/* ============================================================
   SEO КП — Minimal B&W landing
   Дизайн-направление: editorial minimalism, monochrome.
   Только чёрный, белый и один нейтральный серый. Тонкая типографика,
   много воздуха, анимации только функциональные (подсказки скролла,
   реакция на курсор), без декоративных элементов.
   ============================================================ */

:root {
  --ink: #0a0a0a;          /* почти-чёрный */
  --paper: #fafafa;        /* почти-белый, тёплый */
  --paper-pure: #ffffff;
  --line: #e5e5e5;         /* тонкие разделители */
  --line-strong: #1a1a1a;  /* жирные акценты */
  --muted: #6b6b6b;        /* второстепенный текст */
  --hover: #f0f0f0;
  --radius: 0px;           /* минимализм = острые края, но допускаем 2px на инпутах */

  --t-fast: 180ms cubic-bezier(0.2, 0, 0, 1);
  --t-med: 380ms cubic-bezier(0.2, 0, 0, 1);
  --t-slow: 700ms cubic-bezier(0.2, 0, 0, 1);

  --max: 1180px;
  --gutter: clamp(20px, 4vw, 48px);
}

* { box-sizing: border-box; margin: 0; padding: 0; }
*:focus-visible { outline: 2px solid var(--ink); outline-offset: 3px; }

html { scroll-behavior: smooth; }

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Helvetica Neue", sans-serif;
  font-feature-settings: "ss01", "cv11";
  background: var(--paper);
  color: var(--ink);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

/* Тонкая сетка как фон — едва заметная, как пунктир в блокноте */
body::before {
  content: "";
  position: fixed; inset: 0;
  background-image:
    linear-gradient(to right, rgba(10,10,10,0.025) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(10,10,10,0.025) 1px, transparent 1px);
  background-size: 80px 80px;
  pointer-events: none;
  z-index: 0;
  mask-image: radial-gradient(ellipse at center, black 30%, transparent 80%);
}

main, header, footer { position: relative; z-index: 1; }

a { color: inherit; }

/* ---------- Header ---------- */
header {
  max-width: var(--max);
  margin: 0 auto;
  padding: 28px var(--gutter);
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid transparent;
  transition: border-color var(--t-med), backdrop-filter var(--t-med);
}
header.scrolled {
  position: sticky;
  top: 0;
  background: rgba(250,250,250,0.85);
  backdrop-filter: saturate(180%) blur(12px);
  -webkit-backdrop-filter: saturate(180%) blur(12px);
  border-bottom-color: var(--line);
  z-index: 50;
}
.logo {
  display: flex; align-items: center; gap: 12px;
  font-weight: 700; font-size: 17px; letter-spacing: -0.01em;
}
.logo-mark {
  width: 32px; height: 32px;
  border: 1.5px solid var(--ink);
  display: grid; place-items: center;
  transition: transform var(--t-fast), background var(--t-fast), color var(--t-fast);
}
.logo:hover .logo-mark { background: var(--ink); color: var(--paper); transform: rotate(-90deg); }
.logo-mark svg { width: 16px; height: 16px; }

nav { display: flex; gap: 4px; }
nav a {
  position: relative;
  text-decoration: none;
  font-size: 14px; font-weight: 500;
  padding: 8px 16px;
  color: var(--muted);
  transition: color var(--t-fast);
}
nav a::after {
  content: "";
  position: absolute; left: 16px; right: 16px; bottom: 6px;
  height: 1px; background: var(--ink);
  transform: scaleX(0); transform-origin: left;
  transition: transform var(--t-med);
}
nav a:hover { color: var(--ink); }
nav a:hover::after { transform: scaleX(1); }

/* Auth-кнопки в navbar */
nav a.nav-login {
  color: var(--ink);
  font-weight: 500;
}
nav a.nav-cta {
  margin-left: 8px;
  padding: 8px 18px;
  border: 1.5px solid var(--ink);
  background: var(--ink);
  color: var(--paper);
  font-weight: 600;
  transition: background var(--t-fast), color var(--t-fast);
}
nav a.nav-cta::after { display: none; }
nav a.nav-cta:hover { background: var(--paper); color: var(--ink); }

