/*
Theme Name: Subashis Portfolio
Theme URI: http://example.com
Author: Subashis Roy Bhowmik
Description: AI Researcher Portfolio
Version: 1.0
*/

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background: #0a0a0a;
    color: #ffffff;
    line-height: 1.6;
    overflow-x: hidden;
}

/* Smooth Scroll */
html {
    scroll-behavior: smooth;
}

/* Custom Scrollbar */
::-webkit-scrollbar {
    width: 8px;
}
::-webkit-scrollbar-track {
    background: #0a0a0a;
}
::-webkit-scrollbar-thumb {
    background: #333;
    border-radius: 4px;
}
::-webkit-scrollbar-thumb:hover {
    background: #667eea;
}

/* Gradient Text */
.gradient-text {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* Glass Effect */
.glass {
    background: rgba(255, 255, 255, 0.03);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.08);
}

/* Loader */
.loader {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: #0a0a0a;
    z-index: 9999;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: opacity 0.5s ease;
}
.loader-text {
    font-size: 1.5rem;
    font-weight: 600;
    color: #667eea;
    letter-spacing: 0.2em;
}
.loader.hidden {
    opacity: 0;
    pointer-events: none;
}

/* Navigation - FIXED SIZE */
#navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    padding: 0;
    transition: all 0.3s ease;
}
#navbar.nav-hidden {
    transform: translateY(-100%);
}
#navbar.nav-visible {
    transform: translateY(0);
    background: rgba(10, 10, 10, 0.9);
    backdrop-filter: blur(20px);
}
.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}
.logo {
    font-size: 1.25rem;
    font-weight: 700;
    text-decoration: none;
    color: #fff;
}
.nav-links {
    display: flex;
    gap: 2rem;
    list-style: none;
}
.nav-links a {
    color: #a0a0a0;
    text-decoration: none;
    font-size: 0.9rem;
    font-weight: 500;
    transition: color 0.3s;
}
.nav-links a:hover {
    color: #667eea;
}
.nav-cta {
    padding: 0.5rem 1.25rem;
    background: linear-gradient(135deg, #667eea, #764ba2);
    color: #fff;
    border-radius: 50px;
    font-size: 0.85rem;
    font-weight: 600;
    text-decoration: none;
    transition: transform 0.3s, box-shadow 0.3s;
}
.nav-cta:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 30px rgba(102, 126, 234, 0.3);
}

/* Mobile Menu */
.mobile-menu-btn {
    display: none;
    background: none;
    border: none;
    color: #fff;
    cursor: pointer;
}

/* Hero Section - POLISHED */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 6rem 2rem 4rem;
    position: relative;
}
.hero-content {
    max-width: 900px;
    text-align: center;
}
.hero-label {
    display: inline-block;
    padding: 0.5rem 1rem;
    background: rgba(102, 126, 234, 0.1);
    border: 1px solid rgba(102, 126, 234, 0.3);
    border-radius: 50px;
    color: #667eea;
    font-size: 0.8rem;
    font-weight: 600;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    margin-bottom: 1.5rem;
}
.hero-title {
    font-size: clamp(2.5rem, 5vw, 4rem);
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 1rem;
}
.hero-subtitle {
    font-size: clamp(1.1rem, 2vw, 1.5rem);
    color: #a0a0a0;
    font-weight: 400;
    margin-bottom: 0.5rem;
}
.hero-description {
    font-size: 1.1rem;
    color: #808080;
    max-width: 600px;
    margin: 0 auto 2rem;
}
.hero-typing {
    font-size: 1.25rem;
    color: #667eea;
    font-weight: 500;
    margin-bottom: 2.5rem;
    min-height: 2rem;
}
.hero-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    margin-bottom: 3rem;
}
.btn {
    padding: 0.875rem 2rem;
    border-radius: 50px;
    font-weight: 600;
    text-decoration: none;
    transition: all 0.3s;
    font-size: 0.95rem;
}
.btn-primary {
    background: linear-gradient(135deg, #667eea, #764ba2);
    color: #fff;
}
.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 15px 40px rgba(102, 126, 234, 0.4);
}
.btn-secondary {
    border: 2px solid rgba(102, 126, 234, 0.5);
    color: #fff;
}
.btn-secondary:hover {
    background: rgba(102, 126, 234, 0.1);
    border-color: #667eea;
}
.hero-social {
    display: flex;
    gap: 1.5rem;
    justify-content: center;
}
.hero-social a {
    width: 44px;
    height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.05);
    color: #a0a0a0;
    transition: all 0.3s;
}
.hero-social a:hover {
    background: rgba(102, 126, 234, 0.2);
    color: #667eea;
    transform: translateY(-3px);
}

