/* ============================================================
   Nevola Engine — Design System
   nevolagroup.com
   ============================================================ */

:root {
  /* Color tokens — Light mode default */
  --color-bg: #FAFAF8;
  --color-surface: #FFFFFF;
  --color-surface-alt: #F4F3EF;
  --color-text: #0F1419;
  --color-text-muted: #5B6068;
  --color-text-faint: #9CA0A6;
  --color-border: rgba(15, 20, 25, 0.08);
  --color-border-strong: rgba(15, 20, 25, 0.16);
  --color-accent: #1B7F8C;
  --color-accent-hover: #146570;
  --color-accent-soft: rgba(27, 127, 140, 0.08);
  --color-code-bg: #0F1419;
  --color-code-text: #E8E8E5;

  /* Typography */
  --font-display: 'Space Grotesk', system-ui, -apple-system, sans-serif;
  --font-body: 'Inter', system-ui, -apple-system, sans-serif;
  --font-mono: 'JetBrains Mono', ui-monospace, 'SF Mono', Menlo, monospace;

  /* Type scale (fluid) */
  --text-xs: clamp(0.75rem, 0.72rem + 0.13vw, 0.8125rem);
  --text-sm: clamp(0.875rem, 0.85rem + 0.13vw, 0.9375rem);
  --text-base: clamp(1rem, 0.95rem + 0.25vw, 1.0625rem);
  --text-lg: clamp(1.125rem, 1.05rem + 0.38vw, 1.25rem);
  --text-xl: clamp(1.5rem, 1.35rem + 0.75vw, 1.875rem);
  --text-2xl: clamp(2rem, 1.65rem + 1.75vw, 3rem);
  --text-hero: clamp(2.5rem, 2rem + 2.5vw, 4.25rem);

  /* Spacing scale */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;
  --space-24: 6rem;
  --space-32: 8rem;

  /* Radius */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-xl: 20px;

  /* Layout */
  --container-max: 1200px;
  --container-narrow: 760px;
  --container-prose: 65ch;

  /* Motion */
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
  --ease-in-out: cubic-bezier(0.65, 0, 0.35, 1);
  --duration-fast: 0.18s;
  --duration-base: 0.3s;
  --duration-slow: 0.5s;

  /* Shadows (tone-matched to warm surface) */
  --shadow-sm: 0 1px 2px rgba(15, 20, 25, 0.04);
  --shadow-md: 0 4px 12px rgba(15, 20, 25, 0.06), 0 1px 2px rgba(15, 20, 25, 0.04);
  --shadow-lg: 0 12px 32px rgba(15, 20, 25, 0.08), 0 2px 6px rgba(15, 20, 25, 0.04);
}

/* Dark mode */
@media (prefers-color-scheme: dark) {
  :root {
    --color-bg: #0B0B0C;
    --color-surface: #131315;
    --color-surface-alt: #1A1A1C;
    --color-text: #E8E8E5;
    --color-text-muted: #9A9A95;
    --color-text-faint: #66666A;
    --color-border: rgba(232, 232, 229, 0.08);
    --color-border-strong: rgba(232, 232, 229, 0.16);
    --color-accent: #4FA8B5;
    --color-accent-hover: #75BFCB;
    --color-accent-soft: rgba(79, 168, 181, 0.10);
    --color-code-bg: #050506;
    --color-code-text: #D8D8D5;
  }
}

/* ============================================================
   Reset & base
   ============================================================ */

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

html {
  -webkit-text-size-adjust: 100%;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
  font-feature-settings: 'ss01', 'cv01', 'cv02';
}

body {
  margin: 0;
  background: var(--color-bg);
  color: var(--color-text);
  font-family: var(--font-body);
  font-size: var(--text-base);
  line-height: 1.55;
  font-weight: 400;
  letter-spacing: -0.005em;
  min-height: 100vh;
}

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

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

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
  color: inherit;
}

code,
pre,
kbd {
  font-family: var(--font-mono);
  font-size: 0.92em;
  font-feature-settings: 'liga' 0, 'calt' 0;
}

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

/* Focus */
:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 3px;
  border-radius: var(--radius-sm);
}

