:root {
  --ink: #101828;
  --muted: #475467;
  --soft: #f8fafc;
  --line: #e4e7ec;
  --brand: #2563eb;
  --ai: #7c3aed;
  --cta: #10b981;
  --danger: #ef4444;
  --white: #fff;
  --shadow: 0 18px 50px rgba(16, 24, 40, .08);
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  color: var(--ink);
  background: var(--soft);
}
a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }
.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 16px clamp(18px, 5vw, 70px);
  background: rgba(255,255,255,.88);
  backdrop-filter: blur(18px);
  border-bottom: 1px solid rgba(228,231,236,.8);
}
.brand { display: inline-flex; align-items: center; gap: 10px; font-weight: 850; font-size: 20px; }
.brand img { width: 38px; height: 38px; }
.main-nav { display: flex; align-items: center; gap: 18px; color: var(--muted); font-weight: 650; }
.menu-toggle { display: none; border: 1px solid var(--line); background: white; border-radius: 8px; padding: 9px 11px; }
.hero {
  min-height: calc(100vh - 76px);
  display: grid;
  grid-template-columns: 1.05fr .95fr;
  gap: 42px;
  align-items: center;
  padding: clamp(48px, 7vw, 96px) clamp(18px, 5vw, 70px);
  background:
    radial-gradient(circle at 15% 10%, rgba(37,99,235,.13), transparent 28%),
    linear-gradient(135deg, #ffffff 0%, #f8fafc 55%, #eef2ff 100%);
}
.hero h1 { font-size: clamp(42px, 6vw, 78px); line-height: 1.02; margin: 0 0 22px; letter-spacing: 0; }
.hero p { color: var(--muted); font-size: clamp(18px, 2vw, 22px); line-height: 1.6; max-width: 680px; }
.hero-art {
  min-height: 520px;
  border-radius: 8px;
  background:
    linear-gradient(145deg, rgba(16,24,40,.92), rgba(37,99,235,.78)),
    url('/assets/img/placeholder-cover.jpg');
  background-size: cover;
  color: white;
  padding: 34px;
  box-shadow: var(--shadow);
  display: grid;
  align-content: end;
  overflow: hidden;
}
.ebook-preview {
  background: rgba(255,255,255,.1);
  border: 1px solid rgba(255,255,255,.22);
  border-radius: 8px;
  padding: 28px;
  backdrop-filter: blur(12px);
}
.ebook-preview h2 { font-size: 36px; margin: 0 0 12px; }
.actions { display: flex; flex-wrap: wrap; gap: 12px; align-items: center; margin-top: 28px; }
.btn, button.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 46px;
  padding: 12px 18px;
  border-radius: 8px;
  border: 0;
  background: var(--brand);
  color: white;
  font-weight: 760;
  cursor: pointer;
}
.btn.secondary { background: var(--ink); }
.btn.ghost { background: white; color: var(--ink); border: 1px solid var(--line); }
.btn.success { background: var(--cta); }
.btn.danger { background: var(--danger); }
.btn-small { min-height: 38px; padding: 9px 13px; font-size: 14px; }
.section { padding: clamp(42px, 6vw, 84px) clamp(18px, 5vw, 70px); }
.section h2 { font-size: clamp(30px, 4vw, 48px); margin: 0 0 14px; }
.section-lead { color: var(--muted); max-width: 760px; font-size: 18px; line-height: 1.7; }
.grid { display: grid; gap: 18px; }
.grid-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid-4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }
.card {
  background: white;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 22px;
  box-shadow: 0 8px 24px rgba(16,24,40,.05);
}
.card.highlight { border-color: rgba(124,58,237,.35); box-shadow: var(--shadow); }
.card h3 { margin: 0 0 10px; font-size: 21px; }
.muted { color: var(--muted); }
.price { font-size: 38px; font-weight: 850; margin: 12px 0; }
.layout {
  display: grid;
  grid-template-columns: 260px minmax(0, 1fr);
  min-height: calc(100vh - 76px);
}
.sidebar {
  background: white;
  border-right: 1px solid var(--line);
  padding: 22px;
}
.sidebar nav { display: grid; gap: 8px; }
.sidebar a { padding: 12px 14px; border-radius: 8px; color: var(--muted); font-weight: 700; }
.sidebar a.active, .sidebar a:hover { color: var(--brand); background: #eff6ff; }
.content { padding: clamp(18px, 4vw, 42px); min-width: 0; }
