@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&family=Outfit:wght@400;500;600;700;800&display=swap');

/* --- CASCADE LAYERS --- */
@layer reset, variables, base, layout, components, utilities;

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

  html {
    scroll-behavior: smooth;
    -webkit-text-size-adjust: 100%;
  }

  body {
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    overflow-x: hidden;
  }

  img, picture, svg, video {
    display: block;
    max-width: 100%;
    height: auto;
  }

  button, input, select, textarea {
    font: inherit;
    color: inherit;
    background: none;
    border: none;
  }

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

  ul, ol {
    list-style: none;
  }
}

@layer variables {
  :root {
    /* Fonts */
    --font-heading: 'Outfit', sans-serif;
    --font-body: 'Inter', sans-serif;

    /* Theme colors - default (Dark) */
    --bg-base: hsl(40, 13%, 9%);
    --bg-surface: hsla(30, 14%, 15%, 0.75);
    --bg-surface-hover: hsla(30, 14%, 22%, 0.8);
    --bg-section-alt: hsla(30, 14%, 5%, 0.45);
    --border-color: hsla(43, 49%, 92%, 0.08);
    --border-color-hover: hsla(43, 49%, 92%, 0.15);

    --text-primary: hsl(43, 49%, 92%);
    --text-secondary: hsl(43, 20%, 70%);
    --text-muted: hsl(43, 15%, 50%);

    --color-accent-h: 45;
    --color-accent-s: 79%;
    --color-accent-l: 55%;
    --color-accent: hsl(var(--color-accent-h), var(--color-accent-s), var(--color-accent-l));
    --color-accent-subtle: hsla(var(--color-accent-h), var(--color-accent-s), var(--color-accent-l), 0.15);
    --color-accent-hover: hsl(var(--color-accent-h), var(--color-accent-s), calc(var(--color-accent-l) - 8%));

    --color-cyan-h: 43;
    --color-cyan-s: 89%;
    --color-cyan-l: 38%;
    --color-cyan: hsl(var(--color-cyan-h), var(--color-cyan-s), var(--color-cyan-l));
    --color-cyan-subtle: hsla(var(--color-cyan-h), var(--color-cyan-s), var(--color-cyan-l), 0.15);

    --color-success: hsl(142, 70%, 45%);
    --color-error: hsl(350, 80%, 55%);

    /* Shadows */
    --shadow-sm: 0 2px 8px -2px rgba(0, 0, 0, 0.5);
    --shadow-md: 0 8px 24px -4px rgba(0, 0, 0, 0.6), 0 2px 8px -2px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 20px 48px -8px rgba(0, 0, 0, 0.8), 0 4px 16px -4px rgba(0, 0, 0, 0.5);
    --shadow-glow: 0 0 30px hsla(var(--color-accent-h), var(--color-accent-s), var(--color-accent-l), 0.25);

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

    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-smooth: 0.4s cubic-bezier(0.16, 1, 0.3, 1);
  }

  /* Light Theme overrides using system settings */
  @media (prefers-color-scheme: light) {
    :root:not([data-theme="dark"]) {
      --bg-base: hsl(37, 32%, 94%);
      --bg-surface: hsla(37, 100%, 96%, 0.85);
      --bg-surface-hover: hsla(37, 100%, 92%, 0.9);
      --bg-section-alt: hsla(37, 31%, 13%, 0.035);
      --border-color: hsla(37, 31%, 13%, 0.08);
      --border-color-hover: hsla(37, 31%, 13%, 0.15);

      --text-primary: hsl(37, 31%, 13%);
      --text-secondary: hsl(37, 20%, 35%);
      --text-muted: hsl(37, 15%, 55%);

      --color-accent-l: 46%;
      --color-cyan-l: 32%;

      --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.05);
      --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.08);
      --shadow-lg: 0 20px 48px rgba(0, 0, 0, 0.12);
      --shadow-glow: 0 0 30px hsla(var(--color-accent-h), var(--color-accent-s), var(--color-accent-l), 0.15);
    }
  }

  /* Explicit themes when toggled manually */
  :root[data-theme="light"] {
    --bg-base: hsl(37, 32%, 94%);
    --bg-surface: hsla(37, 100%, 96%, 0.85);
    --bg-surface-hover: hsla(37, 100%, 92%, 0.9);
    --bg-section-alt: hsla(37, 31%, 13%, 0.035);
    --border-color: hsla(37, 31%, 13%, 0.08);
    --border-color-hover: hsla(37, 31%, 13%, 0.15);

