/* CSS Architecture: Modern Cascade Layers */
@layer reset, base, layout, components, utilities;

@layer reset {
  /* Box sizing and margin resets */
  *, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
  }

  /* HTML5 structural improvements */
  html {
    scroll-behavior: smooth;
    -webkit-text-size-adjust: 100%;
  }

  body {
    min-block-size: 100vh;
    text-rendering: optimizeSpeed;
    line-height: 1.5;
  }

  img, picture, video, canvas, svg {
    display: block;
    max-inline-size: 100%;
    block-size: auto;
  }

  input, button, textarea, select {
    font: inherit;
  }

  /* List resets for navigation and lists */
  ul, ol {
    list-style: none;
  }

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

@layer base {
  /* Root Design Tokens & Theming */
  :root {
    /* Color Schemes: Light and Dark system integration */
    color-scheme: light dark;
  }

  :root.light {
    color-scheme: light;
  }

  :root.dark {
    color-scheme: dark;
  }

  :root {

    /* Fonts */
    --font-heading: 'Outfit', sans-serif;
    --font-body: 'Plus Jakarta Sans', sans-serif;

    /* Theme-agnostic design tokens (tints and semantic roles) */
    --clr-primary-light: #6366f1; /* Indigo */
    --clr-primary-dark: #4f46e5;
    --clr-primary: light-dark(var(--clr-primary-light), var(--clr-primary-dark));
    
    --clr-secondary-light: #ec4899; /* Pink */
    --clr-secondary-dark: #db2777;
    --clr-secondary: light-dark(var(--clr-secondary-light), var(--clr-secondary-dark));

    --clr-bg-light: #f8fafc; /* Slate 50 */
    --clr-bg-dark: #0a0f1d; /* Deep Dark Space */
    --clr-bg: light-dark(var(--clr-bg-light), var(--clr-bg-dark));

    --clr-surface-light: rgba(255, 255, 255, 0.7);
    --clr-surface-dark: rgba(15, 23, 42, 0.65);
    --clr-surface: light-dark(var(--clr-surface-light), var(--clr-surface-dark));

    --clr-border-light: rgba(226, 232, 240, 0.8);
    --clr-border-dark: rgba(51, 65, 85, 0.4);
    --clr-border: light-dark(var(--clr-border-light), var(--clr-border-dark));

    --clr-text-light: #1e293b; /* Slate 800 */
    --clr-text-dark: #f1f5f9; /* Slate 100 */
    --clr-text: light-dark(var(--clr-text-light), var(--clr-text-dark));

    --clr-text-muted-light: #64748b; /* Slate 500 */
    --clr-text-muted-dark: #94a3b8; /* Slate 400 */
    --clr-text-muted: light-dark(var(--clr-text-muted-light), var(--clr-text-muted-dark));

    --glow-color-light: rgba(99, 102, 241, 0.15);
    --glow-color-dark: rgba(99, 102, 241, 0.3);
    --glow-color: light-dark(var(--glow-color-light), var(--glow-color-dark));

    /* Layout Spacing */
    --space-xs: 0.5rem;
    --space-sm: 1rem;
    --space-md: 2rem;
    --space-lg: 4rem;
    --space-xl: 8rem;

    /* Border Radii */
    --radius-sm: 8px;
    --radius-md: 16px;
    --radius-lg: 24px;
    --radius-pill: 9999px;

    /* Shadow Layers */
    --shadow-light: 0 4px 30px rgba(0, 0, 0, 0.03), 0 1px 3px rgba(0, 0, 0, 0.02);
    --shadow-dark: 0 10px 40px rgba(0, 0, 0, 0.25), 0 1px 10px rgba(0, 0, 0, 0.1);
    --shadow: light-dark(var(--shadow-light), var(--shadow-dark));
  }

  body {
    background-color: var(--clr-bg);
    color: var(--clr-text);
    font-family: var(--font-body);
    overflow-x: hidden;
    position: relative;
    transition: background-color 0.4s ease, color 0.4s ease;
  }

