/* ReadWrite — landing page
   Editorial "ink on paper" theme: a serif voice for the reading/writing idea,
   a clean sans for everything operational. Light by default, dark by preference. */

:root {
  --paper: #faf8f3;
  --paper-2: #f3efe6;
  --ink: #1c1a17;
  --ink-soft: #4a463f;
  --ink-faint: #807a6f;
  --line: #e4ddd0;
  --line-strong: #d4cbb9;
  --accent: #b5471f; /* vermilion — a seal-stamp red */
  --accent-soft: #d8714b;
  --read: #2f6f6b; /* teal for the "read" side */
  --write: #b5471f; /* vermilion for the "write" side */
  --card: #ffffff;
  --shadow: 0 1px 2px rgba(28, 26, 23, 0.04), 0 8px 30px rgba(28, 26, 23, 0.06);
  --radius: 14px;
  --maxw: 1080px;
  --serif: 'Iowan Old Style', 'Palatino Linotype', Palatino, 'Book Antiqua', Georgia, serif;
  --sans:
    -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB',
    'Microsoft YaHei', Roboto, Helvetica, Arial, sans-serif;
  --mono: ui-monospace, 'SF Mono', 'JetBrains Mono', Menlo, Consolas, monospace;
}

@media (prefers-color-scheme: dark) {
  :root {
    --paper: #16140f;
    --paper-2: #1d1a13;
    --ink: #f0ece2;
    --ink-soft: #c6bfb0;
    --ink-faint: #8a8273;
    --line: #2c281f;
    --line-strong: #3a3528;
    --accent: #e07a4f;
    --accent-soft: #e89a76;
    --read: #5fb8b0;
    --write: #e07a4f;
    --card: #1f1c15;
    --shadow: 0 1px 2px rgba(0, 0, 0, 0.3), 0 12px 40px rgba(0, 0, 0, 0.4);
  }
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 17px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

a {
  color: var(--accent);
  text-decoration: none;
}
a:hover {
  text-decoration: underline;
}

.wrap {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 24px;
}

h1,
h2,
h3 {
  font-family: var(--serif);
  font-weight: 600;
  line-height: 1.15;
  letter-spacing: -0.01em;
}

/* ---------- nav ---------- */
.nav {
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: saturate(140%) blur(12px);
  background: color-mix(in srgb, var(--paper) 82%, transparent);
  border-bottom: 1px solid var(--line);
}
.nav .wrap {
  display: flex;
  align-items: center;
  gap: 16px;
  height: 60px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--serif);
  font-size: 19px;
  font-weight: 600;
  color: var(--ink);
}
.brand:hover {
  text-decoration: none;
}
.brand img {
  width: 28px;
  height: 28px;
  border-radius: 7px;
}
.nav-links {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: 22px;
}
.nav-links a {
  color: var(--ink-soft);
  font-size: 15px;
}
.nav-links a:hover {
  color: var(--ink);
  text-decoration: none;
}
.nav-cta {
  padding: 7px 14px;
  border: 1px solid var(--line-strong);
  border-radius: 9px;
  color: var(--ink) !important;
}
@media (max-width: 720px) {
  .nav-links .hide-sm {
    display: none;
  }
}

/* ---------- hero ---------- */
.hero {
  padding: 76px 0 40px;
  text-align: center;
  position: relative;
}
.hero .eyebrow {
  display: inline-block;
  font-size: 13px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent);
  font-weight: 600;
  margin-bottom: 18px;
}
.hero h1 {
  font-size: clamp(40px, 7vw, 76px);
  margin: 0 0 18px;
}
.hero h1 .read {
  color: var(--read);
}
.hero h1 .write {
  color: var(--write);
}
.hero .lede {
  max-width: 660px;
  margin: 0 auto 12px;
  font-size: clamp(18px, 2.4vw, 21px);
  color: var(--ink-soft);
}
.hero .sub {
  max-width: 620px;
  margin: 0 auto 30px;
  color: var(--ink-faint);
  font-size: 16px;
}
.cta-row {
  display: flex;
  gap: 14px;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 12px;
}
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 13px 24px;
  border-radius: 11px;
  font-weight: 600;
  font-size: 16px;
  border: 1px solid transparent;
  transition:
    transform 0.12s ease,
    box-shadow 0.12s ease,
    background 0.12s ease;
}
.btn:hover {
  text-decoration: none;
  transform: translateY(-1px);
}
.btn-primary {
  background: var(--accent);
  color: #fff;
  box-shadow: var(--shadow);
}
.btn-primary:hover {
  background: var(--accent-soft);
}
.btn-ghost {
  background: var(--card);
  color: var(--ink);
  border-color: var(--line-strong);
}
.platforms {
  font-size: 13px;
  color: var(--ink-faint);
}

/* ---------- app mockup ---------- */
.mockup {
  margin: 44px auto 0;
  max-width: 980px;
  border-radius: 16px;
  border: 1px solid var(--line);
  background: var(--card);
  box-shadow: var(--shadow);
  overflow: hidden;
}
.mockup svg {
  display: block;
  width: 100%;
  height: auto;
}

/* ---------- sections ---------- */
section {
  padding: 64px 0;
}
.section-head {
  max-width: 720px;
  margin: 0 auto 44px;
  text-align: center;
}
.section-head .kicker {
  font-size: 13px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent);
  font-weight: 600;
}
.section-head h2 {
  font-size: clamp(28px, 4vw, 40px);
  margin: 10px 0 14px;
}
.section-head p {
  color: var(--ink-soft);
  margin: 0;
}

