/* «Контроль ДЗ» website — the app's «Тетрадь» design (src/lib/theme.ts): warm paper, ballpoint ink-blue accent,
   red margin line, ruled lines as decoration only. System fonts, no scripts, light and dark. */
:root {
  --bg: #f4f2ed;
  --card: #ffffff;
  --fill: #ece9e1;
  --ink: #1a1916;
  --ink2: #46433d;
  --muted: #6a665e;
  --line: #e3dfd5;
  --border: #8e897e;
  --brand: #2a4bb0;
  --brand-fill: #2a4bb0;
  --brand-soft: #e6eaf8;
  --ok: #1d7346;
  --ok-soft: #e1f1e6;
  --warn: #975400;
  --warn-soft: #fbefd9;
  --bad: #bc3226;
  --margin: #e7a39b;
  --rule: #d9e2ee;
  --radius-l: 18px;
  --radius-m: 14px;
  --radius-s: 10px;
  color-scheme: light dark;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #131311;
    --card: #1e1d1a;
    --fill: #2a2925;
    --ink: #f3f0e9;
    --ink2: #d0cbc1;
    --muted: #a29d92;
    --line: #34322d;
    --border: #75705f;
    --brand: #9aaeff;
    --brand-fill: #3554c4;
    --brand-soft: #1e2542;
    --ok: #62c98f;
    --ok-soft: #163021;
    --warn: #edb44e;
    --warn-soft: #33291a;
    --bad: #ff8d7e;
    --margin: #6b3530;
    --rule: #26303d;
  }
}

*,
*::before,
*::after {
  box-sizing: border-box;
}
html {
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
}
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font: 16px/1.5 -apple-system, BlinkMacSystemFont, "SF Pro Text", "Segoe UI", Roboto, "Helvetica Neue", Arial,
    sans-serif;
  letter-spacing: -0.01em;
  overflow-x: hidden;
}
img {
  max-width: 100%;
  height: auto;
  display: block;
}
a {
  color: var(--brand);
  text-underline-offset: 0.18em;
}
a:hover {
  text-decoration-thickness: 2px;
}
:focus-visible {
  outline: 3px solid var(--brand);
  outline-offset: 2px;
  border-radius: 6px;
}
h1,
h2,
h3 {
  line-height: 1.15;
  letter-spacing: -0.025em;
  margin: 0 0 12px;
  text-wrap: balance;
}
h1 {
  font-size: clamp(34px, 8.5vw, 56px);
  letter-spacing: -0.035em;
}
h2 {
  font-size: clamp(26px, 5.5vw, 36px);
}
h3 {
  font-size: 18px;
  letter-spacing: -0.015em;
}
p {
  margin: 0 0 12px;
}
.wrap {
  width: 100%;
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 16px;
}
@media (min-width: 600px) {
  .wrap {
    padding: 0 24px;
  }
}
.skip {
  position: absolute;
  left: -9999px;
}
.skip:focus {
  left: 16px;
  top: 8px;
  z-index: 10;
  background: var(--card);
  padding: 8px 12px;
}

/* header */
.top {
  border-bottom: 1px solid var(--line);
  background: var(--bg);
}
.top .wrap {
  display: flex;
  align-items: center;
  gap: 12px;
  min-height: 60px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--ink);
  text-decoration: none;
  font-weight: 700;
  font-size: 18px;
  letter-spacing: -0.02em;
  margin-right: auto;
}
.brand img {
  width: 32px;
  height: 32px;
  border-radius: 9px;
}
.langs {
  display: flex;
  gap: 2px;
  background: var(--fill);
  border-radius: 999px;
  padding: 3px;
  font-size: 13px;
  font-weight: 600;
}
.langs a,
.langs span {
  padding: 4px 9px;
  border-radius: 999px;
  text-decoration: none;
  color: var(--ink2);
}
.langs span {
  background: var(--card);
  color: var(--ink);
}
.nav-support {
  font-size: 15px;
  font-weight: 600;
  text-decoration: none;
  display: none;
}
@media (min-width: 520px) {
  .nav-support {
    display: inline;
  }
}