/* ---------- Reveal-on-scroll ---------- */
[data-reveal] {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity var(--t-slow), transform var(--t-slow);
}
[data-reveal].is-visible {
  opacity: 1; transform: none;
}
[data-reveal-stagger] > * {
  opacity: 0; transform: translateY(20px);
  transition: opacity var(--t-slow), transform var(--t-slow);
}
[data-reveal-stagger].is-visible > * { opacity: 1; transform: none; }
[data-reveal-stagger].is-visible > *:nth-child(1) { transition-delay:  60ms; }
[data-reveal-stagger].is-visible > *:nth-child(2) { transition-delay: 120ms; }
[data-reveal-stagger].is-visible > *:nth-child(3) { transition-delay: 180ms; }
[data-reveal-stagger].is-visible > *:nth-child(4) { transition-delay: 240ms; }
[data-reveal-stagger].is-visible > *:nth-child(5) { transition-delay: 300ms; }
[data-reveal-stagger].is-visible > *:nth-child(6) { transition-delay: 360ms; }
[data-reveal-stagger].is-visible > *:nth-child(7) { transition-delay: 420ms; }
[data-reveal-stagger].is-visible > *:nth-child(8) { transition-delay: 480ms; }

/* ---------- Hero ---------- */
.hero {
  max-width: var(--max);
  margin: 80px auto 120px;
  padding: 0 var(--gutter);
}

.pill {
  display: inline-flex; align-items: center; gap: 10px;
  border: 1px solid var(--line);
  background: var(--paper-pure);
  padding: 7px 14px 7px 12px;
  border-radius: 100px;
  font-size: 12.5px;
  font-weight: 500;
  letter-spacing: 0.01em;
  margin-bottom: 32px;
  transition: border-color var(--t-fast), transform var(--t-fast);
}
.pill:hover { border-color: var(--ink); transform: translateY(-1px); }
.pill .dot {
  width: 6px; height: 6px;
  background: var(--ink); border-radius: 50%;
  position: relative;
}
.pill .dot::after {
  content: "";
  position: absolute; inset: -3px;
  border-radius: 50%;
  background: var(--ink); opacity: 0.3;
  animation: ping 1.6s cubic-bezier(0, 0, 0.2, 1) infinite;
}
@keyframes ping {
  0%   { transform: scale(0.6); opacity: 0.6; }
  80%, 100% { transform: scale(2.2); opacity: 0; }
}

h1 {
  font-size: clamp(44px, 7.5vw, 96px);
  font-weight: 700;
  letter-spacing: -0.04em;
  line-height: 0.98;
  margin-bottom: 28px;
  max-width: 14ch;
}
h1 .accent {
  font-style: italic;
  font-weight: 500;
  /* Подчёркивание чёрной чертой */
  background-image: linear-gradient(var(--ink), var(--ink));
  background-repeat: no-repeat;
  background-size: 100% 6px;
  background-position: 0 96%;
  padding: 0 0.05em 0.04em;
}
.lead {
  font-size: clamp(16px, 1.6vw, 19px);
  color: var(--muted);
  max-width: 60ch;
  margin-bottom: 44px;
}

/* ---------- Form ---------- */
.audit-form {
  max-width: 720px;
  margin-bottom: 24px;
}
.audit-form__row {
  display: flex;
  gap: 0;
  border: 1.5px solid var(--ink);
  background: var(--paper-pure);
  transition: box-shadow var(--t-fast), transform var(--t-fast);
}
.audit-form__row:focus-within {
  box-shadow: 6px 6px 0 var(--ink);
  transform: translate(-2px, -2px);
}
.audit-form__row input[name="url"] {
  flex: 1; min-width: 0;
  border: 0; outline: 0; background: transparent;
  font: inherit; font-size: 16px;
  padding: 18px 22px;
  color: var(--ink);
}
.audit-form__row input[name="url"]::placeholder {
  color: var(--muted);
  font-weight: 400;
}
.audit-form__row button {
  cursor: pointer;
  border: 0;
  background: var(--ink);
  color: var(--paper);
  font: inherit; font-weight: 600; font-size: 15px;
  padding: 0 28px;
  display: inline-flex; align-items: center; gap: 10px;
  position: relative; overflow: hidden;
  transition: background var(--t-fast);
}
.audit-form__row button::before {
  content: "";
  position: absolute; inset: 0;
  background: var(--paper);
  transform: translateY(101%);
  transition: transform var(--t-med);
}
.audit-form__row button:hover::before { transform: translateY(0); }
.audit-form__row button > * { position: relative; z-index: 1; transition: color var(--t-fast); }
.audit-form__row button:hover > * { color: var(--ink); }
.audit-form__row button svg {
  width: 18px; height: 18px;
  transition: transform var(--t-med);
}
.audit-form__row button:hover svg { transform: translateX(4px); }

