:root{
--bgColor-primary : #ffffff;
--bgColor-secondary : #f5f5f5;

--text-primary : #222222;
--text-secondary : #666666;

--accent-color : #3a86fe;
--border-color : #e0e0e0;

--shadow-soft : rgba(0, 0, 0, 0.05);

--section-padding : 5rem;

--transition-speed : 0.03s;
}

body.darkMode{
    --bgColor-primary : #121212;
    --bgColor-secondary : #1e1e1e;

    --text-primary : #f0f0f0;
    --text-secondary : #b0b0b0;

    --border-color : #333333;
    --shadow-soft : rgba(0, 0, 0, 0.3);
}

*{
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
html{
    scroll-behavior: smooth;
}

body{
    font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
    background-color: var(--bgColor-primary);
    color: var(--text-primary);
    line-height: 1.6;
    transition : background-color var(--transition-speed), color var(--transition-speed);
}

.container{
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

h1,h2,h3{
    color: var(--text-primary);
    font-weight: 700;
}

p{
    color: var(--text-secondary);
    font-size: 1.6rem;
}
.sectionTitle{
    text-align: center;
    font-size: 2.2rem;
    margin-bottom: 3rem;
}

section{
    padding: var(--section-padding) 0;
    scroll-margin-top: 80px;
    /* min-height: 100vh; */
}

.highlight{
    color: var(--accent-color);
}

header{
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;

    background-color: var(--bgColor-primary);
    border-bottom: 1px solid var(--border-color);
    box-shadow: 0 4px 12px var(--shadow-soft);

    z-index: 99;
}

.navContainer{
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}

.logo{
    text-decoration: none;
    font-size: 1.5rem;
    font-weight: 700;
    display: flex;
    align-items: center;
    gap: 0.4rem;
    color: var(--accent-color);
}
.logoText{
    color: var(--text-primary);
}

.navMenu{
    list-style: none;
    display: flex;
    align-items: center;
    gap: 1.5rem;
}

.navLink{
    text-decoration: none;
    font-weight: 500;
    color: var(--text-secondary);
    position: relative;

    padding: 0.3rem 0;
    transition: color var(--transition-speed);
}

.navLink:hover{
    color: var(--accent-color);
}

.navLink.active{
    color: var(--accent-color);
}
.navLink.active::after{
    content: "";
    position: absolute;
    left: 0;
    bottom: -4px;
    width: 100%;
    height: 2px;
    background-color: var(--accent-color);
}

.themeToggle{
    width: 60px;
    height: 26px;
    border-radius: 26px;

    border: 1px solid var(--border-color);
    background-color: var(--bgColor-secondary);

    cursor: pointer;
    position: relative;
    /* need to complete toggle button */
}

.toggleKnob{
    position: absolute;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background-color: var(--accent-color);
    top: 50%;
    left: 3px;
    transform: translateY(-50%);
    transition: left 0.3s ease;
}

body.darkMode .toggleKnob{
    left: 27px;
}

.hamburgerBtn{
    display: none;
    background: none;
    border: none;
    font-size: 1.6rem;
    cursor: pointer;
    color: var(--text-primary);
}


@media (max-width : 768px){
    .hamburgerBtn{
        display: block;
    }
    .navMenu{
        position: fixed;
        top: 70px;
        left: -100%;

        width: 100%;
        height: calc(100vh - 70px);
        background-color: var(--bgColor-primary);
        flex-direction: column;
        justify-content: flex-start;
        padding-top: 2rem;
        transition: left 0.4s ease;
    }
    .navMenu.active{
        left: 0;
    }
    .navLink{
        font-size: 1.2rem;
        padding: 1rem;
    }
}
/* hero section */

.hero{
    padding-top: calc(70px + 4rem);
    padding-bottom: 4rem;
    text-align: center;
    background-color: var(--bgColor-primary);
    /* min-height: 100vh; */
}
.hero h1{
    font-size: 3.2rem;
    font-weight: 700;
    line-height: 1.1;
    max-width: 800px;
    margin: 0 auto 1.2rem;
}

.about{
    background-color: var(--bgColor-secondary);
}
.aboutContent{
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: 4rem;
    align-items: center;
}

.aboutImage{
    display: flex;
    justify-content: center;
}

#profileImage{
    width: 100%;
    max-width: 300px;
    aspect-ratio: 1/1;
    object-fit: cover;
    border-radius: 50%;
    border: 4px solid var(--bgColor-primary);
    box-shadow: 0 15px 30px var(--shadow-soft);
}

@media(max-width : 780px){
    .aboutContent{
        grid-template-columns: 1fr;
        text-align: center;
    }
    .aboutText .btn{
        display: inline-block;
    }
}

.skill{
    background-color: var(--bgColor-primary);
}

.skillsGrid{
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}
.skillCard{
    background-color: var(--bgColor-secondary);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 2rem;
    text-align: center;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}
.skillCard:hover{
    transform: translate(-6px);
    box-shadow: 0 15px 30px var(--shadow-soft);
}

.skillCard h3{
    margin-bottom: 1rem;
    font-size: 1.2rem;
    font-weight: 500;
}
.skillCard p {
    font-size: 14px;
}

.project{
    background-color: var(--bgColor-secondary);
}
.projectsGrid{
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
}
.projectCard{
    background-color: var(--bgColor-primary);
    border: 1px solid var(--border-color);
    border-radius: 10px;

    overflow: hidden;

    transition: transform 0.3s ease, box-shadow 0.3s ease;
}
.projectCard:hover{
    transform: translate(-6px);
    box-shadow: 0 20px 40px var(--shadow-soft);
}
.projectImage{
    height: 180px;
    background-color: var(--accent-color);
    color: #ffffff;
    display: flex;
    justify-content: center;
    align-items: center;

    font-size: 2.5rem;
}

.projectInfo{
    padding: 1.5rem;
}
.projectInfo h3{
    margin-bottom: 0.6rem;
}
.projectInfo p{
    margin-bottom: 1rem;
    font-size: 15px;
}
.contact{
    background-color: var(--bgColor-primary);
    text-align: center;
}

.contactText{
    max-width: 600px;
    margin: 0 auto 2rem;
    font-size: 1rem;
    color: var(--text-secondary);
}
.contactLinks{
    display: flex;
    justify-content: center;
    gap: 1.5rem;
    flex-wrap: wrap;
}

.contactLink{
    display: flex;
    justify-content: center;
    text-align: center;

    width: 52px;
    height: 52px;

    border-radius: 50%;
    background-color: var(--bgColor-secondary);

    text-decoration: none;
    color: var(--text-primary);
    font-weight: 500;

    transition: transform 0.3s ease, background-color var(--transition-speed), color var(--transition-speed);
}

.contactLink:hover{
    transform: translateY(-6px);
    background-color: var(--accent-color);
    color: #ffffff;
}

.footer{
    border-top: 1px solid var(--border-color);
    background-color: var(--bgColor-secondary);

    padding: 2rem 0;
    text-align: left;
}

.footer p{
    font-size: 14px;
    color: var(--text-secondary);
}

.btn{
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 165px;
    padding: 0.72rem 1.25rem;
    margin-top: 15px;
    border-radius: 999px;
    border: 1px solid var(--accent-color);
    background-color: var(--accent-color);
    color: #ffffff;
    text-decoration: none;
    font-weight: 600;
    font-size: 0.95rem;
    letter-spacing: 0.2px;
    transition: transform 0.25s ease, box-shadow 0.25s ease, background-color var(--transition-speed), color var(--transition-speed);
}

.btn:hover{
    transform: translateY(-2px);
    box-shadow: 0 10px 20px var(--shadow-soft);
}