/* --- Basic Setup --- */
:root {
    --bg-dark: #020617;
    --bg-dark-alt: #030712;
    --bg-light: #f5f7ff;
    --bg-light-alt: #ffffff;
    --text-light: #e5e7eb;
    --text-mid: #9ca3af;
    --text-dark: #0f172a;
    --accent-blue: #3b82f6;
    --accent-blue-soft: rgba(59, 130, 246, 0.12);
    --callout-bg: rgba(15, 23, 42, 0.8);
    --shadow-soft: 0 20px 40px rgba(15, 23, 42, 0.6);
    --transition-fast: 0.3s ease;
}

*,
*::before,
*::after {
    box-sizing: border-box;
}

body {
    font-family: 'Poppins', system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    margin: 0;
    background-color: var(--bg-dark);
    color: var(--text-light);
    overflow-x: hidden;
    position: relative;
    scroll-behavior: smooth;
}

/* Light Theme */
body.light-theme {
    background-color: var(--bg-light);
    color: var(--text-dark);
}

body.light-theme .left-column {
    background: linear-gradient(160deg, #e5edff, #ffffff);
    color: var(--text-dark);
    box-shadow: 0 12px 35px rgba(15, 23, 42, 0.15);
}

body.light-theme .identity h1,
body.light-theme h2,
body.light-theme .project h3,
body.light-theme .blog-card h3,
body.light-theme .github-project-card h4 {
    color: var(--text-dark);
}

body.light-theme .identity .title,
body.light-theme .identity .affiliation,
body.light-theme .identity .email,
body.light-theme footer,
body.light-theme .blog-intro {
    color: #4b5563;
}

body.light-theme .callout-box {
    background-color: #e6efff;
    border-left-color: var(--accent-blue);
}

body.light-theme .right-column {
    background: radial-gradient(circle at 0% 0%, #e5edff 0%, #f9fafb 40%, #e5edff 100%);
}

body.light-theme .card-section,
body.light-theme .testimonial,
body.light-theme .blog-card,
body.light-theme .github-project-card,
body.light-theme .project {
    background: rgba(255, 255, 255, 0.9);
    border-color: rgba(148, 163, 184, 0.35);
    box-shadow: 0 18px 50px rgba(148, 163, 184, 0.25);
    backdrop-filter: blur(0);
}

body.light-theme input,
body.light-theme textarea {
    background-color: #f9fafb;
    color: var(--text-dark);
    border-color: rgba(148, 163, 184, 0.7);
}

body.light-theme .cert-modal {
    background-color: rgba(15, 23, 42, 0.75);
}

/* Animated Background – Dark Gradient Restored */
.animated-bg {
    position: fixed;
    inset: 0;
    background:
        radial-gradient(circle at 0% 0%, rgba(59, 130, 246, 0.35), transparent 55%),
        radial-gradient(circle at 100% 100%, rgba(8, 47, 73, 0.45), transparent 55%),
        radial-gradient(circle at 0% 100%, rgba(56, 189, 248, 0.25), transparent 55%),
        linear-gradient(135deg, #020617 0%, #020617 40%, #020617 100%);
    opacity: 0.9;
    pointer-events: none;
    animation: float-bg 24s ease-in-out infinite alternate;
    z-index: -2;
}

@keyframes float-bg {
    0% {
        transform: translate3d(0, 0, 0) scale(1);
    }
    100% {
        transform: translate3d(-20px, -30px, 0) scale(1.05);
    }
}

/* Container Layout */
.container {
    display: flex;
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    min-height: 100vh;
    padding: 24px 18px 40px;
    gap: 24px;
}

/* --- Left Column (Identity) --- */
.left-column {
    width: 35%;
    max-width: 360px;
    padding: 32px 26px;
    position: sticky;
    top: 18px;
    align-self: flex-start;
    display: flex;
    flex-direction: column;
    justify-content: center;
    text-align: center;
    background: linear-gradient(150deg, rgba(15, 23, 42, 0.95), rgba(15, 23, 42, 0.7));
    box-shadow: var(--shadow-soft);
    border-radius: 24px;
    border: 1px solid rgba(148, 163, 184, 0.4);
    backdrop-filter: blur(22px);
    z-index: 2;
}

