/* header.html専用のスタイル */
.header {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1001;
  background: transparent;
  padding: 15px 20px;
  box-sizing: border-box;
  transition: background-color 0.3s ease-in-out, box-shadow 0.3s ease-in-out;
}
.header.is-fixed {
    position: fixed;
    background-color: rgba(10, 30, 62, 0.9);
    backdrop-filter: blur(8px);
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}
.header__inner {
  width: 100%;
  max-width: 1280px;
  margin: 0 auto;
  padding: 0;
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.logo a { 
  display: flex; 
  align-items: center; 
  gap: 10px; 
  text-decoration: none; 
}
.logo img { 
  height: 48px; 
  transition: height 0.3s ease;
}
.since-text { 
  font-family: 'Bebas Neue', sans-serif; 
  font-size: 1.2rem; 
  color: #fff; 
  letter-spacing: 0.08em; 
  text-shadow: 1px 1px 3px rgba(0,0,0,0.5); 
}

/\* --- レスポンシブ対応 --- \*/
@media (max-width: 768px) {
.header {
padding: 15px;
}
.header\_\_inner {
padding: 0;
}
.logo img {
max-height: 40px;
}
.since-text {
font-size: 1rem;
}
}
@media (max-width: 600px) {
.logo a {
flex-direction: column;
gap: 5px;
align-items: flex-start;
}
.since-text {
font-size: 0.8rem;
}
.header {
padding: 10px 15px;
}
}