.header {
    height: 57px;
    background: #104289;
    position: relative;
    align-items: center;
    display: flex;
}

.header .logo img {
    display: block;
}

.header .logo {
    display: flex;
    padding-left: 10px;
    color: #fff;
    font-size: large;
}

/* 特殊字顏色 */
.spec-font-color {
    color: #e86817;
    font-weight: bold;
}

.spec-font-color2 {
    background-color: #e86817;
    font-weight: bold;
    color: #baefff;
    padding: 5px;
}

.menu_btn {
    width: 40px;
    height: 40px;
    background: #104289;
    display: block;
    position: absolute;
    top: 5px;
    right: 10px;
}

.menu_btn span {
    opacity: 0;
}

.menu_btn::before {
    content: '';
    position: absolute;
    height: 2px;
    left: 2px;
    right: 2px;
    width: 36px;
    background: white;
    top: 0;
    bottom: 0;
    margin: auto;
    /*利用 box-shadow 設定另外兩根，陰影的好處在於可以使用影分身之術*/
    box-shadow: 0 8px 0 white, 0 -8px 0 white;
    /*x 軸不偏移，y軸偏移, 要否模糊, 色彩*/
}

nav {
    /*在手機上出現，高度滿版*/
    width: 80%;
    height: calc(100vh - 57px);
    /*用 calc 將他的高度做到剛剛好*/
    /* background: lightgray; */
    background: #104289;
    position: absolute;
    left: -100%;
    /*先讓 nav在外面 stand by，當 menu control 被打勾再讓它進來*/
    top: 57px;
    transition: 0.5s;
    /*讓他有移動的感覺*/
    border-bottom: 0px;
}

nav a {
    display: block;
    text-decoration: none;
    /* color: black; */
    color: #fff;
    font-weight: bold;
    padding: 10px 20px;
    /* border-bottom: 1px solid black; */
    border-bottom: 1px solid #104289;
    transition: 0.4s;
}

/* nav a:hover {
    background: #ffe100;
} */

#menu_control {
    position: absolute;
    z-index: -2;
    opacity: 0;
    /*加上opacity 確保他就算出現，在畫面上也看不到 */
}

/*同一層可以用 ~ 選*/
#menu_control:checked~.header nav {
    left: 0;
}

@media screen and (min-width: 768px) {
    .menu_btn {
        display: none;
    }

    /*桌機版，logo nav 橫向排列*/
    .header {
        display: flex;
        justify-content: space-between;
        align-items: center;
    }

    nav {
        display: flex;
        position: relative;
        left: 0;
        width: auto;
        height: auto;
        top: 0;
        background: transparent;
    }

    nav a {
        border-bottom: none;
        color: white;
        transition: 0.4s;
    }

    nav a:hover {
        /* background: black; */
        border-radius: 4px;
    }

}


/*手機板 */
@media screen and (max-width: 767px) {
    nav {
        display: flex;
        flex-direction: column;
        height: auto;
    }

    .dropdown-content {
        display: flex;
        flex-direction: column;
        position: static;
    }

    .dropdown-content a {
        display: block;
        text-align: left;
        width: 100%;
        padding-left: 40px;
    }
}