/* --- Global Styles & Variables --- */
:root {
    --bg-main: #0f172a;
    --bg-card: #1e293b;
    --primary: #38bdf8;
    --primary-hover: #0284c7;
    --text-main: #f8fafc;
    --text-secondary: #94a3b8;
    --border-color: #334155;
    --font-family: 'Poppins', sans-serif;
    --shadow-color: rgba(56, 189, 248, 0.3);
    --transition-speed: 0.3s;
}

/* Light theme variables */
[data-theme="light"] {
    --bg-main: #f0f4f8;
    --bg-card: #ffffff;
    --text-main: #1a202c;
    --text-secondary: #4a5568;
    --border-color: #e2e8f0;
    --shadow-color: rgba(0, 0, 0, 0.1);
}

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

body {
    font-family: var(--font-family);
    background-color: var(--bg-main);
    color: var(--text-main);
    line-height: 1.6;
    transition: background-color 0.3s ease, color 0.3s ease;
}

a {
    text-decoration: none;
    color: inherit;
}

ul {
    list-style: none;
}

section {
    padding: 5rem 8%;
}

.section-title {
    font-size: 2.2rem;
    text-align: center;
    margin-bottom: 2rem;
    font-weight: 700;
}

.section-title span {
    color: var(--primary);
}

/* --- Loading Screen --- */
#loader {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: var(--bg-main);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 9999;
    transition: opacity 0.5s ease, visibility 0.5s ease;
}

#loader.hidden {
    opacity: 0;
    visibility: hidden;
}

.loader-content {
    text-align: center;
}

.loader-spinner {
    width: 50px;
    height: 50px;
    border: 3px solid var(--border-color);
    border-top-color: var(--primary);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin: 0 auto 1rem;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* --- Header & Navigation --- */
.header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    padding: 1.2rem 8%;
    background: rgba(15, 23, 42, 0.9);
    backdrop-filter: blur(10px);
    display: flex;
    justify-content: space-between;
    align-items: center;
    z-index: 1000;
    border-bottom: 1px solid var(--border-color);
    transition: all 0.3s ease;
}

[data-theme="light"] .header {
    background: rgba(240, 244, 248, 0.9);
}

.logo {
    font-size: 1.8rem;
    font-weight: 700;
    color: var(--text-main);
}

.logo span {
    color: var(--primary);
}

.navbar ul {
    display: flex;
    gap: 2rem;
}

.navbar a {
    font-weight: 500;
    color: var(--text-secondary);
    transition: color 0.3s ease;
    position: relative;
}

.navbar a::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary);
    transition: width 0.3s ease;
}

.navbar a:hover::after,
.navbar a.active::after {
    width: 100%;
}

.navbar a:hover {
    color: var(--primary);
}

/* --- Buttons --- */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    border-radius: 8px;
    font-weight: 600;
    font-size: 0.95rem;
    cursor: pointer;
    transition: all 0.3s ease;
    border: none;
}

.primary-btn {
    background-color: var(--primary);
    color: var(--bg-main);
}

.primary-btn:hover {
    background-color: var(--primary-hover);
    color: #fff;
    transform: translateY(-2px);
    box-shadow: 0 4px 15px var(--shadow-color);
}

.secondary-btn {
    background-color: transparent;
    color: var(--primary);
    border: 2px solid var(--primary);
}

.secondary-btn:hover {
    background-color: var(--primary);
    color: var(--bg-main);
    transform: translateY(-2px);
    box-shadow: 0 4px 15px var(--shadow-color);
}

/* --- Hero Section --- */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding-top: 7rem;
}

.hero-container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 4rem;
    width: 100%;
}

.hero-image-wrapper {
    flex: 1;
    display: flex;
    justify-content: center;
}

.hero-img {
    width: 320px;
    height: 320px;
    border-radius: 50%;
    object-fit: cover;
    border: 4px solid var(--primary);
    box-shadow: 0 0 30px var(--shadow-color);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.hero-img:hover {
    transform: scale(1.05);
    box-shadow: 0 0 50px var(--shadow-color);
}

.hero-description {
    flex: 1.2;
}

/* Hero Text - Fixed Display */
.hero-text {
    display: block;
}

.hero-text .greeting {
    font-size: 1.2rem;
    color: var(--primary);
    font-weight: 600;
    display: block;
}

.hero-text h1 {
    font-size: 3rem;
    font-weight: 700;
    margin: 0.3rem 0;
    color: var(--text-main);
    display: block;
}

