/*body {*/
/*    margin: 0;*/
/*    font-family: Arial, sans-serif;*/
/*    display: flex;*/
/*}*/

body {
    font-family: Regular, Roman, sans-serif; /* CJK font: Microsoft YaHei or SimSun */
    overflow: hidden;
}

.sidebar {
    width: 700px;
    background-color: rgba(265, 265, 265, 0.8);
    border-right: 1px solid #ccc;
    padding: 20px;
    box-sizing: border-box;
    height: 100vh;
    position: fixed;
    left: 0;
    top: 0;
    overflow-y: auto;
    transition: transform 0.3s ease;
    z-index: 4;
    box-shadow: 2px 0 5px rgba(0, 0, 0, 0.7);
    transform: translateX(0);
}

.sidebar.hidden {
    transform: translateX(-100%);
}

.open-btn {
    position: fixed;
    left: 0;
    top: 50%;
    transform: translateY(-50%);
    z-index: 1001;
    background-color: #6e6e6e;
    color: #FFFFFF;
    padding: 10px;
    border: none;
    cursor: pointer;
    display: none;
}

.open-btn.visible {
    display: block;
}


.main-content {
    margin-left: 0px; /* matches the sidebar width */
    width: calc(100%);
    height: 100vh;
    position: relative;
}

/*.info-box {*/
/*    position: fixed;*/
/*    width: 20vw; !* viewport width follows the screen *!*/
/*    max-width: 300px; !* cap the width *!*/
/*    height: 50vh; !* viewport height follows the screen *!*/
/*    max-height: 300px; !* cap the height *!*/
/*    background-color: #f9f9f9;*/
/*    border: 1px solid #ccc;*/
/*    border-radius: 10px;*/
/*    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);*/
/*    padding: 2%; !* scales with relative units *!*/
/*    font-family: Arial, sans-serif;*/
/*    font-size: 1rem; !* root font size, easy scaling *!*/
/*    display: none;*/
/*    overflow-y: auto*/
/*}*/

.info-box {
    position: fixed;
    right: 20px;
    bottom: 20px;
    width: 40%;
    height: 80%;
    background-color: #ffffff;
    border-radius: 8px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
    overflow: hidden;
    z-index: 5; /* stay above other content */
    transition: transform 0.3s ease, opacity 0.3s ease;
    display: none;
    flex-direction: column;
}

/* dropdown arrow */
.dropdown-arrow {
    width: 0;
    height: 0;
    border-left: 5px solid transparent;
    border-right: 5px solid transparent;
    border-top: 5px solid #666;
    transition: transform 0.3s ease;
}

/* arrow rotation when expanded */


@media (max-width: 600px) {
    .info-box {
        width: 40%; /* takes most of the width */
        height: 60%; /* height for small screens */
        bottom: 2%; /* margin tweak */
        right: 2%;
        padding: 5%; /* more inner spacing */
    }
}

@media (min-width: 1200px) {
    .info-box {
        width: 40%;
        height: 80%;
        bottom: 2%;
        right: 2%;
        font-size: 1.2rem; /* slightly larger font */
    }
}


.video-popup {
    display: none;
    position: fixed;
    flex-direction: column;
    top: 30%;
    left: 40%;
    z-index: 10;
    justify-content: center;
    align-items: center;
    background-color: #f5f7fa;
}


.pdf-popup {
    display: none;
    position: fixed;
    flex-direction: column;
    top: 10%;
    left: 20%;
    bottom: 10%;
    right: 20%;
    z-index: 10;
    background-color: rgba(233, 255, 255, 0.3);
    justify-content: center;
    align-items: center;
}

#pdf-iframe {
    width: 100%;
    height: 100%;
}

.close-btn2 {
    position: absolute;
    top: 10px;
    right: 10px;
    cursor: pointer;
}

.video-title {
    position: absolute;
    top: 10px;
    left: 10px;
    cursor: pointer;
}

/*tooltip*/
.tooltip {
    position: fixed;
    text-align: center;
    width: auto;
    max-width: 90%; /* narrower cap on small screens */
    height: auto;
    padding: 1rem; /* relative units keep spacing scalable */
    font-size: 1rem; /* font size follows the global scale */
    font-family: sans-serif;
    background: lightgray;
    border: 1px solid #ddd;
    border-radius: 5px;
    pointer-events: none; /* no pointer events */
    display: none;
    z-index: 100;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1); /* visual polish */
}

/* small screens */
@media (max-width: 600px) {
    .tooltip {
        font-size: 0.9rem; /* font size tweak */
        padding: 0.8rem; /* tighter padding */
        max-width: 80%; /* tighter width cap */
    }
}

/* large screens */
@media (min-width: 1200px) {
    .tooltip {
        font-size: 1.2rem; /* larger font for readability */
        padding: 1.2rem; /* larger padding */
        max-width: 60%; /* allow wider content */
    }
}

text {
    font-family: Regular, Roman, sans-serif;
}

/* :lang keeps CJK and latin glyphs apart */
text:lang(zh) {
    font-family: Regular, sans-serif;
}

text:lang(en) {
    font-family: Roman, serif;
}

br {
    display: block;
    margin-bottom: 1px;
    font-size: 1px;
    line-height: 1px;
}