/* ============================================================
   Retention Studio LP
   配色：くすみセージグリーン／清潔・落ち着き・信頼感
   外部依存なし・モバイル優先・軽量
   ============================================================ */

:root {
  --bg:          #F6F5F0;  /* 生成りの白 */
  --surface:     #FFFFFF;
  --surface-alt: #ECEFE6;  /* くすみセージ・極淡 */
  --ink:         #2B2F2A;  /* 墨色 */
  --ink-soft:    #565B51;
  --ink-mute:    #8A8E83;
  --sage:        #7C8A6B;  /* 基調セージ */
  --sage-dark:   #5F6E50;  /* CTA */
  --sage-deep:   #4B5740;  /* hover */
  --sage-tint:   #E3E8DA;
  --line:        #E2E0D6;
  --shadow:      0 1px 2px rgba(43,47,42,.04), 0 8px 24px rgba(43,47,42,.05);
  --radius:      14px;
  --radius-sm:   10px;
  --maxw:        1080px;
  --space:       clamp(56px, 9vw, 104px);
}

/* ---------- base ---------- */
*, *::before, *::after { box-sizing: border-box; }

html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: -apple-system, BlinkMacSystemFont, "Hiragino Kaku Gothic ProN",
    "Hiragino Sans", "Yu Gothic", "YuGothic", "Meiryo", sans-serif;
  font-size: 16px;
  line-height: 1.85;
  letter-spacing: .01em;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

img { max-width: 100%; height: auto; }

a { color: var(--sage-dark); }

strong { font-weight: 700; }

.container { width: 100%; max-width: var(--maxw); margin: 0 auto; padding: 0 20px; }
.container.narrow { max-width: 760px; }

.skip-link {
  position: absolute; left: -9999px; top: 0;
  background: var(--ink); color: #fff; padding: 10px 16px; z-index: 100;
}
.skip-link:focus { left: 8px; top: 8px; }

.sp-only { display: inline; }

/* ---------- buttons ---------- */
.btn {
  display: inline-block;
  background: var(--sage-dark);
  color: #fff;
  text-decoration: none;
  font-weight: 700;
  letter-spacing: .02em;
  border-radius: 999px;
  padding: 16px 32px;
  line-height: 1.4;
  text-align: center;
  transition: background .18s ease, transform .18s ease;
  box-shadow: 0 6px 18px rgba(75,87,64,.22);
}
.btn:hover { background: var(--sage-deep); transform: translateY(-1px); }
.btn:active { transform: translateY(0); }
.btn:focus-visible { outline: 3px solid var(--sage); outline-offset: 3px; }
.btn-lg { font-size: 1.0625rem; padding: 18px 40px; }
.btn-sm { padding: 9px 18px; font-size: .875rem; box-shadow: none; }

/* ---------- header ---------- */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: rgba(246,245,240,.9);
  backdrop-filter: saturate(140%) blur(8px);
  border-bottom: 1px solid var(--line);
}
.header-inner {
  display: flex; align-items: center; justify-content: space-between;
  height: 62px;
}
.logo {
  font-weight: 800;
  font-size: 1.1rem;
  letter-spacing: .04em;
  color: var(--ink);
  text-decoration: none;
}

/* ---------- section frame ---------- */
.section { padding-block: var(--space); }
.section-alt { background: var(--surface-alt); }

.eyebrow {
  color: var(--sage-dark);
  font-weight: 700;
  font-size: .8125rem;
  letter-spacing: .14em;
  margin: 0 0 14px;
}
.section-title {
  font-size: clamp(1.5rem, 4.4vw, 2.125rem);
  line-height: 1.45;
  font-weight: 800;
  letter-spacing: .01em;
  margin: 0 0 18px;
}
.sub-title {
  font-size: clamp(1.125rem, 2.6vw, 1.3rem);
  font-weight: 800;
  margin: 48px 0 20px;
}
.lead { color: var(--ink-soft); margin: 0 0 28px; max-width: 60ch; }
.note-line { color: var(--ink-mute); font-size: .9375rem; margin-top: 22px; }

/* ---------- hero ---------- */
.hero {
  background:
    radial-gradient(120% 90% at 85% -10%, var(--sage-tint) 0%, rgba(227,232,218,0) 55%),
    var(--bg);
  padding-block: clamp(60px, 11vw, 120px);
  border-bottom: 1px solid var(--line);
}
.hero-title {
  font-size: clamp(1.85rem, 6.4vw, 3.25rem);
  line-height: 1.32;
  font-weight: 800;
  letter-spacing: .01em;
  margin: 0 0 24px;
}
.hero-title .hl {
  background: linear-gradient(transparent 62%, var(--sage-tint) 62%);
  padding: 0 .08em;
}
.hero-sub {
  font-size: clamp(1rem, 2.4vw, 1.1875rem);
  color: var(--ink-soft);
  margin: 0 0 36px;
  max-width: 40ch;
}
.hero-cta { margin-top: 8px; }
.cta-note { color: var(--ink-mute); font-size: .875rem; margin: 16px 0 0; }