/* notebook hero: ruled lines + red margin */
.hero {
  position: relative;
  padding: 40px 0 32px;
  background-image: repeating-linear-gradient(
    to bottom,
    transparent 0,
    transparent 39px,
    var(--rule) 39px,
    var(--rule) 40px
  );
  overflow: hidden;
}
.hero::before {
  content: "";
  position: absolute;
  top: 0;
  bottom: 0;
  left: 8px;
  width: 2px;
  background: var(--margin);
  opacity: 0.9;
}
@media (min-width: 600px) {
  .hero::before {
    left: max(12px, calc(50% - 552px));
  }
}
.hero .wrap {
  display: grid;
  gap: 32px;
  align-items: center;
}
@media (min-width: 860px) {
  .hero {
    padding: 64px 0 56px;
  }
  .hero .wrap {
    grid-template-columns: 1.15fr 0.85fr;
  }
}
.eyebrow {
  display: inline-block;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--brand);
  background: var(--brand-soft);
  border-radius: 6px;
  padding: 3px 8px;
  margin-bottom: 16px;
}
.lead {
  font-size: clamp(18px, 2.6vw, 21px);
  line-height: 1.45;
  color: var(--ink2);
  max-width: 36em;
}
.stores {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin: 24px 0 12px;
}
.store {
  display: inline-flex;
  flex-direction: column;
  justify-content: center;
  min-width: 168px;
  min-height: 56px;
  padding: 8px 18px;
  border-radius: var(--radius-m);
  background: var(--ink);
  color: var(--bg);
  text-decoration: none;
  line-height: 1.2;
}
.store small {
  font-size: 12px;
  opacity: 0.8;
}
.store b {
  font-size: 18px;
  letter-spacing: -0.02em;
}
.store[aria-disabled="true"] {
  background: var(--card);
  color: var(--ink);
  border: 1px solid var(--border);
  cursor: default;
}
.note {
  font-size: 14px;
  color: var(--muted);
}
.phone {
  justify-self: center;
  width: min(300px, 78vw);
  border-radius: 34px;
  padding: 8px;
  background: var(--ink);
  box-shadow: 0 24px 48px -24px rgba(74, 63, 42, 0.45);
}
.phone img {
  border-radius: 27px;
  aspect-ratio: 585 / 1266;
  width: 100%;
}
@media (prefers-color-scheme: dark) {
  .phone {
    background: #3a3833;
    box-shadow: none;
  }
}

/* sections */
section {
  padding: 48px 0;
}
.section-head {
  max-width: 40em;
  margin-bottom: 24px;
}
.section-head p {
  color: var(--ink2);
  font-size: 18px;
}
.caps {
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 8px;
}
.steps {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 12px;
  counter-reset: step;
}
@media (min-width: 760px) {
  .steps {
    grid-template-columns: repeat(3, 1fr);
  }
}
.steps li {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius-l);
  padding: 20px;
  counter-increment: step;
}
.steps li::before {
  content: counter(step);
  display: grid;
  place-items: center;
  width: 32px;
  height: 32px;
  border-radius: 10px;
  background: var(--brand-fill);
  color: #fff;
  font-weight: 700;
  margin-bottom: 12px;
}
.steps p,
.card p {
  color: var(--ink2);
  margin: 0;
}
.grid {
  display: grid;
  gap: 12px;
}
@media (min-width: 600px) {
  .grid {
    grid-template-columns: repeat(2, 1fr);
  }
}
@media (min-width: 960px) {
  .grid {
    grid-template-columns: repeat(3, 1fr);
  }
}
.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius-l);
  padding: 20px;
}
.card.wide {
  grid-column: 1 / -1;
}
.tile {
  display: grid;
  place-items: center;
  width: 40px;
  height: 40px;
  border-radius: var(--radius-s);
  background: var(--brand-soft);
  color: var(--brand);
  margin-bottom: 12px;
}
.tile svg {
  width: 22px;
  height: 22px;
  fill: none;
  stroke: currentColor;
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
}
.tile.ok {
  background: var(--ok-soft);
  color: var(--ok);
}
.tile.warn {
  background: var(--warn-soft);
  color: var(--warn);
}
.card ul {
  margin: 8px 0 0;
  padding-left: 20px;
  color: var(--ink2);
}
.card li + li {
  margin-top: 4px;
}
.badge {
  display: inline-block;
  font-size: 12px;
  font-weight: 600;
  border-radius: 6px;
  padding: 2px 7px;
  background: var(--fill);
  color: var(--ink2);
  vertical-align: 2px;
  margin-left: 4px;
}

