/* ========================================
   0. CUSTOM PROPERTIES (DESIGN TOKENS)
   ======================================== */

:root {
  /* Colors */
  --color-bg: #0C0C0E;
  --color-bg-raised: #161618;
  --color-bg-raised-2: #1E1E21;
  --color-surface-line: #2A2A2E;
  --color-text: #E8E6E1;
  --color-text-secondary: #8A8680;
  --color-accent: #4A90D9;
  --color-accent-bright: #5B9BD5;
  --color-accent-muted: rgba(74, 144, 217, 0.12);
  --color-signal: #14B8A6;
  --color-signal-dim: rgba(20, 184, 166, 0.15);
  --color-danger: #EF4444;
  --color-warn: #F59E0B;

  /* Typography */
  --font-sans: 'Instrument Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', system-ui, sans-serif;
  --font-mono: 'IBM Plex Mono', ui-monospace, 'Cascadia Code', 'Courier New', monospace;
  --text-xs: 0.75rem;
  --text-sm: 0.875rem;
  --text-base: 1rem;
  --text-lg: 1.125rem;
  --text-xl: 1.5rem;
  --text-2xl: 2rem;
  --text-hero: clamp(2.25rem, 5vw, 3.25rem);
  --leading-tight: 1.15;
  --leading-normal: 1.6;
  --tracking-tight: -0.02em;
  --tracking-wide: 0.08em;

  /* Spacing */
  --space-xs: 0.5rem;
  --space-sm: 1rem;
  --space-md: 1.5rem;
  --space-lg: 2.5rem;
  --space-xl: 4rem;
  --space-section: clamp(4rem, 8vw, 7rem);

  /* Layout */
  --max-width: 1120px;
  --radius: 6px;
  --radius-lg: 10px;

  /* Transitions */
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
  --duration-fast: 150ms;
  --duration-normal: 300ms;

  /* Grid dot pattern */
  --grid-dot: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='32' height='32'%3E%3Ccircle cx='16' cy='16' r='1' fill='%232A2A2E'/%3E%3C/svg%3E");
}


/* ========================================
   1. RESET & BASE
   ======================================== */

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

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

body {
  font-family: var(--font-sans);
  font-size: var(--text-base);
  line-height: var(--leading-normal);
  color: var(--color-text);
  background-color: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

::selection {
  background: var(--color-accent-muted);
  color: var(--color-text);
}

img, svg {
  display: block;
  max-width: 100%;
}

a {
  color: var(--color-accent);
  text-decoration: none;
  transition: color var(--duration-fast) ease;
}

a:hover {
  color: var(--color-accent-bright);
}

ul, ol {
  list-style: none;
}


/* ========================================
   2. TYPOGRAPHY
   ======================================== */

h1, h2, h3, h4 {
  font-weight: 600;
  line-height: var(--leading-tight);
  letter-spacing: var(--tracking-tight);
  color: var(--color-text);
}

h1 { font-size: var(--text-hero); }
h2 { font-size: var(--text-2xl); }
h3 { font-size: var(--text-lg); }

.text-mono { font-family: var(--font-mono); }
.text-xs { font-size: var(--text-xs); }
.text-sm { font-size: var(--text-sm); }
.text-secondary { color: var(--color-text-secondary); }


/* ========================================
   3. LAYOUT UTILITIES
   ======================================== */

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-md);
}

.section {
  padding: var(--space-section) 0;
}

.section__header {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  flex-wrap: wrap;
  margin-bottom: var(--space-xs);
}

.section__title {
  margin-bottom: var(--space-xs);
}

.section__header .section__title {
  margin-bottom: 0;
}

.section__intro {
  color: var(--color-text-secondary);
  max-width: 640px;
  margin-bottom: var(--space-lg);
  font-size: var(--text-lg);
}

.bg-grid {
  background-image: var(--grid-dot);
  background-size: 32px 32px;
}

.grid {
  display: grid;
  gap: var(--space-md);
}

.grid--2 { grid-template-columns: repeat(2, 1fr); }
.grid--3 { grid-template-columns: repeat(3, 1fr); }