/* ---------- cards grid ---------- */
.cards { display: grid; gap: 18px; }
.cards-3 { grid-template-columns: 1fr; }
.cards-4 { grid-template-columns: 1fr 1fr; }

.card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 26px 24px;
  box-shadow: var(--shadow);
}
.card h3 { margin: 0 0 10px; font-size: 1.125rem; font-weight: 800; }
.card p { margin: 0; color: var(--ink-soft); font-size: .9375rem; }

/* 課題 */
.problem-card { position: relative; padding-top: 30px; }
.problem-no {
  display: block;
  font-size: .8125rem; font-weight: 800; letter-spacing: .1em;
  color: var(--sage); margin-bottom: 8px;
}

/* ---------- contrast (×/○) ---------- */
.contrast {
  display: grid; gap: 14px;
  grid-template-columns: 1fr;
  margin: 14px 0 44px;
}
.contrast-item {
  display: flex; align-items: center; gap: 14px;
  padding: 18px 22px; border-radius: var(--radius); font-size: 1.0625rem;
}
.contrast-item p { margin: 0; }
.contrast-mark {
  flex: 0 0 auto;
  width: 34px; height: 34px; border-radius: 50%;
  display: grid; place-items: center;
  font-weight: 800; font-size: 1.1rem;
}
.is-not {
  background: #F1EFE9; color: var(--ink-mute);
  border: 1px solid var(--line);
}
.is-not .contrast-mark { background: #E4E2DA; color: #9A9E92; }
.is-not strong { color: var(--ink-soft); }
.is-do {
  background: var(--sage-dark); color: #fff;
}
.is-do .contrast-mark { background: rgba(255,255,255,.18); color: #fff; }
.is-do strong { color: #fff; }

/* ---------- flow diagram ---------- */
.flow-diagram {
  list-style: none; margin: 0 0 8px; padding: 0;
  display: grid; gap: 14px;
}
.flow-node {
  position: relative;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 18px 20px;
  box-shadow: var(--shadow);
}
.flow-node .flow-step {
  display: block; font-weight: 800; font-size: 1.0625rem; margin-bottom: 4px;
}
.flow-node .flow-desc { color: var(--ink-soft); font-size: .9rem; }
/* connector (vertical, mobile) */
.flow-node:not(:last-child)::after {
  content: "▼";
  position: absolute; left: 50%; bottom: -15px; transform: translateX(-50%);
  color: var(--sage); font-size: .7rem; line-height: 1;
}
.flow-node.is-classify { border-color: var(--sage); border-width: 2px; }
.flow-node.is-goal { background: var(--sage-tint); border-color: var(--sage); }

/* 4分類 */
.class-card { padding: 22px 18px; }
.class-card h4 {
  margin: 0 0 8px; font-size: 1rem; font-weight: 800; color: var(--sage-deep);
}
.class-card p { font-size: .875rem; }

/* ---------- steps ---------- */
.steps { list-style: none; margin: 0; padding: 0; counter-reset: none; }
.step {
  display: grid; grid-template-columns: 48px 1fr; gap: 18px;
  padding: 22px 0; border-bottom: 1px solid var(--line);
}
.step:last-child { border-bottom: 0; }
.step-no {
  width: 44px; height: 44px; border-radius: 50%;
  background: var(--sage-dark); color: #fff;
  display: grid; place-items: center; font-weight: 800; font-size: 1.1rem;
}
.step-body h3 { margin: 6px 0 6px; font-size: 1.125rem; font-weight: 800; }
.step-body p { margin: 0; color: var(--ink-soft); font-size: .9375rem; }

/* ---------- price ---------- */
.price-cards { align-items: stretch; }
.price-card {
  display: flex; flex-direction: column; position: relative; text-align: center;
}
.plan-name { margin: 0 0 6px; font-weight: 800; font-size: 1.0625rem; }
.plan-price {
  margin: 0 0 12px; font-size: 1.875rem; font-weight: 800; letter-spacing: .01em;
  color: var(--ink);
}
.plan-unit { font-size: .9375rem; font-weight: 700; color: var(--ink-soft); }
.plan-desc { color: var(--ink-soft); font-size: .9rem; }
.price-card.is-featured {
  border: 2px solid var(--sage); box-shadow: 0 10px 30px rgba(95,110,80,.16);
}
.plan-badge {
  position: absolute; top: -13px; left: 50%; transform: translateX(-50%);
  background: var(--sage-dark); color: #fff;
  font-size: .75rem; font-weight: 700; letter-spacing: .06em;
  padding: 5px 16px; border-radius: 999px; white-space: nowrap;
}

