/* ========================================
   CSS Variables & Theme Configuration
   ======================================== */
:root {
    /* Dark Theme (Default) */
    --bg-primary: #0a0a0f;
    --bg-secondary: #12121a;
    --bg-tertiary: #1a1a25;
    --bg-card: rgba(26, 26, 37, 0.8);
    --text-primary: #f0f0f5;
    --text-secondary: #a0a0b0;
    --text-muted: #6a6a7a;
    --accent-primary: #6366f1;
    --accent-secondary: #8b5cf6;
    --accent-gradient: linear-gradient(135deg, #6366f1 0%, #8b5cf6 50%, #a855f7 100%);
    --border-color: rgba(255, 255, 255, 0.08);
    --shadow-color: rgba(0, 0, 0, 0.3);
    --glass-bg: rgba(26, 26, 37, 0.7);
    --glass-border: rgba(255, 255, 255, 0.1);
    --nav-bg: rgba(10, 10, 15, 0.85);

    /* Spacing */
    --section-padding: 100px 20px;
    --container-width: 1200px;

    /* Typography */
    --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-mono: 'JetBrains Mono', monospace;

    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-medium: 0.3s ease;
    --transition-slow: 0.5s ease;
}

[data-theme="light"] {
    --bg-primary: #fafafa;
    --bg-secondary: #ffffff;
    --bg-tertiary: #f5f5f5;
    --bg-card: rgba(255, 255, 255, 0.9);
    --text-primary: #1a1a2e;
    --text-secondary: #4a4a5a;
    --text-muted: #8a8a9a;
    --accent-primary: #4f46e5;
    --accent-secondary: #7c3aed;
    --accent-gradient: linear-gradient(135deg, #4f46e5 0%, #7c3aed 50%, #9333ea 100%);
    --border-color: rgba(0, 0, 0, 0.08);
    --shadow-color: rgba(0, 0, 0, 0.1);
    --glass-bg: rgba(255, 255, 255, 0.7);
    --glass-border: rgba(0, 0, 0, 0.05);
    --nav-bg: rgba(250, 250, 250, 0.85);
}

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

html {
    scroll-behavior: smooth;
    scroll-padding-top: 80px;
}

body {
    font-family: var(--font-primary);
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.7;
    overflow-x: hidden;
    transition: background-color var(--transition-medium), color var(--transition-medium);
}

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

ul {
    list-style: none;
}

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

button {
    font-family: inherit;
    cursor: pointer;
    border: none;
    background: none;
}

/* ========================================
   Navigation
   ======================================== */
.nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(10, 10, 15, 0.5);
    backdrop-filter: blur(30px);
    -webkit-backdrop-filter: blur(30px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    transition: all var(--transition-medium);
}

[data-theme="light"] .nav {
    background: rgba(250, 250, 250, 0.5);
    border-bottom: 1px solid rgba(0, 0, 0, 0.05);
}

.nav-container {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 15px 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;

}

.nav-logo {
    font-size: 1.5rem;
    font-weight: 700;
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.nav-links {
    display: flex;
    gap: 40px;
}

.nav-links a {
    font-size: 0.95rem;
    font-weight: 500;
    color: var(--text-secondary);
    position: relative;
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--accent-gradient);
    transition: width var(--transition-medium);
}

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

.nav-links a:hover::after {
    width: 100%;
}

.theme-toggle {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 44px;
    height: 44px;
    border-radius: 50%;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    transition: all var(--transition-fast);
}

.theme-toggle:hover {
    background: var(--accent-primary);
    border-color: var(--accent-primary);
    transform: rotate(15deg);
}

.theme-toggle .sun-icon { display: none; align-items: center; justify-content: center; }
.theme-toggle .moon-icon { display: flex; align-items: center; justify-content: center; }

[data-theme="light"] .theme-toggle .sun-icon { display: flex; }
[data-theme="light"] .theme-toggle .moon-icon { display: none; }

.mobile-menu-btn {
    display: none;
    flex-direction: column;
    gap: 5px;
    padding: 10px;
}

