* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    border: none;
    text-decoration: none;
    background-color: transparent;

    font-family: 'Nunito Sans', sans-serif;
}

:root.dark {
    --text-color-primary: #cdcdcd;
    --text-color-secondary: #979797;
    --text-color-tertiary: #e7e7e7;
    --text-color-article-header: #f2f2f2;
    --text-color-link: #244cbb;
    --bg-color-primary: #151516;
    --bg-color-secondary: #1a1a1d;
    --bg-color-blockquote: #2c2c30;
    --bg-color-hover-categories: #2e2e33;
    --bg-color-hover-home-nav-buttons: #cdcdcd;
    --shadow-color-header: #0a0a0a;
    --border-hero: 0.1rem solid #979797;
    --icon-theme-button: url(../image/light-mode.svg);
    --icon-search-button: url(../image/search.svg);
    --icon-burger-button: url(../image/burger.svg);
    --icon-facebook: url(../image/social-media/facebook.svg);
    --icon-twitter: url(../image/social-media/twitter.svg);
    --icon-instagram: url(../image/social-media/instagram.svg);
    --icon-linkedin: url(../image/social-media/linkedin.svg);
    --icon-submit: url(../image/submit-light.svg);
}

:root.light {
    --text-color-primary: #1b1b1b;
    --text-color-secondary: #1b1b1b;
    --text-color-tertiary: #1b1b1b;
    --text-color-article-header: #f2f2f2;
    --text-color-link: #244cbb;
    --bg-color-primary: #ffffff;
    --bg-color-secondary: #f0f0f0;
    --bg-color-blockquote: #c9c9c9;
    --bg-color-hover-categories: #d4d4d4;
    --bg-color-hover-home-nav-buttons: #cdcdcd;
    --shadow-color-header: #cecece;
    --border-hero: none;
    --icon-theme-button: url(../image/dark-mode.svg);
    --icon-search-button: url(../image/search-black.svg);
    --icon-burger-button: url(../image/burger-black.svg);
    --icon-facebook: url(../image/social-media/facebook-black.svg);
    --icon-twitter: url(../image/social-media/twitter-black.svg);
    --icon-instagram: url(../image/social-media/instagram-black.svg);
    --icon-linkedin: url(../image/social-media/linkedin-black.svg);
    --icon-submit: url(../image/submit.svg);
}

.theme-transition {
    transition: background-color 0.5s;
}

::-webkit-scrollbar {
    width: 1.4rem;
  }

::-webkit-scrollbar-track {
    background: var(--bg-color-secondary); 
  }
   
  /* Handle */
  ::-webkit-scrollbar-thumb {
    background: #666666; 
  }
  
  /* Handle on hover */
  ::-webkit-scrollbar-thumb:hover {
    background: #555555; 
  }

html {
    font-size: 62.5%; /* for 1rem=10px */
}

body {
    background-color: var(--bg-color-primary);
    min-height: 100vh;
    margin: auto;
    transition: unset;
}

main {
    width: 92vw;
    max-width: 115rem;
    margin: auto;
}

img {
    max-width: 100%;
    max-height: 100%;
    display: block;
}

input {
    background-repeat: no-repeat;
    outline: none;
    font-size: 1.6rem;
    color: black;
}

input::placeholder {
    color: var(--text-color-secondary);
}

input[type="submit"] {
    cursor: pointer;
}

ol, ul {
    list-style-type: none;
}

button {
    cursor: pointer;
    color: var(--text-color-primary);
}

a {
    color: var(--text-color-primary);
}

.icon-button {
    background-size: contain;
    background-position: center;
    background-repeat: no-repeat;
}

.text-icon-button { /*bunun box-sizing: property'sini değiştirmeyi düşün*/
    display: flex; /*bu class'a dahil elementlerin görünürlüğünü değiştirmek için display: none; gibi çözümler kullanırsan bu property bozulacaktır.*/
    justify-content: center;
    align-items: center;
    white-space: nowrap;
}

/***********************************************/
header {
    width: 100%;
    background-color: var(--bg-color-primary);
}

header > .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    width: 92vw;
    max-width: 115rem;
    height: 6.2rem;
    margin: auto;
    transition: height 0.5s, background-color 0.5s, box-shadow 0.5s;
}