    --text-primary: hsl(37, 31%, 13%);
    --text-secondary: hsl(37, 20%, 35%);
    --text-muted: hsl(37, 15%, 55%);

    --color-accent-l: 46%;
    --color-cyan-l: 32%;

    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 20px 48px rgba(0, 0, 0, 0.12);
    --shadow-glow: 0 0 30px hsla(var(--color-accent-h), var(--color-accent-s), var(--color-accent-l), 0.15);
  }

  :root[data-theme="dark"] {
    --bg-base: hsl(40, 13%, 9%);
    --bg-surface: hsla(30, 14%, 15%, 0.75);
    --bg-surface-hover: hsla(30, 14%, 22%, 0.8);
    --bg-section-alt: hsla(30, 14%, 5%, 0.45);
    --border-color: hsla(43, 49%, 92%, 0.08);
    --border-color-hover: hsla(43, 49%, 92%, 0.15);

    --text-primary: hsl(43, 49%, 92%);
    --text-secondary: hsl(43, 20%, 70%);
    --text-muted: hsl(43, 15%, 50%);

    --color-accent-l: 55%;
    --color-cyan-l: 38%;

    --shadow-sm: 0 2px 8px -2px rgba(0, 0, 0, 0.5);
    --shadow-md: 0 8px 24px -4px rgba(0, 0, 0, 0.6), 0 2px 8px -2px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 20px 48px -8px rgba(0, 0, 0, 0.8), 0 4px 16px -4px rgba(0, 0, 0, 0.5);
    --shadow-glow: 0 0 30px hsla(var(--color-accent-h), var(--color-accent-s), var(--color-accent-l), 0.25);
  }
}

@layer base {
  body {
    background-color: var(--bg-base);
    color: var(--text-primary);
    font-family: var(--font-body);
    font-size: 1rem;
    color-scheme: dark light;
    transition: background-color var(--transition-smooth), color var(--transition-smooth);
    background-image: 
      radial-gradient(circle at 10% 20%, hsla(var(--color-accent-h), var(--color-accent-s), var(--color-accent-l), 0.05) 0%, transparent 40%),
      radial-gradient(circle at 90% 80%, hsla(var(--color-cyan-h), var(--color-cyan-s), var(--color-cyan-l), 0.04) 0%, transparent 40%);
    background-attachment: fixed;
  }

  /* Typography */
  h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-heading);
    font-weight: 700;
    line-height: 1.2;
    color: var(--text-primary);
    text-wrap: balance;
  }

  h1 {
    font-size: clamp(2.25rem, 1.25rem + 5vw, 4.5rem);
    letter-spacing: -0.03em;
  }

  h2 {
    font-size: clamp(1.75rem, 1.25rem + 2.5vw, 3rem);
    letter-spacing: -0.02em;
    margin-bottom: 1rem;
  }

  h3 {
    font-size: clamp(1.25rem, 1rem + 1vw, 1.75rem);
    margin-bottom: 0.75rem;
  }

  p {
    font-size: clamp(0.95rem, 0.9rem + 0.3vw, 1.1rem);
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    text-wrap: pretty;
  }

  /* Buttons & Interactions */
  button, .btn {
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    font-weight: 600;
    border-radius: var(--radius-pill);
    padding: 0.75rem 1.75rem;
    transition: all var(--transition-fast);
  }

  .btn-primary {
    background: var(--color-accent);
    color: hsl(0, 0%, 100%);
    box-shadow: var(--shadow-sm), var(--shadow-glow);
  }

  .btn-primary:hover:not(:disabled) {
    background: var(--color-accent-hover);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md), 0 0 35px hsla(var(--color-accent-h), var(--color-accent-s), var(--color-accent-l), 0.4);
  }

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

  .btn-secondary:hover:not(:disabled) {
    background: var(--bg-surface-hover);
    border-color: var(--border-color-hover);
    transform: translateY(-2px);
  }

  .btn-text {
    padding: 0.5rem 1rem;
    color: var(--color-accent);
  }

  .btn-text:hover {
    color: var(--color-accent-hover);
    background: var(--color-accent-subtle);
  }

