/* ============================================
   ARK-OS — Design System
   Material 3 + Custom Premium Aesthetics
   ============================================ */

/* --- Material 3 Design Tokens --- */
:root {
  /* Teal/Cyan primary for dark theme */
  --md-sys-color-primary: #80CBC4;
  --md-sys-color-on-primary: #003733;
  --md-sys-color-primary-container: #00504A;
  --md-sys-color-on-primary-container: #A0F0E9;

  --md-sys-color-secondary: #B0CCC8;
  --md-sys-color-on-secondary: #1B3533;
  --md-sys-color-secondary-container: #324B49;
  --md-sys-color-on-secondary-container: #CCE8E4;

  --md-sys-color-tertiary: #ADC7E8;
  --md-sys-color-on-tertiary: #17324E;
  --md-sys-color-tertiary-container: #2F4966;
  --md-sys-color-on-tertiary-container: #D0E4FF;

  --md-sys-color-error: #FFB4AB;
  --md-sys-color-on-error: #690005;
  --md-sys-color-error-container: #93000A;
  --md-sys-color-on-error-container: #FFDAD6;

  --md-sys-color-background: #0a0d0f;
  --md-sys-color-on-background: #E0E3E1;
  --md-sys-color-surface: #0f1214;
  --md-sys-color-on-surface: #E0E3E1;
  --md-sys-color-surface-variant: #1a1e22;
  --md-sys-color-on-surface-variant: #BEC9C6;
  --md-sys-color-surface-container: #141819;
  --md-sys-color-surface-container-high: #1e2224;
  --md-sys-color-outline: #899390;
  --md-sys-color-outline-variant: #3F4947;

  --md-sys-color-inverse-surface: #E0E3E1;
  --md-sys-color-inverse-on-surface: #2E3130;

  --md-ref-typeface-brand: 'Inter', sans-serif;
  --md-ref-typeface-plain: 'Inter', sans-serif;

  --md-sys-shape-corner-small: 8px;
  --md-sys-shape-corner-medium: 12px;
  --md-sys-shape-corner-large: 16px;
  --md-sys-shape-corner-extra-large: 28px;

  /* Custom tokens */
  --ark-swift-orange: #F05138;
  --ark-swift-red: #FC3221;
  --ark-terminal-green: #a3be8c;
  --ark-terminal-bg: #0c0e12;
  --ark-glow-cyan: rgba(128, 203, 196, 0.15);
  --ark-glow-orange: rgba(240, 81, 56, 0.15);
}

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

html, body, h1, h2, h3, h4, h5, h6, p, figure, blockquote, dl, dd {
  margin: 0;
  padding: 0;
}

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

body {
  font-family: 'Inter', sans-serif;
  background: var(--md-sys-color-background);
  color: var(--md-sys-color-on-background);
  min-height: 100vh;
  overflow-x: hidden;
  line-height: 1.6;
}

a {
  color: var(--md-sys-color-primary);
  text-decoration: none;
}

/* --- Background Canvas --- */
#bg-canvas {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 0;
  pointer-events: none;
}

/* --- Header --- */
#main-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: rgba(10, 13, 15, 0.7);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid rgba(255,255,255,0.06);
  transition: background 0.3s ease;
}

.header-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 12px 32px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo-link {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
}

.logo {
  height: 40px;
  width: 40px;
  border-radius: 10px;
  object-fit: contain;
  filter: invert(1);
}

.logo-text {
  font-weight: 800;
  font-size: 1.25rem;
  letter-spacing: -0.02em;
  color: var(--md-sys-color-on-surface);
}

nav {
  display: flex;
  align-items: center;
  gap: 16px;
}

/* --- Main Content --- */
main {
  position: relative;
  z-index: 1;
}

/* --- Hero Section --- */
.hero {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 140px 40px 120px;
  position: relative;
}

.hero-badge {
  margin-bottom: 40px;
}

.hero-title {
  font-size: clamp(4rem, 12vw, 8rem);
  font-weight: 900;
  letter-spacing: -0.04em;
  line-height: 0.95;
  margin-bottom: 32px;
}