.profile-pic {
    width: 150px;
    height: 150px;
    border-radius: 26px;
    border: 3px solid var(--accent-blue);
    margin: 0 auto 18px;
    object-fit: cover;
    box-shadow: 0 24px 50px rgba(37, 99, 235, 0.6);
}

.identity h1 {
    font-size: 1.9rem;
    color: #f9fafb;
    margin-bottom: 6px;
}

/* Typing Animation Styles */
.typing-wrapper {
    font-size: 0.95rem;
    margin-bottom: 10px;
    color: var(--accent-blue);
    min-height: 1.2em;
}

.typing-cursor {
    display: inline-block;
    margin-left: 2px;
    animation: blink-cursor 0.8s steps(1) infinite;
}

@keyframes blink-cursor {
    0%, 50% {
        opacity: 1;
    }
    51%, 100% {
        opacity: 0;
    }
}

.identity .title {
    font-size: 1.02rem;
    color: var(--text-mid);
    margin-bottom: 4px;
}

.identity .email,
.identity .affiliation {
    color: var(--text-mid);
    margin-bottom: 4px;
}

.research-link {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    margin: 18px 0 12px;
    color: var(--accent-blue);
    text-decoration: none;
    font-weight: 500;
    border: 1px solid rgba(59, 130, 246, 0.8);
    padding: 8px 16px;
    border-radius: 999px;
    transition: background-color var(--transition-fast), color var(--transition-fast), transform var(--transition-fast), box-shadow var(--transition-fast), border-color var(--transition-fast);
    background: radial-gradient(circle at 0 0, rgba(59, 130, 246, 0.25), transparent 55%);
}

.research-link:hover {
    background-color: var(--accent-blue);
    color: #ffffff;
    transform: translateY(-2px) scale(1.01);
    box-shadow: 0 18px 35px rgba(37, 99, 235, 0.7);
    border-color: transparent;
}

.social-links {
    margin-top: 10px;
}

.social-links a {
    color: var(--text-mid);
    font-size: 1.5rem;
    margin: 0 8px;
    transition: color var(--transition-fast), transform var(--transition-fast), text-shadow var(--transition-fast);
}

.social-links a:hover {
    color: var(--accent-blue);
    transform: translateY(-3px) scale(1.05);
    text-shadow: 0 0 18px rgba(59, 130, 246, 0.9);
}

/* Skill Meters (Sidebar + Main) */
.skill-meters {
    margin-top: 22px;
}

.skill-meter {
    margin-bottom: 10px;
}

.skill-meter span {
    font-size: 0.82rem;
    display: inline-block;
    margin-bottom: 4px;
    color: var(--text-mid);
}

.meter-bar {
    width: 100%;
    height: 6px;
    background-color: rgba(15, 23, 42, 0.9);
    border-radius: 999px;
    overflow: hidden;
}

.meter-fill {
    height: 100%;
    width: 0;
    background: linear-gradient(90deg, var(--accent-blue), #a855f7);
    border-radius: 999px;
    transition: width 1.2s ease-out;
}

/* Main Content */
.right-column {
    width: 65%;
    padding: 18px 4px 10px;
    position: relative;
    z-index: 1;
    background: radial-gradient(circle at 0 0, rgba(15, 23, 42, 0.8), transparent 60%),
                radial-gradient(circle at 100% 100%, rgba(30, 64, 175, 0.7), transparent 60%),
                linear-gradient(135deg, rgba(15, 23, 42, 0.95), rgba(15, 23, 42, 0.9));
    border-radius: 30px;
    border: 1px solid rgba(148, 163, 184, 0.35);
    box-shadow: 0 24px 60px rgba(15, 23, 42, 0.85);
    backdrop-filter: blur(30px);
}

/* Navigation */
.main-nav {
    position: sticky;
    top: 0;
    z-index: 10;
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 26px;
    padding: 10px 20px;
    border-radius: 22px;
    background: radial-gradient(circle at 0 0, rgba(15, 23, 42, 0.98), rgba(15, 23, 42, 0.93));
    border: 1px solid rgba(148, 163, 184, 0.45);
    backdrop-filter: blur(22px);
    box-shadow: 0 18px 40px rgba(15, 23, 42, 0.75);
}

.nav-left {
    display: flex;
    align-items: center;
    gap: 8px;
}

.nav-logo {
    font-weight: 700;
    font-size: 1.05rem;
    letter-spacing: 0.09em;
    text-transform: uppercase;
    color: #e5e7eb;
}