/* Skip link */
.skip-link {
  position: absolute;
  top: -100px;
  left: var(--space-4);
  background: var(--color-text);
  color: var(--color-bg);
  padding: var(--space-2) var(--space-4);
  border-radius: var(--radius-sm);
  font-weight: 500;
  z-index: 100;
  transition: top var(--duration-fast) var(--ease-out);
}

.skip-link:focus {
  top: var(--space-4);
}

/* ============================================================
   Typography
   ============================================================ */

h1, h2, h3, h4, h5, h6 {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 500;
  letter-spacing: -0.02em;
  line-height: 1.15;
  color: var(--color-text);
}

p {
  margin: 0 0 var(--space-4);
  color: var(--color-text);
}

p:last-child {
  margin-bottom: 0;
}

.eyebrow {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: 500;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-accent);
  margin-bottom: var(--space-4);
}

.muted {
  color: var(--color-text-muted);
}

/* ============================================================
   Layout
   ============================================================ */

.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding-inline: clamp(1.25rem, 4vw, 2.5rem);
}

.container--narrow {
  max-width: var(--container-narrow);
}

section {
  padding-block: clamp(var(--space-16), 8vw, var(--space-32));
}

section.compact {
  padding-block: clamp(var(--space-12), 5vw, var(--space-16));
}

/* ============================================================
   Header
   ============================================================ */

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  padding-block: var(--space-4);
  background: color-mix(in srgb, var(--color-bg) 86%, transparent);
  backdrop-filter: saturate(180%) blur(12px);
  -webkit-backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid transparent;
  transition: border-color var(--duration-base) var(--ease-out);
}

.site-header.is-scrolled {
  border-bottom-color: var(--color-border);
}

.site-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-8);
}

.site-header__logo {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-family: var(--font-display);
  font-size: var(--text-base);
  font-weight: 600;
  letter-spacing: -0.01em;
  color: var(--color-text);
}

.site-header__logo svg {
  width: 24px;
  height: 24px;
  color: var(--color-text);
}

.site-header__nav {
  display: flex;
  align-items: center;
  gap: var(--space-6);
  font-size: var(--text-sm);
  font-weight: 450;
}

.site-header__nav a {
  color: var(--color-text-muted);
}

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

@media (max-width: 720px) {
  .site-header__nav a:not(.btn) {
    display: none;
  }
}

/* ============================================================
   Buttons
   ============================================================ */

.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: 0.625rem var(--space-4);
  font-size: var(--text-sm);
  font-weight: 500;
  border-radius: var(--radius-md);
  transition:
    background var(--duration-fast) var(--ease-out),
    color var(--duration-fast) var(--ease-out),
    border-color var(--duration-fast) var(--ease-out),
    transform var(--duration-fast) var(--ease-out);
  border: 1px solid transparent;
  white-space: nowrap;
  text-decoration: none;
}

.btn--primary {
  background: var(--color-text);
  color: var(--color-bg);
}

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

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

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

.btn--ghost {
  background: transparent;
  color: var(--color-text-muted);
  padding-inline: var(--space-2);
}

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

.btn--lg {
  padding: 0.875rem 1.25rem;
  font-size: var(--text-base);
}

.btn .arrow {
  transition: transform var(--duration-fast) var(--ease-out);
}

.btn:hover .arrow {
  transform: translateX(3px);
}

/* ============================================================
   Hero
   ============================================================ */

.hero {
  padding-block: clamp(var(--space-24), 12vw, var(--space-32));
}

.hero__inner {
  max-width: 880px;
}

.hero__headline {
  font-size: var(--text-hero);
  font-weight: 500;
  letter-spacing: -0.035em;
  line-height: 1.02;
  margin-bottom: var(--space-6);
  max-width: 18ch;
}

.hero__subhead {
  font-size: var(--text-lg);
  color: var(--color-text-muted);
  max-width: 56ch;
  margin-bottom: var(--space-8);
  line-height: 1.5;
}

.hero__cta {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-3);
}

/* ============================================================
   Logo strip
   ============================================================ */

.logo-strip {
  border-top: 1px solid var(--color-border);
  border-bottom: 1px solid var(--color-border);
  padding-block: var(--space-12);
}

.logo-strip__label {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: 500;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  text-align: center;
  margin-bottom: var(--space-6);
}

