/* SocialSNS株式会社 コーポレートサイト
   依存なしの静的CSS。トークンは :root に集約し、ダークは data-theme と OS 設定の両方で切り替える。 */

:root {
  --bg: #fafafa;
  --bg-2: #ffffff;
  --bg-3: #f1f1f3;
  --fg: #111113;
  --fg-2: #5c5c66;
  --fg-3: #8a8a94;
  --line: #e4e4e8;
  --line-2: #d0d0d6;
  --accent: #1f4fd8;
  --accent-fg: #ffffff;
  --accent-soft: #e8eefc;
  --ok: #15803d;
  --shadow: 0 1px 2px rgba(0,0,0,.04), 0 8px 24px -12px rgba(0,0,0,.12);
  --radius: 14px;
  --radius-sm: 9px;
  --w: 1120px;
  --font: "Inter", "Noto Sans JP", system-ui, -apple-system, "Segoe UI", "Hiragino Sans", "Yu Gothic UI", sans-serif;
  color-scheme: light;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #0b0b0e;
    --bg-2: #121216;
    --bg-3: #19191f;
    --fg: #f2f2f4;
    --fg-2: #a3a3ad;
    --fg-3: #6f6f7a;
    --line: #232329;
    --line-2: #32323a;
    --accent: #7aa2ff;
    --accent-fg: #0b0b0e;
    --accent-soft: #16203a;
    --ok: #4ade80;
    --shadow: 0 1px 2px rgba(0,0,0,.4), 0 8px 24px -12px rgba(0,0,0,.6);
    color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --bg: #0b0b0e;
  --bg-2: #121216;
  --bg-3: #19191f;
  --fg: #f2f2f4;
  --fg-2: #a3a3ad;
  --fg-3: #6f6f7a;
  --line: #232329;
  --line-2: #32323a;
  --accent: #7aa2ff;
  --accent-fg: #0b0b0e;
  --accent-soft: #16203a;
  --ok: #4ade80;
  --shadow: 0 1px 2px rgba(0,0,0,.4), 0 8px 24px -12px rgba(0,0,0,.6);
  color-scheme: dark;
}

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.75;
  font-feature-settings: "palt";
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
a { color: inherit; text-decoration: none; }
a:hover { color: var(--accent); }
img, svg { display: block; max-width: 100%; }
h1, h2, h3, h4 { margin: 0; font-weight: 600; letter-spacing: -0.015em; line-height: 1.25; }
p { margin: 0; }
ul { margin: 0; padding: 0; list-style: none; }
button { font: inherit; color: inherit; background: none; border: 0; cursor: pointer; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; border-radius: 4px; }

.wrap { width: 100%; max-width: var(--w); margin: 0 auto; padding: 0 20px; }
@media (min-width: 768px) { .wrap { padding: 0 32px; } }

/* ---------- header ---------- */
.header {
  position: sticky; top: 0; z-index: 50;
  background: color-mix(in srgb, var(--bg) 78%, transparent);
  backdrop-filter: saturate(160%) blur(14px);
  -webkit-backdrop-filter: saturate(160%) blur(14px);
  border-bottom: 1px solid var(--line);
}
.header .wrap { display: flex; align-items: center; justify-content: space-between; height: 64px; gap: 16px; }
.brand { display: inline-flex; align-items: center; gap: 10px; font-weight: 600; letter-spacing: -0.01em; }
.brand:hover { color: inherit; }
.brand-mark { width: 28px; height: 28px; border-radius: 8px; background: var(--fg); color: var(--bg); display: grid; place-items: center; flex: none; }
.brand-mark svg { width: 16px; height: 16px; }
.brand-text { line-height: 1.1; }
.brand small { display: block; font-size: 11px; font-weight: 500; color: var(--fg-3); line-height: 1; margin-top: 4px; letter-spacing: 0; }