.hero-text h3 {
    font-size: 1.5rem;
    color: var(--text-secondary);
    margin-bottom: 1rem;
    font-weight: 500;
    display: block;
}

.hero-text .hero-tech {
    font-size: 1rem;
    margin-bottom: 0.8rem;
    display: block;
}

.hero-text .hero-tech strong {
    color: var(--primary);
}

.hero-text .availability {
    color: var(--text-secondary);
    font-size: 0.95rem;
    margin-bottom: 0.5rem;
    display: block;
}

.hero-text .location {
    color: var(--text-secondary);
    font-size: 0.95rem;
    margin-bottom: 1.8rem;
    display: block;
}

.hero-text .location i {
    color: var(--primary);
}

.hero-buttons {
    display: flex;
    gap: 1.2rem;
}

/* --- About Section --- */
.about-intro {
    text-align: center;
    max-width: 700px;
    margin: 0 auto 3rem auto;
    color: var(--text-secondary);
}

.about-intro h3 {
    color: var(--text-main);
    margin-bottom: 0.5rem;
}

.about-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
}

.about-card {
    background: var(--bg-card);
    padding: 2rem;
    border-radius: 12px;
    border: 1px solid var(--border-color);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.about-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.2);
}

.card-icon {
    font-size: 2rem;
    color: var(--primary);
    margin-bottom: 1rem;
}

.about-card h3 {
    font-size: 1.3rem;
    margin-bottom: 1rem;
}

.degree {
    font-weight: 600;
}

.institution {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-bottom: 0.8rem;
}

.year-badge {
    display: inline-block;
    background: rgba(56, 189, 248, 0.1);
    color: var(--primary);
    padding: 0.2rem 0.6rem;
    border-radius: 4px;
    font-size: 0.85rem;
}

.learning-list li {
    color: var(--text-secondary);
    margin-bottom: 0.4rem;
}

.learning-list i {
    color: var(--primary);
    margin-right: 0.4rem;
}

/* --- Skills Section --- */
.skills-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 1.8rem;
}

.skills-card {
    background: var(--bg-card);
    padding: 1.8rem;
    border-radius: 12px;
    border: 1px solid var(--border-color);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.skills-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.2);
}

.skills-card h3 {
    font-size: 1.2rem;
    margin-bottom: 1rem;
    color: var(--primary);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.skills-card ul li {
    background: var(--bg-main);
    padding: 0.5rem 0.8rem;
    border-radius: 6px;
    margin-bottom: 0.5rem;
    font-size: 0.9rem;
    border: 1px solid var(--border-color);
    transition: all 0.3s ease;
}

.skills-card ul li:hover {
    border-color: var(--primary);
    transform: translateX(5px);
}

/* --- Projects Section --- */
.projects-subtitle {
    text-align: center;
    color: var(--text-secondary);
    margin-top: -1.5rem;
    margin-bottom: 3rem;
}

.projects-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 2.5rem;
}

.project-card {
    background: var(--bg-card);
    border-radius: 12px;
    overflow: hidden;
    border: 1px solid var(--border-color);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    display: flex;
    flex-direction: column;
}

.project-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
}

.project-img-wrapper {
    width: 100%;
    height: 200px;
    overflow: hidden;
    background: var(--bg-main);
}

.project-img-wrapper img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.4s ease;
}

/* Shimmer loading animation */
.project-img-wrapper img.loading {
    animation: shimmer 1.5s infinite;
}

@keyframes shimmer {
    0% { opacity: 0.3; }
    50% { opacity: 1; }
    100% { opacity: 0.3; }
}

.project-card:hover .project-img-wrapper img {
    transform: scale(1.05);
}

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

.project-content h3 {
    font-size: 1.3rem;
    margin-bottom: 0.8rem;
}

.project-content p {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-bottom: 1.2rem;
    flex-grow: 1;
}

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

.tech-stack span {
    background: rgba(56, 189, 248, 0.1);
    color: var(--primary);
    font-size: 0.8rem;
    padding: 0.3rem 0.7rem;
    border-radius: 20px;
    transition: all 0.3s ease;
}

.tech-stack span:hover {
    background: var(--primary);
    color: var(--bg-main);
    transform: scale(1.05);
}

.project-buttons {
    display: flex;
    gap: 0.8rem;
}

.live-demo-button {
    background: var(--primary);
    color: var(--bg-main);
    padding: 0.5rem 1rem;
    font-size: 0.85rem;
}

.live-demo-button:hover {
    background: var(--primary-hover);
    color: #fff;
    transform: translateY(-2px);
}

