/* ── relmea learn / shared styles ─────────────────────────────
   トークン（色・角丸・影・タイポ）は relmea.com の pages/page.css を踏襲。
   視覚的に地続きに見えることを最優先し、必要な分だけを持つ。
─────────────────────────────────────────────────────────── */

:root {
  --bg: #ffffff;
  --bg-soft: #f5f7fa;
  --bg-tint: #fafbfd;
  --ink: #0a0a0a;
  --ink-2: #2a2a2a;
  --ink-3: #64748b;
  --line: #e2e8f0;
  --line-2: #edf1f7;
  --accent: #1a73e8;
  --accent-dark: #1558b8;
  --accent-soft: #e6f0fd;
  --warn: #b91c1c;
  --ok: #137333;
  --r-sm: 8px;
  --r-md: 12px;
  --r-lg: 20px;
  --max: 1100px;
  --pad: clamp(20px, 4vw, 48px);
  --shadow-soft: 0 1px 2px rgba(10, 10, 10, .04), 0 8px 24px rgba(10, 10, 10, .06);
  --shadow-cta: 0 8px 24px rgba(26, 115, 232, .25);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
html, body { margin: 0; padding: 0; overflow-x: hidden; max-width: 100%; }

body {
  background: var(--bg);
  color: var(--ink);
  font-family: "Noto Sans JP", "Inter", system-ui, -apple-system, sans-serif;
  font-size: 16px;
  line-height: 1.8;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
button { font-family: inherit; cursor: pointer; }
h1, h2, h3 { margin: 0; letter-spacing: -.02em; }
p { margin: 0; }

.wrap { max-width: var(--max); margin: 0 auto; padding-left: var(--pad); padding-right: var(--pad); }

/* ── Buttons ─────────────────────────────────── */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 10px;
  padding: 14px 26px; border-radius: 999px;
  font-weight: 600; font-size: 15px;
  border: 1px solid transparent; white-space: nowrap;
  transition: transform .12s ease, box-shadow .15s ease, background .15s ease;
}
.btn-primary { background: var(--accent); color: #fff; box-shadow: var(--shadow-cta); }
.btn-primary:hover { background: var(--accent-dark); transform: translateY(-1px); }
.btn-primary:disabled { background: var(--ink-3); box-shadow: none; cursor: default; transform: none; }
.btn-ghost { background: transparent; color: var(--ink); border-color: var(--line); }
.btn-ghost:hover { background: var(--bg-soft); border-color: var(--ink-3); }
.btn-sm { padding: 9px 18px; font-size: 14px; }

.eyebrow {
  display: inline-flex; align-items: center; gap: 8px;
  font-size: 12px; letter-spacing: .12em; font-weight: 600;
  color: var(--accent); text-transform: uppercase;
}
.eyebrow::before { content: ""; width: 24px; height: 1px; background: var(--accent); }

/* ── Header ─────────────────────────────────── */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: rgba(255, 255, 255, .85);
  backdrop-filter: saturate(180%) blur(12px);
  -webkit-backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid var(--line);
}
.site-header .wrap {
  display: flex; align-items: center; justify-content: space-between;
  height: 64px; gap: 16px;
}
.brand {
  display: inline-flex; align-items: baseline; gap: 8px;
  font-weight: 700; font-size: 20px; letter-spacing: -.02em;
}
.brand .sub {
  font-size: 13px; font-weight: 500; color: var(--ink-3); letter-spacing: 0;
}
.head-nav { display: flex; align-items: center; gap: 14px; font-size: 14px; color: var(--ink-2); }
.head-nav a:hover { color: var(--ink); }
@media (max-width: 640px) {
  .head-nav .hide-sm { display: none; }
  .brand .sub { display: none; }
}

/* 現在の階層バッジ（JSで書き換え） */
.tier-badge {
  display: inline-flex; align-items: center; gap: 6px;
  padding: 5px 12px; border-radius: 999px;
  font-size: 12px; font-weight: 600;
  background: var(--bg-soft); color: var(--ink-3);
  border: 1px solid var(--line);
}
.tier-badge .dot { width: 6px; height: 6px; border-radius: 99px; background: var(--ink-3); }
.tier-badge.is-member { background: var(--accent-soft); color: var(--accent-dark); border-color: #cfe2fb; }
.tier-badge.is-member .dot { background: var(--ok); }

/* ── Hero ─────────────────────────────────── */
.hero {
  padding: 80px 0 56px;
  border-bottom: 1px solid var(--line-2);
  background:
    radial-gradient(50% 60% at 90% 0%, rgba(26, 115, 232, .07), transparent 70%),
    var(--bg);
}
.hero h1 {
  font-size: clamp(30px, 4.4vw, 46px);
  line-height: 1.28; font-weight: 800;
  margin: 22px 0 20px; max-width: 780px;
}
.hero p.lead {
  font-size: clamp(15px, 1.3vw, 17px); line-height: 1.9;
  color: var(--ink-2); max-width: 660px;
}
.hero .meta-row {
  display: flex; gap: 20px; flex-wrap: wrap;
  margin-top: 26px; font-size: 13px; color: var(--ink-3);
}
.hero .meta-row span { display: inline-flex; align-items: center; gap: 6px; }
.hero .meta-row span::before {
  content: ""; width: 6px; height: 6px; border-radius: 99px; background: var(--ink-3);
}

/* ── Sections ─────────────────────────────── */
section.band { padding: 64px 0; }
section.band + section.band { border-top: 1px solid var(--line-2); }
section.band.soft { background: var(--bg-tint); }
.section-head { margin-bottom: 32px; }
.section-head h2 {
  font-size: clamp(22px, 2.4vw, 30px); font-weight: 700; margin: 14px 0 10px;
}
.section-head p { color: var(--ink-3); font-size: 15px; max-width: 620px; }