  /* Custom Focus outline */
  *:focus-visible {
    outline: 2px solid var(--color-accent);
    outline-offset: 4px;
  }

  /* Accessibility settings */
  @media (prefers-reduced-motion: reduce) {
    * {
      animation-delay: 0s !important;
      animation-duration: 0s !important;
      animation-iteration-count: 1 !important;
      transition-duration: 0s !important;
      scroll-behavior: auto !important;
    }
  }
}

@layer layout {
  .container {
    width: 100%;
    max-width: 1200px;
    margin-inline: auto;
    padding-inline: 1.5rem;
  }

  .section {
    padding-block: clamp(4rem, 2rem + 6vh, 8rem);
  }

  /* Grid helper systems */
  .grid-2 {
    display: grid;
    grid-template-columns: 1fr;
    gap: 2.5rem;
    align-items: center;
  }

  .grid-3 {
    display: grid;
    grid-template-columns: 1fr;
    gap: 2rem;
  }

  @media (min-width: 768px) {
    .grid-2 {
      grid-template-columns: repeat(2, 1fr);
    }

    .grid-3 {
      grid-template-columns: repeat(3, 1fr);
    }
  }

  .flex-center {
    display: flex;
    align-items: center;
    justify-content: center;
  }

  .flex-between {
    display: flex;
    align-items: center;
    justify-content: space-between;
  }
}

@layer components {
  /* --- NAVBAR --- */
  .navbar {
    position: sticky;
    top: 0;
    z-index: 100;
    background: hsla(40, 13%, 9%, 0.7);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-bottom: 1px solid var(--border-color);
    transition: background var(--transition-fast), border var(--transition-fast);
  }

  :root[data-theme="light"] .navbar {
    background: hsla(37, 32%, 94%, 0.7);
  }

  .nav-container {
    height: 70px;
    display: flex;
    align-items: center;
    justify-content: space-between;
  }

  .logo {
    font-family: var(--font-heading);
    font-size: 1.5rem;
    font-weight: 800;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--text-primary);
  }

  .logo span {
    background: linear-gradient(135deg, var(--color-accent), var(--color-cyan));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
  }

  .nav-menu {
    display: flex;
    align-items: center;
    gap: 2rem;
  }

  .nav-link {
    font-weight: 500;
    color: var(--text-secondary);
    transition: color var(--transition-fast);
    padding: 0.5rem 0.25rem;
    position: relative;
  }

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

  .nav-link::after {
    content: "";
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--color-accent);
    transition: width var(--transition-fast);
  }

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

  .nav-actions {
    display: flex;
    align-items: center;
    gap: 1rem;
  }

  .theme-toggle {
    background: none;
    border: none;
    cursor: pointer;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    transition: all var(--transition-fast);
  }

  .theme-toggle:hover {
    background: var(--bg-surface-hover);
    border-color: var(--border-color-hover);
  }

  .theme-toggle .sun-icon {
    display: none;
  }

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

  :root[data-theme="light"] .theme-toggle .sun-icon {
    display: block;
  }

  /* Hamburger Menu */
  .menu-btn {
    display: none;
    flex-direction: column;
    gap: 5px;
    width: 30px;
    height: 20px;
    justify-content: space-between;
    cursor: pointer;
  }

  .menu-btn span {
    width: 100%;
    height: 3px;
    background-color: var(--text-primary);
    border-radius: 2px;
    transition: all var(--transition-fast);
  }

  @media (max-width: 768px) {
    .menu-btn {
      display: flex;
      z-index: 110;
    }

    .nav-menu {
      position: fixed;
      top: 0;
      right: -100%;
      width: 80%;
      height: 100vh;
      background: var(--bg-base);
      flex-direction: column;
      justify-content: center;
      gap: 3rem;
      box-shadow: var(--shadow-lg);
      transition: right var(--transition-smooth);
      z-index: 105;
    }

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

    .nav-actions {
      margin-right: 3rem;
    }
  }

  /* --- GLASS CARDS --- */
  .card {
    background: var(--bg-surface);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 2rem;
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    transition: all var(--transition-smooth);
    box-shadow: var(--shadow-sm);
  }

  .card:hover {
    transform: translateY(-5px);
    border-color: var(--border-color-hover);
    box-shadow: var(--shadow-md), var(--shadow-glow);
  }

