/* ==========================================================
   Design tokens
   ========================================================== */

:root {
  --bg: #f7f8fc;
  --bg-alt: #eef0f7;
  --surface: #ffffff;
  --border: rgba(15, 23, 42, 0.07);
  --border-hover: rgba(99, 102, 241, 0.28);
  --text-1: #0f1729;
  --text-2: #3e4c68;
  --text-3: #6b7a94;
  --accent: #6366f1;
  --accent-subtle: rgba(99, 102, 241, 0.08);
  --accent-gradient: linear-gradient(135deg, #818cf8, #6366f1);

  --s-1: 0.25rem;
  --s-2: 0.5rem;
  --s-3: 0.75rem;
  --s-4: 1rem;
  --s-5: 1.5rem;
  --s-6: 2rem;
  --s-7: 2.5rem;
  --s-8: 3rem;
  --s-9: 4rem;
  --s-10: 5rem;
  --s-11: 6rem;
  --s-12: 8rem;

  --max-w: 1100px;
  --radius: 1rem;
  --radius-lg: 1.5rem;
  --radius-sm: 0.625rem;

  --ease: cubic-bezier(0.22, 1, 0.36, 1);
  --dur: 220ms;
}

/* ==========================================================
   Reset
   ========================================================== */

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

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: "Inter", ui-sans-serif, system-ui, -apple-system, sans-serif;
  font-feature-settings: "cv01", "cv02", "cv03", "cv04";
  line-height: 1.6;
  color: var(--text-1);
  background: var(--bg);
}

a {
  color: inherit;
  text-decoration: none;
}

h1, h2, h3, p { margin: 0; }
img, svg { display: block; }
button { font: inherit; cursor: pointer; border: none; background: none; }

/* ==========================================================
   Container
   ========================================================== */

.container {
  width: 100%;
  max-width: var(--max-w);
  margin-inline: auto;
  padding-inline: var(--s-5);
}

/* ==========================================================
   Skip link
   ========================================================== */

.skip-link {
  position: absolute;
  top: -100%;
  left: var(--s-4);
  background: var(--text-1);
  color: #fff;
  padding: var(--s-2) var(--s-3);
  border-radius: var(--radius-sm);
  font-size: 0.85rem;
  font-weight: 500;
  z-index: 200;
}

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

/* ==========================================================
   Floating header
   ========================================================== */

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  padding: var(--s-3) var(--s-4) 0;
}

.nav-bar {
  max-width: var(--max-w);
  margin-inline: auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  min-height: 3.25rem;
  padding: 0 var(--s-5);
  border-radius: var(--radius);
  background: rgba(247, 248, 252, 0.82);
  backdrop-filter: blur(20px) saturate(1.6);
  -webkit-backdrop-filter: blur(20px) saturate(1.6);
  border: 1px solid var(--border);
  box-shadow: 0 2px 16px rgba(15, 23, 42, 0.04);
  transition:
    box-shadow 300ms var(--ease),
    border-color 300ms var(--ease),
    background 300ms var(--ease);
}

.site-header.scrolled .nav-bar {
  background: rgba(247, 248, 252, 0.96);
  box-shadow: 0 4px 24px rgba(15, 23, 42, 0.08);
  border-color: rgba(15, 23, 42, 0.1);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: var(--s-2);
  font-weight: 660;
  font-size: 1.06rem;
  letter-spacing: -0.02em;
}

.brand-mark {
  display: inline-grid;
  place-items: center;
  width: 1.625rem;
  height: 1.625rem;
  border-radius: 7px;
  background: var(--accent-gradient);
  color: #fff;
  font-size: 0.8rem;
  font-weight: 700;
}

/* ==========================================================
   Nav links — mobile-first hidden, desktop visible
   ========================================================== */

.nav-links {
  display: none;
  align-items: center;
  gap: var(--s-1);
}

.nav-links a {
  display: inline-flex;
  align-items: center;
  min-height: 2.5rem;
  padding: 0 var(--s-3);
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-2);
  cursor: pointer;
  transition:
    color var(--dur),
    background var(--dur);
}

.nav-links a:hover {
  color: var(--text-1);
  background: var(--accent-subtle);
}

.nav-links a:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

.nav-links.is-open {
  display: flex;
  flex-direction: column;
  order: 3;
  width: 100%;
  padding: var(--s-2) 0 var(--s-3);
  border-top: 1px solid var(--border);
  margin-top: var(--s-2);
  gap: 0;
}

