body {
  margin: 0;
  font-family: sans-serif;
  background: #f4fbff;
  color: #234;
}

.site-header {
  background: #e3f4ff;
  padding: 16px 14px;
  border-bottom: 2px solid #c7e9ff;
}

.logo {
  font-size: 20px;
  font-weight: bold;
  color: #008bd0;
}

.username {
  font-size: 12px;
  margin-top: 4px;
  color: #5fa9cc;
}

.user-buttons {
  display: grid;
  grid-template-columns: repeat(3,1fr);
  gap: 6px;
  margin-top: 8px;
}

.btn {
  background: white;
  border: 1px solid #c7e9ff;
  border-radius: 8px;
  text-align: center;
  padding: 8px 0;
  font-size: 12px;
  color: #008bd0;
  text-decoration: none;
}
.more-btn{
  background: #008bd0;
  border: 1px solid #008bd0;
  border-radius: 8px;
  text-align: center;
  padding: 8px 0;
  font-size: 12px;
  color: white;
  text-decoration: none;
}
.main,li{
    margin: 16px;
}
.main-nav {
  display: grid;
  grid-template-columns: repeat(3,1fr);
  background: #e3f4ff;
  gap: 1px;
}

.main-nav a {
  background: white;
  padding: 12px 0;
  font-size: 12px;
  text-align: center;
  text-decoration: none;
  color: #008bd0;
}

/* text */
h1,h2,h3,h4,h5,h6 {
  color: #008bd0;
  border-left: 4px solid #bfe9ff;
  padding-left: 8px;
}
.smallSize{
  font-size:17px;
}
p {
  font-size: 14px;
  line-height: 1.8;
}

a {
  color: #008bd0;
}

/* table */
table {
  width: 100%;
  border-collapse: collapse;
  background: white;
  font-size: 13px;
}

th {
  background: #e3f4ff;
  padding: 8px;
  border-bottom: 2px solid #c7e9ff;
}

td {
  padding: 8px;
  border-bottom: 1px solid #eef8ff;
}

/*カテゴリ*/
.category{
  display:inline-block;
  padding:2px 8px;
  border-radius:6px;
  font-size:12px;
  border:1.5px solid #999;
  border-color:#999;
  color:#666;
}

.Java{
  border-color:#f89820;
  color:#f89820;
}

.Python{
  border-color:#3776ab;
  color:#3776ab;
}

.HTML{
  border-color:#e44d26;
  color:#e44d26;
}

.CSS{
  border-color:#264de4;
  color:#264de4;
}

.JavaScript{
  border-color:#f7df1e;
  color:#f7df1e;
}

.PHP{
  border-color:#777bb3;
  color:#777bb3;
}

.DB{
  border-color:#6d4c41;
  color:#6d4c41;
}

.SQL{
  border-color:#003b57;
  color:#003b57;
}

.Application{border-color:#009688;color:#009688;}
.AI{border-color:#c2185b;color:#c2185b;}
.IoT{border-color:#00acc1;color:#00acc1;}
.Game{border-color:#8e24aa;color:#8e24aa;}
.Bot{border-color:#43a047;color:#43a047;}
.Server{border-color:#546e7a;color:#546e7a;}
.API{border-color:#1e88e5;color:#1e88e5;}
.btn.disabled {
  background: #e0e0e0 !important;
  border: 1px solid #cfcfcf !important;
  color: #9a9a9a !important;
  pointer-events: auto;     /* 押せなくしない */
  cursor: not-allowed;
}

/* さらに“使えない感”を強めたい場合 */
.btn.disabled:hover {
  background: #e0e0e0;
}

.tooltip {
  position: relative;
  cursor: pointer;
  border-bottom: 1px dotted #555;
}

.tooltip-text {
  visibility: hidden;
  opacity: 0;
  transition: opacity 0.2s ease;

  position: absolute;
  bottom: 125%;
  left: 50%;
  transform: translateX(-50%);

  background-color: rgba(0,0,0,0.8);
  color: #fff;
  padding: 6px 10px;
  border-radius: 6px;
  white-space: nowrap;
  font-size: 13px;
  z-index: 100;
}

.tooltip:hover .tooltip-text {
  visibility: visible;
  opacity: 1;
}