  /* Styled background glowing mesh (decorations) */
  body::before {
    content: "" / "";
    position: absolute;
    inset-block-start: -10%;
    inset-inline-start: -10%;
    block-size: 50vw;
    inline-size: 50vw;
    background: radial-gradient(circle, var(--glow-color) 0%, transparent 70%);
    z-index: -1;
    pointer-events: none;
  }

  body::after {
    content: "" / "";
    position: absolute;
    inset-block-end: 10%;
    inset-inline-end: -10%;
    block-size: 60vw;
    inline-size: 60vw;
    background: radial-gradient(circle, rgba(236, 72, 153, 0.08) 0%, transparent 60%);
    z-index: -1;
    pointer-events: none;
  }

  /* Typography Defaults */
  h1, h2, h3, h4 {
    font-family: var(--font-heading);
    font-weight: 700;
    line-height: 1.15;
    letter-spacing: -0.02em;
  }

  /* Fluid typography clamp calculations */
  h1 {
    font-size: clamp(2.5rem, 1.2rem + 5vw, 4.5rem);
  }

  h2 {
    font-size: clamp(1.8rem, 1.2rem + 3vw, 3rem);
  }

  h3 {
    font-size: clamp(1.4rem, 1.1rem + 1.5vw, 2.2rem);
  }

  p {
    font-size: clamp(1rem, 0.95rem + 0.25vw, 1.15rem);
    line-height: 1.6;
    color: var(--clr-text-muted);
  }

  /* Focus Outlines */
  :focus-visible {
    outline: 2px solid var(--clr-primary);
    outline-offset: 4px;
  }

  /* Selection styling */
  ::selection {
    background-color: var(--clr-primary);
    color: #fff;
  }

  /* Scrollbar customization */
  scrollbar-color: var(--clr-primary) transparent;
  scrollbar-width: thin;
}

@layer layout {
  /* Grid containers */
  .grid-container {
    display: grid;
    inline-size: 90%;
    max-inline-size: 1200px;
    margin-inline: auto;
    gap: var(--space-md);
  }

  /* Navigation Header layout */
  .header-container {
    position: fixed;
    inset-block-start: 0;
    inset-inline: 0;
    z-index: 100;
    padding-block: var(--space-xs);
    background-color: color-mix(in srgb, var(--clr-bg) 20%, transparent);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-block-end: 1px solid var(--clr-border);
    transition: padding-block 0.3s ease, background-color 0.3s ease;
  }

  /* Active shrink on scroll handled via class toggled in JS */
  .header-container.shrunk {
    padding-block: calc(var(--space-xs) / 2);
    background-color: color-mix(in srgb, var(--clr-bg) 80%, transparent);
    box-shadow: var(--shadow);
  }

  .nav-bar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    inline-size: 90%;
    max-inline-size: 1200px;
    margin-inline: auto;
  }

  .nav-logo {
    font-family: var(--font-heading);
    font-weight: 800;
    font-size: 1.5rem;
    color: var(--clr-text);
  }

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

  .nav-list {
    display: flex;
    gap: var(--space-md);
  }

  .nav-link {
    font-weight: 500;
    color: var(--clr-text-muted);
    position: relative;
    padding-block: 0.5rem;
    transition: color 0.2s ease;
  }

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

  .nav-link::after {
    content: "" / "";
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--clr-primary);
    transition: width 0.3s ease;
  }

  .nav-link:hover::after, .nav-link.active::after {
    width: 100%;
  }

  .nav-actions {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
  }

  /* Hide navigation menu on mobile */
  @media (max-width: 768px) {
    .nav-list {
      display: none; /* simple mobile fallback or toggle */
    }
    .nav-cta {
      display: none;
    }
  }

  /* Section default spacings */
  section {
    padding-block: var(--space-xl);
    inline-size: 90%;
    max-inline-size: 1200px;
    margin-inline: auto;
  }

  .section-header {
    text-align: center;
    margin-block-end: var(--space-lg);
  }

  .section-title {
    margin-block-end: var(--space-xs);
  }

  .section-subtitle {
    max-inline-size: 600px;
    margin-inline: auto;
  }

  /* Hero grid layout */
  .hero-section {
    padding-block-start: calc(var(--space-xl) + 2rem);
    display: flex;
    align-items: center;
    min-block-size: 100vh;
  }

  .hero-grid {
    grid-template-columns: 1.2fr 0.8fr;
    align-items: center;
  }

  @media (max-width: 992px) {
    .hero-grid {
      grid-template-columns: 1fr;
      text-align: center;
      gap: var(--space-lg);
    }
    .hero-image-container {
      order: -1;
    }
    .hero-actions {
      justify-content: center;
    }
    .hero-socials {
      justify-content: center;
    }
  }

