.epbr-wrap{
  max-width: 900px;
  margin: 20px auto;
  font-family: Arial, Helvetica, sans-serif;
  color:#111;
}
.epbr-card{
  background:#fff;
  border:1px solid #d9d9d9;
  border-radius:10px;
  padding:22px;
  box-shadow:0 2px 10px rgba(0,0,0,.05);
}
.epbr-card h2{
  margin:0 0 10px;
  font-size:28px;
}
.epbr-instruction{
  margin:0 0 20px;
  line-height:1.45;
}
.epbr-diagrams{
  display:grid;
  grid-template-columns:1fr 1fr;
  gap:24px;
  align-items:start;
  margin:10px 0 24px;
}
.epbr-diagram-block{
  text-align:center;
}
.epbr-diagram-title{
  font-size:18px;
  margin-bottom:6px;
}
.epbr-diagram-block svg{
  width:100%;
  max-width:260px;
  height:auto;
}
.epbr-table-wrap{
  overflow-x:auto;
}
.epbr-table{
  width:100%;
  border-collapse:collapse;
  margin-top:8px;
}
.epbr-table th,.epbr-table td{
  border:1px solid #999;
  padding:10px;
  text-align:left;
  vertical-align:middle;
}
.epbr-table th{
  background:#f3f3f3;
}
.epbr-table input{
  width:110px;
  max-width:100%;
  font-size:17px;
  padding:7px 8px;
  border:1px solid #777;
  border-radius:4px;
  box-sizing:border-box;
}
.epbr-unc-cell{
  white-space:nowrap;
}
.epbr-feedback{
  min-height:26px;
  margin:18px 0 4px;
  font-size:16px;
  line-height:1.45;
}
.epbr-feedback.correct{
  background:#eef8ef;
  border:1px solid #8fbf92;
  padding:12px;
  border-radius:6px;
}
.epbr-feedback.incorrect{
  background:#fff5ea;
  border:1px solid #d6a46d;
  padding:12px;
  border-radius:6px;
}
.epbr-buttons{
  display:flex;
  gap:10px;
  flex-wrap:wrap;
  margin-top:16px;
}
.epbr-buttons button{
  font-size:16px;
  padding:10px 18px;
  border:1px solid #222;
  border-radius:6px;
  background:#fff;
  cursor:pointer;
}
.epbr-buttons button:hover{
  background:#f4f4f4;
}
@media (max-width:650px){
  .epbr-diagrams{grid-template-columns:1fr;}
  .epbr-card{padding:15px;}
  .epbr-card h2{font-size:23px;}
  .epbr-table th,.epbr-table td{padding:7px;}
  .epbr-table input{width:85px;}
}


/* v1.1: force visible button labels and clearer marking colours */
#epbr-app .epbr-buttons button,
#epbr-app .epbr-buttons button:link,
#epbr-app .epbr-buttons button:visited {
  color:#111 !important;
  background:#fff !important;
  -webkit-text-fill-color:#111 !important;
  opacity:1 !important;
  font-weight:700 !important;
  line-height:1.2 !important;
  min-width:120px !important;
}
#epbr-app .epbr-buttons button:hover,
#epbr-app .epbr-buttons button:focus {
  color:#111 !important;
  background:#f1f1f1 !important;
  -webkit-text-fill-color:#111 !important;
}
#epbr-app input.epbr-correct {
  background:#dff3df !important;
  border:2px solid #2e7d32 !important;
}
#epbr-app input.epbr-wrong {
  background:#f8dddd !important;
  border:2px solid #b3261e !important;
}


/* v1.4 fixed uncertainty display + working-value note */
#epbr-app .epbr-fixed-unc{
  display:inline-block;
  min-width:70px;
  font-weight:600;
}
#epbr-app .epbr-round-note{
  margin-top:6px;
  font-size:12px;
  line-height:1.3;
  color:#555;
  max-width:280px;
}