  /* --- GRAPHIC / IMAGE CONTAINERS --- */
  .image-wrapper {
    position: relative;
    border-radius: var(--radius-lg);
    overflow: hidden;
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow-lg);
  }

  .image-wrapper::after {
    content: "";
    position: absolute;
    inset: 0;
    background: linear-gradient(180deg, transparent 50%, rgba(0,0,0,0.4));
    pointer-events: none;
  }

  /* --- FEATURES INTERACTIVE SHOWCASE (Tabs) --- */
  .showcase-tabs {
    display: inline-flex;
    background: var(--bg-surface);
    border: 1px solid var(--border-color);
    padding: 0.4rem;
    border-radius: var(--radius-pill);
    margin-bottom: 3rem;
  }

  .tab-btn {
    border-radius: var(--radius-pill);
    padding: 0.6rem 1.5rem;
    font-size: 0.95rem;
    font-weight: 600;
    color: var(--text-secondary);
    transition: all var(--transition-fast);
  }

  .tab-btn.active {
    background: var(--color-accent);
    color: #fff;
    box-shadow: var(--shadow-sm);
  }

  .showcase-panel {
    display: none;
    animation: fadeIn 0.5s ease forwards;
  }

  .showcase-panel.active {
    display: block;
  }

  @keyframes fadeIn {
    from { opacity: 0; transform: translateY(15px); }
    to { opacity: 1; transform: translateY(0); }
  }

  /* --- FEATURE LIST & PILLS --- */
  .feature-item {
    display: flex;
    gap: 1rem;
    margin-bottom: 1.5rem;
    align-items: flex-start;
  }

  .feature-icon-wrapper {
    flex-shrink: 0;
    width: 48px;
    height: 48px;
    border-radius: var(--radius-sm);
    background: var(--color-accent-subtle);
    color: var(--color-accent);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
  }

  .feature-pill {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.4rem 1rem;
    background: var(--bg-surface);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-pill);
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--text-secondary);
    margin: 0.25rem;
  }

  .feature-pill svg {
    color: var(--color-accent);
  }

  /* --- FOOTER --- */
  .footer {
    background: hsl(40, 13%, 4%);
    border-top: 1px solid var(--border-color);
    padding-block: 4rem 2rem;
    color: var(--text-secondary);
  }

  .footer h4 {
    color: var(--text-primary);
    margin-bottom: 1.25rem;
  }

  .footer-links {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
  }

  .footer-link:hover {
    color: var(--text-primary);
  }

  .footer-bottom {
    margin-top: 3rem;
    padding-top: 2rem;
    border-top: 1px solid var(--border-color);
    font-size: 0.85rem;
    text-align: center;
  }

  /* --- FORMS --- */
  .form-group {
    margin-bottom: 1.5rem;
  }

  .form-label {
    display: block;
    font-weight: 500;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
  }

  .form-control {
    width: 100%;
    padding: 0.75rem 1rem;
    border-radius: var(--radius-sm);
    background: var(--bg-surface);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    transition: all var(--transition-fast);
  }

  .form-control:focus {
    border-color: var(--color-accent);
    outline: none;
    box-shadow: 0 0 10px hsla(var(--color-accent-h), var(--color-accent-s), var(--color-accent-l), 0.15);
  }

  /* User interaction styles */
  .form-control:user-invalid {
    border-color: var(--color-error);
    background-color: hsla(350, 80%, 55%, 0.03);
  }

  .form-control:user-valid {
    border-color: var(--color-success);
    background-color: hsla(142, 70%, 45%, 0.03);
  }

  /* --- STATS SECTION --- */
  .stat-card {
    text-align: center;
    padding: 2.5rem;
  }

  .stat-number {
    font-family: var(--font-heading);
    font-size: clamp(2.5rem, 2rem + 2vw, 4rem);
    font-weight: 800;
    background: linear-gradient(135deg, var(--color-accent), var(--color-cyan));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 0.5rem;
  }
}

@layer utilities {
  .text-center { text-align: center; }
  .margin-top-sm { margin-top: 1rem; }
  .margin-top-md { margin-top: 2rem; }
  .margin-top-lg { margin-top: 4rem; }
  .gradient-text {
    background: linear-gradient(135deg, var(--color-accent), var(--color-cyan));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
  }
  
  .glow-box {
    box-shadow: var(--shadow-glow);
  }
}