.nav-links.is-open a {
  width: 100%;
  min-height: 2.75rem;
  justify-content: flex-start;
  padding: 0 var(--s-3);
}

/* ==========================================================
   Hamburger toggle
   ========================================================== */

.nav-toggle {
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 5px;
  width: 2.5rem;
  height: 2.5rem;
  padding: 0.5rem;
  border-radius: var(--radius-sm);
  transition: background var(--dur);
}

.nav-toggle:hover {
  background: var(--accent-subtle);
}

.nav-toggle span {
  display: block;
  width: 18px;
  height: 2px;
  background: var(--text-1);
  border-radius: 2px;
  transition:
    transform 300ms var(--ease),
    opacity 200ms;
}

.nav-toggle.is-open span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.nav-toggle.is-open span:nth-child(2) {
  opacity: 0;
}

.nav-toggle.is-open span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

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

.hero {
  position: relative;
  overflow: hidden;
  padding: var(--s-11) 0 var(--s-9);
}

.hero-glow {
  position: absolute;
  inset: 0;
  z-index: -2;
  background:
    radial-gradient(ellipse 75% 55% at 50% -5%, rgba(99, 102, 241, 0.22), transparent),
    radial-gradient(ellipse 50% 40% at 82% 10%, rgba(56, 189, 248, 0.14), transparent),
    radial-gradient(ellipse 45% 50% at 15% 20%, rgba(168, 85, 247, 0.1), transparent);
  animation: glowShift 16s ease-in-out infinite alternate;
}

.hero-grid {
  position: absolute;
  inset: 0;
  z-index: -1;
  background-image: radial-gradient(circle, rgba(99, 102, 241, 0.06) 1px, transparent 1px);
  background-size: 28px 28px;
  mask-image: radial-gradient(ellipse 55% 55% at 50% 40%, black, transparent);
  -webkit-mask-image: radial-gradient(ellipse 55% 55% at 50% 40%, black, transparent);
}

@keyframes glowShift {
  from { transform: translateY(0) scale(1); opacity: 1; }
  to   { transform: translateY(-5%) scale(1.04); opacity: 0.75; }
}

.hero-layout {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  gap: var(--s-7);
}

.hero-copy {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--s-4);
  max-width: 680px;
}

h1 {
  font-size: clamp(2.25rem, 7.5vw, 4.25rem);
  font-weight: 780;
  line-height: 1.08;
  letter-spacing: -0.04em;
  text-wrap: balance;
}

.subtitle {
  font-size: clamp(1.02rem, 2.8vw, 1.2rem);
  color: var(--text-2);
  max-width: 40ch;
  line-height: 1.65;
}

/* ==========================================================
   Badge
   ========================================================== */

.badge {
  display: inline-flex;
  align-items: center;
  gap: var(--s-2);
  width: fit-content;
  padding: 0.4rem var(--s-4);
  border-radius: 999px;
  background: var(--accent-subtle);
  color: var(--accent);
  font-size: 0.75rem;
  font-weight: 620;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.badge::before {
  content: "";
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: currentColor;
  animation: pulse 2.4s ease-in-out infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50%      { opacity: 0.35; transform: scale(0.6); }
}

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

.hero-pills {
  list-style: none;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--s-2);
}

.hero-pills li {
  padding: var(--s-2) var(--s-4);
  border-radius: 999px;
  border: 1px solid var(--border);
  background: var(--surface);
  font-size: 0.84rem;
  font-weight: 500;
  color: var(--text-2);
  cursor: default;
  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.03);
  transition:
    transform var(--dur) var(--ease),
    box-shadow var(--dur) var(--ease),
    border-color var(--dur) var(--ease);
}

.hero-pills li:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.06);
  border-color: var(--border-hover);
}

/* ==========================================================
   Sections — generous vertical rhythm
   ========================================================== */

.section {
  padding: var(--s-9) 0;
}

.section-heading {
  font-size: clamp(1.35rem, 4.5vw, 2rem);
  font-weight: 720;
  letter-spacing: -0.03em;
  margin-bottom: var(--s-6);
  text-align: center;
}

.section-heading::before {
  content: '';
  display: block;
  width: 2rem;
  height: 3px;
  background: var(--accent-gradient);
  border-radius: 999px;
  margin: 0 auto var(--s-4);
}

/* ==========================================================
   Value section (Problem → Solution)
   ========================================================== */

