/* =========================================================================
   Rank — global design system styles
   ========================================================================= */
@import url("https://fonts.googleapis.com/css2?family=Space+Grotesk:wght@400;500;600;700&family=Inter:wght@400;500;600;700&family=JetBrains+Mono:wght@400;500&display=swap");

:root {
  --color-canvas:       #ffffff;
  --color-primary:      #17171c;
  --color-ink:          #212121;
  --color-deep-green:   #003c33;
  --color-soft-stone:   #eeece7;
  --color-pale-green:   #edfce9;
  --color-pale-blue:    #f1f5ff;
  --color-coral:        #ff7759;
  --color-coral-soft:   #ffad9b;
  --color-action-blue:  #1863dc;
  --color-focus-blue:   #4c6ee6;
  --color-body-muted:   #616161;
  --color-slate:        #75758a;
  --color-muted:        #93939f;
  --color-hairline:     #d9d9dd;
  --color-border-light: #e5e7eb;
  --color-card-border:  #f2f2f2;
  --color-error:        #b30000;

  --font-display: "Space Grotesk", "Inter", ui-sans-serif, system-ui, -apple-system, sans-serif;
  --font-body:    "Inter", ui-sans-serif, system-ui, -apple-system, sans-serif;
  --font-mono:    "JetBrains Mono", ui-monospace, "SFMono-Regular", Menlo, monospace;

  --r-xs:   4px;
  --r-sm:   8px;
  --r-md:   16px;
  --r-lg:   22px;
  --r-pill: 32px;
  --r-full: 9999px;

  --ease: cubic-bezier(0.2, 0.8, 0.2, 1);
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  font-family: var(--font-body);
  background: var(--color-canvas);
  color: var(--color-ink);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  padding-top: 65px;
}

::selection { background: var(--color-coral); color: var(--color-primary); }
:focus-visible { outline: 2px solid var(--color-focus-blue); outline-offset: 2px; }

a { color: var(--color-ink); text-decoration: none; transition: opacity 180ms var(--ease); }

/* =========================================================================
   Header / Nav
   ========================================================================= */
header {
  background: var(--color-canvas);
  border-bottom: 1px solid var(--color-card-border);
  padding: 0 32px;
  height: 65px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
}

.header-left {
  display: flex;
  align-items: center;
  gap: 32px;
}

.header-right {
  display: flex;
  align-items: center;
  gap: 12px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
}

.logo-icon {
  width: 52px;
  height: 52px;
  background-image: url("assets/rank-mark.png");
  background-size: contain;
  background-position: center;
  background-repeat: no-repeat;
  display: inline-block;
}

.logo-name {
  font-family: var(--font-display);
  font-size: 18px;
  font-weight: 600;
  letter-spacing: -0.4px;
  color: var(--color-primary);
  text-decoration: none;
}

nav {
  display: flex;
  align-items: center;
  gap: 28px;
}

nav a {
  color: var(--color-ink);
  font-size: 14px;
  font-weight: 400;
  transition: opacity 180ms var(--ease);
}
nav a:hover { opacity: 0.6; }

.rank-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-body);
  font-weight: 500;
  font-size: 14px;
  line-height: 1.71;
  background: var(--color-primary);
  color: #ffffff;
  border: 0;
  padding: 10px 22px;
  border-radius: var(--r-pill);
  cursor: pointer;
  transition: background 180ms var(--ease), transform 100ms;
}
.rank-btn:hover { background: #000; }
.rank-btn:active { transform: scale(0.98); }


/* =========================================================================
   Hero
   ========================================================================= */
main {
  padding: 96px 32px 80px;
  max-width: 980px;
  margin: 0 auto;
  text-align: center;
}

main h1 {
  font-family: var(--font-display);
  font-size: 84px;
  line-height: 1;
  letter-spacing: -1.6px;
  color: var(--color-primary);
  font-weight: 500;
  text-wrap: balance;
}

.subtitle {
  margin: 28px auto 0;
  font-family: var(--font-body);
  font-size: 18px;
  line-height: 1.5;
  color: var(--color-body-muted);
  max-width: 580px;
  font-weight: 400;
}