/* ========================================
   4. COMPONENTS
   ======================================== */

/* --- Skip link --- */
.skip-link {
  position: absolute;
  top: -100%;
  left: var(--space-sm);
  background: var(--color-accent);
  color: var(--color-bg);
  padding: var(--space-xs) var(--space-sm);
  border-radius: var(--radius);
  z-index: 1000;
  font-weight: 600;
  font-size: var(--text-sm);
}

.skip-link:focus {
  top: var(--space-sm);
}

/* --- Buttons --- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.75rem 1.5rem;
  border-radius: var(--radius);
  font-family: var(--font-sans);
  font-size: var(--text-sm);
  font-weight: 600;
  cursor: pointer;
  transition: all var(--duration-normal) var(--ease-out);
  border: 1px solid transparent;
  text-decoration: none;
  min-height: 44px;
}

.btn--primary {
  background: var(--color-accent);
  color: #fff;
  border-color: var(--color-accent);
}

.btn--primary:hover {
  background: var(--color-accent-bright);
  border-color: var(--color-accent-bright);
  color: #fff;
}

.btn--secondary {
  background: transparent;
  color: var(--color-text-secondary);
  border-color: var(--color-surface-line);
}

.btn--secondary:hover {
  color: var(--color-text);
  border-color: var(--color-text-secondary);
}

/* --- Cards --- */
.card {
  background: var(--color-bg-raised);
  border: 1px solid var(--color-surface-line);
  border-radius: var(--radius-lg);
  padding: var(--space-md);
}

.card__title {
  margin-bottom: var(--space-xs);
}

.card__body {
  color: var(--color-text-secondary);
  font-size: var(--text-sm);
  line-height: var(--leading-normal);
}

/* --- Badges --- */
.badge {
  display: inline-flex;
  align-items: center;
  padding: 0.25rem 0.625rem;
  border-radius: 100px;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: 400;
  letter-spacing: var(--tracking-wide);
  text-transform: uppercase;
  white-space: nowrap;
}

.badge--status {
  background: var(--color-accent-muted);
  color: var(--color-accent);
  border: 1px solid rgba(74, 144, 217, 0.2);
}

.badge--confidence {
  background: var(--color-signal-dim);
  color: var(--color-signal);
  border: 1px solid rgba(20, 184, 166, 0.2);
}

.badge--action {
  background: var(--color-bg-raised);
  color: var(--color-text-secondary);
  border: 1px solid var(--color-surface-line);
  text-transform: none;
  letter-spacing: normal;
  font-family: var(--font-sans);
  font-size: var(--text-xs);
}

/* --- Signal dot --- */
.signal-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--color-signal);
  display: inline-block;
  flex-shrink: 0;
}

.signal-dot--live {
  animation: pulse-dot 2s ease-in-out infinite;
}

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

a:focus:not(:focus-visible),
button:focus:not(:focus-visible) {
  outline: none;
}


/* ========================================
   5. NAVIGATION
   ======================================== */

.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  padding: var(--space-sm) 0;
  transition: background var(--duration-normal) ease,
              backdrop-filter var(--duration-normal) ease;
}

.nav--scrolled {
  background: rgba(12, 12, 14, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-surface-line);
}

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

.nav__wordmark {
  font-weight: 700;
  font-size: var(--text-base);
  color: var(--color-text);
  letter-spacing: var(--tracking-tight);
  text-decoration: none;
}

.nav__wordmark:hover {
  color: var(--color-text);
}

.nav__toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  width: 44px;
  height: 44px;
  align-items: center;
  justify-content: center;
  flex-direction: column;
  gap: 5px;
}

.nav__toggle span {
  display: block;
  width: 20px;
  height: 1.5px;
  background: var(--color-text);
  transition: all var(--duration-normal) ease;
}

.nav__links {
  display: flex;
  align-items: center;
  gap: var(--space-lg);
}

.nav__links a {
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  transition: color var(--duration-fast) ease;
  padding: var(--space-xs) 0;
}

.nav__links a:hover {
  color: var(--color-text);
}


/* ========================================
   6. HERO
   ======================================== */

.hero {
  padding-top: calc(var(--space-section) + 4rem);
  padding-bottom: var(--space-xl);
  min-height: 85vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.hero__content {
  max-width: 720px;
}

.hero__heading {
  margin-bottom: var(--space-md);
}

.hero__sub {
  color: var(--color-text-secondary);
  font-size: var(--text-lg);
  max-width: 600px;
  margin-bottom: var(--space-lg);
}