.audit-form__advanced { margin-top: 18px; }
.audit-form__advanced > summary {
  cursor: pointer;
  font-size: 13.5px;
  color: var(--muted);
  display: inline-flex; align-items: center; gap: 8px;
  padding: 6px 0;
  list-style: none;
  user-select: none;
  transition: color var(--t-fast);
}
.audit-form__advanced > summary::-webkit-details-marker { display: none; }
.audit-form__advanced > summary::before {
  content: "+";
  width: 16px; height: 16px;
  display: inline-grid; place-items: center;
  font-weight: 600; font-size: 14px;
  border: 1px solid currentColor; border-radius: 50%;
  transition: transform var(--t-fast);
}
.audit-form__advanced[open] > summary::before { transform: rotate(45deg); }
.audit-form__advanced > summary:hover { color: var(--ink); }
.audit-form__advanced-body {
  margin-top: 14px;
  display: flex; flex-direction: column; gap: 10px;
}
.audit-form__advanced-body input,
.audit-form__advanced-body textarea {
  font: inherit; font-size: 14.5px;
  padding: 12px 14px;
  border: 1px solid var(--line);
  background: var(--paper-pure);
  color: var(--ink);
  outline: 0;
  transition: border-color var(--t-fast);
  resize: vertical;
}
.audit-form__advanced-body input:focus,
.audit-form__advanced-body textarea:focus { border-color: var(--ink); }

.form-meta {
  display: flex; flex-wrap: wrap; gap: 22px;
  font-size: 13.5px; color: var(--muted);
  margin-top: 22px;
}
.form-meta span {
  display: inline-flex; align-items: center; gap: 7px;
}
.form-meta svg { width: 14px; height: 14px; color: var(--ink); }

/* ---------- Stats / Trust strip ---------- */
.trust {
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  padding: 60px var(--gutter);
}
.trust-inner {
  max-width: var(--max);
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1fr 3fr;
  gap: 40px;
  align-items: center;
}
.trust-label {
  font-size: 11px; font-weight: 600;
  text-transform: uppercase; letter-spacing: 0.18em;
  color: var(--muted);
}
.stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}
.stat .value {
  font-size: clamp(32px, 4vw, 52px);
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1;
  margin-bottom: 8px;
}
.stat .label {
  font-size: 13px;
  color: var(--muted);
  line-height: 1.4;
}

/* ---------- Sections ---------- */
.feature-section {
  max-width: var(--max);
  margin: 0 auto;
  padding: 100px var(--gutter);
}
.section-title {
  display: grid;
  grid-template-columns: 1fr 2fr;
  gap: 60px;
  margin-bottom: 64px;
  align-items: end;
  border-bottom: 1px solid var(--line);
  padding-bottom: 32px;
}
.section-title h2 {
  font-size: clamp(34px, 4.5vw, 56px);
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.02;
}
.section-title h2 .accent {
  font-style: italic;
  font-weight: 500;
  background-image: linear-gradient(var(--ink), var(--ink));
  background-repeat: no-repeat;
  background-size: 100% 4px;
  background-position: 0 96%;
}
.section-title p {
  font-size: 16px;
  color: var(--muted);
  max-width: 50ch;
}