  /* About Grid */
  .about-grid {
    grid-template-columns: 1fr 1fr;
  }

  @media (max-width: 868px) {
    .about-grid {
      grid-template-columns: 1fr;
    }
  }

  /* Timeline (Experience) Layout */
  .timeline-container {
    position: relative;
    max-inline-size: 800px;
    margin-inline: auto;
    padding-inline-start: var(--space-md);
  }

  /* Vertical line helper */
  .timeline-container::before {
    content: "" / "";
    position: absolute;
    inset-block: 0;
    inset-inline-start: 7px;
    inline-size: 2px;
    background: linear-gradient(to bottom, var(--clr-primary), var(--clr-secondary), transparent);
  }

  .timeline-item {
    position: relative;
    margin-block-end: var(--space-md);
    padding: var(--space-md);
    background-color: var(--clr-surface);
    border: 1px solid var(--clr-border);
    border-radius: var(--radius-md);
  }

  .timeline-dot {
    position: absolute;
    inset-inline-start: -24px;
    inset-block-start: 2rem;
    inline-size: 16px;
    block-size: 16px;
    border-radius: var(--radius-pill);
    background-color: var(--clr-primary);
    border: 4px solid var(--clr-bg);
  }

  .timeline-date {
    font-weight: 700;
    font-size: 0.85rem;
    color: var(--clr-secondary);
    letter-spacing: 0.05em;
    margin-block-end: 0.25rem;
  }

  .timeline-role {
    font-size: 1.25rem;
    margin-block-end: 0.25rem;
  }

  .timeline-company {
    font-weight: 600;
    color: var(--clr-text);
    margin-block-end: var(--space-sm);
  }

  .timeline-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-block-start: var(--space-sm);
  }

  /* Project Grid layout */
  .projects-grid {
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: var(--space-md);
  }

  /* Contact container */
  .contact-container {
    max-inline-size: 800px;
    margin-inline: auto;
    padding: var(--space-md);
    border-radius: var(--radius-lg);
  }
}

@layer components {
  /* Buttons */
  .btn-primary, .btn-secondary {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding-inline: var(--space-md);
    padding-block: 0.75rem;
    border-radius: var(--radius-pill);
    font-weight: 600;
    font-size: 1rem;
    cursor: pointer;
    transition: transform 0.2s cubic-bezier(0.175, 0.885, 0.32, 1.275), box-shadow 0.2s ease, background-color 0.2s ease;
    border: none;
    min-block-size: 44px; /* Accessible touch target */
  }

  .btn-primary {
    background: linear-gradient(135deg, var(--clr-primary), var(--clr-secondary));
    color: #fff;
    box-shadow: 0 4px 15px rgba(99, 102, 241, 0.3);
  }

  .btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(99, 102, 241, 0.5);
  }

  .btn-primary:active {
    transform: translateY(0);
  }

  .btn-secondary {
    background-color: var(--clr-surface);
    color: var(--clr-text);
    border: 1px solid var(--clr-border);
    backdrop-filter: blur(8px);
  }

  .btn-secondary:hover {
    transform: translateY(-2px);
    background-color: var(--clr-bg);
    border-color: var(--clr-primary);
  }

  /* Glassmorphism Card Style */
  .glass {
    background: var(--clr-surface);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--clr-border);
    box-shadow: var(--shadow);
  }

  /* Hero actions / socials */
  .hero-actions {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-sm);
    margin-block-end: var(--space-md);
  }

  .hero-socials {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
  }

  .socials-label {
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--clr-text-muted);
  }

  .social-icon-link {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    inline-size: 40px;
    block-size: 40px;
    border-radius: var(--radius-pill);
    background-color: var(--clr-surface);
    border: 1px solid var(--clr-border);
    color: var(--clr-text-muted);
    transition: color 0.2s ease, border-color 0.2s ease, transform 0.2s ease;
    min-block-size: 40px;
  }

  .social-icon-link:hover {
    color: var(--clr-primary);
    border-color: var(--clr-primary);
    transform: translateY(-2px);
  }

  /* Avatar Graphic Container */
  .hero-image-container {
    position: relative;
    display: flex;
    justify-content: center;
  }