/* screenshots: scroll strip on phones, row on wide screens */
.shots {
  display: flex;
  gap: 16px;
  overflow-x: auto;
  scroll-snap-type: x mandatory;
  padding: 4px 16px 16px;
  margin: 0 -16px;
  -webkit-overflow-scrolling: touch;
}
.shots figure {
  flex: 0 0 min(230px, 64vw);
  margin: 0;
  scroll-snap-align: center;
}
.shots img {
  border-radius: 22px;
  border: 1px solid var(--line);
  aspect-ratio: 585 / 1266;
  width: 100%;
}
.shots figcaption {
  font-size: 14px;
  color: var(--ink2);
  margin-top: 10px;
  text-align: center;
}
@media (min-width: 1000px) {
  .shots {
    overflow: visible;
    margin: 0;
    padding: 4px 0 0;
    justify-content: space-between;
  }
  .shots figure {
    flex: 1 1 0;
  }
}

/* price */
.price {
  display: grid;
  gap: 16px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 24px;
  padding: 24px;
}
@media (min-width: 760px) {
  .price {
    grid-template-columns: auto 1fr;
    align-items: center;
    gap: 40px;
    padding: 32px 40px;
  }
}
.amount {
  font-size: clamp(44px, 9vw, 64px);
  font-weight: 700;
  letter-spacing: -0.04em;
  line-height: 1;
  font-variant-numeric: tabular-nums;
}
.amount small {
  font-size: 20px;
  font-weight: 600;
  letter-spacing: -0.01em;
  color: var(--muted);
}
.trial {
  display: inline-block;
  margin-top: 12px;
  background: var(--ok-soft);
  color: var(--ok);
  font-weight: 600;
  border-radius: 8px;
  padding: 4px 10px;
}
.checks {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 8px;
}
.checks li {
  position: relative;
  padding-left: 30px;
  color: var(--ink2);
}
.checks li::before {
  content: "";
  position: absolute;
  left: 2px;
  top: 4px;
  width: 16px;
  height: 9px;
  border-left: 3px solid var(--ok);
  border-bottom: 3px solid var(--ok);
  transform: rotate(-45deg);
}

/* text pages */
.page {
  padding: 32px 0 56px;
}
.page .wrap {
  max-width: 760px;
}
.page h1 {
  font-size: clamp(30px, 7vw, 44px);
}
.page h2 {
  font-size: 22px;
  margin-top: 36px;
}
.page .lead {
  margin-bottom: 24px;
}
.faq details {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius-m);
  padding: 0 16px;
}
.faq details + details {
  margin-top: 8px;
}
.faq summary {
  cursor: pointer;
  font-weight: 600;
  padding: 14px 24px 14px 0;
  list-style: none;
  position: relative;
}
.faq summary::-webkit-details-marker {
  display: none;
}
.faq summary::after {
  content: "+";
  position: absolute;
  right: 0;
  top: 11px;
  font-size: 22px;
  font-weight: 400;
  color: var(--muted);
}
.faq details[open] summary::after {
  content: "−";
}
.faq details > div {
  padding: 0 0 14px;
  color: var(--ink2);
}
.faq details > div p:last-child,
.faq details > div ul:last-child,
.faq details > div ol:last-child {
  margin-bottom: 0;
}
ol.howto {
  padding-left: 22px;
}
ol.howto li + li {
  margin-top: 6px;
}
.callout {
  background: var(--brand-soft);
  border-radius: var(--radius-m);
  padding: 16px 18px;
  margin: 16px 0;
}
.callout.warn {
  background: var(--warn-soft);
}
.mail {
  font-weight: 600;
  font-size: 18px;
  word-break: break-all;
}
dl.req {
  display: grid;
  grid-template-columns: max-content 1fr;
  gap: 6px 16px;
  margin: 0;
}
dl.req dt {
  color: var(--muted);
}
dl.req dd {
  margin: 0;
}
@media (max-width: 420px) {
  dl.req {
    grid-template-columns: 1fr;
    gap: 0;
  }
  dl.req dd {
    margin-bottom: 8px;
  }
}

/* footer */
footer {
  border-top: 1px solid var(--line);
  padding: 32px 0 40px;
  font-size: 14px;
  color: var(--muted);
}
footer .wrap {
  display: grid;
  gap: 16px;
}
footer nav {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 18px;
}
footer nav a {
  color: var(--ink2);
}
footer p {
  margin: 0;
}

@media (prefers-reduced-motion: no-preference) {
  html {
    scroll-behavior: smooth;
  }
}
@media print {
  .top,
  footer,
  .stores {
    display: none;
  }
  body {
    background: #fff;
  }
}

/* spacing helpers (the CSP forbids inline style attributes) */
.mt {
  margin: 12px 0 0;
}
.m0 {
  margin: 0;
}
h2.flush {
  margin-top: 0;
}