/* ==========================================================================
   ATUL MUNDAKKAL - PORTFOLIO DESIGN SYSTEM & STYLESHEET
   Pure Vanilla CSS - Zero Dependencies - Cloudflare Pages Optimized
   ========================================================================== */

/* --- CSS Variables & Design Tokens --- */
:root {
    /* Color Palette */
    --bg-main: #0f172a;           /* Slate 900 */
    --bg-card: #1e293b;           /* Slate 800 */
    --bg-card-hover: #273549;     /* Slate 750 */
    --border-color: #334155;      /* Slate 700 */
    --border-hover: #475569;      /* Slate 600 */

    --text-primary: #f8fafc;      /* Slate 50 */
    --text-secondary: #94a3b8;    /* Slate 400 */
    --text-muted: #64748b;        /* Slate 500 */

    --accent-shopify: #96bf48;    /* Shopify Green Accent */
    --accent-shopify-hover: #7ba635;
    --accent-blue: #38bdf8;       /* Sky Blue Accent */

    /* Typography */
    --font-sans: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
    --font-mono: 'Consolas', 'Monaco', 'Courier New', monospace;

    /* Spacing & Layout */
    --container-max-width: 1100px;
    --header-height: 70px;
    --radius-sm: 6px;
    --radius-md: 12px;
    --radius-lg: 16px;

    /* Transitions & Shadow */
    --transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
    --shadow-md: 0 10px 25px -5px rgba(0, 0, 0, 0.3), 0 8px 10px -6px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 20px 30px -10px rgba(0, 0, 0, 0.4);
}

/* --- Base Reset & Norms --- */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
    scroll-padding-top: var(--header-height);
    font-size: 16px;
}

body {
    background-color: var(--bg-main);
    color: var(--text-primary);
    font-family: var(--font-sans);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    overflow-x: hidden;
}

/* --- Accessibility & Focus States --- */
:focus-visible {
    outline: 2px solid var(--accent-shopify);
    outline-offset: 3px;
}

.visually-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

/* --- Typography Helpers --- */
h1, h2, h3, h4, h5, h6 {
    color: var(--text-primary);
    line-height: 1.25;
    font-weight: 700;
}

a {
    color: inherit;
    text-decoration: none;
    transition: var(--transition);
}

ul {
    list-style: none;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

/* --- Container & Layout --- */
.container {
    width: 100%;
    max-width: var(--container-max-width);
    margin: 0 auto;
    padding: 0 24px;
}

.section {
    padding: 90px 0;
}

.section.bg-card {
    background-color: rgba(30, 41, 59, 0.4);
    border-top: 1px solid var(--border-color);
    border-bottom: 1px solid var(--border-color);
}

.section-header {
    text-align: center;
    max-width: 650px;
    margin: 0 auto 50px auto;
}

.section-title {
    font-size: 2.25rem;
    margin-bottom: 12px;
    letter-spacing: -0.02em;
}

.section-description {
    color: var(--text-secondary);
    font-size: 1.1rem;
}

/* ==========================================================================
   HEADER & NAVIGATION
   ========================================================================== */
.header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: var(--header-height);
    background-color: rgba(15, 23, 42, 0.85);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border-color);
    z-index: 1000;
    transition: var(--transition);
}

.nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 100%;
    max-width: var(--container-max-width);
    margin: 0 auto;
    padding: 0 24px;
}

.logo {
    font-weight: 800;
    font-size: 1.35rem;
    font-family: var(--font-mono);
    color: var(--text-primary);
}

.logo-accent {
    color: var(--accent-shopify);
}

.nav-list {
    display: flex;
    gap: 24px;
    align-items: center;
}

.nav-link {
    font-size: 0.92rem;
    font-weight: 500;
    color: var(--text-secondary);
    padding: 6px 0;
    position: relative;
}

