/* --- 1. Root Variables & Global Setup --- */
:root {
    /* --- Light Mode Colors --- */
    --bg-light: #f8f9fa;
    --card-bg-light: #ffffff;
    --text-light: #212529;
    --subtle-text-light: #6c757d;
    --accent-light: #0056b3; /* A strong, professional blue */
    --hover-light: #007bff;
    --border-light: #dee2e6;

    /* --- Dark Mode Colors --- */
    --bg-dark: #121212;
    --card-bg-dark: #1e1e1e;
    --text-dark: #e9ecef;
    --subtle-text-dark: #adb5bd;
    --accent-dark: #4dabf7; /* A brighter blue for dark mode */
    --hover-dark: #1c7ed6;
    --border-dark: #343a40;

    /* --- Typography & Layout --- */
    --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    --shadow: 0 4px 8px rgba(0,0,0,0.1); /* Slightly softer shadow */
    --transition-speed: 0.3s;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-family);
    transition: background-color var(--transition-speed), color var(--transition-speed);
    background-color: var(--bg-light);
    color: var(--text-light);
    line-height: 1.6; /* Improved readability */
}

body.dark-mode {
    background-color: var(--bg-dark);
    color: var(--text-dark);
}

/* --- 2. Navigation Bar --- */
.navbar {
    position: fixed;
    width: 100%;
    top: 0;
    left: 0;
    background: rgba(255, 255, 255, 0.85);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    z-index: 1000;
    box-shadow: 0 2px 4px rgba(0,0,0,0.05);
    transition: background-color var(--transition-speed);
}

body.dark-mode .navbar {
    background: rgba(30, 30, 30, 0.85);
}

.nav-container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 1.5rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 60px;
}

.nav-brand {
    font-weight: 700;
    font-size: 1.2rem;
    text-decoration: none;
    color: inherit;
}

.nav-menu {
    display: flex;
    align-items: center;
    gap: 1.5rem;
}

.nav-links {
    list-style: none;
    display: flex;
    gap: 1.5rem;
}

.nav-links a {
    text-decoration: none;
    color: var(--subtle-text-light);
    font-weight: 500;
    transition: color var(--transition-speed);
}

body.dark-mode .nav-links a {
    color: var(--subtle-text-dark);
}

.nav-links a:hover {
    color: var(--hover-light);
}

body.dark-mode .nav-links a:hover {
    color: var(--hover-dark);
}

.nav-controls {
    display: flex;
    align-items: center;
    gap: 1rem;
}

/* --- 3. Language Switcher --- */
.lang-switcher {
    position: relative;
}

.lang-button {
    background: none;
    border: 1px solid var(--border-light);
    color: var(--subtle-text-light);
    padding: 0.3rem 0.6rem;
    border-radius: 6px;
    cursor: pointer;
    font-family: inherit;
    font-weight: 500;
    display: flex;
    align-items: center;
    gap: 0.4rem;
}

body.dark-mode .lang-button {
    border-color: var(--border-dark);
    color: var(--subtle-text-dark);
}

.lang-dropdown {
    display: none;
    position: absolute;
    top: 100%;
    right: 0;
    background: var(--card-bg-light);
    list-style: none;
    border-radius: 8px;
    padding: 0.5rem 0;
    box-shadow: var(--shadow);
    width: 120px;
    overflow: hidden;
    z-index: 1001;
    border-top: 5px solid transparent; 
}

body.dark-mode .lang-dropdown {
    background: var(--card-bg-dark);
}

.lang-switcher:hover .lang-dropdown {
    display: block;
}

.lang-dropdown a {
    display: block;
    padding: 0.5rem 1rem;
    text-decoration: none;
    color: inherit;
    transition: background-color var(--transition-speed);
}

.lang-dropdown a:hover {
    background-color: var(--bg-light);
}

body.dark-mode .lang-dropdown a:hover {
    background-color: var(--bg-dark);
}

.lang-dropdown a.active {
    font-weight: 700;
    color: var(--accent-light);
}

body.dark-mode .lang-dropdown a.active {
    color: var(--accent-dark);
}

/* --- 4. Theme Toggle Button --- */
#theme-toggle {
    background: none;
    border: none;
    cursor: pointer;
    font-size: 1.4rem;
    color: var(--subtle-text-light);
    transition: color var(--transition-speed), transform var(--transition-speed);
}

body.dark-mode #theme-toggle {
    color: var(--subtle-text-dark);
}

#theme-toggle:hover {
    color: var(--text-light);
    transform: scale(1.1);
}

body.dark-mode #theme-toggle:hover {
    color: var(--text-dark);
}

/* --- 5. Hero Section --- */
.hero {
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    min-height: 100vh;
    padding-top: 60px;
}

