/* ============================================================
   kata contract — base.css
   構造とコンポーネントの骨格。--k-* 変数のみ参照し、見た目の実値を持たない。
   実値の供給元＝デザインシステム（wire.css / design-systems/*.css）。
   規約本文：kata-contract.md
   ============================================================ */

* { margin: 0; padding: 0; box-sizing: border-box; }

body {
  background: var(--k-bg);
  color: var(--k-ink);
  font-family: var(--k-font-body);
  font-size: 15px;
  line-height: var(--k-lh-body);
}
img { max-width: 100%; display: block; }
a { color: inherit; }

/* ---------- 構造 ---------- */
.k-section { padding: var(--k-section-pad) 24px; background: var(--k-bg); }
.k-section--alt { background: var(--k-surface); }
.k-section--invert {
  background: var(--k-accent);
  --k-ink: var(--k-on-accent);
  --k-sub: color-mix(in srgb, var(--k-on-accent) 72%, transparent);
  --k-line: color-mix(in srgb, var(--k-on-accent) 30%, transparent);
  color: var(--k-ink);
}
.k-section--invert .k-eyebrow { color: var(--k-on-accent); }
.k-section--invert .k-btn--primary { background: var(--k-on-accent); color: var(--k-accent); }

.k-inner { max-width: 1080px; margin-inline: auto; }
.k-inner--narrow { max-width: 720px; }

.k-stack { display: flex; flex-direction: column; gap: var(--k-gap); align-items: flex-start; }
.k-center { text-align: center; }
.k-center.k-stack, .k-center .k-stack { align-items: center; }
.k-center .k-actions { justify-content: center; }
.k-head { margin-bottom: 56px; }

.k-split { display: grid; grid-template-columns: 1fr 1fr; gap: 64px; align-items: center; }
.k-split--rev > :first-child { order: 2; }
.k-grid-2 { display: grid; grid-template-columns: repeat(2, 1fr); gap: 24px; }
.k-grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.k-grid-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; }
.k-row { display: flex; align-items: center; gap: 14px; }

.k-cover { position: relative; border-radius: var(--k-radius); overflow: hidden; }
.k-cover > .k-media { position: absolute; inset: 0; min-height: 0; border: 0; border-radius: 0; }
.k-cover-content {
  position: relative; max-width: 520px;
  margin: 56px; padding: 48px;
  background: var(--k-bg); border-radius: var(--k-radius);
}

/* ---------- 文字 ---------- */
.k-eyebrow {
  font-family: var(--k-font-num); font-size: 12px; font-weight: 600;
  letter-spacing: .22em; text-transform: uppercase; color: var(--k-accent);
}
.k-h1 {
  font-family: var(--k-font-display); font-weight: var(--k-fw-display);
  font-size: clamp(28px, 5.4vw, var(--k-fs-h1));
  letter-spacing: var(--k-ls-display); line-height: var(--k-lh-display);
  max-width: 22em;
}
.k-h2 {
  font-family: var(--k-font-display); font-weight: var(--k-fw-display);
  font-size: clamp(22px, 3.6vw, var(--k-fs-h2));
  letter-spacing: var(--k-ls-display); line-height: var(--k-lh-display);
  max-width: 26em;
}
.k-h3 {
  font-family: var(--k-font-display); font-weight: var(--k-fw-display);
  font-size: 17px; letter-spacing: calc(var(--k-ls-display) * .6); line-height: 1.6;
}
.k-lead { font-size: 16px; color: var(--k-sub); max-width: 36em; }
.k-body { font-size: 14px; color: var(--k-sub); max-width: 40em; }
.k-caption { font-size: 12px; color: var(--k-sub); letter-spacing: .06em; }
.k-num {
  font-family: var(--k-font-num); font-size: 38px; font-weight: 700;
  line-height: 1.15; letter-spacing: -.01em; color: var(--k-accent);
}
.k-num small { font-size: 15px; font-weight: 500; color: var(--k-ink); margin-left: 2px; }
.k-label { font-size: 12px; letter-spacing: .1em; color: var(--k-sub); }
.k-quote { font-family: var(--k-font-display); font-size: 16px; line-height: 2; }
.k-more { font-size: 13px; letter-spacing: .08em; color: var(--k-accent-2); text-decoration: none; }

/* ---------- 部品 ---------- */
.k-actions { display: flex; gap: 14px; flex-wrap: wrap; }
.k-btn {
  display: inline-block; padding: 14px 30px;
  font-family: var(--k-font-body); font-size: 14px; font-weight: 500; letter-spacing: .04em;
  border-radius: var(--k-radius-btn); text-decoration: none; transition: opacity .15s;
}
.k-btn:hover { opacity: .82; }
.k-btn--primary { background: var(--k-accent); color: var(--k-on-accent); }
.k-btn--ghost { color: var(--k-ink); border: 1px solid var(--k-line); background: transparent; }
.k-btn--sm { padding: 10px 20px; font-size: 13px; }

.k-card {
  background: var(--k-surface); border: var(--k-card-border);
  border-radius: var(--k-radius); box-shadow: var(--k-shadow);
  padding: 30px 28px;
}
.k-section--alt .k-card { background: var(--k-bg); }