.hero-btn {
  margin-top: 36px;
  padding: 14px 28px;
  font-size: 15px;
}

.gradient-text {
  background: linear-gradient(90deg, var(--color-deep-green) 0%, var(--color-coral) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* =========================================================================
   Why section
   ========================================================================= */
.why-section {
  padding: 80px 32px;
  max-width: 1100px;
  margin: 0 auto;
  text-align: center;
}

.why-section h2 {
  font-family: var(--font-body);
  font-size: 48px;
  font-weight: 400;
  letter-spacing: -0.48px;
  line-height: 1.1;
  color: var(--color-primary);
  text-wrap: balance;
}

.why-subtitle {
  margin: 16px auto 0;
  color: var(--color-body-muted);
  font-size: 18px;
  line-height: 1.4;
  max-width: 580px;
}

.cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  margin-top: 56px;
}

.card {
  border: 1px solid var(--color-card-border);
  border-top: 1px solid var(--color-hairline);
  border-radius: var(--r-sm);
  padding: 28px 24px;
  text-align: left;
  background: var(--color-canvas);
  display: flex;
  flex-direction: column;
  gap: 14px;
  min-height: 220px;
}

.card-icon {
  width: 40px;
  height: 40px;
  color: var(--color-primary);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 0;
}
.card-icon svg { width: 40px; height: 40px; }

.card h3 {
  font-family: var(--font-body);
  font-size: 24px;
  font-weight: 400;
  letter-spacing: -0.2px;
  line-height: 1.3;
  color: var(--color-primary);
}

.card p {
  font-size: 15px;
  color: var(--color-body-muted);
  line-height: 1.5;
  margin: 0;
}

@media (max-width: 720px) {
  .cards { grid-template-columns: 1fr; }
  main h1 { font-size: 56px; letter-spacing: -1.2px; }
  .why-section h2, .how-section h2 { font-size: 36px; }
}

/* =========================================================================
   How it works section
   ========================================================================= */
.how-section {
  margin: 80px auto;
  max-width: 1280px;
  padding: 80px 48px;
  background: var(--color-pale-green);
  border-radius: var(--r-lg);
  text-align: center;
}

.how-section h2 {
  font-family: var(--font-body);
  font-size: 48px;
  font-weight: 400;
  letter-spacing: -0.48px;
  line-height: 1.1;
  color: var(--color-primary);
  text-wrap: balance;
}

.how-subtitle {
  margin: 16px auto 0;
  color: var(--color-body-muted);
  font-size: 18px;
  line-height: 1.4;
  max-width: 540px;
}

.steps {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: 12px;
  margin-top: 56px;
  align-items: start;
  text-align: left;
}

.step {
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.step-top {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 4px;
}

.step-number {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.06em;
  color: var(--color-slate);
  text-transform: uppercase;
  flex-shrink: 0;
}
.step-number::before { content: "0"; }

.step-connector {
  flex: 1;
  height: 1px;
  background: rgba(0, 60, 51, 0.18);
}

.step-icon {
  width: 32px;
  height: 32px;
  color: var(--color-primary);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 0;
}
.step-icon svg { width: 32px; height: 32px; }

.step h3 {
  font-family: var(--font-body);
  font-size: 18px;
  font-weight: 500;
  color: var(--color-primary);
  line-height: 1.3;
}

.step p {
  font-size: 13px;
  color: var(--color-body-muted);
  line-height: 1.5;
}

@media (max-width: 900px) {
  .steps { grid-template-columns: 1fr 1fr; }
  .step-connector { display: none; }
}
@media (max-width: 560px) {
  .steps { grid-template-columns: 1fr; }
  .how-section { padding: 48px 24px; }
}

/* =========================================================================
   Footer
   ========================================================================= */
footer {
  background: var(--color-primary);
  color: rgba(255, 255, 255, 0.55);
  text-align: center;
  padding: 32px 24px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}
footer p { margin: 0; }