:root {
    --primary-color: #2c5042; /* Dark Slate sea-green */
    --secondary-color: #34db9b; /* Professional jade */
    --accent-color: #ecf0f1; /* Light Grey */
    --accent-dark: #bdc3c7; /* Medium Grey */
    --background-color: #f8f9fa; /* Very Light Grey */
    --text-color: #34495e; /* Darker Text */
    --heading-color: #2c5042; /* Dark Slate sea-green */
    --light-text-color: #f1f1f1; /* For dark backgrounds */
    --white-color: #ffffff;
    --border-radius: 8px;
    --shadow: 0 4px 15px rgba(0, 0, 0, 0.07);
    --transition-speed: 0.3s;
    --font-primary: 'Poppins', sans-serif;
    --font-secondary: 'Playfair Display', serif;
}

/* Basic Reset & Body Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-primary);
    line-height: 1.7;
    color: var(--text-color);
    background-color: var(--background-color);
}

.container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 20px;
}

h1, h2, h3, h4, h5, h6 {
    color: var(--heading-color);
    margin-bottom: 0.8rem;
}

h1 {
    font-family: var(--font-secondary);
    font-weight: 700;
}

h2.section-title {
    font-size: 2.2rem;
    font-weight: 600;
    color: var(--primary-color);
    text-align: center;
    margin-top: 4rem;
    margin-bottom: 2.5rem;
    position: relative;
    padding-bottom: 0.75rem;
    display: flex;
    align-items: center;
    justify-content: center;
}

h2.section-title::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 70px;
    height: 4px;
    background-color: var(--secondary-color);
    border-radius: 2px;
}

.icon-left {
    margin-right: 0.8rem;
    color: var(--secondary-color);
}

a {
    color: var(--secondary-color);
    text-decoration: none;
    transition: color var(--transition-speed) ease;
}

a:hover {
    color: var(--primary-color);
    text-decoration: none; 
}

ul {
    list-style: none; 
    padding-left: 0;
}

/* Card Style */
.card {
    background: var(--white-color);
    padding: 1.5rem 2rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    transition: transform var(--transition-speed) ease, box-shadow var(--transition-speed) ease;
    margin-bottom: 1.5rem;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 20px rgba(44, 62, 80, 0.12);
}

/* --- Header/Hero Section --- */
#hero {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: var(--light-text-color);
    text-align: center;
    padding: 5rem 20px 4rem;
    position: relative;
    overflow: hidden; 
}
.hero-container {
    position: relative;
    z-index: 2;
}

#hero .profile-pic {
    width: 180px; 
    height: 180px;
    border-radius: 50%;
    border: 5px solid rgba(255, 255, 255, 0.8);
    margin-bottom: 1.5rem;
    box-shadow: 0 0 25px rgba(0, 0, 0, 0.2);
    object-fit: cover; 
    background-color: var(--white-color);
}

#hero h1 {
    color: var(--white-color);
    font-size: 3rem;
    margin-bottom: 0.5rem;
}

#hero h2 {
    color: var(--accent-color);
    font-weight: 400;
    font-size: 1.5rem;
    margin-top: 0;
    margin-bottom: 1.5rem;
    border-bottom: none;
}

#hero .tagline {
    font-size: 1.1rem;
    margin-bottom: 1.5rem;
    max-width: 700px;
    margin-left: auto;
    margin-right: auto;
    color: var(--accent-dark);
    font-weight: 300;
}

#hero .location {
    margin-bottom: 2rem;
    color: var(--accent-dark);
    font-size: 1rem;
}
#hero .location i {
    margin-right: 8px;
}

.hero-actions {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 1rem;
    flex-wrap: wrap; 
}

#hero .cta-button {
    display: inline-flex; 
    align-items: center;
    gap: 0.5rem;
    background-color: var(--white-color);
    color: var(--primary-color);
    padding: 12px 25px;
    border-radius: var(--border-radius);
    font-weight: 600;
    transition: background-color var(--transition-speed) ease, color var(--transition-speed) ease, transform var(--transition-speed) ease;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

#hero .cta-button:hover {
    background-color: var(--accent-color);
    color: var(--primary-color);
    text-decoration: none;
    transform: translateY(-2px);
}

#hero .cta-button.secondary {
    background-color: transparent;
    border: 2px solid var(--accent-dark);
    color: var(--accent-dark);
}
#hero .cta-button.secondary:hover {
    background-color: var(--accent-dark);
    color: var(--primary-color);
}

/* --- Navigation --- */
#mainNav {
    background: var(--white-color);
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.08);
    padding: 0.5rem 0;
}

.nav-container {
    display: flex;
    justify-content: flex-end; 
    align-items: center;
    position: relative;
}

.nav-list {
    display: flex;
    list-style: none;
    gap: 0.8rem; 
    margin: 0; 
}

.nav-list a {
    color: var(--text-color);
    text-decoration: none;
    padding: 0.8rem 1rem;
    border-radius: var(--border-radius);
    transition: background-color var(--transition-speed) ease, color var(--transition-speed) ease;
    font-weight: 600;
    font-size: 0.95rem;
}

.nav-list a:hover,
.nav-list a.active-link {
    background-color: var(--accent-color);
    color: var(--primary-color);
}

