html[data-theme="dark"] {
    --background-color: #111827;
    --card-background: #1F2937;
    --primary-color: #38BDF8; 
    --secondary-color: #0EA5E9;
    --accent-color: var(--primary-color);
    --text-color: #9CA3AF;
    --heading-color: #F9FAFB;
    --border-color: #374151;
    --shadow-color: rgba(0, 0, 0, 0.4);
    --header-background-color: rgba(17, 24, 39, 0.8);
}

html[data-theme="light"] {
    --background-color: #F9FAFB;
    --card-background: #FFFFFF;
    --primary-color: #0EA5E9;
    --secondary-color: #38BDF8;
    --accent-color: var(--primary-color);
    --text-color: #4B5563;
    --heading-color: #111827;
    --border-color: #E5E7EB;
    --shadow-color: rgba(0, 0, 0, 0.1);
    --header-background-color: rgba(255, 255, 255, 0.8);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Poppins', sans-serif;
    background-color: var(--background-color);
    color: var(--text-color);
    line-height: 1.6;
    overflow-x: hidden;
}

.container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 2rem;
}

/* --- Theme Switch --- */
.theme-switch-wrapper {
    display: flex;
    align-items: center;
}

.theme-switch {
    position: relative;
    display: inline-block;
    width: 60px;
    height: 34px;
}

.theme-switch input {
    opacity: 0;
    width: 0;
    height: 0;
}

.slider {
    position: absolute;
    cursor: pointer;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: #ccc;
    transition: .4s;
    border-radius: 34px;
}

.slider:before {
    position: absolute;
    content: "";
    height: 26px;
    width: 26px;
    left: 4px;
    bottom: 4px;
    background-color: white;
    transition: .4s;
    border-radius: 50%;
}

input:checked + .slider {
    background-color: var(--primary-color);
}

input:checked + .slider:before {
    transform: translateX(26px);
}

.slider.round {
    border-radius: 34px;
}

.slider.round:before {
    border-radius: 50%;
}

/* --- Animations --- */
.fade-in {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

.fade-in.is-visible {
    opacity: 1;
    transform: translateY(0);
}

/* --- Header --- */
header {
    position: fixed;
    width: 100%;
    top: 0;
    left: 0;
    background-color: var(--header-background-color);
    backdrop-filter: blur(10px);
    z-index: 1000;
    border-bottom: 1px solid var(--border-color);
}

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

.logo {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--heading-color);
}

nav ul {
    list-style: none;
    display: flex;
    gap: 2rem;
}

nav a {
    color: var(--heading-color);
    text-decoration: none;
    font-weight: 400;
    transition: color 0.3s;
}

nav a:hover {
    color: var(--accent-color);
}

/* --- Hero Section --- */
#hero-animation {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
}

.hero {
    position: relative;
    height: 100vh;
    display: flex;
    align-items: center;
    text-align: center;
    overflow: hidden;
}

.hero-content h1 {
    font-size: clamp(2.5rem, 5vw, 4.5rem);
    font-weight: 700;
    margin-bottom: 1rem;
    color: var(--heading-color);
}

.hero-content p {
    font-size: 1.2rem;
    margin-bottom: 2.5rem;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
    color: var(--text-color);
}

.btn {
    background-color: var(--primary-color);
    color: #111827;
    padding: 0.8rem 2.5rem;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 600;
    transition: background-color 0.3s, transform 0.3s;
    border: none;
}

.btn:hover {
    background-color: var(--secondary-color);
    transform: translateY(-3px);
    cursor: pointer;
}

/* --- General Section Styling --- */
section {
    padding: 6rem 0;
}

.section-title {
    text-align: center;
    font-size: 2.8rem;
    margin-bottom: 4rem;
    color: var(--heading-color);
}

/* --- About Section --- */
.about-content {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 3rem;
    align-items: flex-start;
}

.about-skills ul {
    list-style: none;
    display: flex;
    flex-wrap: wrap;
    gap: 0.8rem;
    margin-top: 1rem;
}

.about-skills li {
    background-color: var(--card-background);
    color: var(--text-color);
    padding: 0.5rem 1rem;
    border-radius: 20px;
    font-size: 0.9rem;
    border: 1px solid var(--border-color);
}

/* --- Portfolio Section --- */
#portfolio {
    background-color: var(--card-background);
}

.portfolio-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.portfolio-item {
    background-color: var(--background-color);
    border-radius: 10px;
    border: 1px solid var(--border-color);
    overflow: hidden;
    transition: transform 0.3s, box-shadow 0.3s, border-color 0.3s;
}

.portfolio-item:hover {
    transform: translateY(-5px);
    border-color: var(--primary-color);
}

.portfolio-item img {
    width: 100%;
    height: 200px;
    object-fit: cover;
    display: block;
}

.portfolio-item h3 {
    font-size: 1.3rem;
    padding: 1.5rem 1.5rem 0.5rem;
    color: var(--heading-color);
}

.portfolio-item p {
    padding: 0 1.5rem 1.5rem;
}

/* --- Contact Section --- */
.contact-form {
    max-width: 600px;
    margin: 0 auto;
    display: grid;
    gap: 1.5rem;
}

.contact-form input,
.contact-form textarea {
    width: 100%;
    padding: 1rem;
    background-color: var(--card-background);
    border: 1px solid var(--border-color);
    border-radius: 5px;
    font-family: 'Poppins', sans-serif;
    color: var(--heading-color);
    font-size: 1rem;
}

.contact-form input::placeholder,
.contact-form textarea::placeholder {
    color: var(--text-color);
}

.contact-form button {
    justify-self: center;
    width: auto;
}

/* --- Footer --- */
footer {
    background-color: var(--card-background);
    text-align: center;
    padding: 2rem 0;
    border-top: 1px solid var(--border-color);
}

/* --- Responsive --- */
@media (max-width: 768px) {
    nav ul {
        display: none; 
    }

    .about-content {
        grid-template-columns: 1fr;
    }

    .section-title {
        font-size: 2.2rem;
    }
}