/* deliverables */
.deliverables {
  background: var(--surface); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 24px 24px 20px; margin-top: 24px;
  box-shadow: var(--shadow);
}
.deliverables-title { margin: 0 0 14px; font-weight: 800; }
.deliverables-list { margin: 0; padding-left: 0; list-style: none; }
.deliverables-list li {
  position: relative; padding: 7px 0 7px 28px; color: var(--ink-soft);
  font-size: .9375rem; border-bottom: 1px dashed var(--line);
}
.deliverables-list li:last-child { border-bottom: 0; }
.deliverables-list li::before {
  content: ""; position: absolute; left: 6px; top: 15px;
  width: 8px; height: 8px; border-radius: 50%; background: var(--sage);
}
.deliverables-note { margin: 14px 0 0; font-size: .875rem; color: var(--ink-mute); }

/* ---------- difference ---------- */
.diff-card { padding-top: 30px; }
.diff-no {
  display: block; font-size: 1.5rem; font-weight: 800;
  color: var(--sage); line-height: 1; margin-bottom: 12px;
}

/* ---------- belief ---------- */
.belief { text-align: center; }
.belief .section-title { margin-bottom: 22px; }
.belief-text {
  color: var(--ink-soft); font-size: 1.0625rem; margin: 0 auto; max-width: 54ch;
  text-align: left;
}

/* ---------- CTA section ---------- */
.cta-section { background: var(--sage-dark); color: #fff; text-align: center; }
.cta-title {
  font-size: clamp(1.375rem, 4vw, 2rem); font-weight: 800; line-height: 1.5;
  margin: 0 0 14px;
}
.cta-sub { color: rgba(255,255,255,.85); margin: 0 0 30px; }
.cta-section .btn { background: #fff; color: var(--sage-deep); box-shadow: 0 8px 22px rgba(0,0,0,.18); }
.cta-section .btn:hover { background: #F3F3EE; }
.cta-mail { margin: 22px 0 0; font-size: .9375rem; color: rgba(255,255,255,.85); }
.cta-mail a { color: #fff; text-decoration: underline; }

/* ---------- footer ---------- */
.site-footer { background: var(--ink); color: #D7D9D2; padding: 56px 0 28px; }
.footer-inner {
  display: grid; gap: 32px; grid-template-columns: 1fr;
}
.footer-logo { color: #fff; font-size: 1.25rem; margin: 0 0 10px; }
.footer-tag { color: #A9AC9F; font-size: .875rem; margin: 0; line-height: 1.7; }
.footer-info { margin: 0; display: grid; gap: 12px; }
.footer-info > div {
  display: grid; grid-template-columns: 96px 1fr; gap: 10px;
  border-bottom: 1px solid rgba(255,255,255,.1); padding-bottom: 10px;
}
.footer-info dt { margin: 0; color: #9C9F93; font-size: .8125rem; }
.footer-info dd { margin: 0; font-size: .9375rem; }
.footer-info a { color: #E7E9E1; text-decoration: underline; }
.copyright {
  text-align: center; color: #8A8D82; font-size: .8125rem;
  margin: 40px 0 0;
}

/* ---------- mobile fixed CTA ---------- */
.mobile-cta {
  display: none;
  position: fixed; left: 12px; right: 12px; bottom: 12px; z-index: 60;
  background: var(--sage-dark); color: #fff; text-decoration: none;
  text-align: center; font-weight: 700; padding: 15px 16px;
  border-radius: 999px; box-shadow: 0 8px 24px rgba(43,47,42,.28);
}
.mobile-cta:active { background: var(--sage-deep); }

/* ============================================================
   Responsive
   ============================================================ */
@media (max-width: 640px) {
  .header-cta { display: none; }
  .mobile-cta { display: block; }
  body { padding-bottom: 76px; } /* 固定CTA分の余白 */
  .sp-only { display: inline; }
}

@media (min-width: 641px) {
  .sp-only { display: none; }

  .cards-3 { grid-template-columns: repeat(3, 1fr); }
  .cards-4 { grid-template-columns: repeat(4, 1fr); }

  .contrast { grid-template-columns: 1fr 1fr; gap: 18px; }

  /* flow → 横並び */
  .flow-diagram {
    grid-template-columns: repeat(5, 1fr);
    gap: 26px; align-items: stretch;
  }
  .flow-node { display: flex; flex-direction: column; justify-content: center; }
  .flow-node:not(:last-child)::after {
    content: "▶";
    left: auto; right: -19px; bottom: auto; top: 50%;
    transform: translateY(-50%);
  }

  .footer-inner { grid-template-columns: 1.1fr 1fr; align-items: start; }
}

@media (min-width: 980px) {
  .hero-inner { max-width: 760px; }
}

/* reduce motion */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .btn { transition: none; }
}