.hero-content {
    max-width: 800px;
    padding: 2rem 1.5rem;
}

.profile-pic {
    width: 150px;
    height: 150px;
    border-radius: 50%;
    object-fit: cover;
    margin-bottom: 1.5rem;
    box-shadow: var(--shadow);
    border: 3px solid var(--card-bg-light);
}

body.dark-mode .profile-pic {
    border-color: var(--card-bg-dark);
}

.hero h1 {
    font-size: clamp(2.5rem, 5vw, 3.5rem);
    font-weight: 800;
}

.headline {
    font-size: clamp(1.1rem, 2.5vw, 1.3rem);
    color: var(--subtle-text-light);
    margin: 0.5rem 0 1.5rem;
    font-weight: 400;
}

body.dark-mode .headline {
    color: var(--subtle-text-dark);
}

.bio {
    max-width: 600px;
    margin: 0 auto 2rem;
    font-size: 1.1rem;
    line-height: 1.7;
}

.cta-button {
    display: inline-block;
    background: var(--accent-light);
    color: #fff;
    padding: 0.8rem 1.6rem;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 600;
    transition: background-color var(--transition-speed), transform var(--transition-speed);
}

body.dark-mode .cta-button {
    background: var(--accent-dark);
    color: var(--bg-dark);
}

.cta-button:hover {
    background: var(--hover-light);
    transform: translateY(-3px);
    box-shadow: 0 4px 10px rgba(0,0,0,0.1);
}

body.dark-mode .cta-button:hover {
    background: var(--hover-dark);
}

/* --- 6. Content Sections Layout --- */
.content-section {
    max-width: 1100px;
    margin: 0 auto;
    padding: 5rem 1.5rem;
}

.content-section h2 {
    text-align: center;
    font-size: clamp(2rem, 4vw, 2.5rem);
    margin-bottom: 3rem;
}

/* --- 7. Project & Activity Card Grid --- */
.grid-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.card {
    background: var(--card-bg-light);
    border-radius: 12px;
    box-shadow: var(--shadow);
    overflow: hidden;
    transition: transform var(--transition-speed), box-shadow var(--transition-speed);
    display: flex;
    flex-direction: column;
}

body.dark-mode .card {
    background: var(--card-bg-dark);
}

.card:hover {
    transform: translateY(-8px);
    box-shadow: 0 10px 20px rgba(0,0,0,0.15);
}

.card-img {
    width: 100%;
    height: 200px;
    object-fit: cover;
    object-position: center;
}

.card-content {
    padding: 1.5rem;
    flex-grow: 1;
    display: flex;
    flex-direction: column;
}

.card h3 {
    margin-bottom: 0.5rem;
    font-size: 1.25rem;
}

.card p {
    color: var(--subtle-text-light);
    margin-bottom: 1rem;
    line-height: 1.6;
}

body.dark-mode .card p {
    color: var(--subtle-text-dark);
}

.tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-bottom: 1.5rem;
}

.tags span {
    background: var(--bg-light);
    color: var(--subtle-text-light);
    padding: 0.25rem 0.75rem;
    border-radius: 12px;
    font-size: 0.8rem;
    font-weight: 500;
}

body.dark-mode .tags span {
    background: var(--bg-dark);
    color: var(--subtle-text-dark);
}

.card-link {
    text-decoration: none;
    color: var(--accent-light);
    font-weight: 600;
    transition: letter-spacing var(--transition-speed);
    margin-top: auto; /* Pushes single link to the bottom */
}

body.dark-mode .card-link {
    color: var(--accent-dark);
}

.card-link:hover {
    letter-spacing: 0.5px;
}

/* --- 8. Contact Section --- */
#contact {
    text-align: center;
}

#contact .socials {
    display: flex;
    justify-content: center;
    gap: 2rem;
    font-size: 2rem;
    margin: 2rem 0 3rem;
}