/* ---------- Features (3x2 grid) ---------- */
.features {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  border-top: 1px solid var(--line);
  border-left: 1px solid var(--line);
}
.feature {
  border-right: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  padding: 36px 32px 40px;
  position: relative;
  background: var(--paper);
  transition: background var(--t-med);
}
.feature::before {
  /* Тонкая черта поверх — расширяется при hover */
  content: "";
  position: absolute; left: 0; top: -1px; right: 0;
  height: 1px; background: var(--ink);
  transform: scaleX(0); transform-origin: left;
  transition: transform var(--t-med);
}
.feature:hover { background: var(--paper-pure); }
.feature:hover::before { transform: scaleX(1); }
.feature-icon {
  width: 44px; height: 44px;
  border: 1.5px solid var(--ink);
  display: grid; place-items: center;
  margin-bottom: 22px;
  transition: background var(--t-fast), color var(--t-fast), transform var(--t-med);
}
.feature:hover .feature-icon {
  background: var(--ink); color: var(--paper);
  transform: translateY(-2px) rotate(-2deg);
}
.feature-icon svg { width: 20px; height: 20px; stroke-width: 1.6; }
.feature h3 {
  font-size: 18px; font-weight: 700;
  margin-bottom: 10px;
  letter-spacing: -0.01em;
}
.feature p {
  font-size: 14.5px; color: var(--muted);
  line-height: 1.55;
}

/* ---------- Steps (numbered) ---------- */
.steps {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0;
  border-top: 1px solid var(--line);
}
.step {
  position: relative;
  padding: 36px 24px 36px 0;
  border-right: 1px solid var(--line);
  counter-increment: step;
}
.step:last-child { border-right: 0; }
.step::before {
  content: counter(step, decimal-leading-zero);
  display: block;
  font-size: 12px; font-weight: 600;
  color: var(--muted);
  letter-spacing: 0.1em;
  margin-bottom: 28px;
}
.step h3 {
  font-size: 19px; font-weight: 700;
  margin-bottom: 8px;
  letter-spacing: -0.01em;
}
.step p { font-size: 14px; color: var(--muted); }
.steps { counter-reset: step; }

/* ---------- Pricing ---------- */
.price-cta {
  background: var(--ink);
  color: var(--paper);
  padding: 100px var(--gutter);
  margin-top: 80px;
  position: relative; overflow: hidden;
}
.price-cta::before {
  content: "";
  position: absolute; inset: 0;
  background-image:
    linear-gradient(to right, rgba(255,255,255,0.04) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(255,255,255,0.04) 1px, transparent 1px);
  background-size: 80px 80px;
  pointer-events: none;
  mask-image: radial-gradient(ellipse at center, black 20%, transparent 75%);
}
.price-card {
  max-width: var(--max);
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: end;
  position: relative;
}
.price-card .label {
  font-size: 11px; font-weight: 600;
  text-transform: uppercase; letter-spacing: 0.18em;
  color: rgba(250,250,250,0.55);
  margin-bottom: 18px;
}
.price-card .price {
  font-size: clamp(80px, 14vw, 200px);
  font-weight: 700;
  line-height: 0.9;
  letter-spacing: -0.05em;
  display: flex; align-items: flex-start;
  gap: 8px;
}
.price-card .price .currency {
  font-size: 0.4em;
  margin-top: 0.18em;
  font-weight: 500;
  opacity: 0.6;
}
.price-card .price-sub {
  font-size: 16px;
  color: rgba(250,250,250,0.7);
  line-height: 1.6;
  margin-bottom: 24px;
}
.price-card a {
  align-self: end;
  display: inline-flex; align-items: center; gap: 12px;
  background: var(--paper);
  color: var(--ink);
  padding: 18px 28px;
  font-weight: 600;
  text-decoration: none;
  font-size: 15px;
  border: 1.5px solid var(--paper);
  position: relative; overflow: hidden;
  transition: transform var(--t-fast);
}
.price-card a::before {
  content: "";
  position: absolute; inset: 0;
  background: var(--ink);
  transform: translateY(101%);
  transition: transform var(--t-med);
}
.price-card a:hover::before { transform: translateY(0); }
.price-card a > * { position: relative; z-index: 1; transition: color var(--t-fast); }
.price-card a:hover > * { color: var(--paper); }
.price-card a svg { width: 16px; height: 16px; transition: transform var(--t-med); }
.price-card a:hover svg { transform: translateX(4px); }