.k-media {
  background: var(--k-media-bg);
  border: 1px solid var(--k-line); border-radius: var(--k-radius);
  min-height: 180px; width: 100%;
}
.k-avatar {
  width: 44px; height: 44px; flex: none; border-radius: 999px;
  background: var(--k-media-bg); border: 1px solid var(--k-line);
}
.k-badge {
  display: inline-block; font-size: 11px; letter-spacing: .08em;
  color: var(--k-sub); border: 1px solid var(--k-line);
  border-radius: 999px; padding: 6px 13px;
}
.k-divider { border: 0; border-top: 1px solid var(--k-line); }

.k-faq details { border-bottom: 1px solid var(--k-line); padding: 20px 4px; }
.k-faq details:first-child { border-top: 1px solid var(--k-line); }
.k-faq summary {
  cursor: pointer; list-style: none; font-weight: 600; font-size: 14.5px;
  display: flex; justify-content: space-between; align-items: center; gap: 16px;
}
.k-faq summary::-webkit-details-marker { display: none; }
.k-faq summary::after { content: "＋"; color: var(--k-sub); flex: none; }
.k-faq details[open] summary::after { content: "－"; }
.k-faq details p { margin-top: 12px; font-size: 13.5px; color: var(--k-sub); }

/* ---------- 枠物 ---------- */
.k-nav {
  display: flex; justify-content: space-between; align-items: center; gap: 24px;
  padding: 18px 32px; background: var(--k-bg); border-bottom: 1px solid var(--k-line);
}
.k-nav-links { display: flex; gap: 26px; }
.k-nav-links a { font-size: 13.5px; letter-spacing: .04em; text-decoration: none; color: var(--k-sub); }
.k-logo { font-family: var(--k-font-display); font-weight: 700; letter-spacing: .06em; font-size: 16px; }

.k-footer { padding: 64px 24px 40px; background: var(--k-bg); border-top: 1px solid var(--k-line); }
.k-footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 40px; margin-bottom: 48px; }
.k-footer-links { display: flex; flex-direction: column; gap: 10px; }
.k-footer-links a { font-size: 13px; color: var(--k-sub); text-decoration: none; }

/* ---------- 部品 v1.1（W1追加：フォーム・料金・タブ・ロゴ・ステップ） ---------- */
.k-field { display: flex; flex-direction: column; gap: 8px; width: 100%; }
.k-input {
  width: 100%; padding: 13px 16px;
  font-family: inherit; font-size: 14px; color: var(--k-ink);
  background: var(--k-surface); border: 1px solid var(--k-line); border-radius: var(--k-radius);
}
textarea.k-input { min-height: 110px; resize: vertical; }

.k-logo-chip {
  height: 60px; display: flex; align-items: center; justify-content: center;
  background: var(--k-surface); border: 1px solid var(--k-line); border-radius: var(--k-radius);
  color: var(--k-sub); font-size: 11px; letter-spacing: .14em;
}
.k-step-no { font-family: var(--k-font-num); font-size: 12px; font-weight: 700; letter-spacing: .16em; color: var(--k-accent); }

.k-tabs { display: flex; gap: 8px; flex-wrap: wrap; justify-content: center; }
.k-tab {
  font-size: 13px; letter-spacing: .04em; padding: 9px 18px; text-decoration: none;
  color: var(--k-sub); border: 1px solid var(--k-line); border-radius: 999px;
}
.k-tab.is-active { background: var(--k-accent); color: var(--k-on-accent); border-color: var(--k-accent); }

.k-price { font-family: var(--k-font-num); font-size: 34px; font-weight: 700; letter-spacing: -.01em; }
.k-price small { font-size: 13px; font-weight: 500; color: var(--k-sub); margin-left: 4px; }
.k-list { list-style: none; display: flex; flex-direction: column; gap: 10px; font-size: 13.5px; color: var(--k-sub); }
.k-list li { position: relative; padding-left: 22px; }
.k-list li::before { content: "✓"; position: absolute; left: 0; color: var(--k-accent-2); }
.k-card--featured { outline: 2px solid var(--k-accent); outline-offset: -1px; }

/* ---------- 部品 v1.2（D2C・読み物：旧価格・固定CTAバー） ---------- */
.k-price-old { text-decoration: line-through; color: var(--k-sub); font-size: 14px; font-family: var(--k-font-num); }
.k-ctabar {
  display: flex; justify-content: space-between; align-items: center; gap: 16px;
  width: 100%;
  background: var(--k-surface); border: 1px solid var(--k-line); border-radius: var(--k-radius);
  box-shadow: var(--k-shadow);
  padding: 14px 20px;
}

/* ---------- レスポンシブ ---------- */
@media (max-width: 860px) {
  .k-split { grid-template-columns: 1fr; gap: 36px; }
  .k-split--rev > :first-child { order: 0; }
  .k-grid-3, .k-grid-4 { grid-template-columns: 1fr 1fr; }
  .k-footer-grid { grid-template-columns: 1fr 1fr; }
  .k-cover-content { margin: 24px; padding: 32px; }
}
@media (max-width: 560px) {
  .k-grid-2, .k-grid-3, .k-grid-4 { grid-template-columns: 1fr; }
  .k-nav-links { display: none; }
}