.nav-links {
    display: flex;
    flex-wrap: wrap;
    justify-content: flex-end;
    gap: 10px;
}

.nav-links a {
    color: var(--text-mid);
    text-decoration: none;
    padding: 6px 10px;
    border-radius: 999px;
    font-weight: 500;
    font-size: 0.86rem;
    transition: color var(--transition-fast), transform var(--transition-fast), background-color var(--transition-fast), box-shadow var(--transition-fast);
}

.nav-links a:hover {
    color: #e5e7eb;
    background-color: rgba(37, 99, 235, 0.20);
    transform: translateY(-1px);
    box-shadow: 0 10px 26px rgba(37, 99, 235, 0.45);
}

/* Theme Toggle Button */
#theme-toggle {
    background: rgba(15, 23, 42, 0.9);
    border: 1px solid rgba(148, 163, 184, 0.6);
    border-radius: 999px;
    padding: 6px 10px;
    cursor: pointer;
    color: var(--text-mid);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background-color var(--transition-fast), color var(--transition-fast), transform var(--transition-fast), box-shadow var(--transition-fast), border-color var(--transition-fast);
}

body.light-theme #theme-toggle {
    background: #eef2ff;
    border-color: rgba(148, 163, 184, 0.8);
}

#theme-toggle:hover {
    background-color: var(--accent-blue);
    color: #fff;
    transform: translateY(-1px) scale(1.02);
    box-shadow: 0 12px 30px rgba(37, 99, 235, 0.7);
}

/* Sections and Typography */
section {
    margin-bottom: 32px;
    position: relative;
}

.card-section {
    background: radial-gradient(circle at 0 0, rgba(15, 23, 42, 0.95), rgba(15, 23, 42, 0.96));
    border-radius: 20px;
    padding: 20px 22px 18px;
    border: 1px solid rgba(148, 163, 184, 0.45);
    box-shadow: 0 18px 40px rgba(15, 23, 42, 0.75);
    backdrop-filter: blur(20px);
}

h2 {
    font-size: 1.5rem;
    color: #f9fafb;
    border-bottom: 1px solid rgba(148, 163, 184, 0.6);
    padding-bottom: 10px;
    margin-bottom: 16px;
}

p,
li {
    line-height: 1.7;
    font-size: 0.98rem;
    margin-bottom: 8px;
}

a {
    color: var(--accent-blue);
    text-decoration: none;
}

a:hover {
    text-decoration: underline;
}

/* Callout Box (Now Section) */
.callout-box {
    background-color: var(--callout-bg);
    border-left: 4px solid var(--accent-blue);
    box-shadow: 0 20px 45px rgba(15, 23, 42, 0.9);
}

/* Achievements */
.achievement {
    margin-bottom: 14px;
    padding: 10px 0;
    border-bottom: 1px dashed rgba(148, 163, 184, 0.45);
}

.achievement:last-child {
    border-bottom: none;
}

/* Projects */
.project h3 {
    margin-bottom: 5px;
    color: #e5e7eb;
}

.project {
    margin-bottom: 16px;
    padding: 14px 16px;
    border-radius: 14px;
    background-color: rgba(15, 23, 42, 0.85);
    border: 1px solid rgba(148, 163, 184, 0.55);
    transition: transform var(--transition-fast), box-shadow var(--transition-fast), border-color var(--transition-fast), background-color var(--transition-fast);
}

.project:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-soft);
    border-color: var(--accent-blue);
    background-color: rgba(15, 23, 42, 0.96);
}

.project-link {
    font-weight: 500;
}

/* GitHub Projects Auto Fetch */
.github-projects-wrapper {
    margin-top: 24px;
}

.github-note {
    font-size: 0.9rem;
    color: var(--text-mid);
}

.github-projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
    gap: 14px;
    margin-top: 12px;
}

.github-project-card {
    padding: 13px 14px;
    border-radius: 14px;
    background-color: rgba(15, 23, 42, 0.9);
    border: 1px solid rgba(148, 163, 184, 0.55);
    transition: transform var(--transition-fast), box-shadow var(--transition-fast), border-color var(--transition-fast), background-color var(--transition-fast);
}

.github-project-card h4 {
    margin: 0 0 6px;
    font-size: 1rem;
    color: #e5e7eb;
}

