:root {
  --bg: #fff;
  --bg-soft: #f5f7fb;
  --bg-dark: #101a2b;
  --text: #16202f;
  --text-soft: #5a6a80;
  --line: #e3e9f1;
  --accent: #1f6feb;
  --accent-dark: #1558c0;
  --accent-soft: #e9f1ff;
  --bad: #c0392b;
  --bad-soft: #fdecea;
  --radius: 12px;
  --wrap: 1160px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0; background: var(--bg); color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  font-size: 16px; line-height: 1.6; -webkit-font-smoothing: antialiased;
}
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
h1, h2, h3 { line-height: 1.25; margin: 0 0 14px; letter-spacing: -.02em; }
h1 { font-size: clamp(2rem, 4.2vw, 3.1rem); font-weight: 760; }
h2 { font-size: clamp(1.4rem, 2.4vw, 1.9rem); font-weight: 720; }
h3 { font-size: 1rem; font-weight: 680; }
p { margin: 0 0 14px; }
code { font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; font-size: .85em; }

.wrap { max-width: var(--wrap); margin: 0 auto; padding: 0 24px; }
.wrap-narrow { max-width: 820px; }
.section { padding: 72px 0; }
.lede { color: var(--text-soft); font-size: 1.08rem; max-width: 800px; }
.section-sub { color: var(--text-soft); max-width: 720px; }
.eyebrow { color: var(--accent); font-size: .8rem; font-weight: 700; letter-spacing: .09em; text-transform: uppercase; margin-bottom: 16px; }
.hint { font-size: .78rem; color: var(--text-soft); margin: 2px 0 0; }

.site-header { position: sticky; top: 0; z-index: 20; background: rgba(255,255,255,.95); backdrop-filter: blur(10px); border-bottom: 1px solid var(--line); }
.header-inner { display: flex; align-items: center; gap: 30px; height: 66px; }
.brand { font-size: 1.12rem; font-weight: 780; color: var(--text); letter-spacing: -.03em; }
.brand:hover { text-decoration: none; }
.brand span { color: var(--accent); }
.nav { display: flex; gap: 24px; margin-left: auto; }
.nav a { color: var(--text-soft); font-size: .92rem; font-weight: 550; }
.nav a:hover { color: var(--text); text-decoration: none; }

.btn {
  display: inline-flex; align-items: center; justify-content: center;
  padding: 11px 18px; border-radius: 8px; border: 1px solid transparent;
  font-family: inherit; font-size: .9rem; font-weight: 640;
  cursor: pointer; text-align: center;
  transition: background .15s, border-color .15s, transform .15s;
}
.btn:hover { text-decoration: none; transform: translateY(-1px); }
.btn-sm { padding: 8px 15px; font-size: .86rem; }
.btn-primary { background: var(--accent); color: #fff; }
.btn-primary:hover { background: var(--accent-dark); }
.btn-ghost { background: #fff; color: var(--text); border-color: var(--line); }
.btn-ghost:hover { border-color: var(--accent); color: var(--accent); }
.btn:disabled { opacity: .6; cursor: wait; transform: none; }

.hero { background: linear-gradient(180deg, var(--bg-soft), #fff); border-bottom: 1px solid var(--line); padding: 64px 0 56px; }
.hero .wrap { max-width: 900px; }
.section-tool { padding-top: 48px; }

.tool-grid { display: grid; grid-template-columns: minmax(320px, 1fr) minmax(340px, .9fr); gap: 24px; align-items: start; }
.panel { background: #fff; border: 1px solid var(--line); border-radius: var(--radius); padding: 26px; }
.results { box-shadow: 0 14px 40px rgba(16,26,43,.06); }
.panel-head { margin-bottom: 22px; padding-bottom: 16px; border-bottom: 1px solid var(--line); }
.panel-head h2 { font-size: 1.25rem; margin-bottom: 4px; }
.panel-head p { color: var(--text-soft); font-size: .86rem; margin: 0; }

.field { display: flex; flex-direction: column; gap: 5px; margin-bottom: 15px; min-width: 0; }
.field label { font-size: .85rem; font-weight: 640; }
.field-row { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
input, select, textarea {
  width: 100%; font-family: inherit; font-size: .93rem; color: var(--text);
  background: #fff; border: 1px solid var(--line); border-radius: 8px; padding: 9px 11px;
}
textarea { resize: vertical; }
input[type="color"] { padding: 3px; height: 40px; cursor: pointer; }
input:focus, select:focus, textarea:focus { outline: 2px solid var(--accent-soft); border-color: var(--accent); }
.group-title { margin: 22px 0 12px; padding-top: 16px; border-top: 1px solid var(--line); font-size: .78rem; text-transform: uppercase; letter-spacing: .08em; color: var(--text-soft); }
.warn { background: #fff6e5; color: #8a5a00; border-radius: 8px; padding: 10px 12px; font-size: .84rem; margin: 0; }
.error { background: var(--bad-soft); color: var(--bad); border-radius: 8px; padding: 10px 12px; font-size: .86rem; margin: 16px 0 0; }