.nav { display: none; align-items: center; gap: 4px; }
.nav a { padding: 8px 12px; border-radius: 8px; font-size: 14px; color: var(--fg-2); }
.nav a:hover, .nav a[aria-current="page"] { color: var(--fg); background: var(--bg-3); }
@media (min-width: 860px) { .nav { display: flex; } }

.header-actions { display: flex; align-items: center; gap: 6px; }
.icon-btn {
  width: 40px; height: 40px; border-radius: 10px; display: grid; place-items: center;
  color: var(--fg-2); border: 1px solid transparent;
}
.icon-btn:hover { background: var(--bg-3); color: var(--fg); }
.icon-btn svg { width: 18px; height: 18px; }
.theme-toggle .sun { display: none; }
:root[data-theme="dark"] .theme-toggle .sun { display: block; }
:root[data-theme="dark"] .theme-toggle .moon { display: none; }
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .theme-toggle .sun { display: block; }
  :root:not([data-theme="light"]) .theme-toggle .moon { display: none; }
}
.menu-btn { display: grid; }
@media (min-width: 860px) { .menu-btn { display: none; } }

.mobile-nav {
  display: none; border-bottom: 1px solid var(--line); background: var(--bg);
}
.mobile-nav.open { display: block; }
.mobile-nav a { display: block; padding: 14px 20px; font-size: 15px; border-top: 1px solid var(--line); min-height: 48px; }
.mobile-nav a:first-child { border-top: 0; }
@media (min-width: 860px) { .mobile-nav { display: none !important; } }

/* ---------- buttons ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  min-height: 46px; padding: 0 20px; border-radius: 11px; font-size: 15px; font-weight: 500;
  border: 1px solid var(--line-2); background: var(--bg-2); color: var(--fg);
  transition: background .15s ease, border-color .15s ease, transform .15s ease, opacity .15s ease;
}
.btn:hover { background: var(--bg-3); color: var(--fg); border-color: var(--fg-3); }
.btn:active { transform: translateY(1px); }
.btn-primary { background: var(--fg); color: var(--bg); border-color: var(--fg); }
.btn-primary:hover { background: var(--fg); color: var(--bg); opacity: .88; border-color: var(--fg); }
.btn svg { width: 16px; height: 16px; }

/* ---------- hero ---------- */
.hero { padding: 72px 0 56px; position: relative; overflow: hidden; }
@media (min-width: 768px) { .hero { padding: 120px 0 88px; } }
.hero::before {
  content: ""; position: absolute; inset: 0; pointer-events: none;
  background-image:
    linear-gradient(to right, var(--line) 1px, transparent 1px),
    linear-gradient(to bottom, var(--line) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: radial-gradient(ellipse 70% 60% at 50% 0%, #000 20%, transparent 70%);
  -webkit-mask-image: radial-gradient(ellipse 70% 60% at 50% 0%, #000 20%, transparent 70%);
  opacity: .7;
}
.hero .wrap { position: relative; }
.eyebrow {
  display: inline-flex; align-items: center; gap: 8px; font-size: 13px; color: var(--fg-2);
  padding: 6px 12px 6px 8px; border: 1px solid var(--line); border-radius: 999px; background: var(--bg-2);
}
.eyebrow .dot { width: 8px; height: 8px; border-radius: 50%; background: var(--ok); box-shadow: 0 0 0 3px color-mix(in srgb, var(--ok) 20%, transparent); }
.hero h1 {
  margin-top: 24px; font-size: clamp(2.1rem, 5.4vw, 4rem); font-weight: 650; letter-spacing: -0.03em; line-height: 1.12;
  max-width: 18ch;
}
.hero .lead { margin-top: 22px; font-size: clamp(1rem, 1.3vw, 1.15rem); color: var(--fg-2); max-width: 44ch; }
.hero .actions { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 32px; }
.hero-meta { display: flex; flex-wrap: wrap; gap: 8px 24px; margin-top: 44px; color: var(--fg-3); font-size: 13px; }
.hero-meta li { display: inline-flex; align-items: center; gap: 8px; }
.hero-meta svg { width: 14px; height: 14px; color: var(--fg-2); }

