/* CSS for mobile menu
 * Styles for the responsive mobile navigation menu.
 * Includes layout, transitions, and visibility toggling for mobile devices.
 * Ensures accessibility and smooth user experience on smaller screens.
 */
.mobile-menu {
    display: none;
}

ul {
    list-style: none;
    padding: 0;
    margin: 0;
    display: flex;
    justify-content: center;
}

li {
    margin: 0 1vw;
    position: relative;
}

a {
    text-decoration: none;
    color: #ecf0f1;
    font-weight: bold;
    font-size: 18px;
    padding: 10px;
    display: block;
    transition: color 0.3s ease;
}

body {
    line-height: 1.4;
}

.menu {
    list-style: none;
    padding: 0;
    margin-top: 50px;
    margin-left: 10px;
    margin-right: 10px;
    display: block;
    justify-content: center;
}

.mobile_submenu {
    list-style: none;
    padding: 0;
    margin-left: 10px;
    margin-right: 10px;
    display: none;
}

.mobile_menu-item {
    font-family: "Ek Mukta", sans-serif;
    text-decoration: none;
    color: whitesmoke;
    font-weight: bold;
    padding: 10px;
    display: block;
    transition: color .3s ease;
    border-bottom: 1px solid #333;
    transition: transform 0.5s cubic-bezier(0.4, 0.01, 0.165, 0.99), opacity 0.6s cubic-bezier(0.4, 0.01, 0.165, 0.99);
}

.mobile_menu-item {
    font-size: 1.2rem;
}

.mobile_submenu-item a {
    font-size: 1rem;
}

.mobile_submenu-item {
    opacity: 0;
}

.menu-about-large {
    font-size: 1.2rem;
    text-align: center;
}

.menu-about-small {
    font-size: 1rem;
    text-align: center;
}

.menu-about-space {
    height: 20px;
}

.mobile-menu {
    position: fixed;
    top: 0;
    left: 0;
    height: 50px;
    width: 100%;
    background: rgba(0, 0, 0, 0.8);
    overflow-y: auto;
    transition: all 0.5s ease-out, background 1s ease-out;
    transition-delay: 0.2s;
    z-index: 9;
}

.mobile-menu {
    scrollbar-width: none;
    /* New property */
}

.mobile-menu::-webkit-scrollbar {
    width: 8px;
    /* Fallback for Webkit browsers */
}

.mobile-menu .burger-container {
    position: relative;
    display: inline-block;
    height: 50px;
    width: 50px;
    cursor: pointer;
    transform: rotate(0deg);
    transition: all 0.3s cubic-bezier(0.4, 0.01, 0.165, 0.99);
    -ms-user-select: none;
    -webkit-user-select: none;
    user-select: none;
    -webkit-tap-highlight-color: transparent;
    /* Safari and Chrome for iOS */
    -webkit-touch-callout: none;
    /* Disable callout on iOS Safari */
    -moz-tap-highlight-color: transparent;
    /* Firefox for Android */
    -ms-touch-action: manipulation;
    /* IE 10+ */
    touch-action: manipulation;
    /* IE 11+, Firefox, Chrome, Safari */
}

.mobile-menu .burger-container #burger {
    width: 18px;
    height: 8px;
    position: relative;
    display: block;
    margin: -4px auto 0;
    top: 50%;
}

.mobile-menu .burger-container #burger .bar {
    width: 100%;
    height: 1px;
    display: block;
    position: relative;
    background: #FFF;
    transition: all 0.3s cubic-bezier(0.4, 0.01, 0.165, 0.99);
    transition-delay: 0s;
}

.mobile-menu .burger-container #burger .bar.topBar {
    transform: translateY(0px) rotate(0deg);
}

.mobile-menu .burger-container #burger .bar.btmBar {
    transform: translateY(6px) rotate(0deg);
}

.mobile-menu.menu-opened {
    height: 100%;
    background-color: #000;
    transition: all 0.3s ease-in, background 0.5s ease-in;
    transition-delay: 0.25s;
}

.mobile-menu.menu-opened .burger-container {
    transform: rotate(90deg);
}

.mobile-menu.menu-opened .burger-container #burger .bar {
    transition: all 0.4s cubic-bezier(0.4, 0.01, 0.165, 0.99);
    transition-delay: 0.2s;
}

