/* ============================================================
   DESIGN TOKENS
   ============================================================ */
:root {
  --color-bg: #fafaf9;
  --color-surface: #ffffff;
  --color-border: #e5e5e3;
  --color-text: #1a1a18;
  --color-text-muted: #6b6b67;
  --color-accent: #1a1a18;
  --color-accent-hover: #3d3d38;
  --color-card-bg: #ffffff;
  --color-investment-bg: #f4f4f2;

  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;

  --size-xs: 0.75rem;
  --size-sm: 0.875rem;
  --size-base: 1rem;
  --size-lg: 1.125rem;
  --size-xl: 1.25rem;
  --size-2xl: 1.5rem;
  --size-3xl: 2rem;
  --size-4xl: 2.75rem;
  --size-5xl: 3.5rem;

  --section-padding: 6rem 1.5rem;
  --section-padding-sm: 4rem 1.5rem;

  --radius: 6px;
  --radius-lg: 10px;

  --nav-height: 64px;
  --shadow-nav: 0 1px 0 var(--color-border);
  --shadow-card: 0 1px 3px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.04);
}

/* ============================================================
   RESET & BASE
   ============================================================ */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; }

body {
  font-family: var(--font-sans);
  font-size: var(--size-base);
  line-height: 1.65;
  color: var(--color-text);
  background: var(--color-bg);
}

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

/* ============================================================
   LAYOUT
   ============================================================ */
.container {
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

.container--narrow {
  max-width: 680px;
}

/* ============================================================
   NAV
   ============================================================ */
#nav {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--nav-height);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 2rem;
  padding: 0 1.5rem;
  background: var(--color-surface);
  box-shadow: var(--shadow-nav);
}

.nav-logo {
  display: flex;
  flex-direction: column;
  text-decoration: none;
  color: var(--color-text);
  font-weight: 600;
  font-size: var(--size-base);
  line-height: 1.2;
  flex-shrink: 0;
}

.nav-tagline {
  font-size: var(--size-xs);
  font-weight: 400;
  color: var(--color-text-muted);
}

.nav-links {
  display: flex;
  gap: 2rem;
  list-style: none;
}

.nav-links a {
  text-decoration: none;
  color: var(--color-text-muted);
  font-size: var(--size-sm);
  font-weight: 500;
  transition: color 0.15s;
}

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

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--color-text);
  border-radius: 2px;
  transition: opacity 0.15s;
}

/* ============================================================
   BUTTONS
   ============================================================ */
.btn-primary {
  display: inline-block;
  padding: 0.75rem 1.75rem;
  background: var(--color-accent);
  color: #fff;
  font-size: var(--size-base);
  font-weight: 600;
  text-decoration: none;
  border: none;
  border-radius: var(--radius);
  cursor: pointer;
  transition: background 0.15s;
}

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

/* ============================================================
   HERO
   ============================================================ */
#hero {
  padding: 7rem 1.5rem 6rem;
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
}

#hero .container {
  max-width: 960px;
}

#hero h1 {
  font-size: clamp(var(--size-3xl), 5vw, 2.875rem);
  font-weight: 700;
  line-height: 1.15;
  letter-spacing: -0.02em;
  margin-bottom: 1.25rem;
}

.hero-sub {
  font-size: var(--size-lg);
  color: var(--color-text-muted);
  max-width: 660px;
  margin-bottom: 2.25rem;
  line-height: 1.6;
}

/* ============================================================
   PROBLEM / SOLUTION
   ============================================================ */
#problem {
  padding: var(--section-padding);
  background: var(--color-bg);
}

#problem .container {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.problem-hook {
  font-size: var(--size-2xl);
  font-weight: 600;
  line-height: 1.3;
  letter-spacing: -0.01em;
}

#problem p {
  font-size: var(--size-lg);
  color: var(--color-text-muted);
}

#problem .problem-hook { color: var(--color-text); }

/* ============================================================
   THE OFFERING
   ============================================================ */
#offering {
  padding: var(--section-padding);
  background: var(--color-surface);
  border-top: 1px solid var(--color-border);
  border-bottom: 1px solid var(--color-border);
}

#offering h2 {
  font-size: var(--size-xs);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--color-text-muted);
  margin-bottom: 0.5rem;
}

.offering-title {
  font-size: var(--size-3xl);
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 1rem;
}

.offering-intro {
  font-size: var(--size-lg);
  color: var(--color-text-muted);
  max-width: 680px;
  margin-bottom: 2.5rem;
  line-height: 1.6;
}

.offering-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
}

.offering-col h4 {
  font-size: var(--size-sm);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-text-muted);
  margin-bottom: 1rem;
}

.offering-col ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
  margin-bottom: 1.5rem;
}

.offering-col ul li {
  padding-left: 1.25rem;
  position: relative;
  color: var(--color-text);
  font-size: var(--size-base);
}

.offering-col ul li::before {
  content: "–";
  position: absolute;
  left: 0;
  color: var(--color-text-muted);
}

.offering-timeline {
  font-size: var(--size-sm);
  color: var(--color-text-muted);
  margin-bottom: 0;
}

.investment-block {
  background: var(--color-investment-bg);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  margin-bottom: 2rem;
}

.investment-price {
  font-size: var(--size-2xl);
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 0.5rem;
}