.section-value {
  background: var(--bg-alt);
}

.value-grid {
  display: grid;
  gap: var(--s-5);
  align-items: stretch;
}

.value-card {
  padding: var(--s-6) var(--s-5);
  border-radius: var(--radius-lg);
  background: var(--surface);
  border: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  gap: var(--s-3);
}

.value-card--accent {
  border-color: rgba(99, 102, 241, 0.18);
  background: linear-gradient(145deg, rgba(99, 102, 241, 0.04) 0%, var(--surface) 100%);
}

.value-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 2.75rem;
  height: 2.75rem;
  border-radius: var(--radius-sm);
  background: var(--accent-subtle);
  color: var(--accent);
}

.value-card h2 {
  font-size: clamp(1.15rem, 3.5vw, 1.45rem);
  font-weight: 660;
  letter-spacing: -0.02em;
}

.value-card p {
  color: var(--text-2);
  font-size: 0.95rem;
  line-height: 1.7;
  max-width: 42ch;
}

.value-divider {
  display: flex;
  justify-content: center;
  align-items: center;
  color: var(--accent);
  opacity: 0.3;
}

.value-divider svg {
  transform: rotate(90deg);
}

/* ==========================================================
   Steps — vertical cards with large gradient numbers
   ========================================================== */

.section-steps {
  overflow: hidden;
}

.steps {
  display: grid;
  gap: var(--s-4);
}

.step {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  padding: var(--s-6) var(--s-5);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border);
  background: var(--surface);
  cursor: default;
  position: relative;
  transition:
    transform var(--dur) var(--ease),
    box-shadow var(--dur) var(--ease),
    border-color var(--dur) var(--ease);
}

.step:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.06);
  border-color: var(--border-hover);
}

.step:focus-within {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

.step-num {
  font-size: 2.5rem;
  font-weight: 800;
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1;
  letter-spacing: -0.03em;
  margin-bottom: var(--s-3);
}

.step-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 3rem;
  height: 3rem;
  border-radius: var(--radius-sm);
  background: var(--accent-subtle);
  color: var(--accent);
  margin-bottom: var(--s-3);
}

.step h3 {
  font-size: 1rem;
  font-weight: 580;
  line-height: 1.45;
  max-width: 22ch;
}

/* ==========================================================
   Features — icon-topped cards
   ========================================================== */

.section-features {
  background: var(--bg-alt);
}

.features {
  display: grid;
  gap: var(--s-4);
}

.feature {
  padding: var(--s-6) var(--s-5);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border);
  background: var(--surface);
  cursor: default;
  display: flex;
  flex-direction: column;
  gap: var(--s-3);
  transition:
    transform var(--dur) var(--ease),
    box-shadow var(--dur) var(--ease),
    border-color var(--dur) var(--ease);
}

.feature:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.06);
  border-color: var(--border-hover);
}

.feature:focus-within {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

.feature-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 2.75rem;
  height: 2.75rem;
  border-radius: var(--radius-sm);
  background: var(--accent-subtle);
  color: var(--accent);
}

.feature h3 {
  font-size: 1.05rem;
  font-weight: 620;
  letter-spacing: -0.01em;
}

.feature p {
  color: var(--text-2);
  font-size: 0.92rem;
  line-height: 1.6;
}

/* ==========================================================
   Audience — accent top border cards
   ========================================================== */

.audience {
  display: grid;
  gap: var(--s-4);
}

.audience-card {
  padding: var(--s-6) var(--s-5);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border);
  background: var(--surface);
  cursor: default;
  display: flex;
  flex-direction: column;
  gap: var(--s-3);
  position: relative;
  overflow: hidden;
  transition:
    transform var(--dur) var(--ease),
    box-shadow var(--dur) var(--ease),
    border-color var(--dur) var(--ease);
}

.audience-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--accent-gradient);
}

.audience-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.06);
  border-color: var(--border-hover);
}

.audience-card:focus-within {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

.audience-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 2.75rem;
  height: 2.75rem;
  border-radius: var(--radius-sm);
  background: var(--accent-subtle);
  color: var(--accent);
}

.audience-card h3 {
  font-size: 1.05rem;
  font-weight: 620;
  letter-spacing: -0.01em;
}

.audience-card p {
  color: var(--text-2);
  font-size: 0.92rem;
  line-height: 1.6;
}

/* ==========================================================
   Closing — gradient card
   ========================================================== */

.closing {
  padding-bottom: var(--s-11);
}

.closing-content {
  background: var(--accent-gradient);
  border-radius: var(--radius-lg);
  padding: var(--s-9) var(--s-6);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--s-4);
  text-align: center;
  color: #ffffff;
  box-shadow: 0 12px 48px rgba(99, 102, 241, 0.25);
}