  .avatar-border {
    position: relative;
    border-radius: var(--radius-lg);
    overflow: hidden;
    aspect-ratio: 1;
    inline-size: 100%;
    max-inline-size: 400px;
    border: 1px solid var(--clr-border);
    box-shadow: var(--shadow);
    z-index: 2;
  }

  .avatar-img {
    inline-size: 100%;
    block-size: 100%;
    object-fit: cover;
  }

  .avatar-glow {
    position: absolute;
    inset: -10px;
    border-radius: var(--radius-lg);
    background: linear-gradient(135deg, var(--clr-primary), var(--clr-secondary));
    filter: blur(20px);
    opacity: 0.45;
    z-index: 1;
    animation: pulse-glow 6s infinite alternate ease-in-out;
  }

  @keyframes pulse-glow {
    0% { transform: scale(0.98); opacity: 0.35; }
    100% { transform: scale(1.02); opacity: 0.55; }
  }

  /* Skills Category card */
  .skills-container {
    display: grid;
    gap: var(--space-md);
    content-visibility: auto;
    contain-intrinsic-block-size: auto 300px;
  }

  .skills-card {
    padding: var(--space-md);
    border-radius: var(--radius-md);
  }

  .skills-header {
    display: flex;
    align-items: center;
    gap: var(--space-xs);
    margin-block-end: var(--space-sm);
  }

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

  .skills-list {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 0.5rem;
  }

  .skills-list li {
    font-weight: 500;
    color: var(--clr-text-muted);
    position: relative;
    padding-inline-start: 1.25rem;
  }

  .skills-list li::before {
    content: "•";
    color: var(--clr-primary);
    position: absolute;
    left: 0;
    font-weight: 700;
  }

  /* Timeline Experience tags */
  .tag {
    font-size: 0.75rem;
    font-weight: 600;
    padding-inline: 0.75rem;
    padding-block: 0.25rem;
    background-color: var(--clr-border);
    color: var(--clr-text);
    border-radius: var(--radius-pill);
    border: 1px solid var(--clr-border);
  }

  /* Project Card elements */
  .project-card {
    border-radius: var(--radius-md);
    overflow: hidden;
    display: flex;
    flex-direction: column;
    transition: transform 0.3s cubic-bezier(0.165, 0.84, 0.44, 1), border-color 0.3s ease;
  }

  .project-card:hover {
    transform: translateY(-5px);
    border-color: var(--clr-primary);
  }

  .project-img-wrapper {
    position: relative;
    aspect-ratio: 1.5;
    overflow: hidden;
    background-color: rgba(0, 0, 0, 0.05);
  }

  .project-img {
    inline-size: 100%;
    block-size: 100%;
    object-fit: cover;
    transition: transform 0.5s ease;
  }

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

  .project-overlay {
    position: absolute;
    inset: 0;
    background: rgba(10, 15, 29, 0.7);
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    backdrop-filter: blur(4px);
    transition: opacity 0.3s ease;
  }

  .project-card:hover .project-overlay {
    opacity: 1;
  }

  .project-link {
    inline-size: 50px;
    block-size: 50px;
    border-radius: var(--radius-pill);
    background-color: #fff;
    color: #000;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 4px 15px rgba(0,0,0,0.3);
    transition: transform 0.2s ease;
  }

  .project-link:hover {
    transform: scale(1.1);
  }

  .project-info {
    padding: var(--space-md);
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    flex-grow: 1;
  }

  .project-tags {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
  }

  .project-tag {
    font-size: 0.7rem;
    font-weight: 700;
    color: var(--clr-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
  }

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

  /* Form & Interactive Controls */
  .contact-form {
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
  }

  .form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-sm);
  }

  @media (max-width: 576px) {
    .form-row {
      grid-template-columns: 1fr;
    }
  }

  .form-group {
    display: flex;
    flex-direction: column;
    gap: 0.35rem;
  }

  .form-group label {
    font-weight: 600;
    font-size: 0.9rem;
    color: var(--clr-text);
  }

  .form-group input, .form-group textarea {
    padding-inline: 1rem;
    padding-block: 0.75rem;
    border-radius: var(--radius-sm);
    border: 1px solid var(--clr-border);
    background-color: var(--clr-surface);
    color: var(--clr-text);
    transition: border-color 0.2s ease, box-shadow 0.2s ease;
  }

