/* ============================================
   Bypart — Stylesheet
   Single shared CSS file for all pages.
   ============================================ */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600&display=swap');

:root {
  --ink: #1a1a1a;
  --paper: #fafaf7;
  --warm-grey: #6b6b66;
  --hairline: #e5e5dc;
  --cream: #f1ede4;
  --max-width: 1100px;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  font-size: 16px;
  line-height: 1.6;
  color: var(--ink);
  background: var(--paper);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

h1, h2, h3, h4 {
  font-weight: 500;
  letter-spacing: -0.02em;
  line-height: 1.15;
}

h1 { font-size: clamp(40px, 6vw, 72px); }
h2 { font-size: clamp(28px, 4vw, 44px); }
h3 { font-size: clamp(20px, 2.5vw, 26px); }
h4 { font-size: 16px; font-weight: 600; }

p {
  margin-bottom: 1.2em;
}

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

a {
  color: var(--ink);
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-thickness: 1px;
}

a:hover {
  text-decoration-thickness: 2px;
}

ul {
  list-style: none;
}

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

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 32px;
}

@media (max-width: 600px) {
  .container { padding: 0 24px; }
}

section {
  padding: 80px 0;
}

@media (max-width: 600px) {
  section { padding: 56px 0; }
}

.divider {
  border-top: 1px solid var(--hairline);
}

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

.header {
  position: sticky;
  top: 0;
  background: var(--paper);
  border-bottom: 1px solid var(--hairline);
  z-index: 100;
}

.header-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 20px 32px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.wordmark {
  font-size: 24px;
  font-weight: 500;
  letter-spacing: -0.04em;
  text-decoration: none;
  color: var(--ink);
}

.wordmark:hover { text-decoration: none; }

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

.nav-links {
  display: flex;
  gap: 28px;
  font-size: 14px;
}

.nav-links a {
  text-decoration: none;
  color: var(--ink);
}

.nav-links a:hover {
  text-decoration: underline;
  text-underline-offset: 3px;
}

.nav-cta {
  background: var(--ink);
  color: var(--paper);
  padding: 9px 18px;
  border-radius: 3px;
  text-decoration: none;
  font-size: 13px;
  font-weight: 500;
}

.nav-cta:hover {
  text-decoration: none;
  background: #000;
}

.menu-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
}

@media (max-width: 800px) {
  .nav-links { display: none; }
  .menu-toggle { display: block; }
  .nav-links.open {
    display: flex;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--paper);
    flex-direction: column;
    padding: 20px 32px;
    gap: 16px;
    border-bottom: 1px solid var(--hairline);
  }
}

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

.hero {
  padding: 120px 0 80px;
  text-align: center;
}

.hero h1 {
  max-width: 900px;
  margin: 0 auto 32px;
}

.hero .strapline {
  font-size: clamp(18px, 2.5vw, 24px);
  color: var(--ink);
  max-width: 720px;
  margin: 0 auto 48px;
  font-weight: 400;
  line-height: 1.4;
}

.hero-ctas {
  display: flex;
  gap: 20px;
  justify-content: center;
  flex-wrap: wrap;
  align-items: center;
}

.button {
  background: var(--ink);
  color: var(--paper);
  padding: 14px 28px;
  border-radius: 3px;
  text-decoration: none;
  font-size: 15px;
  font-weight: 500;
  display: inline-block;
}

.button:hover {
  text-decoration: none;
  background: #000;
}

.button-secondary {
  background: transparent;
  color: var(--ink);
  border: 1px solid var(--ink);
}

.button-secondary:hover {
  background: var(--ink);
  color: var(--paper);
}

.scroll-cue {
  font-size: 14px;
  color: var(--warm-grey);
  text-decoration: underline;
  text-underline-offset: 4px;
}

@media (max-width: 600px) {
  .hero { padding: 80px 0 60px; }
}

/* ============================================
   Panels
   ============================================ */

