/* ============================================================
   Northbound — Meta Ads Growth Studio
   Custom dark-first palette + Clash Display / Satoshi
   ============================================================ */

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

html {
  -moz-text-size-adjust: none;
  -webkit-text-size-adjust: none;
  text-size-adjust: none;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
  scroll-behavior: smooth;
  scroll-padding-top: var(--space-16);
}

/* ---------- Design Tokens ---------- */
:root {
  --font-display: 'Clash Display', 'Satoshi', sans-serif;
  --font-body: 'Satoshi', 'Inter', sans-serif;

  --text-xs: clamp(0.75rem, 0.7rem + 0.25vw, 0.875rem);
  --text-sm: clamp(0.875rem, 0.8rem + 0.35vw, 1rem);
  --text-base: clamp(1rem, 0.95rem + 0.25vw, 1.125rem);
  --text-lg: clamp(1.125rem, 1rem + 0.75vw, 1.5rem);
  --text-xl: clamp(1.5rem, 1.2rem + 1.25vw, 2.25rem);
  --text-2xl: clamp(2rem, 1.2rem + 2.5vw, 3.5rem);
  --text-hero: clamp(2.375rem, 0.6rem + 5.5vw, 5rem);

  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.25rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;
  --space-24: 6rem;
  --space-32: 8rem;

  --radius-sm: 0.5rem;
  --radius-md: 0.75rem;
  --radius-lg: 1rem;
  --radius-full: 9999px;

  --transition-interactive: 180ms cubic-bezier(0.16, 1, 0.3, 1);

  --content-narrow: 640px;
  --content-default: 960px;
  --content-wide: 1200px;

  --color-primary: #3d7bff;
  --color-primary-hover: #5b8fff;
  --color-primary-soft: rgba(61, 123, 255, 0.12);
}

/* Light mode */
:root,
[data-theme='light'] {
  --color-bg: #f6f7f9;
  --color-surface: #ffffff;
  --color-surface-2: #fbfcfe;
  --color-surface-offset: #eef1f5;
  --color-divider: #e5e8ee;
  --color-border: #d7dce4;
  --color-text: #0f1217;
  --color-text-muted: #5b6270;
  --color-text-faint: #9aa1ad;
  --color-text-inverse: #f6f7f9;
  --shadow-sm: 0 1px 2px rgba(15, 18, 23, 0.05);
  --shadow-md: 0 4px 16px rgba(15, 18, 23, 0.07);
  --shadow-lg: 0 16px 48px rgba(15, 18, 23, 0.10);
}

/* Dark mode (default) */
[data-theme='dark'] {
  --color-bg: #0a0b0f;
  --color-surface: #101219;
  --color-surface-2: #14161e;
  --color-surface-offset: #1a1d26;
  --color-divider: #22252f;
  --color-border: #2b2f3b;
  --color-text: #eef0f4;
  --color-text-muted: #9aa0ad;
  --color-text-faint: #767c88;
  --color-text-inverse: #0a0b0f;
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 16px 48px rgba(0, 0, 0, 0.5);
}

body {
  min-height: 100dvh;
  line-height: 1.6;
  font-family: var(--font-body);
  font-size: var(--text-base);
  color: var(--color-text);
  background-color: var(--color-bg);
  overflow-x: hidden;
}

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

ul[role='list'],
ol[role='list'] {
  list-style: none;
}

input,
button,
textarea,
select {
  font: inherit;
  color: inherit;
}

h1, h2, h3, h4, h5, h6 {
  text-wrap: balance;
  line-height: 1.12;
  font-family: var(--font-display);
}

p, li, figcaption {
  text-wrap: pretty;
  max-width: 72ch;
}

::selection {
  background: var(--color-primary);
  color: #fff;
}

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

@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;
  }
}

button { cursor: pointer; background: none; border: none; }

a, button, [role='button'], input, textarea, select {
  transition:
    color var(--transition-interactive),
    background var(--transition-interactive),
    border-color var(--transition-interactive),
    box-shadow var(--transition-interactive),
    transform var(--transition-interactive),
    opacity var(--transition-interactive);
}

.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;
}

/* ---------- Shared primitives ---------- */
.section {
  padding-block: clamp(var(--space-16), 8vw, var(--space-32));
}
.section--tinted {
  background: var(--color-surface);
  border-top: 1px solid var(--color-divider);
  border-bottom: 1px solid var(--color-divider);
}
.section__inner {
  max-width: var(--content-wide);
  margin-inline: auto;
  padding-inline: clamp(var(--space-4), 5vw, var(--space-8));
}