.mobile-menu.menu-opened .burger-container #burger .bar.topBar {
    transform: translateY(4px) rotate(45deg);
}

.mobile-menu.menu-opened .burger-container #burger .bar.btmBar {
    transform: translateY(3px) rotate(-45deg);
}

/* 
 * Desktop Menu
 * ------------
 * This section defines the styles and structure for the desktop navigation menu.
 * It typically includes horizontal navigation links, dropdowns, and hover effects
 * optimized for larger screens (desktops and laptops). Ensure responsive breakpoints
 * are set to hide or adjust this menu on smaller devices.
 */

.desktop-menu {
    position: fixed;
    top: -90vh;
    padding-left: 10vw;
    width: 80vw;
    height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    overflow-y: auto;
    z-index: 10;
    transition: top 1s ease, height 0.5s ease;
}

.menu-background {
    position: fixed;
    top: -90vh;
    width: 100vw;
    height: 100vh;
    pointer-events: none;
    z-index: -1;
    background: black;
    opacity: 0.6;
    transition: top 1s ease, height 0.5s ease, opacity 1s ease;
}

.icon-close {
    position: absolute;
    top: 2vh;
    left: 87vw;
    width: 2vw;
    max-width: 4vh;
    max-height: 4vh;
    height: 2vw;
    opacity: 0;
    z-index: 5;
}

.option-container {
    position: fixed;
    top: 0vh;
    width: 70vw;
    display: grid;
    grid-template-columns: repeat(4, 1fr);
}

.option-item {
    display: grid;
    place-items: center;
    position: relative;
    padding-top: 1vh;
    padding-left: 1vw;
    padding-right: 1vw;
}

.option-item img {
    grid-area: 1 / 1;
    height: auto;
    opacity: 0.7;
    width: 15vw;
    max-width: 20vh;
    max-height: 15vh;
}

.option-item img:hover {
    opacity: 1;
}

.option-item h1 {
    grid-area: 1 / 1;
    color: aliceblue;
    font-size: clamp(1.5vh, 2.5vw, 3vh);
    z-index: 1;
    pointer-events: none;
}

.session-container {
    display: none;
    padding-top: 8vh;
    grid-template-columns: repeat(10, 1fr);
    /* 10 equal columns */
    grid-template-rows: repeat(5, auto);
    /* 5 rows, height based on content */
    width: 75vw;
    padding-top: 15vh;
    padding-left: 2.5vw;
    padding-right: 2.5vw;
}

.session-item {
    display: grid;
    place-items: center;
    position: relative;
}

.session-item img {
    grid-area: 1 / 1;
    width: 7.5vw;
    max-width: 12vh;
    max-height: 12vh;
    height: auto;
    opacity: 0.7;
}

.session-item img:hover {
    opacity: 1;
    width: 6vw;
}

.session-item h1 {
    grid-area: 1 / 1;
    font-size: clamp(2.5vh, 2.5vw, 4vh);
    z-index: 1;
    pointer-events: none;
}

#session-1 {
    filter: sepia(1) hue-rotate(0) saturate(3) brightness(1.9);
    transform: rotate(5deg)
}

#session-2 {
    filter: sepia(1) hue-rotate(10deg) saturate(3) brightness(1.9);
    transform: rotate(15deg)
}

#session-3 {
    filter: sepia(1) hue-rotate(20deg) saturate(3) brightness(1.9);
    transform: rotate(25deg)
}

#session-4 {
    filter: sepia(1) hue-rotate(30deg) saturate(3) brightness(1.9);
    transform: rotate(35deg)
}

#session-5 {
    filter: sepia(1) hue-rotate(40deg) saturate(3) brightness(1.9);
    transform: rotate(45deg)
}

#session-6 {
    filter: sepia(1) hue-rotate(50deg) saturate(3) brightness(1.9);
    transform: rotate(55deg)
}

#session-7 {
    filter: sepia(1) hue-rotate(60deg) saturate(3) brightness(1.9);
    transform: rotate(65deg)
}

#session-8 {
    filter: sepia(1) hue-rotate(70deg) saturate(3) brightness(1.9);
    transform: rotate(75deg);
}