.gradient-text {
  background: linear-gradient(135deg, var(--md-sys-color-primary) 0%, #4DD0E1 40%, var(--ark-swift-orange) 70%, var(--ark-swift-red) 100%);
  background-size: 300% 300%;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  animation: gradient-shift 8s ease infinite;
}

@keyframes gradient-shift {
  0%, 100% { background-position: 0% 50%; }
  50% { background-position: 100% 50%; }
}

.hero-tagline {
  font-size: clamp(1.25rem, 3vw, 1.75rem);
  font-weight: 600;
  color: var(--md-sys-color-on-surface-variant);
  letter-spacing: -0.01em;
  margin-bottom: 32px;
}

.hero-subtitle {
  max-width: 600px;
  font-size: 1.1rem;
  color: var(--md-sys-color-on-surface-variant);
  opacity: 0.7;
  line-height: 1.7;
  margin-bottom: 48px;
}

.hero-subtitle strong {
  color: var(--md-sys-color-on-surface);
  font-weight: 600;
}

.hero-actions {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  justify-content: center;
  margin-bottom: 56px;
}

.hero-status {
  margin-top: 16px;
}

.status-pill {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 20px;
  border-radius: 999px;
  background: rgba(255,255,255, 0.04);
  border: 1px solid rgba(255,255,255,0.08);
  font-size: 0.875rem;
  color: var(--md-sys-color-on-surface-variant);
}

.status-pill.released {
  background: rgba(39, 201, 63, 0.06);
  border-color: rgba(39, 201, 63, 0.2);
  color: #a3be8c;
}

.status-pill.early-dev {
  background: rgba(255, 189, 46, 0.06);
  border-color: rgba(255, 189, 46, 0.2);
  color: #ebcb8b;
}

.status-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--ark-swift-orange);
  animation: pulse-dot 2s ease infinite;
}

.status-dot.status-live {
  background: #27c93f;
  animation: pulse-live 2s ease infinite;
}

@keyframes pulse-dot {
  0%, 100% { opacity: 1; box-shadow: 0 0 0 0 rgba(240, 81, 56, 0.4); }
  50% { opacity: 0.6; box-shadow: 0 0 0 6px rgba(240, 81, 56, 0); }
}

@keyframes pulse-live {
  0%, 100% { opacity: 1; box-shadow: 0 0 0 0 rgba(39, 201, 63, 0.4); }
  50% { opacity: 0.7; box-shadow: 0 0 0 6px rgba(39, 201, 63, 0); }
}

/* --- Animate In (Page Load) --- */
.animate-in {
  opacity: 0;
  transform: translateY(30px);
  animation: fade-up 0.8s ease forwards;
}

.delay-1 { animation-delay: 0.15s; }
.delay-2 { animation-delay: 0.3s; }
.delay-3 { animation-delay: 0.45s; }
.delay-4 { animation-delay: 0.6s; }
.delay-5 { animation-delay: 0.75s; }

@keyframes fade-up {
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* --- Scroll Reveal --- */
.scroll-reveal {
  opacity: 0;
  transform: translateY(40px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}

.scroll-reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

.delay-scroll-1 { transition-delay: 0.15s; }
.delay-scroll-2 { transition-delay: 0.3s; }

/* --- Section Styles --- */
.section-title {
  font-size: clamp(2rem, 5vw, 3rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  text-align: center;
  color: var(--md-sys-color-on-surface);
  margin-bottom: 8px;
}

.section-subtitle {
  text-align: center;
  font-size: 1.1rem;
  color: var(--md-sys-color-on-surface-variant);
  opacity: 0.7;
  margin-bottom: 56px;
}

/* --- Features Section --- */
.features {
  padding: 100px 40px 120px;
  max-width: 1100px;
  margin: 0 auto;
}

.features-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 32px;
}

.feature-card {
  border-radius: 24px;
  position: relative;
  overflow: hidden;
  transition: transform 0.4s cubic-bezier(0.16, 1, 0.3, 1), box-shadow 0.4s ease;
}