.menu-toggle {
    display: none; 
    background: none;
    border: none;
    color: var(--primary-color);
    font-size: 1.3rem;
    cursor: pointer;
    padding: 0.8rem 1rem;
    margin-left: auto; 
}
.menu-toggle i {
    margin-right: 5px;
}


/* --- Main Content Area --- */
main {
    padding-top: 2rem; 
}
.main-content { 
     padding: 0;
}

.content-section {
    padding: 2rem 0; 
}

/* --- About Section --- */
#about .card {
    padding: 2rem 2.5rem;
}
#about p {
    margin-bottom: 1rem;
}
#about strong {
    color: var(--primary-color);
    font-weight: 600;
}

/* --- Skills Section --- */
.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
}

.skill-category h3 {
    margin-bottom: 1rem;
    color: var(--primary-color);
    font-weight: 600;
    border-bottom: 2px solid var(--accent-color);
    padding-bottom: 0.6rem;
    display: flex;
    align-items: center;
    font-size: 1.2rem;
}

.skill-category ul {
    list-style: none;
    padding: 0;
    margin: 0;
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}
.skill-category ul li {
    margin-bottom: 0;
    background-color: var(--accent-color);
    padding: 5px 12px;
    border-radius: 15px; 
    display: inline-block;
    font-size: 0.9rem;
    color: var(--primary-color);
    font-weight: 500;
    transition: background-color var(--transition-speed);
}
.skill-category ul li:hover {
    background-color: var(--accent-dark);
}

/* --- Education Section --- */
.edu-cert-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.5rem;
}

.education h3 {
    color: var(--primary-color);
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
    font-size: 1.2rem;
}

.education p {
    margin-bottom: 0.3rem;
}
.education p:last-of-type {
    margin-bottom: 0;
}
.education .edu-year {
    font-size: 0.9em;
    color: #757575;
}
.education p i {
    margin-right: 8px;
    color: var(--secondary-color);
}

/* --- Contact Section --- */
.contact-details {
    text-align: center; 
    padding: 2rem;
}
.contact-details p {
    margin-bottom: 1.5rem;
    font-size: 1.1rem;
}

.contact-list {
    list-style: none;
    padding: 0;
    display: inline-flex; 
    flex-direction: column; 
    align-items: flex-start; 
    gap: 1rem; 
}

.contact-list li {
    display: flex;
    align-items: center;
    font-size: 1.05rem;
}
.contact-list li i {
    margin-right: 1rem;
    color: var(--primary-color);
    width: 25px;
    text-align: center;
    font-size: 1.2em;
}
.contact-list li a {
    color: var(--secondary-color);
    font-weight: 500;
}
.contact-list li a:hover {
    color: var(--primary-color);
}

/* --- Footer --- */
footer {
    text-align: center;
    margin-top: 4rem;
    padding: 2rem;
    background-color: var(--heading-color);
    color: var(--accent-dark);
    font-size: 0.9rem;
}
footer p {
    margin: 0;
}

/* --- Go Top Button --- */
#goTopBtn {
    position: fixed;
    bottom: 30px;
    right: 30px;
    z-index: 999;
    border: none;
    outline: none;
    background-color: var(--primary-color);
    color: var(--white-color);
    cursor: pointer;
    padding: 0; 
    border-radius: 50%;
    width: 50px;
    height: 50px;
    font-size: 1.4em; 
    box-shadow: 0 4px 10px rgba(0,0,0,0.2);
    transition: opacity 0.4s ease, background-color 0.3s ease, transform 0.3s ease;
    opacity: 0;
    display: flex; 
    justify-content: center;
    align-items: center;
}

#goTopBtn.show {
    opacity: 0.8; 
    display: flex;
}

#goTopBtn:hover {
    background-color: var(--secondary-color);
    opacity: 1;
    transform: scale(1.1);
}

/* --- Animations --- */
.animate-on-scroll {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

.animate-on-scroll.animated {
    opacity: 1;
    transform: translateY(0);
}

/* --- Responsive Design --- */
@media (max-width: 768px) {
    h2.section-title {
        font-size: 1.8rem;
    }
    #hero h1 { font-size: 2.5rem; }
    #hero h2 { font-size: 1.3rem; }
    #hero .profile-pic { width: 150px; height: 150px; }

    .menu-toggle {
        display: block; 
    }

    .nav-container {
         flex-wrap: wrap;
         justify-content: space-between; 
    }

    .nav-list {
        display: none; 
        flex-direction: column;
        width: 100%;
        background: var(--white-color);
        padding: 1rem 0;
        order: 1; 
        border-top: 1px solid var(--accent-dark);
        box-shadow: 0 5px 10px rgba(0,0,0,0.05);
    }

    .nav-list.active {
        display: flex; 
    }

    .nav-list li {
        width: 100%;
        text-align: center;
    }
    .nav-list a {
        display: block;
        padding: 0.8rem 1rem;
        border-radius: 0;
        border-bottom: 1px solid var(--accent-color);
    }
    .nav-list li:last-child a { border-bottom: none; }
    
    .skills-grid, .edu-cert-grid {
        grid-template-columns: 1fr; 
    }

     .contact-list {
        align-items: center; 
     }
     
     .contact-list li i {
         margin-right: 0.5rem; 
     }
}