#session-9 {
    filter: sepia(1) hue-rotate(80deg) saturate(3) brightness(1.9);
    transform: rotate(85deg);
}

#session-10 {
    filter: sepia(1) hue-rotate(90deg) saturate(3) brightness(1.9);
    transform: rotate(95deg);
}

#session-11 {
    filter: sepia(1) hue-rotate(0deg) saturate(3) brightness(1.8);
    transform: rotate(105deg);
}

#session-12 {
    filter: sepia(1) hue-rotate(10deg) saturate(3) brightness(1.8);
    transform: rotate(115deg);
}

#session-13 {
    filter: sepia(1) hue-rotate(20deg) saturate(3) brightness(1.8);
    transform: rotate(125deg);
}

#session-14 {
    filter: sepia(1) hue-rotate(30deg) saturate(3) brightness(1.8);
    transform: rotate(135deg);
}

#session-15 {
    filter: sepia(1) hue-rotate(40deg) saturate(3) brightness(1.8);
    transform: rotate(145deg);
}

#session-16 {
    filter: sepia(1) hue-rotate(50deg) saturate(3) brightness(1.8);
    transform: rotate(155deg);
}

#session-17 {
    filter: sepia(1) hue-rotate(60deg) saturate(3) brightness(1.8);
    transform: rotate(165deg);
}

#session-18 {
    filter: sepia(1) hue-rotate(70deg) saturate(3) brightness(1.8);
    transform: rotate(175deg);
}

#session-19 {
    filter: sepia(1) hue-rotate(80deg) saturate(3) brightness(1.8);
    transform: rotate(185deg);
}

#session-20 {
    filter: sepia(1) hue-rotate(90deg) saturate(3) brightness(1.8);
    transform: rotate(195deg);
}

#session-21 {
    filter: sepia(1) hue-rotate(0deg) saturate(3) brightness(1.7);
    transform: rotate(205deg);
}

#session-22 {
    filter: sepia(1) hue-rotate(10deg) saturate(3) brightness(1.7);
    transform: rotate(215deg);
}

#session-23 {
    filter: sepia(1) hue-rotate(20deg) saturate(3) brightness(1.7);
    transform: rotate(225deg);
}

#session-24 {
    filter: sepia(1) hue-rotate(30deg) saturate(3) brightness(1.7);
    transform: rotate(235deg);
}

#session-25 {
    filter: sepia(1) hue-rotate(40deg) saturate(3) brightness(1.7);
    transform: rotate(245deg);
}

#session-26 {
    filter: sepia(1) hue-rotate(50deg) saturate(3) brightness(1.7);
    transform: rotate(255deg);
}

#session-27 {
    filter: sepia(1) hue-rotate(60deg) saturate(3) brightness(1.7);
    transform: rotate(265deg);
}

#session-28 {
    filter: sepia(1) hue-rotate(70deg) saturate(3) brightness(1.7);
    transform: rotate(275deg);
}

#session-29 {
    filter: sepia(1) hue-rotate(80deg) saturate(3) brightness(1.7);
    transform: rotate(285deg);
}

#session-30 {
    filter: sepia(1) hue-rotate(90deg) saturate(3) brightness(1.7);
    transform: rotate(295deg);
}

#session-31 {
    filter: sepia(1) hue-rotate(0deg) saturate(3) brightness(1.6);
    transform: rotate(305deg);
}

#session-32 {
    filter: sepia(1) hue-rotate(10deg) saturate(3) brightness(1.6);
    transform: rotate(315deg);
}

#session-33 {
    filter: sepia(1) hue-rotate(20deg) saturate(3) brightness(1.6);
    transform: rotate(325deg);
}

#session-34 {
    filter: sepia(1) hue-rotate(30deg) saturate(3) brightness(1.6);
    transform: rotate(335deg);
}

#session-35 {
    filter: sepia(1) hue-rotate(40deg) saturate(3) brightness(1.6);
    transform: rotate(345deg);
}

#session-36 {
    filter: sepia(1) hue-rotate(50deg) saturate(3) brightness(1.6);
    transform: rotate(355deg);
}

#session-37 {
    filter: sepia(1) hue-rotate(60deg) saturate(3) brightness(1.6);
    transform: rotate(5deg);
}

