/* ==========================================================
   VOL.001 ARTICLE
   Simple single-column layout + field-note dialogue treatment
   ========================================================== */
.article-proposal {
  --article-ink: #0d2c4d;
  --article-muted: #5a7184;
  --article-blue: #29abe2;
  --article-blue-dark: #0b63c4;
  --article-accent-pale: #eaf7ff;
  --article-line: #d3e9f8;
  --article-paper: #ffffff;
  background: var(--article-paper);
  color: var(--article-ink);
  font-size: 18px;
  line-height: 1.9;
}

/* Every displayed supporting label is at least 16px. */
.article-proposal small,
.article-proposal time,
.article-proposal .copy { font-size: 1rem; }

.article-proposal .site-header {
  border: 0;
  background: rgba(255, 255, 255, .96);
}
.article-proposal .site-header .inner {
  max-width: 1240px;
  min-height: 82px;
  padding: 10px 30px;
  flex-wrap: nowrap;
}
.article-proposal .site-logo img { width: 205px; height: auto; }
.article-proposal .global-nav { gap: 24px; }
.article-proposal .global-nav a {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 10px 0;
  color: var(--article-ink);
  font-family: var(--font-body);
  font-size: 1rem;
}
.article-masthead { position: relative; overflow: hidden; }
.article-masthead__inner {
  position: relative;
  isolation: isolate;
  width: min(1120px, calc(100% - 48px));
  min-height: 550px;
  margin: 18px auto 0;
  padding: 56px 72px;
  border-radius: 30px;
  display: grid;
  grid-template-columns: minmax(0, 1fr) 350px;
  align-items: center;
  gap: 54px;
  overflow: hidden;
  border: 0;
  background: #ffffff;
  color: var(--article-ink);
}
.article-masthead__copy { position: relative; z-index: 2; }
.article-kicker {
  margin-bottom: 20px;
  font: 700 1rem Arial, sans-serif;
  letter-spacing: .2em;
}
.article-issue {
  display: inline-flex;
  align-items: center;
  margin-bottom: 22px;
  padding: 8px 16px;
  border-radius: 999px;
  background: var(--article-ink);
  color: #fff;
  font: 700 1rem var(--font-head);
}
.article-masthead h1 {
  max-width: 720px;
  color: var(--article-ink);
  font-size: clamp(2.5rem, 4vw, 3.7rem);
  line-height: 1.35;
  letter-spacing: .035em;
}
.article-masthead h1 .title-main { display: block; }
.article-masthead h1 .title-sub {
  display: block;
  margin-top: 14px;
  width: max-content;
  max-width: none;
  font-size: 1.6rem;
  font-weight: 700;
  line-height: 1.65;
  letter-spacing: 0;
  white-space: nowrap;
}
.article-deck {
  max-width: 680px;
  margin-top: 26px;
  font-size: 1.06rem;
  line-height: 1.95;
}
.article-meta {
  margin-top: 30px;
  font-size: 1rem;
  line-height: 1.8;
}
.article-meta a { color: inherit; }
.masthead-art { position: relative; align-self: stretch; min-height: 390px; }
.masthead-art::before,
.masthead-art::after {
  display: none;
}
.masthead-art img {
  position: absolute;
  z-index: 2;
  width: 260px;
  left: 50%;
  bottom: -58px;
  transform: translateX(-50%);
  filter: none;
}

