2a;
  --muted: rgba(20,58,42,.65);

  --green-1: rgba(80, 200, 140, .10);
  --green-2: rgba(80, 200, 140, .18);
  --green-3: rgba(32, 130, 90, .35);
  --green-4: #1f6b4a;

  --border: rgba(20,58,42,.10);
  --shadow: 0 14px 40px rgba(15, 80, 55, .10);
  --radius: 18px;
}

*{ box-sizing: border-box; }
html, body{ padding:0; margin:0; }
body{
  font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial, "Apple Color Emoji","Segoe UI Emoji";
  color: var(--text);
  background:
    radial-gradient(1200px 500px at 10% 0%, rgba(120,220,170,.18), transparent 60%),
    radial-gradient(900px 450px at 90% 10%, rgba(120,220,170,.14), transparent 55%),
    var(--bg);
}

a{ color: inherit; text-decoration: none; }

.container{
  max-width: 960px;
  margin: 0 auto;
  padding: 22px 16px 60px;
}

.card{
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 18px 18px 16px;
}

.h1{
  font-size: 22px;
  font-weight: 750;
  letter-spacing: .2px;
  margin: 0 0 6px;
}

.p{
  margin: 8px 0;
  color: var(--muted);
  line-height: 1.55;
  font-size: 14px;
}

.row{
  display:flex;
  gap: 10px;
  flex-wrap: wrap;
  align-items: center;
}

.badge{
  display:inline-flex;
  align-items:center;
  gap:6px;
  padding: 8px 10px;
  border-radius: 999px;
  border: 1px solid rgba(32,130,90,.18);
  background: rgba(120,220,170,.10);
  color: var(--green-4);
  font-weight: 650;
  font-size: 13px;
}

.input{
  width: 100%;
  padding: 11px 12px;
  border-radius: 14px;
  border: 1px solid rgba(20,58,42,.14);
  background: rgba(255,255,255,.9);
  outline: none;
  transition: box-shadow .15s ease, border-color .15s ease, transform .05s ease;
  font-size: 14px;
}
.input:focus{
  border-color: rgba(32,130,90,.35);
  box-shadow: 0 0 0 4px rgba(80,200,140,.14);
}

.btn{
  appearance:none;
  border: 1px solid rgba(32,130,90,.25);
  background: rgba(80,200,140,.18);
  color: var(--green-4);
  padding: 10px 14px;
  border-radius: 14px;
  font-weight: 750;
  cursor: pointer;
  transition: transform .05s ease, box-shadow .15s ease, background .15s ease;
}
.btn:hover{
  background: rgba(80,200,140,.26);
  box-shadow: 0 10px 20px rgba(15, 90, 60, .10);
}
.btn:active{ transform: translateY(1px); }
.btn:disabled{
  opacity: .45;
  cursor: not-allowed;
  box-shadow: none;
}

/* ---- Section title ---- */
.qtitle{
  font-size: 15px;
  font-weight: 800;
  color: var(--text);
  margin: 10px 0 6px;
}

/* ---- Question block ---- */
.q{
  margin-top: 12px;
  padding: 14px 12px;
  border-radius: 16px;
  border: 1px solid rgba(20,58,42,.10);
  background: rgba(255,255,255,.92);
}
.qhead{
  display:flex;
  gap: 10px;
  align-items: flex-start;
}
.qno{
  width: 28px;
  height: 28px;
  flex: 0 0 28px;
  border-radius: 10px;
  display:flex;
  align-items:center;
  justify-content:center;
  font-weight: 800;
  border: 1px solid rgba(32,130,90,.20);
  background: rgba(120,220,170,.10);
  color: var(--green-4);
}
.qtext{
  font-size: 14px;
  line-height: 1.45;
  margin-top: 2px;
  color: rgba(20,58,42,.92);
}

/* ---- Options (no jump + clear highlight) ---- */
.opts{
  display:flex;
  gap: 10px;
  flex-wrap: wrap;
  margin-top: 10px;
}

.opt{
  border: 1px solid rgba(20,58,42,.14);
  background: rgba(255,255,255,.85);
  color: rgba(20,58,42,.88);
  padding: 9px 12px;
  border-radius: 14px;
  cursor: pointer;
  font-weight: 700;
  min-width: 120px;
  text-align: left;

  /* ✅ 防止“选中跳动”：固定视觉，不改变布局尺寸 */
  transition: box-shadow .15s ease, background .15s ease, border-color .15s ease;
}
.opt:hover{
  border-color: rgba(32,130,90,.25);
  background: rgba(120,220,170,.10);
}
.opt.active{
  border-color: rgba(32,130,90,.45);
  background: rgba(80,200,140,.22);
  box-shadow: 0 10px 18px rgba(15, 90, 60, .10);
}
.opt:focus{
  outline: none;
  box-shadow: 0 0 0 4px rgba(80,200,140,.14);
}

/* ---- Level bar ---- */
.levelBar{
  display:flex;
  gap:10px;
}
.levelSeg{
  flex:1;
  text-align:center;
  padding:10px 8px;
  border-radius:14px;
  border:1px solid rgba(32,130,90,0.18);
  background: rgba(120, 220, 170, 0.10);
  color: var(--green-4);
  font-weight:800;
}
.levelSeg.active{
  background: rgba(80, 200, 140, 0.22);
  border-color: rgba(32,130,90,0.35);
  box-shadow: 0 10px 18px rgba(15, 90, 60, .10);
}

/* ---- Small helpers ---- */
.divider{
  height: 1px;
  background: rgba(20,58,42,.08);
  margin: 14px 0;
}
.small{
  font-size: 12px;
  color: rgba(20,58,42,.60);
}