.feature-card:hover {
  transform: translateY(-6px);
}

.card-label {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 16px 24px;
  font-weight: 600;
  font-size: 0.875rem;
  letter-spacing: 0.02em;
  text-transform: uppercase;
  color: var(--md-sys-color-on-surface-variant);
  border-top: 1px solid rgba(255,255,255,0.06);
}

.card-label .material-symbols-outlined {
  font-size: 18px;
}

/* --- Feature Cards as Links --- */
a.feature-card {
  text-decoration: none;
  color: inherit;
  cursor: pointer;
}

/* --- Linux Kernel Card --- */
.linux-card {
  background: linear-gradient(160deg, rgba(128, 203, 196, 0.06) 0%, rgba(15, 18, 20, 0.95) 50%);
  border: 1px solid rgba(128, 203, 196, 0.1);
  box-shadow: 0 8px 32px rgba(0,0,0,0.4);
  display: flex;
  flex-direction: column;
}

.linux-card:hover {
  box-shadow: 0 16px 48px rgba(0,0,0,0.5), 0 0 60px var(--ark-glow-cyan);
  border-color: rgba(128, 203, 196, 0.22);
}

.linux-logo-bg {
  position: relative;
  display: flex;
  justify-content: center;
  padding: 48px 32px 24px;
}

.tux-icon {
  width: 80px;
  height: 96px;
  filter: drop-shadow(0 4px 20px rgba(128, 203, 196, 0.2));
  transition: transform 0.4s ease;
}

.linux-card:hover .tux-icon {
  transform: scale(1.1);
}

.linux-content {
  padding: 16px 40px 32px;
  flex: 1;
}

.linux-title {
  font-size: 2rem;
  font-weight: 800;
  color: var(--md-sys-color-primary);
  margin-bottom: 12px;
}

.linux-description {
  color: rgba(255,255,255,0.6);
  font-size: 0.95rem;
  line-height: 1.7;
  margin-bottom: 20px;
}

.linux-features {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

.linux-feature {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 10px 20px;
  border-radius: 999px;
  background: rgba(128, 203, 196, 0.06);
  border: 1px solid rgba(128, 203, 196, 0.12);
  font-size: 0.8rem;
  font-weight: 500;
  color: rgba(255,255,255,0.7);
}

.linux-feature .material-symbols-outlined {
  font-size: 16px;
  color: var(--md-sys-color-primary);
}

/* --- Swift Card --- */
.swift-card {
  background: linear-gradient(160deg, rgba(240, 81, 56, 0.08) 0%, rgba(15, 18, 20, 0.95) 50%);
  border: 1px solid rgba(240, 81, 56, 0.12);
  box-shadow: 0 8px 32px rgba(0,0,0,0.4);
  display: flex;
  flex-direction: column;
}

.swift-card:hover {
  box-shadow: 0 16px 48px rgba(0,0,0,0.5), 0 0 60px var(--ark-glow-orange);
  border-color: rgba(240, 81, 56, 0.25);
}

.swift-logo-bg {
  position: relative;
  display: flex;
  justify-content: center;
  padding: 48px 32px 24px;
}

.swift-bird {
  width: 80px;
  height: 80px;
  filter: drop-shadow(0 4px 20px rgba(240, 81, 56, 0.3));
  transition: transform 0.4s ease;
}

.swift-card:hover .swift-bird {
  transform: scale(1.1) rotate(-3deg);
}

.swift-content {
  padding: 16px 40px 32px;
  flex: 1;
}

.swift-title {
  font-size: 2rem;
  font-weight: 800;
  background: linear-gradient(135deg, #F05138, #FC3221);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 12px;
}

.swift-description {
  color: rgba(255,255,255,0.6);
  font-size: 0.95rem;
  line-height: 1.7;
  margin-bottom: 20px;
}

.swift-features {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

.swift-feature {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 10px 20px;
  border-radius: 999px;
  background: rgba(240, 81, 56, 0.08);
  border: 1px solid rgba(240, 81, 56, 0.15);
  font-size: 0.8rem;
  font-weight: 500;
  color: rgba(255,255,255,0.7);
}