.fixed {
    position: sticky;
    top: 0;
    box-shadow: 0rem 0.2rem 1.3rem var(--shadow-color-header);
    margin: 0;
}

header > .container > button {
    width: 2rem;
    height: 2rem;
}

header > .container > ul {
    display: none;
}

header > .container > #light-mode-button {
    display: none;
}

header > .container > .search-button {
    background-image: var(--icon-search-button);
}


header > .container > .burger-menu {
    background-image: var(--icon-burger-button);
}

header > .container > #logo > a {
    font-size: 1.9rem;
    font-weight: 700;
    letter-spacing: 0.4rem;
    color: var(--text-color-primary);
    white-space: nowrap;
}

/***********************************************/

@keyframes search-bar {
    0% {transform: translate(-50%, -200%);}
    100% {transform: translate(-50%, 0);}
}

#search-bar-container {
    display: none;

    position: fixed;
    top: 15rem;
    left: 50%;

    z-index: 1;
    animation: search-bar 0.25s forwards;
}

#search-bar {
    width: 90vw;
    max-width: 50rem;
    height: 6rem;
    background-color: white;
    border-radius: 0.6rem;
    box-shadow: 0 0.2rem 0.5rem var(--DarkGray);

    background-image: url(../image/search-black.svg);
    background-size: 2.2rem;
    background-position: 1.25rem 50%;
    padding-left: 4.5rem;

    font-size: 1.7rem;
}

#search-bar-container > input.icon-button {
    height: 100%;
    width: 7rem;
    border-radius: 0.6rem;
    cursor: pointer;

    background-image: url(../image/submit.svg);
    background-color: white;
    background-size: 2.1rem;

    position: absolute;
    right: 0;

    transition: 0.25s;
}

#search-bar-container > input.icon-button:hover {
    background-position: 65% 50%;
}

/***********************************************/

#mobile-menu::-webkit-scrollbar {
    display: none;
}

#mobile-menu {
    display: none;
    overflow-y: scroll;
    -ms-overflow-style: none;  
    scrollbar-width: none;

    position: fixed;
    top: 0;
    right: 0;

    z-index: 1;

    width: 23rem;
    height: 100vh;
    background-color: #1a1a1d;

    animation-name: mobileMenuSlide;
    animation-duration: 0.5s;
}

#mobile-menu > button#closer {
    display: block;
    width: 2rem;
    height: 2rem;

    background-image: url(/image/kapat.svg);

    margin: 1.5rem 1.2rem 3.5rem auto;
}

#mobile-menu > ul {
    margin-bottom: 3.5rem;
}

#mobile-menu > ul > li {
    border-bottom: 0.1px solid #27272b;
}

#mobile-menu > ul > li:first-child {
    border-top: 0.1px solid #27272b;
}

#mobile-menu > ul > li > a {
    font-size: 2.25rem;
    display: block;
    padding: 0.7rem 0 0.7rem 2.5rem;
    color: #cdcdcd;
}

#mobile-menu > ul > li > button {
    font-size: 2.25rem;
    display: block;
    padding: 0.7rem 0 0.7rem 2.5rem;
    width: 100%;
    text-align: start;
    color: #cdcdcd;
}

#mobile-menu #mobile-categories-list {
    display: none;
    animation-name: list-opener;
    animation-duration: 0.4s;
}

#mobile-menu #mobile-categories-list > li {
    margin-left: 4.5rem;
}

#mobile-menu #mobile-categories-list > li::marker {
    font-size: 1.8rem;
}

#mobile-menu #mobile-categories-list a {
    font-size: 2.05rem;
    color: #cdcdcd;
    display: block;
    padding: 0.3rem 0;
}

@keyframes list-opener {
    0% {height: 0rem;}
    100% {height: 19.8rem;}
}

#mobile-menu > .text-icon-button {
    width: 85%;
    height: 3.65rem;
    gap: 0.8rem;
    font-size: 2.15rem;
    border: 1px solid #cdcdcd;
    border-radius: 1rem;
    margin: auto;
    padding: 0.7rem 0;
    margin-bottom: 2rem;
    color: #cdcdcd;
}

#mobile-menu > .text-icon-button:nth-child(3) > img {
    transform: scale(0.78);
}

#mobile-menu > h4 {
    font-size: 2.25rem;
    font-weight: 400;
    text-align: center;
    color: #cdcdcd;
    margin-top: 4rem;
}

#mobile-menu > div.social-media-links {
    gap: 0;
    justify-content: space-evenly;
    margin-top: 1.5rem;
}