#contact .socials a {
    color: var(--subtle-text-light);
    transition: color var(--transition-speed), transform var(--transition-speed);
}

body.dark-mode #contact .socials a {
    color: var(--subtle-text-dark);
}

#contact .socials a:hover {
    color: var(--hover-light);
    transform: scale(1.2) rotate(5deg);
}

body.dark-mode #contact .socials a:hover {
    color: var(--hover-dark);
}

.final-links {
    display: flex;
    justify-content: center;
    gap: 1rem;
    flex-wrap: wrap;
}

/* --- 9. Footer --- */
.footer {
    text-align: center;
    padding: 2rem;
    color: var(--subtle-text-light);
    border-top: 1px solid var(--border-light);
}

body.dark-mode .footer {
    color: var(--subtle-text-dark);
    border-top-color: var(--border-dark);
}

/* --- 10. Academic Success Section --- */
.awards-list {
    display: flex;
    flex-direction: column;
    gap: 1rem;
    max-width: 800px;
    margin: 0 auto;
    text-align: left;
}

.award-item {
    background: var(--card-bg-light);
    border-radius: 8px;
    padding: 1.25rem 1.5rem;
    box-shadow: var(--shadow);
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: transform var(--transition-speed), box-shadow var(--transition-speed);
    border-left: 4px solid transparent;
}

body.dark-mode .award-item {
    background: var(--card-bg-dark);
}

.award-item:hover {
    transform: translateX(5px);
    box-shadow: 0 6px 12px rgba(0,0,0,0.1);
    border-left-color: var(--accent-light);
}

body.dark-mode .award-item:hover {
    border-left-color: var(--accent-dark);
}

.award-details h3 {
    margin: 0;
    font-size: 1.1rem;
}

.award-details p {
    color: var(--subtle-text-light);
    margin: 0.25rem 0 0;
}

body.dark-mode .award-details p {
    color: var(--subtle-text-dark);
}

.award-place {
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--accent-light);
    white-space: nowrap;
    margin-left: 1.5rem;
    background-color: var(--bg-light);
    padding: 0.25rem 0.75rem;
    border-radius: 6px;
}

body.dark-mode .award-place {
    color: var(--accent-dark);
    background-color: var(--bg-dark);
}

/* --- 11. Academic Year Headers --- */
.academic-year-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    max-width: 800px;
    margin: 3rem auto 1.5rem;
    flex-wrap: wrap; /* Allows wrapping on smaller screens */
}

.academic-year-header {
    font-size: 1.5rem;
    color: var(--accent-light);
    border-bottom: 2px solid var(--accent-light);
    padding-bottom: 0.5rem;
    margin: 0;
}

body.dark-mode .academic-year-header {
    color: var(--accent-dark);
    border-bottom-color: var(--accent-dark);
}

.certificate-link {
    text-decoration: none;
    color: var(--accent-light);
    background-color: var(--bg-light);
    border: 1px solid var(--border-light);
    padding: 0.4rem 0.8rem;
    border-radius: 6px;
    font-weight: 500;
    white-space: nowrap;
    transition: background-color var(--transition-speed), color var(--transition-speed);
}

.certificate-link:hover {
    background-color: var(--accent-light);
    color: white;
}

body.dark-mode .certificate-link {
    color: var(--accent-dark);
    background-color: var(--bg-dark);
    border-color: var(--border-dark);
}

body.dark-mode .certificate-link:hover {
    background-color: var(--accent-dark);
    color: var(--bg-dark);
}

/* --- 12. Certificate Gallery --- */
.certificate-gallery {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin-top: auto; /* Pushes gallery to the bottom */
    padding-top: 1rem; /* Adds space above the gallery */
}

.gallery-image {
    width: 100%;
    max-width: 200px;
    height: auto;
    border-radius: 8px;
    box-shadow: var(--shadow);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.gallery-image:hover {
    transform: scale(1.05);
    box-shadow: 0 4px 12px rgba(0,0,0,0.15);
}

/* --- 13. Responsive Adjustments --- */
@media (max-width: 768px) {
    .nav-menu {
        gap: 1rem;
    }
    .nav-links {
        display: none;
    }
    .hero h1 {
        font-size: 2rem;
    }
    .headline {
        font-size: 1rem;
    }
    .content-section {
        padding: 3rem 1rem;
    }
    .academic-year-container {
        flex-direction: column;
        align-items: flex-start;
        gap: 1rem;
    }
}