.closing-content .badge {
  background: rgba(255, 255, 255, 0.2);
  color: #ffffff;
}

.closing-content .badge::before {
  background: #ffffff;
}

.closing-content h2 {
  font-size: clamp(1.35rem, 5vw, 2.25rem);
  font-weight: 740;
  letter-spacing: -0.03em;
  text-wrap: balance;
  color: #ffffff;
}

.closing-content p:not(.badge) {
  color: rgba(255, 255, 255, 0.85);
  max-width: 34ch;
  font-size: 0.98rem;
  line-height: 1.65;
}

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

.site-footer {
  border-top: 1px solid var(--border);
  padding: var(--s-6) 0;
}

.footer-bar {
  display: flex;
  flex-direction: column;
  gap: var(--s-3);
  align-items: flex-start;
  font-size: 0.86rem;
}

.footer-brand {
  font-weight: 660;
  letter-spacing: -0.01em;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: var(--s-2) var(--s-4);
}

.footer-links a {
  color: var(--text-3);
  min-height: 2.75rem;
  display: inline-flex;
  align-items: center;
  cursor: pointer;
  transition: color var(--dur);
}

.footer-links a:hover {
  color: var(--text-1);
}

.footer-links a:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
  border-radius: 4px;
}

/* ==========================================================
   Reveal animation
   ========================================================== */

.reveal {
  opacity: 0;
  transform: translateY(20px);
  transition:
    opacity 600ms var(--ease),
    transform 600ms var(--ease);
  will-change: opacity, transform;
}

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

.stagger > .reveal:nth-child(1) { transition-delay: 60ms; }
.stagger > .reveal:nth-child(2) { transition-delay: 140ms; }
.stagger > .reveal:nth-child(3) { transition-delay: 220ms; }
.stagger > .reveal:nth-child(4) { transition-delay: 290ms; }
.stagger > .reveal:nth-child(5) { transition-delay: 350ms; }
.stagger > .reveal:nth-child(6) { transition-delay: 410ms; }

/* ==========================================================
   Tablet — 640px
   ========================================================== */

@media (min-width: 640px) {
  .container {
    padding-inline: var(--s-6);
  }

  .site-header {
    padding: var(--s-3) var(--s-5) 0;
  }

  .hero {
    padding: var(--s-12) 0 var(--s-10);
  }

  .section {
    padding: var(--s-10) 0;
  }

  .value-grid {
    grid-template-columns: 1fr auto 1fr;
    gap: var(--s-5);
  }

  .value-divider svg {
    transform: rotate(0deg);
  }

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

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

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

  .closing {
    padding-bottom: var(--s-12);
  }

  .closing-content {
    padding: var(--s-10) var(--s-8);
  }

  .footer-bar {
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
  }
}

/* ==========================================================
   Desktop nav breakpoint — 768px
   ========================================================== */

@media (min-width: 768px) {
  .nav-links,
  .nav-links.is-open {
    display: flex;
    flex-direction: row;
    align-items: center;
    gap: var(--s-1);
    order: unset;
    width: auto;
    padding: 0;
    border-top: none;
    margin-top: 0;
  }

  .nav-toggle {
    display: none;
  }
}

/* ==========================================================
   Desktop — 1024px
   ========================================================== */

@media (min-width: 1024px) {
  .container {
    padding-inline: var(--s-7);
  }

  .hero {
    padding: var(--s-12) 0 var(--s-11);
    min-height: 80vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
  }

  h1 {
    font-size: 4.25rem;
  }

  .section {
    padding: var(--s-11) 0;
  }

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

  .step:not(:last-child)::after {
    content: '';
    position: absolute;
    top: 50%;
    right: calc(-0.5rem - 1px);
    width: 1rem;
    height: 2px;
    background: var(--border);
    transform: translateY(-50%);
  }
}

/* ==========================================================
   Large screens — 1440px
   ========================================================== */

@media (min-width: 1440px) {
  :root {
    --max-w: 1180px;
  }
}

/* ==========================================================
   Reduced motion
   ========================================================== */

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  .hero-glow {
    animation: none;
  }

  .badge::before {
    animation: none;
  }

  .reveal,
  .reveal.is-visible {
    opacity: 1;
    transform: none;
    transition: none;
  }

  .step,
  .feature,
  .audience-card,
  .hero-pills li {
    transition: none;
  }

  .nav-toggle span {
    transition: none;
  }
}