#session-38 {
    filter: sepia(1) hue-rotate(70deg) saturate(3) brightness(1.6);
    transform: rotate(15deg);
}

#session-39 {
    filter: sepia(1) hue-rotate(80deg) saturate(3) brightness(1.6);
    transform: rotate(25deg);
}

#session-40 {
    filter: sepia(1) hue-rotate(90deg) saturate(3) brightness(1.6);
    transform: rotate(35deg);
}

#session-41 {
    filter: sepia(1) hue-rotate(0) saturate(3) brightness(1.5);
    transform: rotate(45deg);
}

#session-42 {
    filter: sepia(1) hue-rotate(10deg) saturate(3) brightness(1.5);
    transform: rotate(55deg);
}

#session-43 {
    filter: sepia(1) hue-rotate(20deg) saturate(3) brightness(1.5);
    transform: rotate(65deg);
}

#session-44 {
    filter: sepia(1) hue-rotate(30deg) saturate(3) brightness(1.5);
    transform: rotate(75deg);
}

#session-45 {
    filter: sepia(1) hue-rotate(40deg) saturate(3) brightness(1.5);
    transform: rotate(85deg);
}

#session-46 {
    filter: sepia(1) hue-rotate(50deg) saturate(3) brightness(1.5);
    transform: rotate(95deg);
}

#session-47 {
    filter: sepia(1) hue-rotate(60deg) saturate(3) brightness(1.5);
    transform: rotate(105deg);
}

#session-48 {
    filter: sepia(1) hue-rotate(70deg) saturate(3) brightness(1.5);
    transform: rotate(115deg);
}

#session-49 {
    filter: sepia(1) hue-rotate(80deg) saturate(3) brightness(1.5);
    transform: rotate(125deg);
}

#session-50 {
    filter: sepia(1) hue-rotate(90deg) saturate(3) brightness(1.5);
    transform: rotate(135deg);
}

.chapter-container {
    display: none;
    grid-template-columns: repeat(7, 1fr);
    /* 10 equal columns */
    grid-template-rows: repeat(3, auto);
    /* 5 rows, height based on content */
    padding-top: 15vh;
    padding-bottom: 8vh;
    width: 75vw;
    padding-left: 2.5vw;
    padding-right: 2.5vw;
}

.chapter-item {
    display: grid;
    place-items: center;
    position: relative;
}

.chapter-item img {
    grid-area: 1 / 1;
    width: 7vw;
    max-width: 12vh;
    max-height: 12vh;
    height: auto;
    opacity: 0.7;
}

.chapter-item img:hover {
    opacity: 1;
    width: 6vw;
}

.chapter-item h1 {
    grid-area: 1 / 1;
    font-size: clamp(2.5vh, 2.5vw, 4vh);
    z-index: 1;
    pointer-events: none;
}

#chapter-1 {
    filter: sepia(1) hue-rotate(30deg) saturate(3) brightness(1.9);
    transform: rotate(5deg)
}

#chapter-2 {
    filter: sepia(1) hue-rotate(40deg) saturate(3) brightness(1.9);
    transform: rotate(15deg)
}

#chapter-3 {
    filter: sepia(1) hue-rotate(50deg) saturate(3) brightness(1.9);
    transform: rotate(25deg)
}

#chapter-4 {
    filter: sepia(1) hue-rotate(60deg) saturate(3) brightness(1.9);
    transform: rotate(35deg)
}

#chapter-5 {
    filter: sepia(1) hue-rotate(70deg) saturate(3) brightness(1.9);
    transform: rotate(45deg)
}

#chapter-6 {
    filter: sepia(1) hue-rotate(80deg) saturate(3) brightness(1.9);
    transform: rotate(55deg)
}

#chapter-7 {
    filter: sepia(1) hue-rotate(90deg) saturate(3) brightness(1.9);
    transform: rotate(65deg)
}

#chapter-8 {
    filter: sepia(1) hue-rotate(30deg) saturate(3) brightness(1.8);
    transform: rotate(75deg);
}

#chapter-9 {
    filter: sepia(1) hue-rotate(40deg) saturate(3) brightness(1.8);
    transform: rotate(85deg);
}

#chapter-10 {
    filter: sepia(1) hue-rotate(50deg) saturate(3) brightness(1.8);
    transform: rotate(95deg);
}