.preview-wrap { display: flex; justify-content: center; align-items: center; background: var(--bg-soft); border: 1px solid var(--line); border-radius: 10px; padding: 24px; min-height: 280px; }
.preview { display: flex; justify-content: center; width: 100%; }
.preview svg { width: 100%; max-width: 300px; height: auto; display: block; }
.meta { text-align: center; font-size: .82rem; color: var(--text-soft); margin: 12px 0 0; }
.actions { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; margin-top: 20px; }
.payload-box { margin-top: 22px; background: var(--bg-soft); border-radius: 8px; padding: 12px 14px; }
.payload-box span { display: block; font-size: .76rem; text-transform: uppercase; letter-spacing: .06em; color: var(--text-soft); margin-bottom: 6px; }
.payload-box code { display: block; word-break: break-all; max-height: 90px; overflow: auto; color: var(--text); }
.results > .hint { margin-top: 12px; }

.section-bulk { background: var(--bg-soft); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.bulk-grid { display: grid; grid-template-columns: 1.1fr .9fr; gap: 24px; margin-top: 28px; }
.bulk-status { font-size: .86rem; color: var(--text-soft); margin: 14px 0 0; min-height: 20px; }
.bulk-info ul { padding-left: 18px; color: var(--text-soft); font-size: .92rem; }
.bulk-info p { color: var(--text-soft); font-size: .9rem; }

.why-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; margin-top: 32px; }
.why { border-top: 2px solid var(--accent); padding-top: 18px; }
.why h3 { font-size: 1rem; }
.why p { color: var(--text-soft); font-size: .9rem; margin: 0; }

details { border-bottom: 1px solid var(--line); padding: 16px 0; }
details:first-of-type { border-top: 1px solid var(--line); }
summary { cursor: pointer; font-weight: 640; list-style: none; position: relative; padding-right: 26px; }
summary::-webkit-details-marker { display: none; }
summary::after { content: "+"; position: absolute; right: 0; top: -2px; font-size: 1.25rem; color: var(--accent); font-weight: 400; }
details[open] summary::after { content: "\2212"; }
details p { color: var(--text-soft); margin: 12px 0 0; font-size: .92rem; }

.cta { background: var(--bg-dark); color: #fff; text-align: center; padding: 56px 0; }
.cta h2 { color: #fff; }
.cta p { color: #b8c5d8; }
.site-footer { border-top: 1px solid var(--line); padding: 24px 0; font-size: .84rem; color: var(--text-soft); }
.footer-inner { display: flex; align-items: center; gap: 18px; flex-wrap: wrap; }
.footer-inner .brand { font-size: 1rem; }

.toast { position: fixed; left: 50%; bottom: 26px; transform: translate(-50%, 20px); background: var(--bg-dark); color: #fff; padding: 12px 18px; border-radius: 8px; max-width: min(520px, calc(100vw - 40px)); font-size: .88rem; opacity: 0; pointer-events: none; transition: opacity .2s, transform .2s; z-index: 50; }
.toast.show { opacity: 1; transform: translate(-50%, 0); }

.section-links { background: var(--bg-soft); border-top: 1px solid var(--line); }
.section-links .why { display: block; color: inherit; }
.section-links .why:hover { text-decoration: none; border-top-color: var(--accent-dark); }
.section-links .why:hover h3 { color: var(--accent); }

.hero-sub { padding: 44px 0 52px; }
.crumbs { display: flex; gap: 10px; align-items: center; font-size: .82rem; color: var(--text-soft); margin-bottom: 22px; }
.crumbs a { color: var(--text-soft); }
.hero-action { margin: 26px 0 0; }
.section-steps { background: var(--bg-soft); border-bottom: 1px solid var(--line); }
.steps { counter-reset: step; list-style: none; padding: 0; margin: 30px 0 0; display: grid; gap: 18px; }
.steps li { counter-increment: step; position: relative; padding-left: 48px; }
.steps li::before { content: counter(step); position: absolute; left: 0; top: -3px; width: 30px; height: 30px; border-radius: 50%; background: var(--accent); color: #fff; display: grid; place-items: center; font-size: .85rem; font-weight: 700; }

.section-guide { border-bottom: 1px solid var(--line); }
.section-guide .guide-body { columns: 2; column-gap: 40px; margin-top: 30px; }
.section-guide .guide-body h2 { font-size: 1.2rem; break-inside: avoid; margin: 0 0 10px; }
.section-guide .guide-body h2:not(:first-child) { margin-top: 28px; }
.section-guide .guide-body h3 { break-inside: avoid; font-size: 1.02rem; margin: 0 0 8px; }
.section-guide .guide-body h3:not(:first-child) { margin-top: 28px; }
.section-guide .guide-body p, .section-guide .guide-body ul { break-inside: avoid; }
.section-guide .guide-body p, .section-guide ul { color: var(--text-soft); font-size: .94rem; }
.section-guide ul { padding-left: 20px; }
.section-guide li { margin-bottom: 6px; }
@media (max-width: 700px) { .section-guide .guide-body { columns: 1; } }

@media (max-width: 980px) {
  .tool-grid, .bulk-grid { grid-template-columns: 1fr; }
  .why-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 600px) {
  .section { padding: 48px 0; }
  .hero { padding: 44px 0 36px; }
  .panel { padding: 20px; }
  .field-row { grid-template-columns: 1fr; gap: 0; }
  .actions { grid-template-columns: 1fr; }
  .why-grid { grid-template-columns: 1fr; }
  .nav { display: none; }
  .btn-sm { display: none; }
}