.nav-link:hover,
.nav-link.active {
    color: var(--text-primary);
}

.nav-link.active::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 2px;
    background-color: var(--accent-shopify);
    border-radius: 2px;
}

/* Mobile Hamburger Toggle */
.nav-toggle {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
    z-index: 1100;
}

.hamburger-bar {
    display: block;
    width: 24px;
    height: 2px;
    margin: 5px 0;
    background-color: var(--text-primary);
    transition: var(--transition);
    border-radius: 2px;
}

/* Hamburger Active State X Animation */
.nav-toggle[aria-expanded="true"] .hamburger-bar:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
}
.nav-toggle[aria-expanded="true"] .hamburger-bar:nth-child(2) {
    opacity: 0;
}
.nav-toggle[aria-expanded="true"] .hamburger-bar:nth-child(3) {
    transform: translateY(-7px) rotate(-45deg);
}

/* ==========================================================================
   HERO SECTION
   ========================================================================== */
.hero-section {
    min-height: 100vh;
    padding-top: calc(var(--header-height) + 60px);
    padding-bottom: 60px;
    display: flex;
    align-items: center;
    position: relative;
    background: radial-gradient(circle at 50% 20%, rgba(150, 191, 72, 0.06) 0%, transparent 60%);
}

.hero-content {
    max-width: 800px;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    background-color: rgba(150, 191, 72, 0.1);
    color: var(--accent-shopify);
    border: 1px solid rgba(150, 191, 72, 0.25);
    padding: 6px 16px;
    border-radius: 30px;
    font-size: 0.88rem;
    font-weight: 600;
    margin-bottom: 24px;
}

.status-dot {
    width: 8px;
    height: 8px;
    background-color: var(--accent-shopify);
    border-radius: 50%;
    box-shadow: 0 0 8px var(--accent-shopify);
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 800;
    letter-spacing: -0.03em;
    margin-bottom: 20px;
    line-height: 1.15;
}

.text-gradient {
    background: linear-gradient(135deg, var(--accent-shopify) 0%, var(--accent-blue) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero-subtitle {
    font-size: 1.2rem;
    color: var(--text-secondary);
    margin-bottom: 30px;
    line-height: 1.6;
}

.hero-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin-bottom: 36px;
}

.tag {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    color: var(--text-secondary);
    padding: 6px 14px;
    border-radius: var(--radius-sm);
    font-size: 0.85rem;
    font-weight: 500;
}

.hero-cta-group {
    display: flex;
    gap: 16px;
    flex-wrap: wrap;
}

/* --- BUTTON SYSTEM --- */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 12px 28px;
    border-radius: var(--radius-md);
    font-size: 0.95rem;
    font-weight: 600;
    cursor: pointer;
    border: 1px solid transparent;
    transition: var(--transition);
}

.btn-primary {
    background-color: var(--accent-shopify);
    color: #0d1604;
}

.btn-primary:hover {
    background-color: var(--accent-shopify-hover);
    box-shadow: 0 4px 15px rgba(150, 191, 72, 0.3);
}

.btn-secondary {
    background-color: var(--bg-card);
    color: var(--text-primary);
    border-color: var(--border-color);
}

.btn-secondary:hover {
    background-color: var(--bg-card-hover);
    border-color: var(--border-hover);
}

.btn-outline {
    background-color: transparent;
    color: var(--text-secondary);
    border-color: var(--border-color);
}

.btn-outline:hover {
    color: var(--text-primary);
    border-color: var(--border-hover);
}

/* ==========================================================================
   ABOUT SECTION
   ========================================================================== */
.about-grid {
    display: grid;
    grid-template-columns: 0.8fr 1.2fr;
    gap: 36px;
    align-items: center;
}

.about-image-wrapper {
    position: relative;
    border-radius: var(--radius-lg);
    overflow: hidden;
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow-md);
    max-width: 320px;
    margin: 0 auto;
}

.about-profile-img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
    transition: var(--transition);
}