/* Particles */
#particles {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
    pointer-events: none;
}

/* Section Styles */
section {
    padding: 5rem 2rem;
}
.section-header {
    text-align: center;
    margin-bottom: 3rem;
}
.section-title {
    font-size: clamp(2rem, 4vw, 3rem);
    font-weight: 700;
    margin-bottom: 0.5rem;
}
.section-subtitle {
    color: #808080;
    font-size: 1.1rem;
}

/* About Section */
.about-grid {
    max-width: 1100px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: 300px 1fr;
    gap: 4rem;
    align-items: start;
}
.about-image {
    position: relative;
}
.about-image-bg {
    position: absolute;
    inset: -10px;
    background: linear-gradient(135deg, #667eea, #764ba2);
    border-radius: 20px;
    opacity: 0.3;
    filter: blur(20px);
}
.about-image img {
    position: relative;
    width: 100%;
    border-radius: 16px;
    aspect-ratio: 1;
    object-fit: cover;
}
.about-content h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: #667eea;
}
.about-content p {
    color: #b0b0b0;
    margin-bottom: 1.5rem;
    line-height: 1.8;
}
.research-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
    margin-bottom: 2rem;
}
.tag {
    padding: 0.5rem 1rem;
    background: rgba(102, 126, 234, 0.1);
    border: 1px solid rgba(102, 126, 234, 0.3);
    border-radius: 50px;
    font-size: 0.85rem;
    color: #a0b0ff;
    transition: all 0.3s;
}
.tag:hover {
    background: rgba(102, 126, 234, 0.2);
    transform: translateY(-2px);
}
.stats {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1rem;
}
.stat-box {
    padding: 1.5rem;
    background: rgba(255, 255, 255, 0.03);
    border-radius: 12px;
    text-align: center;
    border: 1px solid rgba(255, 255, 255, 0.05);
}
.stat-number {
    font-size: 2rem;
    font-weight: 700;
    color: #667eea;
}
.stat-label {
    font-size: 0.85rem;
    color: #808080;
    margin-top: 0.25rem;
}

/* Timeline */
.timeline {
    max-width: 800px;
    margin: 0 auto;
}
.timeline-item {
    position: relative;
    padding-left: 2rem;
    padding-bottom: 2rem;
    border-left: 2px solid rgba(102, 126, 234, 0.2);
}
.timeline-item:last-child {
    border-left-color: transparent;
}
.timeline-item::before {
    content: '';
    position: absolute;
    left: -6px;
    top: 0;
    width: 10px;
    height: 10px;
    background: #667eea;
    border-radius: 50%;
    box-shadow: 0 0 20px rgba(102, 126, 234, 0.5);
}
.timeline-date {
    font-size: 0.85rem;
    color: #667eea;
    font-weight: 600;
    margin-bottom: 0.25rem;
}
.timeline-title {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 0.25rem;
}
.timeline-place {
    color: #a0a0a0;
    font-size: 0.95rem;
    margin-bottom: 0.5rem;
}
.timeline-grade {
    font-size: 0.85rem;
    color: #808080;
}

/* Cards Grid */
.cards-grid {
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
    gap: 1.5rem;
}
.card {
    background: rgba(255, 255, 255, 0.02);
    border: 1px solid rgba(255, 255, 255, 0.05);
    border-radius: 16px;
    padding: 1.5rem;
    transition: all 0.3s;
}
.card:hover {
    background: rgba(255, 255, 255, 0.05);
    transform: translateY(-5px);
    border-color: rgba(102, 126, 234, 0.3);
}
.card-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 0.75rem;
}
.card-meta {
    font-size: 0.8rem;
    color: #667eea;
    font-weight: 600;
}
.card-title {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    line-height: 1.4;
}
.card-text {
    font-size: 0.9rem;
    color: #a0a0a0;
    line-height: 1.6;
}
.card-authors {
    font-size: 0.85rem;
    color: #808080;
    margin-top: 0.5rem;
    font-style: italic;
}