.panel {
  padding: 96px 0;
}

.panel-narrow {
  max-width: 800px;
  margin: 0 auto;
}

.panel-prose {
  max-width: 720px;
  margin: 0 auto;
  font-size: 17px;
  line-height: 1.7;
}

.panel-prose p {
  margin-bottom: 1.4em;
}

.panel h2 {
  margin-bottom: 32px;
  max-width: 800px;
}

@media (max-width: 600px) {
  .panel { padding: 64px 0; }
}

/* ============================================
   How it works (three-column)
   ============================================ */

.how-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 48px;
  margin-top: 56px;
}

.how-step h3 {
  margin-bottom: 12px;
}

.how-step .num {
  font-size: 14px;
  color: var(--warm-grey);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-bottom: 16px;
  display: block;
}

@media (max-width: 800px) {
  .how-grid { grid-template-columns: 1fr; gap: 40px; }
}

/* ============================================
   Closing panel (the Thesis)
   ============================================ */

.closing {
  background: var(--ink);
  color: var(--paper);
  text-align: center;
  padding: 140px 0;
}

.closing h2 {
  font-size: clamp(36px, 6vw, 64px);
  line-height: 1.15;
  margin: 0 auto 48px;
  font-weight: 500;
  letter-spacing: -0.02em;
  max-width: 800px;
}

.closing .button {
  background: var(--paper);
  color: var(--ink);
}

.closing .button:hover {
  background: white;
}

@media (max-width: 600px) {
  .closing { padding: 96px 0; }
}

/* ============================================
   Who Bypart is for
   ============================================ */

.audience-list {
  max-width: 720px;
  margin: 56px auto 0;
  font-size: 17px;
  line-height: 1.7;
}

.audience-list p {
  padding: 20px 0;
  border-bottom: 1px solid var(--hairline);
}

.audience-list p:last-child {
  border-bottom: none;
}

.audience-list strong {
  font-weight: 600;
}

.audience-note {
  max-width: 720px;
  margin: 40px auto 0;
  text-align: center;
  font-size: 16px;
  color: var(--warm-grey);
  line-height: 1.6;
}

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

.pricing-section h3 {
  margin-bottom: 24px;
  font-size: 14px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--warm-grey);
}

.pricing-table {
  width: 100%;
  border-collapse: collapse;
  margin-bottom: 64px;
  font-size: 16px;
}

.pricing-table th,
.pricing-table td {
  text-align: left;
  padding: 18px 16px;
  border-bottom: 1px solid var(--hairline);
}

.pricing-table th {
  font-weight: 600;
  font-size: 13px;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--warm-grey);
  border-bottom: 2px solid var(--ink);
}

.pricing-table td:first-child {
  font-weight: 500;
}

.pricing-notes {
  max-width: 720px;
  color: var(--warm-grey);
  font-size: 14px;
  line-height: 1.7;
  border-top: 1px solid var(--hairline);
  padding-top: 32px;
  margin-top: 32px;
}

.pricing-notes p {
  margin-bottom: 1em;
}

/* ============================================
   Article-style content (For Collectors, For Sellers, About)
   ============================================ */

.article-section {
  max-width: 720px;
  margin: 0 auto;
}

.article-section h3 {
  font-size: 22px;
  font-weight: 500;
  margin-top: 56px;
  margin-bottom: 16px;
}

.article-section h3:first-child {
  margin-top: 0;
}

.article-section p {
  font-size: 17px;
  line-height: 1.7;
  margin-bottom: 1.4em;
}

.article-section ul {
  margin-bottom: 1.4em;
}

.article-section ul li {
  font-size: 17px;
  line-height: 1.7;
  padding: 10px 0;
  border-bottom: 1px solid var(--hairline);
}

.article-section ul li:last-child {
  border-bottom: none;
}

.article-section ul li strong {
  font-weight: 600;
}

.thesis-line {
  font-size: clamp(24px, 3.5vw, 32px);
  font-weight: 500;
  line-height: 1.3;
  text-align: center;
  margin: 64px 0;
  letter-spacing: -0.015em;
  max-width: 700px;
  margin-left: auto;
  margin-right: auto;
}