.swift-feature .material-symbols-outlined {
  font-size: 16px;
  color: var(--ark-swift-orange);
}

/* --- Clone Section --- */
.clone-section {
  padding: 100px 40px 120px;
  max-width: 800px;
  margin: 0 auto;
}

.clone-card {
  background: var(--md-sys-color-surface-container);
  border: 1px solid rgba(255,255,255,0.06);
  border-radius: 24px;
  padding: 48px;
  box-shadow: 0 8px 32px rgba(0,0,0,0.3);
}

.clone-methods {
  display: flex;
  flex-direction: column;
  gap: 16px;
  margin-bottom: 24px;
}

.clone-method {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.clone-label {
  display: flex;
  align-items: center;
  gap: 8px;
  font-weight: 600;
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--md-sys-color-on-surface-variant);
}

.clone-label .material-symbols-outlined {
  font-size: 18px;
}

.clone-command {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 16px 24px;
  background: var(--ark-terminal-bg);
  border: 1px solid rgba(255,255,255,0.06);
  border-radius: 12px;
}

.clone-command code {
  flex: 1;
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.85rem;
  color: var(--ark-terminal-green);
  white-space: nowrap;
  overflow-x: auto;
}

.clone-actions {
  text-align: center;
}

/* --- Philosophy Section --- */
.philosophy {
  padding: 80px 40px 120px;
  max-width: 1100px;
  margin: 0 auto;
}

.philosophy-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.philosophy-card {
  background: var(--md-sys-color-surface-container);
  border: 1px solid rgba(255,255,255,0.04);
  border-radius: 24px;
  padding: 48px;
  text-align: center;
  transition: transform 0.4s cubic-bezier(0.16, 1, 0.3, 1), box-shadow 0.4s ease, border-color 0.3s ease;
}

.philosophy-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 40px rgba(0,0,0,0.3);
  border-color: rgba(255,255,255,0.08);
}

.philosophy-icon {
  font-size: 40px;
  color: var(--md-sys-color-primary);
  margin-bottom: 16px;
  display: block;
}

.philosophy-card h3 {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 8px;
  color: var(--md-sys-color-on-surface);
}

.philosophy-card p {
  color: var(--md-sys-color-on-surface-variant);
  opacity: 0.7;
  font-size: 0.95rem;
  line-height: 1.6;
}

/* --- Footer --- */
footer {
  border-top: 1px solid rgba(255,255,255,0.04);
  padding: 40px 32px;
  text-align: center;
}

.footer-inner {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 8px;
}

.footer-logo {
  height: 28px;
  width: 28px;
  border-radius: 6px;
  object-fit: contain;
  filter: invert(1);
}

.footer-name {
  font-weight: 700;
  font-size: 1rem;
  color: var(--md-sys-color-on-surface);
}

.footer-text {
  font-size: 0.875rem;
  color: var(--md-sys-color-on-surface-variant);
  opacity: 0.6;
}

.footer-sub {
  opacity: 0.4;
  font-size: 0.8rem;
}

footer a {
  color: var(--md-sys-color-primary);
  text-decoration: none;
  transition: opacity 0.2s ease;
}

footer a:hover {
  opacity: 0.8;
}

/* --- Responsive --- */
@media (max-width: 768px) {
  .features-grid {
    grid-template-columns: 1fr;
  }

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

  .header-inner {
    padding: 12px 16px;
  }

  nav {
    gap: 0;
  }

  .hero {
    padding: 100px 20px 60px;
  }

  .features, .clone-section, .philosophy {
    padding-left: 20px;
    padding-right: 20px;
  }

  .swift-features {
    flex-direction: column;
    align-items: flex-start;
  }

  .clone-command code {
    font-size: 0.75rem;
  }

  .hero-title {
    font-size: clamp(3rem, 15vw, 5rem);
  }
}

/* --- Scrollbar --- */
::-webkit-scrollbar {
  width: 8px;
}

::-webkit-scrollbar-track {
  background: var(--md-sys-color-background);
}

::-webkit-scrollbar-thumb {
  background: var(--md-sys-color-outline-variant);
  border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--md-sys-color-outline);
}