.github-project-card p {
    font-size: 0.9rem;
    color: var(--text-mid);
    min-height: 2.4em;
}

.github-meta {
    display: flex;
    gap: 10px;
    font-size: 0.8rem;
    margin: 6px 0;
    color: var(--text-mid);
}

.github-project-card a {
    font-size: 0.9rem;
    font-weight: 500;
}

.github-project-card:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-soft);
    border-color: var(--accent-blue);
    background-color: rgba(15, 23, 42, 0.98);
}

.error {
    color: #f97373;
}

/* Certificates Gallery */
.cert-gallery {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 18px;
}

.cert-item {
    text-align: center;
    cursor: pointer;
    transition: transform var(--transition-fast), box-shadow var(--transition-fast), filter var(--transition-fast);
}

.cert-item img {
    width: 100%;
    border-radius: 14px;
    object-fit: cover;
    box-shadow: 0 16px 40px rgba(15, 23, 42, 0.85);
}

.cert-item p {
    margin-top: 8px;
    font-size: 0.9rem;
    color: var(--text-mid);
}

.cert-item:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-soft);
    filter: brightness(1.05);
}

/* Certificates Modal (Lightbox) */
.cert-modal {
    display: none;
    position: fixed;
    z-index: 99;
    padding-top: 60px;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    overflow: auto;
    background-color: rgba(3, 7, 18, 0.94);
}

.cert-modal-content {
    margin: auto;
    display: block;
    max-width: 80%;
    border-radius: 14px;
    box-shadow: 0 22px 50px rgba(15, 23, 42, 0.95);
}

#cert-caption {
    margin: 18px auto;
    text-align: center;
    color: #f1f5f9;
    font-size: 0.95rem;
}

.cert-close {
    position: absolute;
    top: 20px;
    right: 35px;
    color: #f9fafb;
    font-size: 32px;
    font-weight: bold;
    cursor: pointer;
}

/* Skills Meter Grid (Main Section) */
.skills-meter-grid {
    margin-top: 18px;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 14px;
}

/* Testimonials */
.testimonials-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 18px;
}

.testimonial {
    padding: 16px 18px;
    border-radius: 14px;
    background-color: var(--accent-blue-soft);
    border: 1px solid rgba(148, 163, 184, 0.6);
    font-size: 0.95rem;
}

.testimonial p {
    font-style: italic;
    margin-bottom: 10px;
    color: #e5e7eb;
}

.testimonial h4 {
    margin: 0;
    font-size: 0.95rem;
    color: #f9fafb;
}

.testimonial span {
    font-size: 0.8rem;
    color: var(--text-mid);
}

/* Blog Section */
.blog-intro {
    color: var(--text-mid);
}

.blog-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
    gap: 16px;
    margin-top: 12px;
}

.blog-card {
    padding: 14px 16px;
    border-radius: 14px;
    background-color: rgba(15, 23, 42, 0.9);
    border: 1px solid rgba(148, 163, 184, 0.55);
    transition: transform var(--transition-fast), box-shadow var(--transition-fast), border-color var(--transition-fast), background-color var(--transition-fast);
}

.blog-card h3 {
    margin-top: 0;
    margin-bottom: 8px;
    color: #e5e7eb;
}

.blog-card p {
    font-size: 0.95rem;
    color: var(--text-mid);
}

.blog-meta {
    display: inline-block;
    margin-top: 6px;
    font-size: 0.8rem;
    color: var(--text-mid);
}

.blog-card:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-soft);
    border-color: var(--accent-blue);
    background-color: rgba(15, 23, 42, 0.98);
}

/* Education */
.education {
    padding: 6px 0;
}

/* Contact Form */
#contact-form {
    max-width: 480px;
}

.form-group {
    margin-bottom: 14px;
    display: flex;
    flex-direction: column;
}

label {
    font-size: 0.88rem;
    margin-bottom: 4px;
    color: var(--text-mid);
}

input,
textarea {
    border-radius: 8px;
    border: 1px solid rgba(148, 163, 184, 0.7);
    padding: 8px 10px;
    font-size: 0.95rem;
    background-color: rgba(15, 23, 42, 0.9);
    color: var(--text-light);
    outline: none;
    transition: border-color var(--transition-fast), box-shadow var(--transition-fast), background-color var(--transition-fast), color var(--transition-fast), transform var(--transition-fast);
}

input:focus,
textarea:focus {
    border-color: var(--accent-blue);
    box-shadow: 0 0 0 1px rgba(59, 130, 246, 0.7);
    transform: translateY(-1px);
}