.mobile-menu-btn span {
    width: 25px;
    height: 2px;
    background: var(--text-primary);
    transition: all var(--transition-fast);
}

/* ========================================
   Hero Section
   ======================================== */
.hero {
    min-height: 100vh;
    display: grid;
    grid-template-columns: 1fr 1fr;
    align-items: center;
    gap: 60px;
    padding: var(--section-padding);
    padding-top: 120px;
    max-width: var(--container-width);
    margin: 0 auto;
}

.hero-content {
    animation: fadeInUp 1s ease;
}

.hero-greeting {
    font-size: 1.1rem;
    color: var(--accent-primary);
    font-weight: 500;
    margin-bottom: 10px;
}

.hero-name {
    font-size: clamp(2.5rem, 5vw, 4rem);
    font-weight: 700;
    line-height: 1.1;
    margin-bottom: 15px;
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-title {
    font-size: clamp(1.5rem, 3vw, 2rem);
    font-weight: 600;
    color: var(--text-secondary);
    margin-bottom: 20px;
}

.hero-description {
    font-size: 1.1rem;
    color: var(--text-secondary);
    max-width: 500px;
    margin-bottom: 35px;
    line-height: 1.8;
}

.hero-buttons {
    display: flex;
    gap: 15px;
    flex-wrap: wrap;
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    padding: 14px 28px;
    border-radius: 12px;
    font-size: 1rem;
    font-weight: 600;
    transition: all var(--transition-medium);
}

.btn-primary {
    background: var(--accent-gradient);
    color: white;
    box-shadow: 0 4px 20px rgba(99, 102, 241, 0.3);
}

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 30px rgba(99, 102, 241, 0.4);
}

.btn-secondary {
    background: var(--bg-tertiary);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}

.btn-secondary:hover {
    background: var(--bg-card);
    border-color: var(--accent-primary);
    transform: translateY(-3px);
}

.download-icon {
    width: 20px;
    height: 20px;
}

.hero-visual {
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
}
.neural-img {
    animation: fadeInUp 1s ease;
}

.hero-blob {
    width: 350px;
    height: 350px;
    background: var(--accent-gradient);
    border-radius: 30% 70% 70% 30% / 30% 30% 70% 70%;
    animation: blobMorph 8s ease-in-out infinite;
    filter: blur(60px);
    opacity: 0.5;
}

/* ========================================
   Sections Common Styles
   ======================================== */
.section {
    padding: var(--section-padding);
}

.container {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 20px;
}

.section-title {
    font-size: clamp(2rem, 4vw, 2.5rem);
    font-weight: 700;
    text-align: center;
    margin-bottom: 60px;
    position: relative;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -15px;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 4px;
    background: var(--accent-gradient);
    border-radius: 2px;
}

/* ========================================
   About Section
   ======================================== */
.about-content {
    max-width: 800px;
    margin: 0 auto;
}

.about-text p {
    font-size: 1.1rem;
    color: var(--text-secondary);
    margin-bottom: 20px;
    line-height: 1.9;
}

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

.about-highlights {
    display: flex;
    gap: 40px;
    margin-top: 40px;
    padding-top: 40px;
    border-top: 1px solid var(--border-color);
}

.highlight {
    text-align: center;
}

.highlight-number {
    display: block;
    font-size: 2.5rem;
    font-weight: 700;
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.highlight-label {
    font-size: 0.9rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 1px;
}

/* ========================================
   Experience Section (Timeline)
   ======================================== */
.timeline {
    position: relative;
    max-width: 900px;
    margin: 0 auto;
}

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

.timeline-item {
    position: relative;
    padding-left: 40px;
    padding-bottom: 50px;
    opacity: 0;
    transform: translateX(30px);
    transition: all 0.6s ease;
}

.timeline-item.visible {
    opacity: 1;
    transform: translateX(0);
}

.timeline-marker {
    position: absolute;
    left: -6px;
    top: 0;
    width: 14px;
    height: 14px;
    border-radius: 50%;
    background: var(--accent-primary);
    border: 3px solid var(--bg-primary);
    box-shadow: 0 0 0 4px rgba(99, 102, 241, 0.2);
}

