/* ============================================================
   CYBIONT DS-v1.2 — "Observer Mode"
   ============================================================ */

/* 1. Core Tokens (CSS Variables) */
:root {
  /* Base Colors */
  --color-navy: #003a73;
  --color-midnight: #0b1320;
  --color-snow: #f7f8fa;
  --color-slate-light: #9aa6b8;
  --color-slate-dark: #525e6a;
  --color-signal-blue: #1b4de4;
  --color-emergent-green: #6baf1e;
  --color-white: #ffffff;

  /* Semantic Colors (Light Mode Default) */
  --color-bg: var(--color-snow);
  --color-bg-alt: var(--color-white);
  --color-text: var(--color-midnight);
  --color-text-secondary: var(--color-slate-dark);
  --color-border: #eaecef;
  --color-accent: var(--color-signal-blue);
  --header-bg: rgba(247, 248, 250, 0.7);

  /* Typography & Layout */
  --font-sans: 'Inter', 'IBM Plex Sans', system-ui, sans-serif;
  --font-mono: 'IBM Plex Mono', monospace;
  --max-width: 1140px;
  --gutter: 24px;

  /* Motion */
  --transition-swiss: cubic-bezier(0.4, 0, 0.2, 1);
  --duration-medium: 300ms;
  --duration-fast: 150ms;
}

/* Dark Mode (Observer Mode) */
[data-theme='dark'] {
  --color-bg: var(--color-midnight);
  --color-bg-alt: #1c2532;
  --color-text: var(--color-snow);
  --color-text-secondary: var(--color-slate-light);
  --color-border: #3e4a59;
  --color-accent: #4d7bff; /* Brightened Blue */
  --color-emergent-green: #8fdb3b; /* Brightened Green */
  --header-bg: rgba(11, 19, 32, 0.7);
}

/* 2. CSS Reset & Base Styles */
*, *::before, *::after {
  box-sizing: border-box;
}
html, body {
  margin: 0;
  padding: 0;
  font-family: var(--font-sans);
  background-color: var(--color-bg);
  color: var(--color-text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  overflow-y: scroll;
  transition: background-color var(--duration-medium) var(--transition-swiss), color var(--duration-medium) var(--transition-swiss);
}
img, video {
  max-width: 100%;
  height: auto;
  display: block;
}
button {
    font: inherit;
    cursor: pointer;
}

/* 3. Typography */
h1, h2, h3, h4 {
  color: var(--color-text);
  line-height: 1.2;
  margin-top: 2rem;
  margin-bottom: 1rem;
  font-weight: 700;
}
.section > h1:first-child,
.wrap > h1:first-child,
.wrap > h2:first-child,
.section .page-content > :first-child {
  margin-top: 0;
}
h1 { font-size: 2.5rem; }
h2 { font-size: 1.8rem; border-bottom: 1px solid var(--color-border); padding-bottom: 0.5rem; }
h3 { font-size: 1.4rem; }
h4 { font-size: 1.2rem; }

p, li, td {
  color: var(--color-text-secondary);
  margin-bottom: 1rem;
}
a {
  color: var(--color-accent);
  text-decoration: none;
  transition: color var(--duration-fast) var(--transition-swiss);
}
a:hover, a:focus {
  text-decoration: underline;
}

/* 4. Layout Utilities */
.wrap {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--gutter);
}
.grid2 {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: calc(var(--gutter) * 2);
}
.grid3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--gutter);
}

.section {
  padding: 4rem 0;
}
.section-alt {
    background-color: var(--color-bg-alt);
    border-top: 1px solid var(--color-border);
    border-bottom: 1px solid var(--color-border);
}

/* 5. Components */

/* Header */
header.site {
  position: sticky;
  top: 0;
  z-index: 1000;
  background-color: var(--header-bg);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--color-border);
}
.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 96px;
}
.brand {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  font-weight: 700;
  color: var(--color-text);
  text-decoration: none;
  line-height: 1;
  transition: filter var(--duration-fast) var(--transition-swiss);
}
.brand:hover,
.brand:focus-visible {
  filter: brightness(1.02);
}
.brand img {
    width: 32px;
    height: 32px;
}
.brand strong {
    font-size: clamp(17px, 2.6vw, 21px);
    font-weight: 700;
    letter-spacing: 0.02em;
    color: inherit;
}
@media (min-width: 768px) {
  .brand {
    gap: 6px;
  }
}
@media (min-width: 1024px) {
  .brand {
    gap: 8px;
  }
}
@media (max-width: 400px) {
  .brand {
    flex-direction: column;
    align-items: flex-start;
    gap: 4px;
  }
}
[data-theme='dark'] .brand strong {
    color: #ffffff;
}
.menu {
    display: flex;
    align-items: center;
    justify-content: flex-end;
    gap: 24px;
    flex-wrap: nowrap;
    white-space: nowrap;
}
.menu a, .menu button {
  margin-left: 0;
  padding: 6px 0;
  color: var(--color-text-secondary);
}
.menu a:hover, .menu button:hover {
    color: var(--color-text);
    text-decoration: none;
}

/* Theme Toggle Button */
#theme-toggle {
    background: none;
    border: 1px solid var(--color-border);
    color: var(--color-text-secondary);
    padding: 5px 8px;
    border-radius: 4px;
    font-size: 0.8rem;
}

@media (max-width: 820px) {
  .nav {
    flex-direction: column;
    align-items: flex-start;
    height: auto;
    padding: 12px 0;
    gap: 12px;
  }
  .menu {
    width: 100%;
    justify-content: flex-start;
    gap: 12px;
    flex-wrap: wrap;
    white-space: normal;
  }
}