.about-image-wrapper:hover .about-profile-img {
    transform: scale(1.03);
}

.about-card {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    padding: 36px;
    border-radius: var(--radius-lg);
}

.about-heading {
    font-size: 1.4rem;
    margin-bottom: 16px;
    color: var(--accent-shopify);
}

.about-text {
    color: var(--text-secondary);
    font-size: 1.05rem;
    margin-bottom: 16px;
}

.about-text:last-child {
    margin-bottom: 0;
}

.about-stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 16px;
}

.stat-card {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    padding: 24px;
    border-radius: var(--radius-md);
    text-align: center;
}

.stat-number {
    display: block;
    font-size: 1.8rem;
    font-weight: 800;
    color: var(--text-primary);
    margin-bottom: 4px;
}

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

/* ==========================================================================
   SKILLS SECTION
   ========================================================================== */
.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 24px;
}

.skill-category {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    padding: 30px;
    border-radius: var(--radius-lg);
    transition: var(--transition);
}

.skill-category:hover {
    border-color: var(--border-hover);
    transform: translateY(-3px);
}

.category-header {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 20px;
    padding-bottom: 14px;
    border-bottom: 1px solid var(--border-color);
}

.category-icon {
    font-size: 1.5rem;
}

.category-header h3 {
    font-size: 1.25rem;
}

.skill-list li {
    display: flex;
    align-items: center;
    gap: 10px;
    color: var(--text-secondary);
    margin-bottom: 10px;
    font-size: 0.95rem;
}

.skill-bullet {
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background-color: var(--accent-shopify);
}

/* ==========================================================================
   PROJECTS SECTION
   ========================================================================== */
.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(340px, 1fr));
    gap: 28px;
}

.project-card {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 30px;
    display: flex;
    flex-direction: column;
    transition: var(--transition);
}

.project-card:hover {
    border-color: var(--border-hover);
    box-shadow: var(--shadow-md);
    transform: translateY(-4px);
}

.project-category {
    font-size: 0.8rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--accent-blue);
    margin-bottom: 8px;
    display: block;
}

.project-title {
    font-size: 1.4rem;
    margin-bottom: 12px;
}

.project-desc {
    color: var(--text-secondary);
    font-size: 0.98rem;
    margin-bottom: 16px;
}

.project-detail {
    background-color: rgba(15, 23, 42, 0.5);
    border-left: 2px solid var(--accent-shopify);
    padding: 10px 14px;
    margin-bottom: 12px;
    font-size: 0.88rem;
    color: var(--text-secondary);
    border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
}

.project-detail strong {
    color: var(--text-primary);
}

.tech-stack {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-top: auto;
    padding-top: 16px;
}

.tech-stack span {
    font-family: var(--font-mono);
    font-size: 0.78rem;
    background-color: var(--bg-main);
    color: var(--text-secondary);
    padding: 4px 10px;
    border-radius: var(--radius-sm);
    border: 1px solid var(--border-color);
}

.project-footer {
    display: flex;
    gap: 16px;
    margin-top: 20px;
    padding-top: 16px;
    border-top: 1px solid var(--border-color);
}

.card-link {
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--accent-shopify);
}

.card-link.secondary {
    color: var(--text-secondary);
}

.card-link:hover {
    text-decoration: underline;
}

/* ==========================================================================
   SHOPIFY WORK SECTION
   ========================================================================== */
.shopify-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 24px;
}

.shopify-card {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    padding: 30px;
    border-radius: var(--radius-lg);
}

.shopify-icon {
    font-size: 2rem;
    margin-bottom: 16px;
}

.shopify-card h3 {
    font-size: 1.25rem;
    margin-bottom: 10px;
}

.shopify-card p {
    color: var(--text-secondary);
    font-size: 0.95rem;
    margin-bottom: 16px;
}