.alt {
  background: var(--paper-2);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

/* problem -> solution */
.split {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 22px;
  max-width: 920px;
  margin: 0 auto;
}
@media (max-width: 720px) {
  .split {
    grid-template-columns: 1fr;
  }
}
.split .col {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 26px;
}
.split .col h3 {
  margin: 0 0 8px;
  font-size: 20px;
}
.split .col.problem h3 {
  color: var(--ink-faint);
}
.split .col.solution {
  border-color: color-mix(in srgb, var(--accent) 35%, var(--line));
}
.split .col.solution h3 {
  color: var(--accent);
}
.split .col p {
  margin: 0;
  color: var(--ink-soft);
}

/* feature grid */
.features {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
}
@media (max-width: 720px) {
  .features {
    grid-template-columns: 1fr;
  }
}
.feature {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 26px;
}
.feature .ico {
  width: 40px;
  height: 40px;
  border-radius: 10px;
  display: grid;
  place-items: center;
  font-size: 20px;
  margin-bottom: 14px;
  background: var(--paper-2);
  border: 1px solid var(--line);
}
.feature h3 {
  margin: 0 0 8px;
  font-size: 20px;
}
.feature p {
  margin: 0;
  color: var(--ink-soft);
  font-size: 15.5px;
}
.feature ul {
  margin: 10px 0 0;
  padding-left: 18px;
  color: var(--ink-soft);
  font-size: 15px;
}
.feature li {
  margin: 4px 0;
}

/* AI callout */
.callout {
  max-width: 860px;
  margin: 0 auto;
  background: linear-gradient(
    180deg,
    color-mix(in srgb, var(--accent) 8%, var(--card)),
    var(--card)
  );
  border: 1px solid color-mix(in srgb, var(--accent) 30%, var(--line));
  border-radius: 18px;
  padding: 34px;
}
.callout h3 {
  margin: 0 0 10px;
  font-size: 24px;
}
.callout .two {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
  margin-top: 22px;
}
@media (max-width: 720px) {
  .callout .two {
    grid-template-columns: 1fr;
  }
}
.callout .two h4 {
  margin: 0 0 6px;
  font-family: var(--sans);
  font-size: 16px;
}
.callout .two p {
  margin: 0;
  color: var(--ink-soft);
  font-size: 15px;
}
.tag {
  display: inline-block;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.04em;
  padding: 3px 9px;
  border-radius: 999px;
  margin-bottom: 8px;
}
.tag.api {
  background: color-mix(in srgb, var(--read) 16%, transparent);
  color: var(--read);
}
.tag.cli {
  background: color-mix(in srgb, var(--accent) 16%, transparent);
  color: var(--accent);
}

/* steps */
.steps {
  max-width: 820px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 18px;
}
.step {
  display: flex;
  gap: 18px;
  align-items: flex-start;
}
.step .num {
  flex: 0 0 auto;
  width: 34px;
  height: 34px;
  border-radius: 50%;
  background: var(--accent);
  color: #fff;
  display: grid;
  place-items: center;
  font-weight: 700;
  font-family: var(--serif);
}
.step .body h3 {
  margin: 3px 0 4px;
  font-size: 19px;
}
.step .body p {
  margin: 0;
  color: var(--ink-soft);
  font-size: 15.5px;
}
.step .body code,
.callout code,
.feature code {
  font-family: var(--mono);
  font-size: 0.86em;
  background: var(--paper-2);
  border: 1px solid var(--line);
  border-radius: 5px;
  padding: 1px 6px;
}

pre {
  background: var(--ink);
  color: #f3efe6;
  border-radius: 12px;
  padding: 18px 20px;
  overflow-x: auto;
  font-family: var(--mono);
  font-size: 14px;
  line-height: 1.6;
  margin: 16px 0 0;
}
@media (prefers-color-scheme: dark) {
  pre {
    background: #0d0c08;
    border: 1px solid var(--line-strong);
  }
}
pre .c {
  color: #9b9485;
}

/* faq */
.faq {
  max-width: 780px;
  margin: 0 auto;
}
.faq details {
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--card);
  padding: 0 20px;
  margin-bottom: 12px;
}
.faq summary {
  cursor: pointer;
  font-weight: 600;
  padding: 18px 0;
  list-style: none;
  font-size: 17px;
}
.faq summary::-webkit-details-marker {
  display: none;
}
.faq summary::after {
  content: '+';
  float: right;
  color: var(--accent);
  font-weight: 400;
  font-size: 22px;
  line-height: 1;
}
.faq details[open] summary::after {
  content: '–';
}
.faq details p {
  margin: 0 0 18px;
  color: var(--ink-soft);
  font-size: 15.5px;
}

/* download */
.dl-row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  max-width: 760px;
  margin: 0 auto;
}
@media (max-width: 720px) {
  .dl-row {
    grid-template-columns: 1fr;
  }
}
.dl-card {
  text-align: center;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 26px 20px;
}
.dl-card .os {
  font-family: var(--serif);
  font-size: 20px;
  margin-bottom: 4px;
}
.dl-card .fmt {
  font-size: 13px;
  color: var(--ink-faint);
  margin-bottom: 16px;
}

/* footer */
footer {
  border-top: 1px solid var(--line);
  padding: 40px 0;
  color: var(--ink-faint);
  font-size: 14px;
}
footer .wrap {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  align-items: center;
  justify-content: space-between;
}
footer a {
  color: var(--ink-soft);
}

.center {
  text-align: center;
}
.mt {
  margin-top: 28px;
}