.timeline-content {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 25px;
    transition: all var(--transition-medium);
}

.timeline-content:hover {
    border-color: var(--accent-primary);
    box-shadow: 0 10px 40px var(--shadow-color);
    transform: translateY(-5px);
}

.timeline-header h3 {
    font-size: 1.2rem;
    margin-bottom: 5px;
}

.timeline-company {
    display: block;
    font-size: 0.95rem;
    color: var(--accent-primary);
    margin-bottom: 10px;
}

.timeline-date {
    display: inline-block;
    font-size: 0.85rem;
    color: var(--text-muted);
    background: var(--bg-tertiary);
    padding: 5px 12px;
    border-radius: 20px;
    margin-bottom: 15px;
}

.timeline-details {
    list-style: disc;
    margin-left: 20px;
}

.timeline-details li {
    color: var(--text-secondary);
    margin-bottom: 8px;
    line-height: 1.6;
}

/* ========================================
   Skills Section
   ======================================== */
.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 25px;
}

.skill-category {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 25px;
    transition: all var(--transition-medium);
    opacity: 0;
    transform: translateY(30px);
}

.skill-category.visible {
    opacity: 1;
    transform: translateY(0);
    transition: all 0.6s ease;
}

.skill-category:hover {
    border-color: var(--accent-primary);
    transform: translateY(-5px);
    box-shadow: 0 10px 40px var(--shadow-color);
}

.skill-category-title {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 1.1rem;
    margin-bottom: 20px;
    color: var(--text-primary);
}

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

/* SVG skill icon uses flex alignment via .skill-category-title flex */

.skill-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
}

.skill-tag {
    font-size: 0.85rem;
    padding: 8px 16px;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: 20px;
    color: var(--text-secondary);
    transition: all var(--transition-fast);
}

.skill-tag:hover {
    background: var(--accent-primary);
    border-color: var(--accent-primary);
    color: white;
    transform: translateY(-2px);
}

/* ========================================
   Metric highlight (coloured % results)
   ======================================== */
.metric {
    color: var(--accent-primary);
    font-weight: 600;
}

/* ========================================
   Projects Section
   ======================================== */
.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(340px, 1fr));
    gap: 25px;
}

.project-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 20px;
    padding: 30px;
    transition: all var(--transition-medium);
    opacity: 0;
    transform: translateY(30px);
    display: flex;
    flex-direction: column;
}

.project-card.visible {
    opacity: 1;
    transform: translateY(0);
    transition: all 0.6s ease;
}

.project-card:hover {
    border-color: var(--accent-primary);
    transform: translateY(-8px);
    box-shadow: 0 15px 50px var(--shadow-color);
}

/* Project card header: icon left, github link right */
.project-card-header {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    margin-bottom: 15px;
}

.project-icon-wrap {
    width: 52px;
    height: 52px;
    border-radius: 14px;
    background: rgba(99, 102, 241, 0.12);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--accent-primary);
    flex-shrink: 0;
}

.project-github {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    border-radius: 50%;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    color: var(--text-secondary);
    transition: all var(--transition-fast);
    flex-shrink: 0;
}

.project-github:hover {
    background: var(--accent-primary);
    border-color: var(--accent-primary);
    color: white;
    transform: scale(1.1);
}

.project-title {
    font-size: 1.1rem;
    margin-bottom: 12px;
    font-weight: 600;
}

.project-description {
    color: var(--text-secondary);
    font-size: 0.95rem;
    line-height: 1.7;
    margin-bottom: 20px;
    flex: 1;
}

.project-tech {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.project-tech span {
    font-size: 0.8rem;
    padding: 5px 12px;
    background: rgba(99, 102, 241, 0.15);
    border-radius: 15px;
    color: var(--accent-primary);
    font-family: var(--font-mono);
}

/* ========================================
   Education Section — uses .timeline (same as experience)
   No extra card styles needed.
   ======================================== */

/* skill icon SVG alignment */
.skill-icon-svg {
    flex-shrink: 0;
    color: var(--accent-primary);
}