.btn-primary {
    border: none;
    padding: 10px 18px;
    border-radius: 999px;
    background: linear-gradient(135deg, var(--accent-blue), #6366f1);
    color: #fff;
    font-weight: 500;
    cursor: pointer;
    margin-top: 5px;
    transition: background-color var(--transition-fast), transform var(--transition-fast), box-shadow var(--transition-fast), filter var(--transition-fast);
}

.btn-primary:hover {
    filter: brightness(1.05);
    transform: translateY(-1px) scale(1.01);
    box-shadow: 0 18px 40px rgba(37, 99, 235, 0.8);
}

.form-status {
    font-size: 0.9rem;
    margin-top: 6px;
    color: #22c55e;
}

.error-text {
    color: #f97373;
}

/* Footer */
.footer-section {
    text-align: center;
    padding: 16px 8px 10px;
    color: var(--text-mid);
    border-top: 1px solid rgba(148, 163, 184, 0.4);
    background: radial-gradient(circle at 50% 0, rgba(15, 23, 42, 0.9), rgba(15, 23, 42, 0.95));
    border-radius: 20px;
}

/* Preloader */
#preloader {
    position: fixed;
    inset: 0;
    background: radial-gradient(circle at 0 0, #020617 0%, #020617 40%, #020617 100%);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    z-index: 200;
    transition: opacity 0.5s ease;
}

#preloader p {
    margin-top: 14px;
    color: var(--text-mid);
    font-size: 0.95rem;
}

.spinner {
    width: 42px;
    height: 42px;
    border-radius: 50%;
    border: 4px solid rgba(148, 163, 184, 0.2);
    border-top-color: var(--accent-blue);
    animation: spin 0.9s linear infinite;
}

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

.hide-preloader {
    opacity: 0;
    pointer-events: none;
}

/* Scroll Progress Bar */
#scroll-progress {
    position: fixed;
    top: 0;
    left: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--accent-blue), #a855f7);
    width: 0;
    z-index: 150;
}

/* Back to Top Button */
#back-to-top {
    position: fixed;
    right: 20px;
    bottom: 25px;
    width: 40px;
    height: 40px;
    border-radius: 999px;
    border: none;
    background-color: var(--accent-blue);
    color: #fff;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    box-shadow: 0 18px 40px rgba(15, 23, 42, 0.9);
    opacity: 0;
    pointer-events: none;
    transform: translateY(10px);
    transition: opacity var(--transition-fast), transform var(--transition-fast), box-shadow var(--transition-fast), filter var(--transition-fast);
    z-index: 120;
}

#back-to-top.show {
    opacity: 1;
    pointer-events: auto;
    transform: translateY(0);
}

#back-to-top:hover {
    filter: brightness(1.05);
    box-shadow: 0 22px 50px rgba(15, 23, 42, 0.95);
}

/* Scroll Reveal Animation */
.reveal {
    opacity: 0;
    transform: translateY(15px);
    transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

.reveal-visible {
    opacity: 1;
    transform: translateY(0);
}

/* Responsive Design */
@media (max-width: 900px) {
    .container {
        flex-direction: column;
        padding: 18px 16px 32px;
    }

    .left-column {
        position: relative;
        width: 100%;
        max-width: none;
        height: auto;
        padding: 26px 22px 20px;
        margin-bottom: 12px;
        top: 0;
    }

    .right-column {
        width: 100%;
        padding: 16px 10px 12px;
        border-radius: 22px;
    }

    .main-nav {
        flex-direction: column;
        align-items: flex-start;
        gap: 10px;
        padding: 10px 14px;
    }

    .nav-links {
        justify-content: flex-start;
    }
}

@media (max-width: 600px) {
    .left-column {
        padding: 22px 18px 18px;
    }

    .right-column {
        padding: 18px 12px 18px;
    }

    .card-section {
        padding: 16px 14px 14px;
    }

    h2 {
        font-size: 1.35rem;
    }

    .nav-logo {
        font-size: 0.98rem;
    }

    .nav-links a {
        font-size: 0.8rem;
    }

    #back-to-top {
        right: 15px;
        bottom: 18px;
    }
}