.eyebrow {
  font-family: var(--font-body);
  font-weight: 500;
  font-size: var(--text-xs);
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--color-primary);
  margin-bottom: var(--space-4);
}

.section__title {
  font-size: var(--text-2xl);
  font-weight: 600;
  letter-spacing: -0.01em;
  max-width: 20ch;
}

.section__lede {
  margin-top: var(--space-5);
  font-size: var(--text-base);
  color: var(--color-text-muted);
  max-width: 62ch;
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-family: var(--font-body);
  font-weight: 500;
  font-size: var(--text-sm);
  text-decoration: none;
  border-radius: var(--radius-full);
  padding: var(--space-3) var(--space-6);
  white-space: nowrap;
}
.btn--primary {
  background: var(--color-primary);
  color: #fff;
  box-shadow: 0 8px 24px var(--color-primary-soft);
}
.btn--primary:hover {
  background: var(--color-primary-hover);
  transform: translateY(-1px);
}
.btn--ghost {
  color: var(--color-text);
  border: 1px solid var(--color-border);
}
.btn--ghost:hover {
  border-color: var(--color-text-faint);
}
.btn--sm { padding: var(--space-2) var(--space-5); }
.btn--lg { padding: var(--space-4) var(--space-8); font-size: var(--text-base); }

.icon-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 38px;
  height: 38px;
  border-radius: var(--radius-full);
  color: var(--color-text-muted);
  border: 1px solid var(--color-border);
}
.icon-btn:hover { color: var(--color-text); border-color: var(--color-text-faint); }

.lang-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 38px;
  height: 38px;
  border-radius: var(--radius-full);
  border: 1px solid var(--color-border);
  color: var(--color-text-muted);
  font-family: var(--font-body);
  font-size: var(--text-xs);
  font-weight: 600;
  letter-spacing: 0.05em;
}
.lang-btn:hover { color: var(--color-text); border-color: var(--color-text-faint); }

/* ---------- Header ---------- */
.header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: color-mix(in oklab, var(--color-bg) 82%, transparent);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid transparent;
}
.header--scrolled { border-bottom-color: var(--color-divider); }
.header__inner {
  max-width: var(--content-wide);
  margin-inline: auto;
  padding-inline: clamp(var(--space-4), 5vw, var(--space-8));
  height: 72px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-6);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: var(--space-3);
  text-decoration: none;
  color: var(--color-text);
}
.brand__mark { color: var(--color-primary); }
.brand__word {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: var(--text-lg);
  letter-spacing: -0.01em;
}

.nav { display: flex; align-items: center; gap: var(--space-8); }
.nav__link {
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--color-text-muted);
  text-decoration: none;
}
.nav__link:hover { color: var(--color-text); }

.header__actions { display: flex; align-items: center; gap: var(--space-3); }

/* ---------- Hero ---------- */
.hero {
  position: relative;
  min-height: 92vh;
  display: flex;
  align-items: center;
  overflow: hidden;
}
.hero__glow {
  position: absolute;
  inset: 0;
  pointer-events: none;
  background:
    radial-gradient(60% 50% at 75% 30%, var(--color-primary-soft), transparent 70%);
}
.hero__content {
  position: relative;
  z-index: 2;
  max-width: var(--content-wide);
  margin-inline: auto;
  padding-inline: clamp(var(--space-4), 5vw, var(--space-8));
  padding-block: var(--space-24);
  width: 100%;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: var(--space-6);
}
.hero__title {
  font-size: var(--text-hero);
  font-weight: 600;
  letter-spacing: -0.02em;
  line-height: 1.02;
  max-width: 15ch;
}
.accent { color: var(--color-primary); }
.hero__sub {
  font-size: var(--text-lg);
  color: var(--color-text-muted);
  max-width: 46ch;
}
.hero__cta { display: flex; gap: var(--space-4); flex-wrap: wrap; margin-top: var(--space-4); }
.hero__note {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  letter-spacing: 0.02em;
}

.hero__chart {
  position: absolute;
  right: 0;
  bottom: 0;
  width: min(560px, 55vw);
  opacity: 0.9;
  pointer-events: none;
}
.hero__chart-svg { width: 100%; height: auto; }
/* ---------- Pillars (approach) ---------- */
.pillars {
  margin-top: var(--space-16);
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-8);
}
.pillar {
  padding: var(--space-8);
  border: 1px solid var(--color-divider);
  border-radius: var(--radius-lg);
  background: var(--color-surface-2);
}
.pillar__num {
  font-family: var(--font-body);
  font-weight: 500;
  font-size: var(--text-xs);
  letter-spacing: 0.12em;
  color: var(--color-primary);
  margin-bottom: var(--space-4);
}
.pillar__title {
  font-size: var(--text-lg);
  font-weight: 600;
  margin-bottom: var(--space-3);
}
.pillar__body { font-size: var(--text-base); color: var(--color-text-muted); }