/* Simple single-column reading surface. */
.article-shell {
  width: 100%;
  margin: 0 auto;
  padding: 88px 0 128px;
  display: block;
  background: var(--article-accent-pale);
}
.article-content {
  width: min(900px, calc(100% - 48px));
  min-width: 0;
  margin: 0 auto;
}
.scene-setting {
  margin-bottom: 72px;
  padding: 32px 36px 34px;
  border: 1px solid var(--article-line);
  border-radius: 20px;
  background: #fff;
  color: var(--article-muted);
  font-size: 1rem;
}
.scene-setting::before {
  content: "SCENE 01";
  display: block;
  margin-bottom: 12px;
  color: var(--article-blue-dark);
  font: 700 1rem Arial, sans-serif;
  letter-spacing: .16em;
}
.scene-setting p + p { margin-top: .5em; }
.story-section { scroll-margin-top: 110px; }
.section-marker {
  display: flex;
  align-items: center;
  gap: 16px;
  margin: 82px 0 28px;
}
.section-marker::after { content: ""; height: 3px; flex: 1; background: var(--article-blue); }
.section-marker span {
  color: var(--article-blue-dark);
  font: 700 1rem Arial, sans-serif;
  letter-spacing: .14em;
}
.article-content h2 {
  margin: 0 0 42px;
  color: var(--article-ink);
  font-size: clamp(1.7rem, 3vw, 2.35rem);
  line-height: 1.55;
}

/* Field-note dialogue: no speech bubbles and no visible speaker labels. */
.dialogue {
  display: grid;
  grid-template-columns: 72px minmax(0, 1fr);
  gap: 20px;
  align-items: start;
  margin: 30px 0;
}
.dialogue.tanaka { grid-template-columns: minmax(0, 1fr) 72px; }
.dialogue.tanaka .dialogue-avatar { grid-column: 2; }
.dialogue.tanaka .dialogue-card {
  grid-column: 1;
  grid-row: 1;
  justify-self: stretch;
}
.dialogue-avatar {
  width: 72px;
  height: 72px;
  border: 2px solid var(--article-line);
  border-radius: 50%;
  background: #fff;
  object-fit: cover;
  object-position: top;
}
.dialogue.tanaka .dialogue-avatar { border-color: #9fd8f3; }
.dialogue-card,
.dialogue.tanaka .dialogue-card {
  max-width: none;
  min-height: 72px;
  padding: 3px 0 24px;
  border: 0;
  border-bottom: 1px solid var(--article-line);
  border-radius: 0;
  background: transparent;
}
.dialogue-card p { font-size: 1.06rem; line-height: 1.95; }
.dialogue-card p + p { margin-top: .85em; }

.key-definition {
  margin: 48px 0;
  padding: 36px 40px;
  border-left: 7px solid var(--article-blue);
  background: var(--article-ink);
  color: #fff;
}
.key-definition span {
  display: block;
  margin-bottom: 12px;
  color: #8ed7f5;
  font: 700 1rem Arial, sans-serif;
  letter-spacing: .15em;
}
.key-definition strong {
  font: 700 clamp(1.25rem, 2.5vw, 1.7rem)/1.75 var(--font-head);
}

.concept-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 14px;
  margin: 46px 0;
}
.concept-card {
  min-height: 220px;
  padding: 24px 22px;
  border-top: 5px solid var(--article-blue);
  background: #eff7fb;
}
.concept-card:nth-child(2) { border-color: #0b63c4; background: #f6fbff; }
.concept-card:nth-child(3) { border-color: #16436e; background: #eaf7ff; }
.concept-no { color: var(--article-blue-dark); font: 900 2.8rem/1 Arial, sans-serif; opacity: .24; }
.concept-card h3 { margin: 20px 0 10px; color: var(--article-ink); font-size: 1.12rem; }
.concept-card p { color: var(--article-muted); font-size: 1rem; line-height: 1.75; }

/* ==========================================================
   Accent colour proposals for the three concept cards and
   the closing “mille-feuille” quote. Layout remains unchanged.
   ========================================================== */