#mobile-menu > .social-media-links > a:nth-child(1) {
    background-image: url(/image/social-media/facebook.svg);
}

#mobile-menu > .social-media-links > a:nth-child(2) {
    background-image: url(/image/social-media/twitter.svg);
}

#mobile-menu > .social-media-links > a:nth-child(3) {
    background-image: url(/image/social-media/instagram.svg);
}

#mobile-menu > .social-media-links > a:nth-child(4) {
    background-image: url(/image/social-media/linkedin.svg);
}

@keyframes mobileMenuSlide {
    0% {transform: translateX(100%);}
    100% {transform: translateX(0%);}
}


/***********************************************/

footer {
    display: flex;
    flex-direction: column;
    gap: 3.5rem;
    width: 92vw;
    max-width: 115rem;
    margin: auto;

    padding: 2rem 0;

    border-top: 0.1rem solid var(--text-color-secondary);
}

footer > section {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.3rem;
}


#copyright {
    text-align: center;
    line-height: 2rem;
    font-size: 1.45rem;
    font-weight: 400;
    color: var(--text-color-primary);
}

#copyright > h4 {
    letter-spacing: 0.1rem;
    font-size: 1.45rem;
    font-weight: 400;
}

/***********************************************/

#click-blocker {
    display: none;
    
    position: fixed;
    left: 0;
    top: 0;

    width: 100vw;
    height: 100vh;

    background-color: #000000;
    opacity: 0.6;
}

/***********************************************/

@media screen and (width >= 650px) {

    header > .container > #logo > a {
        font-size: 2.5rem;
        line-height: 4.5rem;
    }

    header > .container > button {
        width: 2.35rem;
        height: 2.35rem;
    }

/***********************/
    #mobile-menu {
        width: 32rem;
    }
}

@media screen and (width >= 992px) {

    header > .container > ul, header > .container > #light-mode-button {
        display: unset;
    }

    header > .container > .burger-menu {
        display: none;
    }

    header > .container {
        display: grid;
        grid-template-columns: 15fr 17.5fr 1.2fr 1.2fr ;
        column-gap: 0.5rem;
    }

    header > .container > #logo {
        order: -1;
        margin-right: 5rem;
    }

    header > .container > #logo > a {
        font-weight: 600;
    }

    header > .container > .search-button {
        order: 1;
    }

    header > .container > ul {
        display: flex;
        gap: 1.8vw;
    }

    header > .container > ul > li > a {
        font-size: 1.45rem;
        padding: 1rem 0;
        position: relative;
    }

    header > .container > ul > li > a::after {
        content: "";
        display: block;

        position: absolute;
        bottom: 0.75rem;

        background-color: var(--text-color-primary);
        height: 0.1rem;
        width: 0%;

        transition: 0.3s;
    }

    header > .container > ul a:hover::after {
        width: 100%;
    }

    header > .container > ul > li > span {
        font-size: 1.45rem;
        padding: 1.3rem 0;
        color: var(--text-color-primary);
    }

    header > .container #flyout-menu-container {
        position: relative;
    }
    
    header > .container #flyout-menu {
        display: none;
        width: 20rem;
        border-radius: 0.8rem;
        background-color: var(--bg-color-secondary);
        box-shadow: 0 0.3rem 0.6rem rgb(8, 8, 8);
        
        text-align: center;
        
        position: absolute;
        left: 50%;
        transform: translateX(-50%);
        top: 2.5rem;

        z-index: 1;
    }
    
    header > .container #flyout-menu-container:hover > #flyout-menu {
        display: block;
    }
    
    header > .container #flyout-menu-container:hover > #flyout-menu:hover {
        display: block;
    }
    
    header > .container #flyout-menu > li > a {
        display: block;
        font-size: 1.45rem;
        padding: 0.7rem 0;
    }
    
    header > .container #flyout-menu > li > a:hover {
        background-color: var(--bg-color-hover-categories);
    }

    header > .container #flyout-menu > li:first-child > a:hover {
        border-radius: 0.75rem 0.75rem 0 0 !important;
    }
    
    header > .container #flyout-menu > li:last-child > a:hover {
        border-radius: 0 0 0.75rem 0.75rem !important;
    }

    header > .container > #light-mode-button {
        background-image: var(--icon-theme-button);
    }

    header > .container > button {
        justify-self: center;
    }

    header > .container > button:hover {
        filter: brightness(65%);
    }

}