.shopify-feature-list li {
    font-size: 0.88rem;
    color: var(--text-secondary);
    margin-bottom: 6px;
    padding-left: 16px;
    position: relative;
}

.shopify-feature-list li::before {
    content: "✓";
    position: absolute;
    left: 0;
    color: var(--accent-shopify);
}

/* ==========================================================================
   EXTENSIONS & CASE STUDIES
   ========================================================================== */
.extension-card {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    padding: 36px;
    border-radius: var(--radius-lg);
    max-width: 800px;
    margin: 0 auto;
}

.extension-badge {
    display: inline-block;
    background-color: rgba(56, 189, 248, 0.1);
    color: var(--accent-blue);
    border: 1px solid rgba(56, 189, 248, 0.25);
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 600;
    margin-bottom: 12px;
}

.extension-title {
    font-size: 1.75rem;
    margin-bottom: 12px;
}

.extension-desc {
    color: var(--text-secondary);
    font-size: 1.05rem;
    margin-bottom: 24px;
}

.extension-features {
    margin-bottom: 28px;
}

.extension-features h4 {
    font-size: 1rem;
    margin-bottom: 10px;
    color: var(--text-primary);
}

.extension-features ul li {
    color: var(--text-secondary);
    margin-bottom: 6px;
    padding-left: 18px;
    position: relative;
}

.extension-features ul li::before {
    content: "•";
    position: absolute;
    left: 0;
    color: var(--accent-blue);
}

.extension-links {
    display: flex;
    gap: 16px;
    flex-wrap: wrap;
}

/* Case Study Breakdown */
.case-study-card {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    padding: 40px;
    border-radius: var(--radius-lg);
}

.case-study-tag {
    color: var(--accent-shopify);
    font-size: 0.85rem;
    font-weight: 700;
    text-transform: uppercase;
}

.case-study-header h3 {
    font-size: 1.6rem;
    margin: 8px 0 24px 0;
}

.case-study-steps {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.step {
    display: flex;
    gap: 20px;
}

.step-num {
    width: 36px;
    height: 36px;
    background-color: var(--bg-main);
    border: 1px solid var(--border-color);
    color: var(--accent-shopify);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    flex-shrink: 0;
}

.step-content h4 {
    font-size: 1.05rem;
    margin-bottom: 4px;
}

.step-content p {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

.result-highlight {
    color: var(--accent-shopify) !important;
    font-weight: 600;
}

/* ==========================================================================
   EXPERIENCE SECTION (TIMELINE)
   ========================================================================== */
.timeline {
    position: relative;
    max-width: 800px;
    margin: 0 auto;
    padding-left: 20px;
}

.timeline::before {
    content: '';
    position: absolute;
    top: 0;
    left: 7px;
    width: 2px;
    height: 100%;
    background-color: var(--border-color);
}

.timeline-item {
    position: relative;
    margin-bottom: 40px;
}

.timeline-item:last-child {
    margin-bottom: 0;
}

.timeline-dot {
    position: absolute;
    top: 6px;
    left: -20px;
    width: 14px;
    height: 14px;
    border-radius: 50%;
    background-color: var(--accent-shopify);
    border: 3px solid var(--bg-main);
}

.timeline-content {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    padding: 28px;
    border-radius: var(--radius-lg);
}

.timeline-header {
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
    align-items: baseline;
    margin-bottom: 14px;
}

.role-title {
    font-size: 1.25rem;
}

.company-name {
    color: var(--accent-shopify);
    font-weight: 600;
    font-size: 0.95rem;
}

.timeline-date {
    color: var(--text-muted);
    font-size: 0.85rem;
}

.timeline-bullets li {
    color: var(--text-secondary);
    margin-bottom: 8px;
    padding-left: 18px;
    position: relative;
    font-size: 0.95rem;
}

.timeline-bullets li::before {
    content: "-";
    position: absolute;
    left: 0;
    color: var(--text-muted);
}