/* ---------- FAQ ---------- */
.faq {
  border-top: 1px solid var(--line);
}
.faq details {
  border-bottom: 1px solid var(--line);
}
.faq summary {
  cursor: pointer;
  list-style: none;
  padding: 24px 0 24px 0;
  display: flex; align-items: center; justify-content: space-between;
  gap: 24px;
  font-size: 17px; font-weight: 500;
  letter-spacing: -0.005em;
  user-select: none;
  transition: padding var(--t-fast);
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after {
  content: "+";
  flex-shrink: 0;
  width: 28px; height: 28px;
  border: 1px solid var(--ink);
  display: grid; place-items: center;
  font-weight: 400; font-size: 18px;
  border-radius: 50%;
  transition: transform var(--t-med), background var(--t-fast), color var(--t-fast);
}
.faq summary:hover::after { background: var(--ink); color: var(--paper); }
.faq details[open] summary { padding-bottom: 12px; }
.faq details[open] summary::after { transform: rotate(45deg); }
.faq details p {
  padding: 0 0 24px 0;
  font-size: 15px;
  color: var(--muted);
  max-width: 70ch;
  line-height: 1.65;
  animation: faq-in var(--t-med) ease;
}
@keyframes faq-in {
  from { opacity: 0; transform: translateY(-4px); }
  to   { opacity: 1; transform: none; }
}

/* ---------- Footer ---------- */
footer {
  border-top: 1px solid var(--line);
  padding: 48px var(--gutter);
  font-size: 13px;
  color: var(--muted);
}
footer .footer-inner {
  max-width: var(--max);
  margin: 0 auto;
  display: flex; flex-wrap: wrap; gap: 16px;
  justify-content: space-between; align-items: center;
}
footer a {
  text-decoration: none;
  margin-right: 24px;
  position: relative;
}
footer a::after {
  content: "";
  position: absolute; left: 0; right: 0; bottom: -2px;
  height: 1px; background: currentColor;
  transform: scaleX(0); transform-origin: left;
  transition: transform var(--t-med);
}
footer a:hover { color: var(--ink); }
footer a:hover::after { transform: scaleX(1); }

/* ---------- Marquee strip (тонкая бегущая строка под hero) ---------- */
.marquee {
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  overflow: hidden;
  white-space: nowrap;
  padding: 18px 0;
  font-size: 13px; font-weight: 500;
  text-transform: uppercase; letter-spacing: 0.2em;
  color: var(--muted);
}
.marquee-track {
  display: inline-flex;
  gap: 48px;
  padding-right: 48px;
  animation: marquee 28s linear infinite;
}
.marquee:hover .marquee-track { animation-play-state: paused; }
.marquee-track > span { display: inline-flex; align-items: center; gap: 48px; }
.marquee-track > span::before {
  content: "—";
  color: var(--ink);
}
@keyframes marquee {
  from { transform: translateX(0); }
  to   { transform: translateX(-50%); }
}

/* ---------- Adaptive ---------- */
@media (max-width: 920px) {
  nav { display: none; }
  .trust-inner, .price-card, .section-title { grid-template-columns: 1fr; gap: 24px; }
  .stats { grid-template-columns: repeat(2, 1fr); gap: 28px; }
  .features { grid-template-columns: 1fr; }
  .steps { grid-template-columns: 1fr; }
  .step { border-right: 0; border-bottom: 1px solid var(--line); padding: 28px 0; }
  .step:last-child { border-bottom: 0; }
  .price-cta { padding: 72px var(--gutter); }
  .price-card a { justify-self: start; }
  .feature-section { padding: 64px var(--gutter); }
  .audit-form__row { flex-direction: column; }
  .audit-form__row button { padding: 16px; justify-content: center; }
  .hero { margin: 40px auto 64px; }
}

/* ---------- Reduced motion ---------- */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
  [data-reveal], [data-reveal-stagger] > * { opacity: 1 !important; transform: none !important; }
}