/* Skills */
.skills-cloud {
    max-width: 900px;
    margin: 0 auto;
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 0.75rem;
    margin-bottom: 3rem;
}
.skill-item {
    padding: 0.625rem 1.25rem;
    background: linear-gradient(135deg, rgba(102, 126, 234, 0.15), rgba(118, 75, 162, 0.15));
    border: 1px solid rgba(102, 126, 234, 0.25);
    border-radius: 50px;
    font-size: 0.9rem;
    transition: all 0.3s;
    cursor: default;
}
.skill-item:hover {
    transform: scale(1.05);
    background: linear-gradient(135deg, rgba(102, 126, 234, 0.3), rgba(118, 75, 162, 0.3));
    box-shadow: 0 10px 30px rgba(102, 126, 234, 0.2);
}
.skills-grid {
    max-width: 1000px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
}
.skill-category {
    padding: 1.5rem;
    background: rgba(255, 255, 255, 0.02);
    border-radius: 16px;
    border: 1px solid rgba(255, 255, 255, 0.05);
}
.skill-category h4 {
    color: #667eea;
    margin-bottom: 1rem;
    font-size: 1rem;
}
.skill-category ul {
    list-style: none;
}
.skill-category li {
    padding: 0.4rem 0;
    color: #b0b0b0;
    font-size: 0.9rem;
    padding-left: 1rem;
    position: relative;
}
.skill-category li::before {
    content: '›';
    position: absolute;
    left: 0;
    color: #667eea;
}

/* Projects */
.projects-grid {
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
    gap: 1.5rem;
}
.project-card {
    position: relative;
    border-radius: 20px;
    overflow: hidden;
    aspect-ratio: 16/10;
    background: linear-gradient(135deg, #1a1a2e, #16213e);
}
.project-image {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.5s;
}
.project-card:hover .project-image {
    transform: scale(1.1);
}
.project-overlay {
    position: absolute;
    inset: 0;
    background: linear-gradient(to top, rgba(0,0,0,0.95) 0%, rgba(0,0,0,0.3) 50%, transparent 100%);
    padding: 1.5rem;
    display: flex;
    flex-direction: column;
    justify-content: flex-end;
    opacity: 0;
    transition: opacity 0.3s;
}
.project-card:hover .project-overlay {
    opacity: 1;
}
.project-title {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
}
.project-desc {
    font-size: 0.9rem;
    color: #b0b0b0;
    margin-bottom: 1rem;
}
.project-tech {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}
.project-tech span {
    padding: 0.25rem 0.75rem;
    background: rgba(255,255,255,0.1);
    border-radius: 50px;
    font-size: 0.75rem;
}

/* Contact */
.contact-box {
    max-width: 700px;
    margin: 0 auto;
    padding: 3rem;
    background: rgba(255, 255, 255, 0.02);
    border-radius: 24px;
    border: 1px solid rgba(255, 255, 255, 0.05);
    text-align: center;
}
.contact-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 2rem;
    margin-bottom: 2rem;
}
.contact-item {
    padding: 1.5rem;
}
.contact-icon {
    width: 56px;
    height: 56px;
    margin: 0 auto 1rem;
    background: linear-gradient(135deg, #667eea, #764ba2);
    border-radius: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
}
.contact-icon svg {
    width: 24px;
    height: 24px;
}
.contact-item h4 {
    margin-bottom: 0.5rem;
    font-size: 1rem;
}
.contact-item a {
    color: #808080;
    text-decoration: none;
    font-size: 0.9rem;
    transition: color 0.3s;
}
.contact-item a:hover {
    color: #667eea;
}
.contact-text {
    color: #808080;
    font-size: 0.95rem;
}

/* Footer */
footer {
    padding: 2rem;
    text-align: center;
    border-top: 1px solid rgba(255, 255, 255, 0.05);
}
footer p {
    color: #606060;
    font-size: 0.9rem;
}

/* Background Variations */
.bg-light {
    background: rgba(255, 255, 255, 0.02);
}

/* Responsive */
@media (max-width: 768px) {
    .nav-links {
        display: none;
    }
    .mobile-menu-btn {
        display: block;
    }
    .hero {
        padding: 5rem 1.5rem 3rem;
    }
    .hero-title {
        font-size: 2rem;
    }
    .about-grid {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
    .about-image {
        max-width: 250px;
        margin: 0 auto;
    }
    .cards-grid,
    .projects-grid {
        grid-template-columns: 1fr;
    }
    .contact-grid {
        grid-template-columns: 1fr;
    }
    section {
        padding: 3rem 1.5rem;
    }
}

/* Animations */
@keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-10px); }
}
.animate-float {
    animation: float 6s ease-in-out infinite;
}

@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.5; }
}

/* Reveal Animation */
.reveal {
    opacity: 0;
    transform: translateY(30px);
    transition: all 0.6s ease;
}
.reveal.active {
    opacity: 1;
    transform: translateY(0);
}