/* contact card no-link: disable pointer cursor */
.contact-card.no-link {
    cursor: default;
}

/* contact icon uses SVG — ensure colour inheritance */
.contact-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 15px;
    color: var(--accent-primary);
}

.contact-card h3 {
    font-size: 1.1rem;
    margin-bottom: 8px;
}

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

/* ========================================
   Contact Section
   ======================================== */
.contact-intro {
    text-align: center;
    font-size: 1.1rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto 50px;
}

.contact-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 25px;
    max-width: 900px;
    margin: 0 auto;
}

.contact-card {
    display: flex;
    flex-direction: column;
    align-items: center;
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 30px;
    text-align: center;
    transition: all var(--transition-medium);
    opacity: 0;
    transform: translateY(30px);
}

.contact-card.visible {
    opacity: 1;
    transform: translateY(0);
    transition: all 0.6s ease;
}

.contact-card:hover {
    border-color: var(--accent-primary);
    transform: translateY(-8px);
    box-shadow: 0 15px 50px var(--shadow-color);
}

/* ========================================
   Footer
   ======================================== */
.footer {
    padding: 40px 20px;
    text-align: center;
    border-top: 1px solid var(--border-color);
    color: var(--text-muted);
    font-size: 0.9rem;
}

/* ========================================
   Animations
   ======================================== */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(40px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes blobMorph {
    0%, 100% {
        border-radius: 30% 70% 70% 30% / 30% 30% 70% 70%;
    }
    25% {
        border-radius: 58% 42% 75% 25% / 76% 46% 54% 24%;
    }
    50% {
        border-radius: 50% 50% 33% 67% / 55% 27% 73% 45%;
    }
    75% {
        border-radius: 33% 67% 58% 42% / 63% 68% 32% 37%;
    }
}

/* Scroll-triggered fade in */
.fade-in {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

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

/* ========================================
   Responsive Design
   ======================================== */
@media (max-width: 968px) {
    .hero {
        grid-template-columns: 1fr;
        text-align: center;
        gap: 40px;
        padding-top: 100px;
    }

    .hero-content {
        order: 1;
    }

    .hero-visual {
        order: 2;
    }

    .hero-blob {
        width: 280px;
        height: 280px;
    }

    .hero-description {
        margin: 0 auto 35px;
    }

    .hero-buttons {
        justify-content: center;
    }

    .nav-links {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        flex-direction: column;
        background: var(--nav-bg);
        backdrop-filter: blur(20px);
        padding: 20px;
        gap: 15px;
        border-bottom: 1px solid var(--border-color);
    }

    .nav-links.active {
        display: flex;
    }

    .mobile-menu-btn {
        display: flex;
    }

    .mobile-menu-btn.active span:nth-child(1) {
        transform: rotate(45deg) translate(5px, 5px);
    }

    .mobile-menu-btn.active span:nth-child(2) {
        opacity: 0;
    }

    .mobile-menu-btn.active span:nth-child(3) {
        transform: rotate(-45deg) translate(7px, -6px);
    }

    .about-highlights {
        flex-direction: column;
        gap: 25px;
    }

    .timeline::before {
        left: 7px;
    }

    .timeline-marker {
        left: 1px;
    }

    .timeline-item {
        padding-left: 35px;
    }
}

@media (max-width: 640px) {
    :root {
        --section-padding: 80px 15px;
    }

    .hero-name {
        font-size: 2rem;
    }

    .hero-title {
        font-size: 1.3rem;
    }

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

    .btn {
        justify-content: center;
        width: 100%;
    }

    .skills-grid,
    .projects-grid {
        grid-template-columns: 1fr;
    }

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

    .section-title {
        font-size: 1.8rem;
    }
}

/* ========================================
   Print Styles
   ======================================== */
@media print {
    .nav,
    .theme-toggle,
    .mobile-menu-btn,
    .hero-visual,
    .hero-buttons {
        display: none !important;
    }

    .hero {
        min-height: auto;
        padding: 40px 20px;
    }

    .section {
        padding: 40px 0;
    }

    body {
        background: white;
        color: black;
    }
}