/* ---------- sections ---------- */
.section { padding: 64px 0; border-top: 1px solid var(--line); }
@media (min-width: 768px) { .section { padding: 96px 0; } }
.section-head { max-width: 640px; margin-bottom: 40px; }
.section-head .label { font-size: 13px; font-weight: 500; color: var(--accent); letter-spacing: .02em; }
.section-head h2 { margin-top: 10px; font-size: clamp(1.6rem, 3vw, 2.25rem); letter-spacing: -0.025em; }
.section-head p { margin-top: 14px; color: var(--fg-2); }

/* bento grid */
.bento { display: grid; gap: 14px; grid-template-columns: 1fr; }
@media (min-width: 768px) { .bento { grid-template-columns: repeat(6, 1fr); } }
.card {
  position: relative; background: var(--bg-2); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 26px; transition: border-color .2s ease, box-shadow .2s ease;
}
.card:hover { border-color: var(--line-2); box-shadow: var(--shadow); }
.card .icon { width: 42px; height: 42px; border-radius: 11px; background: var(--bg-3); display: grid; place-items: center; color: var(--fg); margin-bottom: 20px; }
.card .icon svg { width: 20px; height: 20px; }
.card h3 { font-size: 1.15rem; }
.card p { margin-top: 10px; color: var(--fg-2); font-size: 15px; }
.card .tags { display: flex; flex-wrap: wrap; gap: 6px; margin-top: 18px; }
.tag { font-size: 12px; color: var(--fg-2); padding: 4px 10px; border-radius: 999px; background: var(--bg-3); border: 1px solid var(--line); }
.card .more { display: inline-flex; align-items: center; gap: 6px; margin-top: 18px; font-size: 14px; font-weight: 500; color: var(--fg); }
.card .more svg { width: 14px; height: 14px; transition: transform .15s ease; }
.card .more:hover svg { transform: translateX(3px); }
@media (min-width: 768px) {
  .span-3 { grid-column: span 3; }
  .span-2 { grid-column: span 2; }
  .span-4 { grid-column: span 4; }
  .span-6 { grid-column: span 6; }
}

/* ---------- two column ---------- */
.split { display: grid; gap: 40px; grid-template-columns: 1fr; align-items: start; }
@media (min-width: 900px) { .split { grid-template-columns: 5fr 7fr; gap: 64px; } .split .section-head { margin-bottom: 0; } }

.steps { display: grid; gap: 10px; }
.step { display: grid; grid-template-columns: 40px 1fr; gap: 16px; padding: 18px 20px; border: 1px solid var(--line); border-radius: var(--radius-sm); background: var(--bg-2); }
.step .num { width: 32px; height: 32px; border-radius: 9px; display: grid; place-items: center; font-size: 13px; font-weight: 600; background: var(--bg-3); color: var(--fg-2); font-variant-numeric: tabular-nums; }
.step h3 { font-size: 1rem; }
.step p { margin-top: 4px; color: var(--fg-2); font-size: 14.5px; }

/* ---------- definition table ---------- */
.dl { border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden; background: var(--bg-2); margin: 0; }
.dl .row { display: grid; grid-template-columns: 1fr; gap: 4px; padding: 16px 20px; border-top: 1px solid var(--line); }
.dl .row:first-child { border-top: 0; }
.dl dt { font-size: 13px; color: var(--fg-3); }
.dl dd { margin: 0; font-size: 15px; }
@media (min-width: 640px) { .dl .row { grid-template-columns: 180px 1fr; gap: 24px; padding: 18px 24px; } .dl dt { font-size: 14px; padding-top: 1px; } }
.mono { font-family: ui-monospace, "SFMono-Regular", Menlo, Consolas, monospace; font-size: .95em; letter-spacing: 0; }