/* Buttons */
.button {
    display: inline-block;
    padding: 10px 18px;
    border-radius: 6px;
    font-weight: 600;
    font-size: 0.9375rem;
    text-decoration: none;
    border: 1px solid var(--color-border);
    background-color: var(--color-bg-alt);
    color: var(--color-text);
    transition: opacity var(--duration-fast) var(--transition-swiss);
}
.button:hover {
    opacity: 0.8;
    text-decoration: none;
}
.button.primary {
    background-color: var(--color-accent);
    color: var(--color-white);
    border-color: var(--color-accent);
}
[data-theme="dark"] .button.primary {
    /* Ensure sufficient contrast on dark mode's brightened accent */
    color: var(--color-midnight);
}


/* Cards */
.card {
    background-color: var(--color-bg-alt);
    border: 1px solid var(--color-border);
    padding: var(--gutter);
    border-radius: 8px;
}
.card h3, .card h4 {
    margin-top: 0;
}

/* Founder Portrait (About Page) */
.founder-portrait {
    width: 100%;
    max-width: 480px;
    height: auto;
    border-radius: 8px;
    float: right;
    margin-left: var(--gutter);
    margin-bottom: var(--gutter);
    shape-outside: margin-box;
    border: 1px solid var(--color-border);
}

/* 6. Homepage Specific Styles */

/* Hero Section */
.hero {
  position: relative;
  min-height: 75vh;
  display: flex;
  align-items: center;
  overflow: hidden;
  color: var(--color-snow); /* Hero text is always light */
  background-color: var(--color-midnight); /* Fallback color */
}

.hero-background, .hero-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.hero-background {
    background-size: cover;
    background-position: center;
    z-index: 1;
}

.hero-media {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
    z-index: 2;
    opacity: 1;
    transition: opacity 600ms ease;
}

.hero-media.is-ended {
    opacity: 0;
    pointer-events: none;
}

/* Vignette Overlay */
.hero-overlay {
    z-index: 3;
    /* Matches the provided HTML snapshot styling */
    background: radial-gradient(120% 80% at 50% 30%, rgba(0,0,0,0) 0%, rgba(11, 19, 32, 0.45) 70%, rgba(11, 19, 32, 0.7) 100%);
}

.hero-content {
  position: relative;
  z-index: 5;
  padding-top: 4.5rem;
  padding-bottom: 4rem;
}

.hero-logo {
  width: 64px;
  height: 64px;
  margin-bottom: 2rem;
}

@media (min-width: 768px) {
  .hero-logo {
    width: 128px;
    height: 128px;
  }
}

.kicker {
    font-size: 0.9rem;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    opacity: 0.8;
    line-height: 1.7em;
}
.headline {
    font-size: clamp(2.5rem, 5vw, 3.5rem);
    margin: 1rem 0;
    color: var(--color-snow);
}
.subhead {
    max-width: 65ch;
    font-size: 1.1rem;
    opacity: 0.9;
    color: var(--color-snow);
}
.cta {
    margin-top: 2rem;
    display: flex;
    gap: 1rem;
}

/* Hero Buttons (Specific styles for contrast on hero) */
.hero .button {
    background: rgba(255, 255, 255, 0.1);
    border-color: rgba(255, 255, 255, 0.3);
    color: var(--color-white);
}
.hero .button:hover {
    background: rgba(255, 255, 255, 0.2);
}
.hero .button.primary {
    /* Use the standard signal blue for the primary CTA on the hero */
    background: var(--color-signal-blue);
    border-color: var(--color-signal-blue);
    color: var(--color-white);
}

/* Credibility Strip */
.strip {
    background-color: var(--color-bg-alt);
    border-top: 1px solid var(--color-border);
    border-bottom: 1px solid var(--color-border);
    padding: 1rem 0;
}
.strip .items {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 1rem;
    font-size: 0.85rem;
    color: var(--color-text-secondary);
}

/* 7. Knowledge Series Layout */
.knowledge-content {
    max-width: 800px; /* Narrower column for long-form readability */
}

/* 8. Footer */
footer.site {
  background-color: var(--color-bg-alt);
  border-top: 1px solid var(--color-border);
  padding: 3rem 0;
  font-size: 0.85rem;
  color: var(--color-text-secondary);
}
.footer-legal {
    margin-top: 1rem;
}
.footer-legal a {
    margin-right: 1rem;
}

/* 9. Accessibility & Responsiveness */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border-width: 0;
}

@media (max-width: 900px) {
  .grid2, .grid3 {
    grid-template-columns: 1fr;
    gap: var(--gutter);
  }
  .hero-content {
      padding-top: 2.5rem;
      padding-bottom: 2rem;
  }
  .founder-portrait {
      /* Center portrait on mobile instead of floating */
      float: none;
      margin: 0 auto var(--gutter) auto;
  }
}

/* Reduced Motion Preference */
@media (prefers-reduced-motion: reduce) {
  .hero-media {
    display: none;
  }
  * {
    /* Minimize motion */
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

/* 10. Table Styles (for comparison page) */
table {
    width: 100%;
    border-collapse: collapse;
    margin: 2rem 0;
}
th, td {
    border: 1px solid var(--color-border);
    padding: 12px 15px;
    text-align: left;
}
th {
    background-color: var(--color-bg-alt);
    font-weight: 700;
    color: var(--color-text);
}
/* Zebra striping */
tr:nth-child(even) {
    background-color: var(--color-bg-alt);
}