.topbar { display: flex; justify-content: space-between; align-items: center; gap: 18px; margin-bottom: 24px; }
.stats { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 16px; }
.stat .value { font-size: 32px; font-weight: 850; }
form .row { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 14px; }
label { display: grid; gap: 7px; font-weight: 720; color: var(--ink); }
input, select, textarea {
  width: 100%;
  border: 1px solid #d0d5dd;
  border-radius: 8px;
  padding: 12px 13px;
  font: inherit;
  color: var(--ink);
  background: white;
}
textarea { min-height: 120px; resize: vertical; }
.form-card { max-width: 760px; margin: 42px auto; }
.auth-shell { min-height: calc(100vh - 76px); display: grid; place-items: center; padding: 24px; }
.auth-card { width: min(520px, 100%); }
.alert { padding: 13px 15px; border-radius: 8px; margin: 14px 0; border: 1px solid; }
.alert.error { background: #fef2f2; color: #991b1b; border-color: #fecaca; }
.alert.success { background: #ecfdf3; color: #027a48; border-color: #abefc6; }
.table-wrap { overflow-x: auto; background: white; border: 1px solid var(--line); border-radius: 8px; }
table { width: 100%; border-collapse: collapse; min-width: 760px; }
th, td { padding: 14px 15px; text-align: left; border-bottom: 1px solid var(--line); vertical-align: top; }
th { font-size: 13px; text-transform: uppercase; color: #667085; background: #fcfcfd; }
.badge { display: inline-flex; align-items: center; border-radius: 999px; padding: 4px 9px; font-size: 12px; font-weight: 800; background: #eef2ff; color: #3730a3; }
.badge.ok { background: #ecfdf3; color: #027a48; }
.badge.warn { background: #fffaeb; color: #b54708; }
.ebook-content { line-height: 1.75; }
.ebook-content h1 { font-size: 42px; }
.ebook-content h3 { color: var(--brand); margin-top: 34px; }
.site-footer {
  display: flex;
  justify-content: space-between;
  gap: 18px;
  padding: 28px clamp(18px, 5vw, 70px);
  color: var(--muted);
  background: white;
  border-top: 1px solid var(--line);
}
.site-footer div, .site-footer nav { display: flex; flex-wrap: wrap; gap: 14px; }
.seo-page { background: white; max-width: 920px; margin: 34px auto; padding: 34px; border-radius: 8px; border: 1px solid var(--line); }
.install-shell { min-height: 100vh; padding: 32px 18px; background: linear-gradient(135deg,#101828,#1d4ed8); }
.install-card { max-width: 920px; margin: 0 auto; background: white; border-radius: 8px; padding: clamp(22px,4vw,38px); box-shadow: var(--shadow); }
.steps { display: flex; gap: 8px; flex-wrap: wrap; margin: 18px 0 24px; }
.step { padding: 7px 10px; border-radius: 999px; background: #eef2ff; color: #3730a3; font-weight: 800; font-size: 13px; }
.step.active { background: var(--cta); color: white; }
.check-list { display: grid; gap: 10px; }
.check { display: flex; justify-content: space-between; gap: 18px; padding: 12px 14px; background: #f8fafc; border-radius: 8px; }
.hidden-hp { position: absolute; left: -10000px; width: 1px; height: 1px; overflow: hidden; }
@media (max-width: 980px) {
  .hero, .layout { grid-template-columns: 1fr; }
  .hero { min-height: auto; }
  .hero-art { min-height: 380px; }
  .grid-3, .grid-4, .stats { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .sidebar { border-right: 0; border-bottom: 1px solid var(--line); }
}
@media (max-width: 720px) {
  .menu-toggle { display: inline-flex; }
  .main-nav { display: none; position: absolute; left: 16px; right: 16px; top: 70px; background: white; border: 1px solid var(--line); border-radius: 8px; padding: 14px; box-shadow: var(--shadow); }
  .main-nav.is-open { display: grid; }
  .hero h1 { font-size: 42px; }
  .grid-2, .grid-3, .grid-4, .stats, form .row { grid-template-columns: 1fr; }
  .topbar, .site-footer { align-items: flex-start; flex-direction: column; }
  .section, .content { padding-left: 16px; padding-right: 16px; }
}