.logo-strip__items {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: clamp(var(--space-6), 5vw, var(--space-16));
  align-items: center;
}

.logo-strip__item {
  font-family: var(--font-display);
  font-size: var(--text-base);
  font-weight: 500;
  color: var(--color-text-muted);
  letter-spacing: -0.005em;
  transition: color var(--duration-fast) var(--ease-out);
}

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

/* ============================================================
   Section heading block
   ============================================================ */

.section-head {
  margin-bottom: var(--space-12);
  max-width: 60ch;
}

.section-head h2 {
  font-size: var(--text-2xl);
  font-weight: 500;
  letter-spacing: -0.025em;
  margin-bottom: var(--space-4);
}

.section-head p {
  font-size: var(--text-lg);
  color: var(--color-text-muted);
  line-height: 1.5;
}

/* ============================================================
   Problem section
   ============================================================ */

.problem-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-8);
  max-width: 760px;
}

.problem-grid p {
  font-size: var(--text-base);
  color: var(--color-text-muted);
  line-height: 1.65;
}

/* ============================================================
   How it works — primitives
   ============================================================ */

.primitives {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-12);
  margin-top: var(--space-16);
}

@media (min-width: 768px) {
  .primitives {
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-8);
  }
}

.primitive {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.primitive__label {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: 500;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-accent);
}

.primitive__title {
  font-size: var(--text-xl);
  font-weight: 500;
  letter-spacing: -0.02em;
}

.primitive__body {
  font-size: var(--text-base);
  color: var(--color-text-muted);
  line-height: 1.55;
}

.primitive__snippet {
  margin-top: var(--space-3);
  padding: var(--space-3);
  background: var(--color-surface-alt);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-text);
  overflow-x: auto;
}

/* ============================================================
   Code example block
   ============================================================ */

.code-block {
  background: var(--color-code-bg);
  color: var(--color-code-text);
  border-radius: var(--radius-lg);
  overflow: hidden;
  margin-block: var(--space-6);
  border: 1px solid var(--color-border);
}

.code-block__header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-3) var(--space-4);
  background: color-mix(in srgb, var(--color-code-bg) 80%, white 8%);
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: rgba(232, 232, 229, 0.6);
}

.code-block pre {
  margin: 0;
  padding: var(--space-4);
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: 0.875rem;
  line-height: 1.65;
}

.code-block code {
  display: block;
  white-space: pre;
}

.code-block .tk-keyword { color: #C792EA; }
.code-block .tk-string  { color: #C3E88D; }
.code-block .tk-number  { color: #F78C6C; }
.code-block .tk-comment { color: #546E7A; font-style: italic; }
.code-block .tk-func    { color: #82AAFF; }
.code-block .tk-prop    { color: #FFCB6B; }
.code-block .tk-punct   { color: #89DDFF; }

.code-tabs {
  display: flex;
  gap: var(--space-1);
  margin-bottom: 0;
}

.code-tab {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  padding: 0.375rem 0.75rem;
  border-radius: var(--radius-sm);
  color: rgba(232, 232, 229, 0.6);
  cursor: pointer;
  border: 1px solid transparent;
  background: transparent;
}

.code-tab.is-active {
  color: var(--color-code-text);
  background: rgba(255, 255, 255, 0.08);
}

/* ============================================================
   Use cases
   ============================================================ */

.use-cases {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-12);
  margin-top: var(--space-12);
}

@media (min-width: 768px) {
  .use-cases {
    grid-template-columns: 1.3fr 1fr 1fr;
    gap: var(--space-8);
  }
}

.use-case {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  padding-top: var(--space-6);
  border-top: 1px solid var(--color-border);
}

.use-case__tag {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: 500;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-text-faint);
}

.use-case__title {
  font-size: var(--text-lg);
  font-weight: 500;
  letter-spacing: -0.015em;
}

.use-case__body {
  font-size: var(--text-base);
  color: var(--color-text-muted);
  line-height: 1.55;
}

/* ============================================================
   Pricing
   ============================================================ */

.pricing {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-4);
  margin-top: var(--space-12);
}

@media (min-width: 880px) {
  .pricing {
    grid-template-columns: repeat(3, 1fr);
  }
}