.hero__ctas {
  display: flex;
  gap: var(--space-sm);
  flex-wrap: wrap;
  margin-bottom: var(--space-md);
}

.hero__trust {
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
}

.hero__signal {
  margin-top: var(--space-xl);
  max-width: 900px;
  margin-left: auto;
  margin-right: auto;
  opacity: 0.8;
}

.signal-svg {
  width: 100%;
  height: auto;
}


/* ========================================
   7. PRODUCT SECTION
   ======================================== */

/* --- Alert mock --- */
.alert-mock {
  background: var(--color-bg-raised-2);
  border: 1px solid var(--color-surface-line);
  border-radius: var(--radius-lg);
  padding: var(--space-md);
  max-width: 680px;
  margin-top: var(--space-lg);
}

.alert-mock__header {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  padding-bottom: var(--space-sm);
  border-bottom: 1px solid var(--color-surface-line);
  flex-wrap: wrap;
}

.alert-mock__status {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
}

.alert-mock__body {
  padding-top: var(--space-xs);
}

.alert-mock__row {
  display: grid;
  grid-template-columns: 90px 1fr;
  gap: var(--space-sm);
  padding: var(--space-xs) 0;
  border-bottom: 1px solid rgba(42, 42, 46, 0.5);
}

.alert-mock__row--last {
  border-bottom: none;
}

.alert-mock__label {
  color: var(--color-text-secondary);
  font-size: var(--text-xs);
  text-transform: uppercase;
  letter-spacing: var(--tracking-wide);
  padding-top: 2px;
}

.alert-mock__value {
  color: var(--color-text);
  font-size: var(--text-sm);
  line-height: var(--leading-normal);
}

.alert-mock__actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-xs);
}

.alert-mock__footer {
  padding-top: var(--space-sm);
  border-top: 1px solid var(--color-surface-line);
  margin-top: var(--space-xs);
}


/* ========================================
   8. APPROACH SECTION
   ======================================== */

.approach__list {
  max-width: 640px;
}

.approach__list li {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
  padding: var(--space-sm) 0;
  padding-left: var(--space-md);
  border-left: 2px solid var(--color-surface-line);
  position: relative;
}

.approach__list li::before {
  content: '';
  position: absolute;
  left: -5px;
  top: calc(var(--space-sm) + 0.5em);
  width: 8px;
  height: 8px;
  background: var(--color-accent);
  border-radius: 2px;
}

.approach__list li + li {
  margin-top: var(--space-xs);
}

.approach__list strong {
  color: var(--color-text);
  font-weight: 600;
}

.approach__list span {
  color: var(--color-text-secondary);
  font-size: var(--text-sm);
}


/* ========================================
   9. USE CASES SECTION
   ======================================== */

/* Uses .grid--2 and .card classes */


/* ========================================
   10. SECURITY SECTION
   ======================================== */

.security__list {
  max-width: 540px;
}

.security__list li {
  display: flex;
  align-items: flex-start;
  gap: var(--space-sm);
  padding: var(--space-sm) 0;
}

.security__list li + li {
  border-top: 1px solid var(--color-surface-line);
}

.security__icon {
  width: 20px;
  height: 20px;
  flex-shrink: 0;
  color: var(--color-accent);
  margin-top: 2px;
}

.security__list span {
  font-size: var(--text-base);
}


/* ========================================
   11. CONTACT SECTION
   ======================================== */

.contact-form {
  max-width: 480px;
}

.contact-form__field {
  margin-bottom: var(--space-sm);
}

.contact-form__field label {
  display: block;
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  margin-bottom: 0.375rem;
  font-weight: 500;
}

.contact-form__field input,
.contact-form__field textarea {
  width: 100%;
  padding: 0.625rem 0.875rem;
  background: var(--color-bg-raised);
  border: 1px solid var(--color-surface-line);
  border-radius: var(--radius);
  color: var(--color-text);
  font-family: var(--font-sans);
  font-size: var(--text-base);
  transition: border-color var(--duration-fast) ease;
}

.contact-form__field input:focus,
.contact-form__field textarea:focus {
  border-color: var(--color-accent);
  outline: none;
}

