/* Modern Design System - Theme Aware HSL Variables */
:root {
  /* Core Hues */
  --primary-h: 221;
  --primary-s: 83%;
  --primary-l: 53%;

  /* Status & Accents */
  --accent-h: 343;
  --accent-s: 80%;
  --accent-l: 50%;

  /* Theme - LIGHT (Default) */
  --bg-main: hsl(210, 40%, 98%);
  --bg-surface: hsl(0, 0%, 100%);
  --bg-soft: hsl(210, 40%, 96%);
  --bg-footer: hsl(222, 47%, 15%);
  /* Keep footer dark even in light mode for "premium" feel, or make it light? User said it's stuck in dark. Let's make it light in light mode but "soft". */
  --bg-footer: hsl(210, 40%, 94%);

  --text-main: hsl(215, 25%, 20%);
  --text-muted: hsl(215, 16%, 40%);
  --text-light: hsl(0, 0%, 100%);
  --text-footer: var(--text-main);

  --border-color: hsla(214, 32%, 91%, 1);
  --glass-bg: hsla(0, 0%, 100%, 0.8);
  --glass-border: hsla(0, 0%, 100%, 0.4);

  --primary: hsl(var(--primary-h), var(--primary-s), var(--primary-l));
  --primary-hover: hsl(var(--primary-h), var(--primary-s), calc(var(--primary-l) - 10%));
  --accent: hsl(var(--accent-h), var(--accent-s), var(--accent-l));

  /* Footer Specifics - Light Mode */
  --footer-icon-bg: hsla(222, 47%, 15%, 0.1);
  --footer-icon-color: var(--text-main);
  --footer-heading-color: var(--text-main);

  /* Shadows & Radius */
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
  --radius-md: 12px;
  --radius-lg: 20px;
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);

  /* Layout & Glass */
  --header-h: 80px;
  --container-max: 1100px;
  --glass-blur: 12px;

  /* Typography */
  --font-sans: 'Ubuntu', system-ui, -apple-system, sans-serif;
  --font-serif: 'Lora', Georgia, serif;
}

/* Dark Mode Overrides (Shared for media query & explicit class) */
@media (prefers-color-scheme: dark) {
  :root:not(.light-mode) {
    --bg-main: hsl(222, 47%, 9%);
    --bg-surface: hsl(222, 47%, 12%);
    --bg-soft: hsl(222, 47%, 15%);
    --bg-footer: hsl(222, 47%, 7%);

    --text-main: hsl(210, 40%, 98%);
    --text-muted: hsl(215, 20%, 70%);
    --text-footer: hsl(210, 40%, 98%);

    --border-color: hsla(217, 33%, 20%, 1);
    --glass-bg: hsla(222, 47%, 9%, 0.75);
    --glass-border: hsla(222, 47%, 20%, 0.5);

    /* Footer Specifics - Dark Mode */
    --footer-icon-bg: hsla(0, 0%, 100%, 0.1);
    --footer-icon-color: hsl(0, 0%, 100%);
    --footer-heading-color: hsl(0, 0%, 100%);
  }
}

html.dark-mode {
  --bg-main: hsl(222, 47%, 9%);
  --bg-surface: hsl(222, 47%, 12%);
  --bg-soft: hsl(222, 47%, 15%);
  --bg-footer: hsl(222, 47%, 7%);

  --text-main: hsl(210, 40%, 98%);
  --text-muted: hsl(215, 20%, 70%);
  --text-footer: hsl(210, 40%, 98%);

  --border-color: hsla(217, 33%, 20%, 1);
  --glass-bg: hsla(222, 47%, 9%, 0.75);
  --glass-border: hsla(222, 47%, 20%, 0.5);

  /* Footer Specifics - Dark Mode (Explicit Class) */
  --footer-icon-bg: hsla(0, 0%, 100%, 0.1);
  --footer-icon-color: hsl(0, 0%, 100%);
  --footer-heading-color: hsl(0, 0%, 100%);
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: var(--font-sans);
  line-height: 1.6;
  color: var(--text-main);
  background-color: var(--bg-main);
  padding-top: var(--header-h);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  -webkit-font-smoothing: antialiased;
}

main {
  flex: 1;
}

h1,
h2,
h3,
h4,
h5,
h6 {
  font-family: var(--font-serif);
  color: var(--text-main);
  font-weight: 700;
  line-height: 1.2;
}