/* ==========================================================================
   CONTACT SECTION
   ========================================================================== */
.contact-card {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 40px;
    max-width: 900px;
    margin: 0 auto;
}

.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 40px;
}

.contact-info h3,
.contact-action h3 {
    font-size: 1.35rem;
    margin-bottom: 12px;
}

.contact-info p {
    color: var(--text-secondary);
    margin-bottom: 24px;
    font-size: 0.98rem;
}

.contact-method {
    display: flex;
    align-items: center;
    gap: 16px;
    margin-bottom: 18px;
}

.contact-icon {
    font-size: 1.4rem;
}

.contact-label {
    display: block;
    font-size: 0.8rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.contact-value {
    color: var(--text-primary);
    font-size: 1rem;
    font-weight: 500;
}

.contact-value:hover {
    color: var(--accent-shopify);
}

.social-links-grid {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.social-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 12px;
    background-color: var(--bg-main);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    font-weight: 600;
    font-size: 0.95rem;
    transition: var(--transition);
}

.social-btn:hover {
    border-color: var(--accent-shopify);
    color: var(--accent-shopify);
}

.btn-copy {
    width: 100%;
}

/* ==========================================================================
   FOOTER
   ========================================================================== */
.footer {
    border-top: 1px solid var(--border-color);
    padding: 40px 0;
    background-color: var(--bg-main);
}

.footer-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 20px;
    text-align: center;
}

.footer-name {
    font-weight: 700;
    font-size: 1.1rem;
    display: block;
}

.footer-title {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.footer-links {
    display: flex;
    gap: 20px;
}

.footer-links a {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.footer-links a:hover {
    color: var(--accent-shopify);
}

.footer-bottom {
    display: flex;
    align-items: center;
    justify-content: space-between;
    width: 100%;
    padding-top: 20px;
    border-top: 1px solid var(--border-color);
    color: var(--text-muted);
    font-size: 0.85rem;
}

.back-to-top {
    background: none;
    border: 1px solid var(--border-color);
    color: var(--text-secondary);
    padding: 6px 14px;
    border-radius: var(--radius-sm);
    cursor: pointer;
    font-size: 0.85rem;
    transition: var(--transition);
}

.back-to-top:hover {
    color: var(--text-primary);
    border-color: var(--border-hover);
}

/* ==========================================================================
   RESPONSIVE MEDIA QUERIES (320px, 375px, 768px, 1024px)
   ========================================================================== */
@media (max-width: 900px) {
    .about-grid {
        grid-template-columns: 1fr;
    }

    .contact-grid {
        grid-template-columns: 1fr;
        gap: 28px;
    }
}

@media (max-width: 768px) {
    .section {
        padding: 60px 0;
    }

    .hero-title {
        font-size: 2.5rem;
    }

    .nav-toggle {
        display: block;
    }

    .nav-menu {
        position: fixed;
        top: var(--header-height);
        right: -100%;
        width: 80%;
        max-width: 300px;
        height: calc(100vh - var(--header-height));
        background-color: var(--bg-card);
        border-left: 1px solid var(--border-color);
        padding: 30px;
        transition: right 0.3s ease;
        box-shadow: var(--shadow-lg);
    }

    .nav-menu.active {
        right: 0;
    }

    .nav-list {
        flex-direction: column;
        align-items: flex-start;
        gap: 20px;
    }

    .nav-link {
        font-size: 1.1rem;
    }

    .case-study-card {
        padding: 24px;
    }

    .step {
        flex-direction: column;
        gap: 8px;
    }

    .footer-bottom {
        flex-direction: column;
        gap: 14px;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 2rem;
    }

    .hero-cta-group {
        flex-direction: column;
        width: 100%;
    }

    .btn {
        width: 100%;
    }

    .stat-number {
        font-size: 1.4rem;
    }

    .about-card,
    .contact-card,
    .extension-card {
        padding: 20px;
    }
}