/* ============================================
   Page-level hero (sub-pages)
   ============================================ */

.page-hero {
  padding: 100px 0 60px;
  text-align: left;
  border-bottom: 1px solid var(--hairline);
}

.page-hero .container {
  max-width: 820px;
}

.page-hero h1 {
  font-size: clamp(36px, 5vw, 56px);
  margin-bottom: 24px;
}

.page-hero .strapline {
  font-size: clamp(17px, 2vw, 20px);
  color: var(--ink);
  font-weight: 400;
  max-width: 680px;
  line-height: 1.5;
}

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

.footer {
  background: var(--ink);
  color: var(--paper);
  padding: 80px 0 40px;
  margin-top: 0;
}

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

.footer-top {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 48px;
  padding-bottom: 64px;
  border-bottom: 1px solid rgba(255,255,255,0.15);
}

.footer-brand .wordmark {
  color: var(--paper);
  font-size: 28px;
  display: block;
  margin-bottom: 16px;
}

.footer-brand p {
  color: rgba(255,255,255,0.7);
  font-size: 14px;
  line-height: 1.6;
  max-width: 280px;
}

.footer-col h4 {
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: rgba(255,255,255,0.5);
  margin-bottom: 20px;
  font-weight: 500;
}

.footer-col ul {
  list-style: none;
}

.footer-col li {
  margin-bottom: 12px;
}

.footer-col a {
  color: var(--paper);
  text-decoration: none;
  font-size: 14px;
}

.footer-col a:hover {
  text-decoration: underline;
  text-underline-offset: 3px;
}

.footer-bottom {
  padding-top: 32px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 12px;
  color: rgba(255,255,255,0.5);
  flex-wrap: wrap;
  gap: 16px;
}

.footer-bottom .trust {
  font-size: 12px;
  color: rgba(255,255,255,0.5);
}

@media (max-width: 800px) {
  .footer-top {
    grid-template-columns: 1fr 1fr;
    gap: 40px;
  }
}

@media (max-width: 500px) {
  .footer-top {
    grid-template-columns: 1fr;
    gap: 32px;
  }
}

/* ============================================
   App Store badge placeholder
   ============================================ */

.appstore-note {
  font-size: 12px;
  color: var(--warm-grey);
  text-align: center;
  margin-top: 16px;
  font-style: italic;
}

/* ============================================
   Legal page
   ============================================ */

.legal-section {
  max-width: 720px;
  margin: 0 auto;
}

.legal-section h2 {
  font-size: 24px;
  margin-top: 56px;
  margin-bottom: 16px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--hairline);
}

.legal-section h2:first-child {
  margin-top: 0;
}

.legal-section p, .legal-section li {
  font-size: 16px;
  line-height: 1.7;
  margin-bottom: 1em;
}

.legal-section ul {
  padding-left: 0;
}

.legal-section li {
  padding-left: 24px;
  position: relative;
}

.legal-section li::before {
  content: "—";
  position: absolute;
  left: 0;
  color: var(--warm-grey);
}

/* ============================================
   Press / Support page
   ============================================ */

.contact-block {
  max-width: 720px;
  margin: 0 auto;
}

.contact-item {
  padding: 24px 0;
  border-bottom: 1px solid var(--hairline);
}

.contact-item:last-child {
  border-bottom: none;
}

.contact-item h3 {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 6px;
}

.contact-item a {
  font-size: 16px;
}

.support-list {
  max-width: 720px;
  margin: 0 auto;
}

.support-list li {
  padding: 18px 0;
  border-bottom: 1px solid var(--hairline);
  font-size: 16px;
}

.support-list li:first-child {
  border-top: 1px solid var(--hairline);
}

/* ============================================
   Utility
   ============================================ */

.muted {
  color: var(--warm-grey);
}

.center {
  text-align: center;
}