h1 {
  font-size: clamp(2.5rem, 8vw, 4rem);
}

h2 {
  font-size: clamp(1.8rem, 5vw, 2.5rem);
  margin-bottom: 2rem;
  position: relative;
}

h3 {
  font-size: 1.5rem;
}

h2::after {
  content: '';
  display: block;
  width: 50px;
  height: 4px;
  background: var(--primary);
  margin-top: 0.5rem;
  border-radius: 2px;
}

p {
  margin-bottom: 1.5rem;
  color: var(--text-muted);
}

.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* Glassmorphism Utility */
.glass {
  background: var(--glass-bg);
  backdrop-filter: blur(var(--glass-blur));
  -webkit-backdrop-filter: blur(var(--glass-blur));
  border: 1px solid var(--glass-border);
}

/* Cards */
.card {
  background: var(--bg-surface);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  padding: 2rem;
  transition: var(--transition);
  border: 1px solid var(--border-color);
}

.card:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow-lg);
  border-color: var(--primary);
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.8rem 1.8rem;
  border-radius: 100px;
  text-decoration: none;
  font-weight: 600;
  transition: var(--transition);
  font-size: 0.95rem;
  cursor: pointer;
  gap: 0.5rem;
}

.btn-primary {
  background: var(--primary);
  color: var(--text-light);
  border: none;
  box-shadow: 0 4px 14px 0 hsla(var(--primary-h), var(--primary-s), var(--primary-l), 0.39);
}

.btn-primary:hover {
  background: var(--primary-hover);
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.23);
}

.btn-secondary {
  background: transparent;
  color: var(--primary);
  border: 2px solid var(--primary);
}

.btn-secondary:hover {
  background: hsla(var(--primary-h), var(--primary-s), var(--primary-l), 0.1);
  transform: translateY(-2px);
}

/* Sections */
section {
  padding: 5rem 0;
}

.section-alt {
  background: var(--bg-soft);
}

.section-heading {
  text-align: center;
  max-width: 700px;
  margin: 0 auto 4rem;
}

/* Animations - Reveal on Scroll */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.8s ease-out, transform 0.8s ease-out;
}

.reveal.active {
  opacity: 1;
  transform: translateY(0);
}

/* Accessibility */
.skip-link {
  position: absolute;
  top: -40px;
  left: 0;
  background: var(--primary);
  color: white;
  padding: 8px;
  z-index: 1000;
  transition: top 0.3s;
}

.skip-link:focus {
  top: 0;
}

.no-scrollbar::-webkit-scrollbar {
  display: none;
}

.no-scrollbar {
  -ms-overflow-style: none;
  scrollbar-width: none;
}

/* Enhanced Focus Indicators for Accessibility */
*:focus {
  outline: none;
}

*:focus-visible {
  outline: 3px solid var(--primary);
  outline-offset: 2px;
  border-radius: 4px;
}

a:focus-visible,
button:focus-visible,
input:focus-visible,
textarea:focus-visible,
select:focus-visible {
  outline: 3px solid var(--primary);
  outline-offset: 2px;
  box-shadow: 0 0 0 4px hsla(var(--primary-h), var(--primary-s), var(--primary-l), 0.25);
}

/* Skeleton Loader for Preloading Animation */
.skeleton {
  background: linear-gradient(90deg,
      var(--bg-soft) 25%,
      var(--bg-surface) 50%,
      var(--bg-soft) 75%);
  background-size: 200% 100%;
  animation: skeleton-loading 1.5s infinite ease-in-out;
  border-radius: var(--radius-md);
}

@keyframes skeleton-loading {
  0% {
    background-position: 200% 0;
  }

  100% {
    background-position: -200% 0;
  }
}

.skeleton-text {
  height: 1em;
  margin-bottom: 0.5em;
}

.skeleton-title {
  height: 2em;
  width: 60%;
  margin-bottom: 1em;
}

.skeleton-image {
  width: 100%;
  aspect-ratio: 1 / 1;
}

/* Page Loading Overlay */
.page-loader {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: var(--bg-main);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 9999;
  opacity: 1;
  transition: opacity 0.3s ease-out;
}

.page-loader.loaded {
  opacity: 0;
  pointer-events: none;
}

.loader-spinner {
  width: 50px;
  height: 50px;
  border: 4px solid var(--bg-soft);
  border-top-color: var(--primary);
  border-radius: 50%;
  animation: spin 1s linear infinite;
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}