#chapter-11 {
    filter: sepia(1) hue-rotate(60deg) saturate(3) brightness(1.8);
    transform: rotate(105deg);
}

#chapter-12 {
    filter: sepia(1) hue-rotate(70deg) saturate(3) brightness(1.8);
    transform: rotate(115deg);
}

#chapter-13 {
    filter: sepia(1) hue-rotate(80deg) saturate(3) brightness(1.8);
    transform: rotate(125deg);
}

#chapter-14 {
    filter: sepia(1) hue-rotate(90deg) saturate(3) brightness(1.8);
    transform: rotate(135deg);
}

#chapter-15 {
    filter: sepia(1) hue-rotate(30deg) saturate(3) brightness(1.7);
    transform: rotate(145deg);
}

#chapter-16 {
    filter: sepia(1) hue-rotate(40deg) saturate(3) brightness(1.7);
    transform: rotate(155deg);
}

#chapter-17 {
    filter: sepia(1) hue-rotate(50deg) saturate(3) brightness(1.7);
    transform: rotate(165deg);
}

#chapter-18 {
    filter: sepia(1) hue-rotate(60deg) saturate(3) brightness(1.7);
    transform: rotate(175deg);
}

#chapter-19 {
    filter: sepia(1) hue-rotate(70deg) saturate(3) brightness(1.7);
    transform: rotate(185deg);
}

#chapter-20 {
    filter: sepia(1) hue-rotate(80deg) saturate(3) brightness(1.7);
    transform: rotate(195deg);
}

#chapter-21 {
    filter: sepia(1) hue-rotate(90deg) saturate(3) brightness(1.7);
    transform: rotate(205deg);
}

.chapter-sub-item {
    display: grid;
    place-items: center;
    position: relative;
}

.chapter-sub-item img {
    grid-area: 1 / 1;
    width: 7vw;
    max-width: 12vh;
    max-height: 12vh;
    height: auto;
    opacity: 1;
    z-index: 1;
    padding-right: 75%;
    pointer-events: none;
}

.chapter-sub-item header:hover {
    opacity: 1;
}

.chapter-sub-item header {
    grid-area: 1 / 1;
    width: 30vw;
    max-height: 6vh;
    height: 3vw;
    opacity: 0.7;
    background-color: #a6c9e5;
}

.chapter-sub-item h1 {
    grid-area: 1 / 1;
    font-size: clamp(2.5vh, 2.5vw, 4vh);
    z-index: 1;
    pointer-events: none;
}

.chapter-1-sub-container {
    display: none;
    grid-template-columns: repeat(2, 1fr);
    grid-template-rows: repeat(3, auto);
    width: 100%;
}

.chapter-2-sub-container {
    display: none;
    padding-top: 10vh;
    grid-template-columns: repeat(2, 1fr);
    width: 100%;
}

.chapter-3-sub-container {
    display: none;
    padding-top: 10vh;
    grid-template-columns: repeat(2, 1fr);
    grid-template-rows: repeat(2, auto);
    width: 100%;
}

.chapter-4-sub-container {
    display: none;
    padding-top: 10vh;
    grid-template-columns: repeat(2, 1fr);
    grid-template-rows: repeat(2, auto);
    width: 100%;
}

.chapter-5-sub-container {
    display: none;
    padding-top: 10vh;
    grid-template-columns: repeat(2, 1fr);
    grid-template-rows: repeat(2, auto);
    width: 100%;
}

.chapter-6-sub-container {
    display: none;
    padding-top: 10vh;
    grid-template-columns: repeat(2, 1fr);
    grid-template-rows: repeat(2, auto);
    width: 100%;
}

.chapter-7-sub-container {
    display: none;
    padding-top: 10vh;
    grid-template-columns: repeat(2, 1fr);
    width: 100%;
}

.chapter-8-sub-container {
    display: none;
    padding-top: 10vh;
    grid-template-columns: repeat(2, 1fr);
    grid-template-rows: repeat(2, auto);
    width: 100%;
}

.chapter-9-sub-container {
    display: none;
    padding-top: 10vh;
    grid-template-columns: repeat(1, 1fr);
    width: 100%;
}

.chapter-10-sub-container {
    display: none;
    padding-top: 10vh;
    grid-template-columns: repeat(2, 1fr);
    width: 100%;
}