.investment-block p {
  font-size: var(--size-sm);
  color: var(--color-text-muted);
  line-height: 1.55;
}

.offering-optional {
  font-size: var(--size-sm);
  color: var(--color-text-muted);
  margin-top: 1rem;
  padding-top: 1rem;
  border-top: 1px solid var(--color-border);
}

/* ============================================================
   BACKGROUND
   ============================================================ */
#background {
  padding: var(--section-padding);
  background: var(--color-bg);
}

#background h2 {
  font-size: var(--size-xs);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--color-text-muted);
  margin-bottom: 1rem;
}

.background-body {
  font-size: var(--size-lg);
  line-height: 1.7;
  max-width: 700px;
  margin-bottom: 1rem;
}

.background-body:last-of-type {
  margin-bottom: 3rem;
}

.logo-row {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  align-items: center;
}

.logo-placeholder {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.5rem 1.25rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  font-size: var(--size-sm);
  font-weight: 500;
  color: var(--color-text-muted);
  background: var(--color-surface);
  min-width: 90px;
}

/* ============================================================
   CASE STUDIES
   ============================================================ */
#case-studies {
  padding: var(--section-padding);
  background: var(--color-surface);
  border-top: 1px solid var(--color-border);
  border-bottom: 1px solid var(--color-border);
}

#case-studies h2 {
  font-size: var(--size-xs);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--color-text-muted);
  margin-bottom: 2rem;
}

.cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1.5rem;
}

.card {
  background: var(--color-card-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 1.75rem;
  box-shadow: var(--shadow-card);
}

.card-label {
  display: inline-block;
  font-size: var(--size-xs);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-text-muted);
  margin-bottom: 0.75rem;
}

.card h3 {
  font-size: var(--size-xl);
  font-weight: 600;
  letter-spacing: -0.01em;
  margin-bottom: 0.85rem;
  line-height: 1.3;
}

.card p {
  font-size: var(--size-sm);
  color: var(--color-text-muted);
  line-height: 1.65;
}

.card p + p {
  margin-top: 0.65rem;
}

/* ============================================================
   CONTACT
   ============================================================ */
#contact {
  padding: var(--section-padding);
  background: var(--color-bg);
}

#contact h2 {
  font-size: var(--size-3xl);
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 1rem;
}

.contact-intro {
  font-size: var(--size-lg);
  color: var(--color-text-muted);
  margin-bottom: 2.5rem;
  line-height: 1.6;
  max-width: 560px;
}

form {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.form-group label {
  font-size: var(--size-sm);
  font-weight: 500;
  color: var(--color-text);
}

.required {
  color: var(--color-text-muted);
  margin-left: 2px;
}

.field-hint {
  font-weight: 400;
  color: var(--color-text-muted);
}

.form-group input,
.form-group textarea {
  font-family: var(--font-sans);
  font-size: var(--size-base);
  color: var(--color-text);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 0.65rem 0.875rem;
  width: 100%;
  transition: border-color 0.15s, box-shadow 0.15s;
  outline: none;
}

.form-group input:focus,
.form-group textarea:focus {
  border-color: var(--color-accent);
  box-shadow: 0 0 0 3px rgba(26,26,24,0.08);
}

.form-group textarea {
  resize: vertical;
  min-height: 120px;
}

form .btn-primary { align-self: flex-start; }

.form-success {
  font-size: var(--size-lg);
  color: var(--color-text);
  padding: 2rem 0;
}

.form-error {
  font-size: var(--size-sm);
  color: #c0392b;
  margin-top: 0.75rem;
}

/* ============================================================
   FOOTER
   ============================================================ */
#footer {
  background: var(--color-surface);
  border-top: 1px solid var(--color-border);
  padding: 2rem 1.5rem;
}

.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1rem;
}

.footer-logo {
  font-weight: 600;
  font-size: var(--size-sm);
}

.footer-links {
  display: flex;
  gap: 1.5rem;
}

.footer-links a {
  text-decoration: none;
  color: var(--color-text-muted);
  font-size: var(--size-sm);
  transition: color 0.15s;
}

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

.footer-copy {
  font-size: var(--size-xs);
  color: var(--color-text-muted);
}

/* ============================================================
   RESPONSIVE
   ============================================================ */
@media (max-width: 768px) {
  :root {
    --section-padding: 4rem 1.25rem;
  }

  /* Nav mobile */
  .nav-toggle { display: flex; }

  .nav-links {
    display: none;
    position: absolute;
    top: var(--nav-height);
    left: 0;
    right: 0;
    background: var(--color-surface);
    flex-direction: column;
    padding: 1rem 1.5rem 1.5rem;
    gap: 1rem;
    box-shadow: 0 4px 12px rgba(0,0,0,0.08);
    border-bottom: 1px solid var(--color-border);
  }

  .nav-links.is-open { display: flex; }

  .nav-links a { font-size: var(--size-base); }

  /* Offering grid */
  .offering-grid {
    grid-template-columns: 1fr;
    gap: 2.5rem;
  }

  /* Footer */
  .footer-inner {
    flex-direction: column;
    align-items: flex-start;
  }
}

@media (max-width: 480px) {
  #hero { padding: 5rem 1.25rem 4rem; }

  .cards-grid {
    grid-template-columns: 1fr;
  }

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