body {
    font-family: Arial, sans-serif;
    background-color: #f8f8f8;
    margin: 0;
    padding: 0;
}

.container {
    width: 90%;
    margin: auto;
    padding: 20px;
    background: #fff;
    border: 5px solid maroon;
    border-radius: 10px;
}

.header {
    background: #5a6872;
    color: white;
    text-align: center;
    padding: 10px;
    font-size: 20px;
    font-weight: bold;
}

.experiment-area {
    display: flex;
    justify-content: space-between;
    margin-top: 20px;
}

.display-area {
    width: 70%;
    height: 400px;
    background: white;
    border: 2px solid maroon;
    border-radius: 5px;
    position: relative;
}

.controls {
    width: 25%;
    display: flex;
    flex-direction: column;
    gap: 10px;
}

button {
    padding: 10px;
    font-size: 14px;
    border: none;
    cursor: pointer;
    border-radius: 5px;
}

.start { background: yellow; }
.reset { background: pink; }

.message-box {
    background: maroon;
    color: white;
    padding: 10px;
    height: 150px;
    font-family: monospace;
    overflow-y: auto;
}

.range-container {
    display: none;
    margin-top: 20px;
}

/* Base line for alignment */
#base-line {
    position: absolute;
    bottom: 10%;
    left: 10%;
    right: 10%;
    height: 2px;
    background-color: black;
    z-index: 1;
}


/* Positioning for the images */
#laser,
#grating,
#screen {
    position: absolute;
    bottom: 20%;
    transform: translateY(50%);
    z-index: 2;
    display: none;
}

#laser {
    right: 10%;
    width: 80px;
}

#grating {
    left: 30%;
    width: 55px;
    transition: left 0.5s ease;
    bottom: 21%;
}

#screen {
    left: 5%;
    width: 200px;
    bottom: 30%;
}

/* For Screen */
.screen-overlay {
    position: absolute;
    top: 10%;
    left: 50%;
    transform: translateX(-50%);
    width: 45%;
    height: 35%;
    background-color: #00000010;
    border: 5px solid black;
    border-radius: 10px;
    display: none;
    justify-content: center;
    align-items: center;
    overflow: hidden;
}

.dot {
    position: absolute;
    background-color: red;
    border-radius: 50%;
    opacity: 0.8;
}

.dot#dot3 {
    width: 20px;
    height: 20px;
    opacity: 1;
}

.dot#dot2, .dot#dot4 {
    width: 15px;
    height: 15px;
    opacity: 0.6;
}

.dot#dot1, .dot#dot5 {
    width: 10px;
    height: 10px;
    opacity: 0.4;
}
/* For Responsive*/
@media screen and (max-width: 768px) {
    .experiment-area {
        flex-direction: column;
        align-items: center;
    }

    .display-area,
    .controls {
        width: 100%;
        margin-bottom: 20px;
    }

    .display-area {
        height: 300px;
    }

    .controls {
        flex-direction: row;
        flex-wrap: wrap;
        justify-content: center;
        gap: 10px;
    }

    button {
        flex: 1 1 40%;
        max-width: 150px;
    }

    .range-container {
        width: 100%;
        text-align: center;
    }

    .screen-overlay {
        width: 80%;
        height: 40%;
    }

    #laser {
        width: 60px;
    }

    #grating {
        width: 40px;
    }

    #screen {
        width: 150px;
    }

    .message-box {
        font-size: 14px;
        height: auto;
        margin-top: 10px;
    }
}

@media screen and (max-width: 480px) {
    .header {
        font-size: 16px;
        padding: 8px;
    }

    button {
        font-size: 12px;
        padding: 8px;
    }

    .message-box {
        font-size: 12px;
    }
}
/*For Table*/
#observationTableContainer {
  margin: 15px;
  padding: 10px;
  background: #f9f9f9;
  border: 2px solid #444;
}

#observationTable {
  width: 100%;
  border-collapse: collapse;
}

#observationTable th,
#observationTable td {
  border: 1px solid #333;
  padding: 6px;
  text-align: center;
}



/* Procedure Toggle */
#procedureToggle {
    position: absolute;
    top: 8px;
    left: 10px;
    display: flex;
    align-items: center;
    gap: 6px;
    cursor: pointer;
    z-index: 10;
}

.info-icon {
    width: 22px;
    height: 22px;
    background: #222;
    color: #fff;
    font-weight: bold;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
}

.info-label {
    font-size: 13px;
    font-weight: bold;
    color: #222;
}

/* Procedure Box */
#procedureBox {
    position: absolute;
    top: 40px;
    left: 10px;
    width: 300px;
    background: #fff;
    border: 2px solid #444;
    padding: 10px;
    font-size: 13px;
    display: none;
    z-index: 10;
    box-shadow: 0 4px 8px rgba(0,0,0,0.2);
    max-height: 260px;
    overflow-y: auto;
}

#procedureBox h4 {
    margin: 0 0 6px 0;
    font-size: 14px;
}

#procedureBox ol {
    padding-left: 18px;
    margin: 0;
}

#procedureBox ol li {
    margin-bottom: 6px;
}

#procedureBox ol li::marker {
    font-weight: bold;
}