  .form-group input:focus, .form-group textarea:focus {
    outline: none;
    border-color: var(--clr-primary);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.25);
  }

  .form-group textarea {
    resize: vertical;
  }

  /* Modern user-invalid validation styling */
  .form-group input:user-invalid, .form-group textarea:user-invalid {
    border-color: #ef4444; /* red 500 */
    box-shadow: 0 0 0 3px rgba(239, 68, 68, 0.15);
  }

  .form-group input:user-invalid + .error-msg, .form-group textarea:user-invalid + .error-msg {
    display: block;
  }

  .error-msg {
    display: none;
    font-size: 0.8rem;
    color: #ef4444;
    font-weight: 500;
  }

  .form-submit-btn {
    align-self: flex-start;
    margin-block-start: var(--space-xs);
  }

  .form-success-banner {
    display: none;
    padding: var(--space-sm);
    border-radius: var(--radius-sm);
    background-color: rgba(16, 185, 129, 0.15);
    color: #10b981;
    border: 1px solid rgba(16, 185, 129, 0.3);
    font-weight: 600;
    margin-block-start: var(--space-sm);
    align-items: center;
    gap: 0.5rem;
  }

  .form-success-banner.visible {
    display: flex;
  }

  .success-icon {
    font-weight: 800;
  }

  /* Theme Toggle Button Styles */
  .theme-toggle-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    inline-size: 40px;
    block-size: 40px;
    border-radius: var(--radius-pill);
    background-color: var(--clr-surface);
    border: 1px solid var(--clr-border);
    color: var(--clr-text);
    cursor: pointer;
    transition: background-color 0.2s ease, transform 0.2s ease;
  }

  .theme-toggle-btn:hover {
    background-color: var(--clr-border);
    transform: scale(1.05);
  }

  /* Show / hide sun/moon based on theme */
  /* Using system class toggles in JS */
  .sun-icon { display: none; }
  .moon-icon { display: block; }

  :root.light .sun-icon { display: block; }
  :root.light .moon-icon { display: none; }
}

@layer utilities {
  /* Text gradient helper */
  .text-gradient {
    background: linear-gradient(135deg, var(--clr-primary) 20%, var(--clr-secondary) 80%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
  }

  .badge {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding-inline: 0.75rem;
    padding-block: 0.25rem;
    background-color: rgba(16, 185, 129, 0.1);
    color: #10b981;
    font-size: 0.8rem;
    font-weight: 700;
    border-radius: var(--radius-pill);
    border: 1px solid rgba(16, 185, 129, 0.2);
    margin-block-end: var(--space-sm);
  }

  .badge::before {
    content: "" / "";
    inline-size: 8px;
    block-size: 8px;
    border-radius: 50%;
    background-color: #10b981;
  }

  .footer-container {
    border-block-start: 1px solid var(--clr-border);
    background-color: color-mix(in srgb, var(--clr-bg) 50%, transparent);
    padding-block: var(--space-md);
  }

  .footer-content {
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
    align-items: center;
    inline-size: 90%;
    max-inline-size: 1200px;
    margin-inline: auto;
    gap: var(--space-sm);
  }

  .footer-meta {
    font-size: 0.85rem;
    color: var(--clr-text-muted);
    display: flex;
    align-items: center;
    gap: 0.5rem;
  }

  .separator {
    color: var(--clr-border);
  }

  @media (max-width: 576px) {
    .footer-content {
      flex-direction: column;
      text-align: center;
    }
  }
}

/* --- Native CSS Scroll-Driven Animations --- */
@keyframes reveal-up {
  from {
    opacity: 0;
    transform: translateY(40px) scale(0.96);
  }
  to {
    opacity: 1;
    transform: translateY(0) scale(1);
  }
}

@supports (animation-timeline: view()) {
  @media (prefers-reduced-motion: no-preference) {
    .about-text-card, 
    .skills-card, 
    .timeline-item, 
    .project-card, 
    .contact-container {
      animation: reveal-up linear both;
      animation-timeline: view();
      animation-range: entry 10% cover 30%;
    }
  }
}

/* Accessibility settings for users preferring reduced motion */
@media (prefers-reduced-motion: reduce) {
  * {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
  .avatar-glow {
    animation: none;
  }
}