/* Header */
.header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 4.66rem;
    background-color: var(--white);
    z-index: 1000;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
    transform: translateY(60px);
    transition: none; /* 初期状態ではアニメーションなし */
}

.header-container {
    margin: 0 auto;
    padding-left: 4.7rem;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo {
    display: flex;
    align-items: center;
    width: 10.75rem;
    z-index: 1001;
    position: relative;
}

.logo-image {
    width: 100%
}

/* Navigation */
.nav {
    display: flex;
    align-items: center;
    gap: 2.5rem;
    height: 100%;
}

/* デスクトップ表示時のnavを確実に非表示 */
@media screen and (min-width: 1201px) {
    .nav {
        position: static;
        transform: none;
        opacity: 1;
        visibility: visible;
        background-color: transparent;
        flex-direction: row;
        justify-content: flex-end;
        padding: 0;
        height: 100%;
    }
}

.nav-list {
    display: flex;
    list-style: none;
    gap: 40px;
    align-items: center;
    height: 100%;
}
.nav-item {
  height: 100%;
  padding-top: 4px;
}
.nav-link {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 2px;
    transition: opacity 0.3s;
    height: 100%;
    border-bottom: 4px solid var(--white);
    transition: all 0.3s ease;

}

.entry-btn,
.entry-btn-tab-header {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 100%;
    background: var(--primary-blue);
    color: var(--white);
    padding: 1rem 4rem;
    border-radius: 0;
    transition: all 0.3s ease;
    z-index: 1001;
    position: relative;
}

@media (hover: hover) {
    .nav-link:hover {
        border-bottom: 4px solid var(--lightblue);
    }
    .nav-link:hover .nav-en, 
    .nav-link:hover .nav-ja {
        color: var(--lightblue);
        transition: color 0.3s ease;
    }
    .entry-btn:hover {
      opacity: 0.53;
    }
  }

.nav-en {
    font-family: var(--font-archivo);
    font-size: 1rem;
    font-weight: 900;
    letter-spacing: 0.05rem;
    color: var(--black);
}

.nav-ja, .entry-ja {
    font-size: 0.625rem;
    font-weight: 300;
    line-height: 0.875rem;
    letter-spacing: 0.03125rem;
}
.nav-ja {
    color: var(--black);
}
.entry-ja {
    color: var(--white);
}

.entry-en {
    font-family: var(--font-archivo);
    font-size: 1.125rem;
    font-weight: 900;
    letter-spacing: 2px;
    line-height: 1.4rem;
    letter-spacing: 0.1rem;
}


  /* Responsive Design */
@media screen and (max-width: 1200px) {
  .header-container {
    padding-left: 2.375rem;
}
    /* Hamburger Menu */
.hamburger {
  display: none;
  flex-direction: column;
  gap: 6px;
  width: 4.375rem;
  z-index: 1001;
  background-color: var(--black);
  padding: 1.3rem;
  justify-content: center;
}

.hamburger span {
  width: 1.75rem;
  height: 3px;
  background-color:var(--white);
  transition: all 0.3s;
}

.hamburger.active span:nth-child(1) {
  transform: rotate(45deg) translate(8px, 5px);
}

.hamburger.active span:nth-child(2) {
  opacity: 0;
}

.hamburger.active span:nth-child(3) {
  transform: rotate(-45deg) translate(8px, -5px);
}
    .hamburger {
        display: flex;
    }

    .nav {
        position: fixed;
        top: 4.6rem;
        left: 0;
        width: 100%;
        height: calc(100vh - 4.6rem);
        background-color: var(--white);
        flex-direction: column;
        justify-content: flex-start;
        padding-top: 10rem;
        gap: 0;
        transform: translateY(-100%);
        transition: transform 0.4s cubic-bezier(0.25, 0.1, 0.25, 1.0);
        opacity: 0;
        visibility: hidden;
        z-index: 999;
        overflow-y: auto;
    }

    .nav.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }

    .nav-list {
        flex-direction: column;
        gap: 0;
        width: 100%;
        height: auto;
        padding: 0rem 7rem 7rem;
    }

    .nav-item {
        width: 100%;
        opacity: 0;
        transform: translateY(20px);
        transition: opacity 0.3s ease, transform 0.3s ease;
        border-bottom: 1px solid var(--lightblue);
    }


    .nav.active .nav-item {
        opacity: 1;
        transform: translateY(0);
    }

    .nav.active .nav-item:nth-child(1) { transition-delay: 0.1s; }
    .nav.active .nav-item:nth-child(2) { transition-delay: 0.2s; }
    .nav.active .nav-item:nth-child(3) { transition-delay: 0.3s; }
    .nav.active .nav-item:nth-child(4) { transition-delay: 0.4s; }
    .nav.active .nav-item:nth-child(5) { transition-delay: 0.5s; }
  
      .nav-link {
        display: flex;
        flex-direction: row;
        align-items: center;
        justify-content: start;
        gap: 2rem;
        text-align: left;
        width: 100%;
        text-decoration: none;
      }
  
      .nav-en {
        font-size: 2rem;
        line-height: 2.3;
      }
  
      .nav-ja {
        font-size: 12px;
      }
  
      .entry-btn {
        width: 100%;
        margin-top: 20px;
        padding: 20px;
        opacity: 0;
        transform: translateY(20px);
        transition: opacity 0.3s ease, transform 0.3s ease;
      }

      .nav.active .entry-btn {
        opacity: 1;
        transform: translateY(0);
        transition-delay: 0.6s;
        height: auto;
        width: 18rem;
      }
      .entry-btn-container {
        height: 100%;
      }
      .footer.tb-sp-only {
        width: 100%;
      }
  }

@media (max-width: 768px) {
  .nav {
    padding: 3rem 0 0;
  }
  .nav.active {
    padding-top: 8rem;
  }

  .nav-list {
    padding: 2rem 4rem 7rem;
}

  .header-container {
    padding-left: 0;
  }

  .logo {
    justify-content: center;
  }

  .logo-image {
      width: 9rem;
  }
  
  .logo-text {
      font-size: 24px;
  }
  .entry-btn, .entry-btn-tab-header {
    padding: 1rem 3.625rem;
  }

  .nav-en {
    font-size: 1.5rem;
    line-height: 1.2;
  }
  .nav-link {
    padding: 1rem 0 0.5rem;
  }

}