/* ---------- Services ---------- */
.services {
  margin-top: var(--space-16);
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-8);
}
.service {
  padding: var(--space-8);
  border: 1px solid var(--color-divider);
  border-radius: var(--radius-lg);
  background: var(--color-bg);
  transition: border-color var(--transition-interactive), transform var(--transition-interactive);
}
.service:hover { border-color: var(--color-border); transform: translateY(-2px); }
.service__head {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  margin-bottom: var(--space-4);
}
.service__icon {
  flex: none;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 46px;
  height: 46px;
  border-radius: var(--radius-md);
  color: var(--color-primary);
  background: var(--color-primary-soft);
}
.service__title { font-size: var(--text-lg); font-weight: 600; }
.service__body { font-size: var(--text-base); color: var(--color-text-muted); }

/* ---------- Process ---------- */
.process {
  margin-top: var(--space-16);
  list-style: none;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-8);
}
.process__step {
  padding-top: var(--space-6);
  border-top: 1px solid var(--color-divider);
}
.process__num {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: var(--text-xl);
  color: var(--color-primary);
}
.process__title {
  font-size: var(--text-lg);
  font-weight: 600;
  margin: var(--space-3) 0 var(--space-3);
}
.process__body { font-size: var(--text-base); color: var(--color-text-muted); }

/* ---------- Why ---------- */
.section__inner--split {
  display: grid;
  grid-template-columns: 1.35fr 1fr;
  gap: clamp(var(--space-12), 6vw, var(--space-32));
  align-items: center;
}
.why__list {
  margin-top: var(--space-8);
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}
.why__list li {
  font-size: var(--text-base);
  color: var(--color-text-muted);
  padding-left: var(--space-6);
  position: relative;
}
.why__list li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0.55em;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--color-primary);
}
.why__list strong { color: var(--color-text); font-weight: 500; }

.why__stat {
  padding: var(--space-10);
  border: 1px solid var(--color-divider);
  border-radius: var(--radius-lg);
  background:
    linear-gradient(160deg, var(--color-primary-soft), transparent 55%),
    var(--color-surface-2);
}
.why__stat-mark {
  color: var(--color-primary);
  margin-bottom: var(--space-6);
}
.why__stat-label {
  font-size: var(--text-xs);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-text-faint);
  margin-bottom: var(--space-2);
}
.why__stat-line {
  font-family: var(--font-display);
  font-size: var(--text-xl);
  font-weight: 600;
  line-height: 1.25;
}

/* ---------- CTA ---------- */
.cta { text-align: center; }
.cta__inner {
  max-width: var(--content-narrow);
  margin-inline: auto;
  padding-inline: var(--space-4);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-5);
}
.cta__title { font-size: var(--text-2xl); font-weight: 600; }
.cta__sub { color: var(--color-text-muted); }
.cta .btn { margin-top: var(--space-4); }

/* ---------- Footer ---------- */
.footer {
  border-top: 1px solid var(--color-divider);
  padding-block: var(--space-16);
}
.footer__inner {
  max-width: var(--content-wide);
  margin-inline: auto;
  padding-inline: clamp(var(--space-4), 5vw, var(--space-8));
  display: flex;
  flex-direction: column;
  gap: var(--space-6);
}
.footer__line {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  max-width: 52ch;
}
.footer__meta {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
}

/* ---------- Reveal animation ---------- */
.reveal {
  opacity: 0;
  transform: translateY(20px);
}
.reveal.is-visible {
  opacity: 1;
  transform: none;
  transition: opacity 0.7s cubic-bezier(0.16, 1, 0.3, 1), transform 0.7s cubic-bezier(0.16, 1, 0.3, 1);
}
@media (prefers-reduced-motion: reduce) {
  .reveal { opacity: 1; transform: none; }
}

/* ---------- Responsive ---------- */
@media (max-width: 900px) {
  .nav { display: none; }
  .pillars { grid-template-columns: 1fr; }
  .services { grid-template-columns: 1fr; }
  .process { grid-template-columns: 1fr 1fr; }
  .section__inner--split { grid-template-columns: 1fr; }
}
@media (max-width: 560px) {
  .hero__chart { width: 120vw; opacity: 0.25; }
  .process { grid-template-columns: 1fr; }
  .brand__word { display: none; }
  .hero__cta { flex-direction: column; align-items: stretch; }
  .hero__cta .btn { justify-content: center; }
}