/* A: Crisp editorial — white cards, navy rules, clear contrast. */
.article-accent-a .concept-card {
  border: 1px solid #b9dbee;
  border-top: 5px solid #0b63c4;
  background: #ffffff;
  box-shadow: 0 8px 22px rgba(13, 44, 77, .07);
}
.article-accent-a .concept-card:nth-child(2) { border-top-color: #1688c9; background: #ffffff; }
.article-accent-a .concept-card:nth-child(3) { border-top-color: #16436e; background: #ffffff; }
.article-accent-a .pull-moment {
  border: 2px solid #9ccfea;
  border-left: 8px solid #0b63c4;
  background: #ffffff;
  box-shadow: 0 10px 28px rgba(13, 44, 77, .08);
}

/* B: Blue layers — three related tints with a soft cyan quote. */
.article-accent-b .concept-card {
  border: 1px solid #a9d7f2;
  border-top: 5px solid #29abe2;
  background: #ffffff;
}
.article-accent-b .concept-card:nth-child(2) { border-top-color: #0b83c6; background: #dff2fc; }
.article-accent-b .concept-card:nth-child(3) { border-top-color: #0b63c4; background: #cfe9f8; }
.article-accent-b .pull-moment {
  border: 1px solid #8ac9eb;
  background: linear-gradient(135deg, #dff3fd 0%, #c8e9f9 100%);
}

/* C: Blue grey — calm, slightly more formal and subdued. */
.article-accent-c .concept-card {
  border: 1px solid #c3d2df;
  border-top: 5px solid #5b7fa3;
  background: #f8fbfd;
}
.article-accent-c .concept-card:nth-child(2) { border-top-color: #416b92; background: #edf4f8; }
.article-accent-c .concept-card:nth-child(3) { border-top-color: #244d73; background: #e2edf4; }
.article-accent-c .concept-no { color: #416b92; opacity: .34; }
.article-accent-c .pull-moment {
  border: 1px solid #afc7d8;
  border-top: 6px solid #416b92;
  background: #dce9f2;
}

.pull-moment {
  position: relative;
  overflow: hidden;
  min-height: 300px;
  margin: 54px 0;
  padding: 52px 52px 48px 242px;
  display: flex;
  align-items: center;
  border: 1px solid var(--article-line);
  background: var(--article-accent-pale);
}
.pull-moment img { position: absolute; width: 185px; left: 38px; bottom: -20px; }
.pull-moment blockquote {
  color: var(--article-ink);
  font: 700 clamp(1.3rem, 3vw, 1.9rem)/1.75 var(--font-head);
}

.summary-panel {
  margin-top: 78px;
  padding: 44px;
  border-top: 7px solid var(--article-ink);
  background: #fff;
}
.summary-panel__label {
  color: var(--article-blue-dark);
  font: 700 1rem Arial, sans-serif;
  letter-spacing: .15em;
}
.summary-panel h2 { margin: 10px 0 28px; font-size: 1.8rem; }
.summary-list { list-style: none; }
.summary-list li {
  display: grid;
  grid-template-columns: 24px 1fr;
  gap: 18px;
  padding: 20px 0;
  border-top: 1px solid var(--article-line);
  font-size: 1.03rem;
}
.summary-list li::before {
  content: "●";
  color: var(--article-blue-dark);
  font-size: 1rem;
}

.quiz-panel {
  margin-top: 24px;
  padding: 36px 40px;
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 30px;
  align-items: center;
  background: var(--article-ink);
  color: #fff;
}
.quiz-panel p:first-child {
  color: #8ed7f5;
  font: 700 1rem Arial, sans-serif;
  letter-spacing: .14em;
}
.quiz-panel h2 { margin: 6px 0 0; color: #fff; font-size: 1.45rem; }
.quiz-button {
  display: inline-flex;
  align-items: center;
  gap: 0;
  padding: 14px 24px;
  border-radius: 999px;
  background: #FFE552;
  color: var(--article-ink);
  font: 700 1rem var(--font-head);
  text-decoration: none;
  white-space: nowrap;
}
.quiz-button::after {
  display: none;
}