.contact-form__field textarea {
  resize: vertical;
  min-height: 100px;
}

.contact-form .btn {
  margin-top: var(--space-xs);
}


/* ========================================
   12. FOOTER
   ======================================== */

.footer {
  padding: var(--space-lg) 0;
  border-top: 1px solid var(--color-surface-line);
}

.footer__inner {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: var(--space-md);
  flex-wrap: wrap;
}

.footer__wordmark {
  display: block;
  font-weight: 700;
  font-size: var(--text-sm);
  color: var(--color-text);
  margin-bottom: 0.375rem;
}

.footer__email {
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
}

.footer__email:hover {
  color: var(--color-accent);
}

.footer__legal {
  text-align: right;
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
}

.footer__legal p + p {
  margin-top: 0.25rem;
}


/* ========================================
   13. ANIMATIONS & KEYFRAMES
   ======================================== */

/* Signal line draw */
.signal-line,
.signal-glow {
  stroke-dasharray: 1;
  stroke-dashoffset: 1;
  animation: draw-signal 2.2s var(--ease-out) 0.5s forwards;
}

.signal-glow {
  animation-delay: 0.6s;
}

@keyframes draw-signal {
  to { stroke-dashoffset: 0; }
}

/* Signal dot pulse */
@keyframes pulse-dot {
  0%, 100% { opacity: 1; box-shadow: 0 0 0 0 var(--color-signal-dim); }
  50% { opacity: 0.6; box-shadow: 0 0 0 6px transparent; }
}

/* Fade-in for sections */
[data-animate] {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s var(--ease-out), transform 0.6s var(--ease-out);
}

[data-animate].is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* Stagger cards within a grid */
.grid[data-animate].is-visible .card:nth-child(1) { transition-delay: 0ms; }
.grid[data-animate].is-visible .card:nth-child(2) { transition-delay: 100ms; }
.grid[data-animate].is-visible .card:nth-child(3) { transition-delay: 200ms; }
.grid[data-animate].is-visible .card:nth-child(4) { transition-delay: 300ms; }

.grid[data-animate] .card {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.5s var(--ease-out), transform 0.5s var(--ease-out);
}

.grid[data-animate].is-visible .card {
  opacity: 1;
  transform: translateY(0);
}


/* ========================================
   14. REDUCED MOTION
   ======================================== */

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }

  html {
    scroll-behavior: auto;
  }

  .signal-line,
  .signal-glow {
    stroke-dashoffset: 0;
    animation: none;
  }

  .signal-traveler {
    display: none;
  }

  .signal-dot--live {
    animation: none;
    opacity: 1;
  }

  [data-animate] {
    opacity: 1;
    transform: none;
    transition: none;
  }

  .grid[data-animate] .card {
    opacity: 1;
    transform: none;
    transition: none;
  }
}


/* ========================================
   15. RESPONSIVE
   ======================================== */

@media (max-width: 768px) {
  .grid--2 { grid-template-columns: 1fr; }
  .grid--3 { grid-template-columns: 1fr; }

  .hero {
    min-height: auto;
    padding-top: calc(var(--space-section) + 2rem);
  }

  .nav__toggle {
    display: flex;
  }

  .nav__links {
    position: fixed;
    top: 0;
    right: 0;
    bottom: 0;
    width: 260px;
    background: var(--color-bg-raised);
    border-left: 1px solid var(--color-surface-line);
    flex-direction: column;
    align-items: flex-start;
    padding: 5rem var(--space-md) var(--space-md);
    gap: var(--space-sm);
    transform: translateX(100%);
    transition: transform var(--duration-normal) var(--ease-out);
    z-index: 99;
  }

  .nav__links.is-open {
    transform: translateX(0);
  }

  .nav__links a {
    font-size: var(--text-base);
    padding: var(--space-xs) 0;
  }

  .alert-mock__row {
    grid-template-columns: 1fr;
    gap: 0.25rem;
  }

  .footer__inner {
    flex-direction: column;
    gap: var(--space-md);
  }

  .footer__legal {
    text-align: left;
  }
}

@media (max-width: 480px) {
  h1 { font-size: clamp(1.75rem, 6vw, 2.25rem); }
  h2 { font-size: var(--text-xl); }

  .hero__ctas {
    flex-direction: column;
  }

  .hero__ctas .btn {
    width: 100%;
    text-align: center;
  }
}