.tier {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
  padding: var(--space-8);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  position: relative;
  transition: border-color var(--duration-base) var(--ease-out);
}

.tier:hover {
  border-color: var(--color-border-strong);
}

.tier.is-featured {
  border-color: var(--color-accent);
}

.tier__badge {
  position: absolute;
  top: var(--space-4);
  right: var(--space-4);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: 500;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-accent);
}

.tier__name {
  font-family: var(--font-display);
  font-size: var(--text-base);
  font-weight: 500;
  letter-spacing: -0.005em;
  color: var(--color-text-muted);
}

.tier__price {
  font-family: var(--font-display);
  font-size: var(--text-2xl);
  font-weight: 500;
  letter-spacing: -0.03em;
  color: var(--color-text);
  font-feature-settings: 'tnum' 1, 'lnum' 1;
}

.tier__price small {
  font-size: var(--text-base);
  font-weight: 400;
  color: var(--color-text-muted);
}

.tier__features {
  list-style: none;
  padding: 0;
  margin: var(--space-4) 0 0;
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.tier__features li {
  display: flex;
  align-items: flex-start;
  gap: var(--space-2);
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  line-height: 1.5;
}

.tier__features li::before {
  content: '';
  flex-shrink: 0;
  display: inline-block;
  width: 16px;
  height: 16px;
  margin-top: 0.2em;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16' fill='none'%3E%3Cpath d='M3 8.5L6.5 12L13 5' stroke='%231B7F8C' stroke-width='1.75' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
}

.tier__cta {
  margin-top: auto;
  padding-top: var(--space-4);
}

.pricing-note {
  margin-top: var(--space-6);
  font-size: var(--text-sm);
  color: var(--color-text-faint);
  text-align: center;
}

/* ============================================================
   Pre-footer CTA
   ============================================================ */

.cta-section {
  text-align: center;
  padding-block: clamp(var(--space-16), 8vw, var(--space-24));
  border-top: 1px solid var(--color-border);
}

.cta-section h2 {
  font-size: var(--text-2xl);
  margin-bottom: var(--space-3);
}

.cta-section p {
  font-size: var(--text-lg);
  color: var(--color-text-muted);
  margin-bottom: var(--space-6);
}

.cta-section__buttons {
  display: inline-flex;
  flex-wrap: wrap;
  gap: var(--space-3);
  justify-content: center;
}

/* ============================================================
   Footer
   ============================================================ */

.site-footer {
  border-top: 1px solid var(--color-border);
  padding-block: var(--space-16) var(--space-8);
  font-size: var(--text-sm);
  color: var(--color-text-muted);
}

.site-footer__grid {
  display: grid;
  grid-template-columns: 1.5fr repeat(3, 1fr);
  gap: var(--space-8);
  margin-bottom: var(--space-12);
}

@media (max-width: 720px) {
  .site-footer__grid {
    grid-template-columns: 1fr 1fr;
  }
  .site-footer__brand {
    grid-column: 1 / -1;
  }
}

.site-footer__brand {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.site-footer__brand .logo-mark {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-family: var(--font-display);
  font-size: var(--text-base);
  font-weight: 600;
  color: var(--color-text);
}

.site-footer__brand .logo-mark svg {
  width: 22px;
  height: 22px;
}

.site-footer__brand p {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  max-width: 32ch;
}

.site-footer__col h4 {
  font-family: var(--font-body);
  font-size: var(--text-xs);
  font-weight: 500;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-text-faint);
  margin-bottom: var(--space-4);
}

.site-footer__col ul {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.site-footer__col a {
  color: var(--color-text-muted);
}

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

.site-footer__bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-3);
  padding-top: var(--space-6);
  border-top: 1px solid var(--color-border);
  font-size: var(--text-xs);
  color: var(--color-text-faint);
}

/* ============================================================
   Utility: hairline divider for inline use
   ============================================================ */

hr.hairline {
  border: none;
  border-top: 1px solid var(--color-border);
  margin-block: var(--space-12);
}

/* ============================================================
   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;
  }
}

/* ============================================================
   Print
   ============================================================ */

@media print {
  .site-header,
  .site-footer,
  .cta-section { display: none; }
  body { background: white; color: black; }
}