.article-endnav {
  width: min(900px, calc(100% - 48px));
  margin: 0 auto 100px;
  padding-top: 32px;
  border-top: 1px solid var(--article-line);
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  gap: 20px;
  align-items: center;
}
.article-endnav a {
  color: var(--article-ink);
  font-family: var(--font-head);
  font-size: 1rem;
  font-weight: 700;
  text-decoration: none;
}
.article-endnav a:last-child { text-align: right; }
.article-endnav .next-unavailable {
  justify-self: end;
  color: #9aa9b5;
  font-family: var(--font-head);
  font-size: 1rem;
  font-weight: 700;
  cursor: default;
}
.article-endnav .back-index {
  padding: 11px 20px;
  border: 1px solid #bcdcec;
  border-radius: 999px;
  color: var(--article-muted);
}
.article-proposal .site-footer { font-size: 1rem; }
.article-proposal .site-footer .copy { font-size: 1rem; }

@media (max-width: 900px) {
  .article-masthead__inner {
    grid-template-columns: minmax(0, 1fr) 230px;
    padding: 60px 46px;
  }
  .article-masthead h1 { font-size: 2.6rem; }
  .masthead-art img { width: 215px; }
}

@media (max-width: 680px) {
  .article-proposal { font-size: 16px; }
  .article-proposal .site-header .inner {
    min-height: 72px;
    padding: 8px 18px;
    justify-content: center;
  }
  .article-proposal .site-logo img { width: 180px; }
  .article-proposal .global-nav { display: none; }
  .article-masthead__inner {
    width: calc(100% - 24px);
    min-height: 680px;
    margin-top: 4px;
    padding: 40px 26px 240px;
    border-radius: 22px;
    display: block;
  }
  .article-kicker { line-height: 1.65; }
  .article-masthead h1 { font-size: 1.8rem; }
  .article-masthead h1 .title-sub {
    width: 142.86%;
    font-size: 1rem;
    transform: scaleX(.7);
    transform-origin: left center;
  }
  .article-deck { font-size: 1rem; }
  .masthead-art {
    position: absolute;
    left: 50%;
    bottom: 0;
    width: 260px;
    min-height: 250px;
    transform: translateX(-50%);
  }
  .masthead-art img { width: 180px; bottom: -34px; }
  .article-shell { width: 100%; padding: 60px 0 104px; }
  .article-content { width: calc(100% - 36px); }
  .scene-setting { padding: 26px 22px; }
  .section-marker { margin-top: 64px; }
  .article-content h2 { font-size: 1.6rem; }
  .dialogue { grid-template-columns: 54px minmax(0, 1fr); gap: 12px; margin: 26px 0; }
  .dialogue.tanaka { grid-template-columns: minmax(0, 1fr) 54px; }
  .dialogue-avatar { width: 54px; height: 54px; border-radius: 50%; }
  .dialogue-card,
  .dialogue.tanaka .dialogue-card { min-height: 54px; padding-bottom: 20px; }
  .dialogue-card p { font-size: 1rem; line-height: 1.9; }
  .key-definition { padding: 30px 24px; }
  .concept-grid { grid-template-columns: 1fr; }
  .concept-card { min-height: 0; }
  .pull-moment { min-height: 380px; padding: 42px 28px 210px; text-align: center; }
  .pull-moment img { width: 150px; left: 50%; bottom: -18px; transform: translateX(-50%); }
  .summary-panel { padding: 32px 22px; }
  .summary-list li { grid-template-columns: 24px 1fr; font-size: 1rem; }
  .quiz-panel { padding: 30px 24px; grid-template-columns: 1fr; }
  .quiz-button { justify-self: start; white-space: normal; }
  .article-endnav { grid-template-columns: 1fr; text-align: center; }
  .article-endnav a:last-child { text-align: center; }
  .article-endnav .next-unavailable { justify-self: center; }
}

@media (prefers-reduced-motion: reduce) {
  .article-proposal * { scroll-behavior: auto !important; }
}