.github-button {
    background: transparent;
    color: var(--text-main);
    border: 1px solid var(--border-color);
    padding: 0.5rem 1rem;
    font-size: 0.85rem;
}

.github-button:hover {
    border-color: var(--primary);
    color: var(--primary);
    transform: translateY(-2px);
}

/* --- Contact Section --- */
.contact-subtitle {
    text-align: center;
    color: var(--text-secondary);
    margin-top: -1.5rem;
    margin-bottom: 3rem;
}

.contact-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 3rem;
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.contact-item {
    display: flex;
    align-items: center;
    gap: 1.2rem;
    background: var(--bg-card);
    padding: 1.2rem 1.5rem;
    border-radius: 10px;
    border: 1px solid var(--border-color);
    transition: all 0.3s ease;
}

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

.contact-item .icon {
    font-size: 1.5rem;
    color: var(--primary);
}

.contact-details h3 {
    font-size: 1rem;
    color: var(--text-secondary);
}

.contact-details p {
    font-weight: 600;
}

.contact-details a {
    color: var(--text-main);
    transition: color 0.3s ease;
}

.contact-details a:hover {
    color: var(--primary);
}

.contact-form {
    background: var(--bg-card);
    padding: 2rem;
    border-radius: 12px;
    border: 1px solid var(--border-color);
}

.form-group {
    margin-bottom: 1.2rem;
}

.form-group label {
    display: block;
    font-size: 0.9rem;
    margin-bottom: 0.4rem;
    color: var(--text-secondary);
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 0.8rem;
    background: var(--bg-main);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    color: var(--text-main);
    font-family: var(--font-family);
    transition: border-color 0.3s ease;
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(56, 189, 248, 0.1);
}

.form-group input.error,
.form-group textarea.error {
    border-color: #ef4444;
}

.error-message {
    color: #ef4444;
    font-size: 0.85rem;
    margin-top: 0.3rem;
    display: none;
}

.error-message.visible {
    display: block;
}

.submit-btn {
    width: 100%;
    justify-content: center;
    background: var(--primary);
    color: var(--bg-main);
}

.submit-btn:hover {
    background: var(--primary-hover);
    color: #fff;
    transform: translateY(-2px);
}

.submit-btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

/* --- Footer --- */
.footer {
    background: #090d16;
    padding: 3rem 8% 1.5rem 8%;
    border-top: 1px solid var(--border-color);
    text-align: center;
}

[data-theme="light"] .footer {
    background: #e2e8f0;
}

.footer-content h2 {
    font-size: 1.8rem;
    margin-bottom: 0.5rem;
}

.footer-content p {
    color: var(--text-secondary);
    max-width: 500px;
    margin: 0 auto 1.5rem auto;
    font-size: 0.9rem;
}

.social-links {
    display: flex;
    justify-content: center;
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.social-links a {
    color: var(--text-secondary);
    transition: all 0.3s ease;
}

.social-links a:hover {
    color: var(--primary);
    transform: translateY(-3px);
}

.copyright {
    font-size: 0.85rem;
    color: var(--text-secondary);
}

/* --- Scroll to Top Button --- */
.scroll-top-btn {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    background: var(--primary);
    color: var(--bg-main);
    width: 50px;
    height: 50px;
    border-radius: 50%;
    border: none;
    font-size: 1.2rem;
    cursor: pointer;
    transition: all 0.3s ease;
    opacity: 0;
    visibility: hidden;
    z-index: 999;
}

.scroll-top-btn.visible {
    opacity: 1;
    visibility: visible;
}

.scroll-top-btn:hover {
    background: var(--primary-hover);
    color: #fff;
    transform: translateY(-3px);
    box-shadow: 0 4px 15px var(--shadow-color);
}

/* --- Theme Toggle Button --- */
.theme-toggle {
    background: none;
    border: none;
    color: var(--text-main);
    font-size: 1.2rem;
    cursor: pointer;
    padding: 0.5rem;
    border-radius: 50%;
    transition: all 0.3s ease;
    margin-left: 0.5rem;
}

.theme-toggle:hover {
    background: var(--bg-card);
    transform: rotate(30deg);
}

/* --- Header Scroll Effect --- */
.header.scrolled {
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.4);
    padding-top: 0.9rem;
    padding-bottom: 0.9rem;
}

/* --- Hamburger Icon --- */
.hamburger {
    display: none;
    font-size: 1.5rem;
    color: var(--text-main);
    cursor: pointer;
    z-index: 1001;
    background: none;
    border: none;
    padding: 0.5rem;
}

.hamburger:hover {
    color: var(--primary);
}