/* ── Lesson cards ─────────────────────────── */
.card-grid {
  display: grid; gap: 16px;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
}
.card {
  display: flex; flex-direction: column; gap: 10px;
  padding: 22px 22px 20px;
  background: var(--bg);
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  transition: border-color .15s ease, box-shadow .15s ease, transform .12s ease;
}
a.card:hover { border-color: #cfd9e6; box-shadow: var(--shadow-soft); transform: translateY(-2px); }
.card .card-top { display: flex; align-items: center; justify-content: space-between; gap: 10px; }
.card .code {
  font-family: "Inter", system-ui, monospace;
  font-size: 12px; font-weight: 700; letter-spacing: .08em;
  color: var(--ink-3);
}
.card h3 { font-size: 17px; font-weight: 700; line-height: 1.5; }
.card p { font-size: 14px; color: var(--ink-3); line-height: 1.75; }
.card .card-foot {
  margin-top: auto; padding-top: 12px;
  font-size: 13px; font-weight: 600; color: var(--accent);
  display: inline-flex; align-items: center; gap: 6px;
}
.card.locked .card-foot { color: var(--ink-3); }

/* 階層ピル */
.pill {
  display: inline-flex; align-items: center; gap: 5px;
  padding: 4px 10px; border-radius: 999px;
  font-size: 11px; font-weight: 700; letter-spacing: .02em;
  border: 1px solid transparent; white-space: nowrap;
}
.pill-free { background: #e8f5ec; color: var(--ok); border-color: #cfe8d8; }
.pill-brain { background: #fff3e0; color: #9a5b00; border-color: #f5dfbd; }
.pill-member { background: var(--accent-soft); color: var(--accent-dark); border-color: #cfe2fb; }

/* ── Article ──────────────────────────────── */
.article { padding: 56px 0 88px; }
.article .kicker {
  display: flex; align-items: center; gap: 12px; flex-wrap: wrap;
  font-size: 12px; color: var(--ink-3); letter-spacing: .08em; font-weight: 600;
}
.article h1 {
  font-size: clamp(26px, 3.4vw, 38px); font-weight: 800; line-height: 1.35;
  margin: 18px 0 18px; max-width: 760px;
}
.article .standfirst {
  font-size: 17px; line-height: 1.9; color: var(--ink-2);
  max-width: 700px; padding-bottom: 28px;
  border-bottom: 1px solid var(--line-2);
}
.prose { max-width: 700px; padding-top: 28px; }
.prose h2 {
  font-size: 21px; font-weight: 700; margin: 40px 0 14px;
  padding-top: 8px;
}
.prose h3 { font-size: 17px; font-weight: 700; margin: 28px 0 10px; }
.prose p { margin: 0 0 18px; color: var(--ink-2); }
.prose ul, .prose ol { margin: 0 0 20px; padding-left: 22px; color: var(--ink-2); }
.prose li { margin-bottom: 8px; }
.prose code {
  font-family: "Inter", ui-monospace, monospace;
  font-size: .9em; padding: 2px 6px; border-radius: 5px;
  background: var(--bg-soft); border: 1px solid var(--line-2);
}

.draft-note {
  margin: 8px 0 0;
  padding: 18px 20px;
  border: 1px dashed var(--line);
  border-radius: var(--r-md);
  background: var(--bg-tint);
  color: var(--ink-3);
  font-size: 14px;
}
.draft-note strong { color: var(--ink-2); }

.backlink {
  display: inline-flex; align-items: center; gap: 6px;
  margin-top: 44px; font-size: 14px; color: var(--ink-3);
}
.backlink:hover { color: var(--accent); }

/* ── Unlock form ──────────────────────────── */
.unlock-grid {
  display: grid; gap: 18px;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  margin-top: 32px;
}
.panel {
  padding: 26px 24px;
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  background: var(--bg);
}
.panel.is-target { border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-soft); }
.panel h2 { font-size: 18px; font-weight: 700; margin-bottom: 8px; }
.panel .hint { font-size: 14px; color: var(--ink-3); margin-bottom: 18px; line-height: 1.75; }
.field { display: flex; flex-direction: column; gap: 8px; margin-bottom: 14px; }
.field label { font-size: 13px; font-weight: 600; color: var(--ink-2); }
.field input {
  width: 100%; padding: 13px 14px;
  font-family: inherit; font-size: 15px;
  color: var(--ink); background: var(--bg);
  border: 1px solid var(--line); border-radius: var(--r-sm);
  transition: border-color .15s ease, box-shadow .15s ease;
}
.field input:focus {
  outline: none; border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-soft);
}
.msg {
  margin-top: 12px; font-size: 14px; line-height: 1.7;
  padding: 12px 14px; border-radius: var(--r-sm); display: none;
}
.msg.show { display: block; }
.msg.err { background: #fdecec; color: var(--warn); border: 1px solid #f7d4d4; }
.msg.ok { background: #e8f5ec; color: var(--ok); border: 1px solid #cfe8d8; }

.notice {
  padding: 16px 18px; border-radius: var(--r-md);
  background: var(--accent-soft); border: 1px solid #cfe2fb;
  color: var(--accent-dark); font-size: 14px; line-height: 1.75;
}

/* ── Footer ───────────────────────────────── */
.site-footer {
  padding: 40px 0; border-top: 1px solid var(--line);
  background: var(--bg-tint);
  font-size: 13px; color: var(--ink-3);
}
.site-footer .wrap { display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap; }
.site-footer a:hover { color: var(--ink); }
.site-footer nav { display: flex; gap: 18px; flex-wrap: wrap; }