.chapter-11-sub-container {
    display: none;
    padding-top: 10vh;
    grid-template-columns: repeat(2, 1fr);
    width: 100%;
}

.chapter-12-sub-container {
    display: none;
    padding-top: 10vh;
    grid-template-columns: repeat(2, 1fr);
    width: 100%;
}

.chapter-13-sub-container {
    display: none;
    padding-top: 10vh;
    grid-template-columns: repeat(2, 1fr);
    width: 100%;
}

.chapter-14-sub-container {
    display: none;
    padding-top: 10vh;
    grid-template-columns: repeat(2, 1fr);
    width: 100%;
}

.chapter-15-sub-container {
    display: none;
    padding-top: 10vh;
    grid-template-columns: repeat(2, 1fr);
    width: 100%;
}

.chapter-16-sub-container {
    display: none;
    padding-top: 10vh;
    grid-template-columns: repeat(2, 1fr);
    width: 100%;
}

.chapter-17-sub-container {
    display: none;
    padding-top: 10vh;
    grid-template-columns: repeat(1, 1fr);
    width: 100%;
}

.chapter-18-sub-container {
    display: none;
    padding-top: 10vh;
    grid-template-columns: repeat(2, 1fr);
    width: 100%;
}

.chapter-19-sub-container {
    display: none;
    padding-top: 10vh;
    grid-template-columns: repeat(2, 1fr);
    grid-template-rows: repeat(2, auto);
    width: 100%;
}

.chapter-20-sub-container {
    display: none;
    padding-top: 10vh;
    grid-template-columns: repeat(2, 1fr);
    width: 100%;
}

.chapter-21-sub-container {
    display: none;
    padding-top: 10vh;
    grid-template-columns: repeat(2, 1fr);
    width: 100%;
}

.third-item {
    grid-column: 1 / span 2;
    /* Span across both columns */
    grid-row: 2;
}

.third-item img {
    padding-right: 37%;
}

.topic-container {
    display: none;
    padding-top: 15vh;
    padding-left: 2.5vw;
    padding-right: 2.5vw;
    width: 75vw;
    grid-template-columns: repeat(3, 1fr);
    /* 10 equal columns */
    grid-template-rows: repeat(6, auto);
    /* 5 rows, height based on content */
}

.topic-item {
    display: grid;
    position: relative;
    align-items: center;
}

.topic-item img {
    grid-area: 1 / 1;
    width: 5vw;
    max-width: 12vh;
    max-height: 12vh;
    height: auto;
    opacity: 1;
    z-index: 1;
    pointer-events: none;
}

.topic-item header:hover {
    opacity: 1;
}

.topic-item header {
    grid-area: 1 / 1;
    width: 20vw;
    max-width: 40vh;
    max-height: 6vh;
    height: 2vw;
    padding-left: 1.5vw;
    margin-left: 1.5vw;
    opacity: 0.7;
    background-color: #a6c9e5;
}

.topic-item h1 {
    grid-area: 1 / 1;
    font-size: clamp(1.5vh, 1.5vw, 3.5vh);
    padding-left: 2vw;
    z-index: 1;
    pointer-events: none;
}

.about-container {
    display: none;
    padding-top: 15vh;
    padding-left: 2.5vw;
    padding-right: 2.5vw;
    place-items: center;
    width: 75vw;
}

.about-item h1 {
    font-size: clamp(1.5vh, 2vw, 3.5vh);
    z-index: 1;
    pointer-events: none;
    color: aliceblue;
}

.about-item h2 {
    font-size: clamp(1.5vh, 1.5vw, 3.5vh);
    z-index: 1;
    pointer-events: none;
    color: aliceblue;
}

a {
    font-size: clamp(1.5vh, 1.5vw, 3.5vh);
    z-index: 1;
    color: aliceblue;
}

.about-space {
    height: 10vh;
}

@media screen and (max-width: 768px) and (orientation: portrait) {

    .desktop-menu {
        display: none;
    }

    .mobile-menu {
        display: block;
    }

}

@media screen and (max-height: 768px) and (orientation: landscape) {

    .desktop-menu {
        display: none;
    }

    .mobile-menu {
        display: block;
    }

}