/* ---------- contact ---------- */
.contact-box {
  display: grid; gap: 28px; padding: 36px 28px; border-radius: 18px; border: 1px solid var(--line);
  background: linear-gradient(180deg, var(--bg-2), var(--bg-3));
}
@media (min-width: 860px) { .contact-box { grid-template-columns: 1fr auto; align-items: center; padding: 48px; } }
.contact-box h2 { font-size: clamp(1.5rem, 2.6vw, 2rem); letter-spacing: -0.025em; }
.contact-box p { margin-top: 12px; color: var(--fg-2); max-width: 52ch; }
.contact-box .actions { display: flex; flex-direction: column; gap: 10px; }
.contact-box .note { font-size: 13px; color: var(--fg-3); }

/* ---------- footer ---------- */
.footer { border-top: 1px solid var(--line); padding: 48px 0 32px; color: var(--fg-2); font-size: 14px; }
.footer-grid { display: grid; gap: 32px; grid-template-columns: 1fr; }
@media (min-width: 768px) { .footer-grid { grid-template-columns: 1.4fr 1fr 1fr 1fr; } }
.footer h4 { font-size: 13px; font-weight: 600; color: var(--fg); margin-bottom: 14px; }
.footer li { margin-top: 8px; }
.footer .addr { margin-top: 14px; font-size: 13px; color: var(--fg-3); line-height: 1.7; }
.footer-bottom { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 10px; margin-top: 40px; padding-top: 20px; border-top: 1px solid var(--line); font-size: 13px; color: var(--fg-3); }

/* ---------- article pages ---------- */
.page { padding: 56px 0 80px; }
@media (min-width: 768px) { .page { padding: 88px 0 120px; } }
.page .wrap { max-width: 760px; }
.page h1 { font-size: clamp(1.9rem, 4vw, 2.75rem); letter-spacing: -0.03em; }
.page .updated { margin-top: 12px; font-size: 13px; color: var(--fg-3); }
.prose { margin-top: 40px; }
.prose h2 { font-size: 1.35rem; margin-top: 48px; padding-top: 28px; border-top: 1px solid var(--line); }
.prose h2:first-child { margin-top: 0; padding-top: 0; border-top: 0; }
.prose h3 { font-size: 1.05rem; margin-top: 28px; }
.prose p { margin-top: 14px; color: var(--fg-2); }
.prose ul, .prose ol { margin-top: 14px; padding-left: 1.4em; color: var(--fg-2); }
.prose ul { list-style: disc; }
.prose ol { list-style: decimal; }
.prose li { margin-top: 6px; }
.prose li::marker { color: var(--fg-3); }
.prose a { color: var(--accent); text-decoration: underline; text-decoration-color: color-mix(in srgb, var(--accent) 40%, transparent); text-underline-offset: 3px; }
.prose code { font-family: ui-monospace, Menlo, Consolas, monospace; font-size: .9em; background: var(--bg-3); border: 1px solid var(--line); border-radius: 6px; padding: 1px 6px; }
.prose .callout { margin-top: 24px; padding: 18px 20px; border-radius: var(--radius-sm); background: var(--accent-soft); border: 1px solid color-mix(in srgb, var(--accent) 30%, transparent); color: var(--fg); font-size: 15px; }
.prose .callout p { margin-top: 6px; color: inherit; }
.prose .dl { margin-top: 20px; }

/* ---------- reveal ---------- */
.reveal { opacity: 0; transform: translateY(14px); transition: opacity .6s ease, transform .6s ease; }
.reveal.in { opacity: 1; transform: none; }
@media (prefers-reduced-motion: reduce) { .reveal { opacity: 1; transform: none; transition: none; } }

.skip { position: absolute; left: -9999px; top: 8px; background: var(--fg); color: var(--bg); padding: 8px 12px; border-radius: 8px; z-index: 100; }
.skip:focus { left: 8px; }