/* =========================================================
   エラビト（erabito.com）デザイン言語 案D「モノトーン・ミニマル」
   ------------------------------------------------------------
   文法：角丸・塗り・影・ピル・ゼブラを全廃し、ヘアライン罫線と
   タイポグラフィのスケールコントラストだけで構造を作る。
   配色：オフホワイト(#fafaf8) × 墨黒(#111)。リンクは下線のみで
   示し、色は使わない。ティール(--color-primary)は診断ツールの
   「選択中」を示す機能色として、この1箇所にのみ残す。
   構造・セレクタは site/style.css を完全踏襲（HTMLは無変更）。
   ========================================================= */

:root {
  /* 機能色（診断ツールの選択状態専用。他の用途には使わない） */
  --color-primary: #0f766e;
  --color-primary-dark: #0b5750;
  --color-primary-darker: #073e39;

  /* ニュートラル（デザインの主役はこちら） */
  --color-ink: #111111;
  --color-text: #1c1c1a;
  --color-text-muted: #5f5f59;
  --color-border: #dedcd4;
  --color-border-strong: #111111;
  --color-bg: #fafaf8;
  --color-bg-alt: #f2f1ec;
  --color-tag-border: #111111;

  --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
    "Hiragino Kaku Gothic ProN", "Hiragino Sans", "Yu Gothic", Meiryo,
    sans-serif;

  /* 見出し専用：太ゴシック・字間タイト（RIMOWA的な硬質さ） */
  --font-heading: -apple-system, BlinkMacSystemFont, "Hiragino Sans",
    "Hiragino Kaku Gothic ProN", "Yu Gothic", sans-serif;

  /* 箱・カードは角丸ゼロ（面を作らない）。ボタンのみ2px */
  --radius-s: 0;
  --radius-m: 0;
  --radius-l: 0;
  --radius-btn: 2px;

  --container-width: 720px;
}

* {
  box-sizing: border-box;
}

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

body {
  margin: 0;
  overflow-x: hidden;
  font-family: var(--font-family);
  font-size: 16px;
  line-height: 1.9;
  color: var(--color-text);
  background: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  font-variant-numeric: proportional-nums;
}

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

a {
  color: var(--color-ink);
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-thickness: 1px;
}

a:hover {
  text-decoration-thickness: 2px;
}

a:focus-visible,
button:focus-visible,
input:focus-visible {
  outline: 2px solid var(--color-ink);
  outline-offset: 2px;
  border-radius: 0;
}

.container {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 22px;
}

/* ---------- header ---------- */

.site-header {
  border-bottom: 1px solid var(--color-border);
  background: var(--color-bg);
}

.site-header__inner {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 26px 22px;
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
}

.site-logo {
  font-family: var(--font-heading);
  font-size: 1.4rem;
  font-weight: 900;
  color: var(--color-ink);
  text-decoration: none;
  letter-spacing: -0.02em;
}

.site-logo:hover {
  text-decoration: underline;
  text-underline-offset: 4px;
}

.site-tagline {
  font-size: 0.7rem;
  color: var(--color-text-muted);
  letter-spacing: 0.1em;
  display: none;
}

@media (min-width: 700px) {
  .site-tagline {
    display: inline;
  }
}

/* ---------- hero (top page) ---------- */

.hero {
  background: var(--color-bg-alt);
  padding: 0 0 48px;
  border-bottom: 1px solid var(--color-border);
}

.hero__media {
  border-bottom: 1px solid var(--color-border);
  overflow: hidden;
  background: var(--color-ink);
}

.hero__media img {
  width: 100%;
  height: clamp(200px, 42vw, 340px);
  object-fit: cover;
  display: block;
  filter: grayscale(35%) contrast(1.05);
}

.hero .container {
  padding-top: 40px;
}

.hero h1 {
  font-family: var(--font-heading);
  font-size: clamp(1.75rem, 4vw + 0.9rem, 2.25rem);
  line-height: 1.32;
  font-weight: 900;
  letter-spacing: -0.02em;
  margin: 0 0 20px;
  color: var(--color-ink);
}

.hero p {
  margin: 0;
  color: var(--color-text-muted);
  font-size: 0.98rem;
  line-height: 1.9;
  max-width: 46ch;
}

/* ---------- article cards (top page) ---------- */

.article-list {
  padding: 56px 0 72px;
}

.article-list h2 {
  font-size: 0.7rem;
  color: var(--color-text-muted);
  margin: 0 0 22px;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--color-border);
}

.article-card {
  position: relative;
  display: block;
  border-top: 1px solid var(--color-border);
  border-radius: 0;
  padding: 30px 4px 30px 20px;
  text-decoration: none;
  color: inherit;
  background: transparent;
  transition: padding-left 0.15s ease, border-color 0.15s ease;
}

.article-card:last-of-type {
  border-bottom: 1px solid var(--color-border);
}

.article-card__media {
  margin: 0 0 18px;
  border: 1px solid var(--color-border);
  overflow: hidden;
}

.article-card__media img {
  width: 100%;
  height: auto;
  aspect-ratio: 3 / 2;
  object-fit: cover;
  display: block;
  filter: grayscale(35%) contrast(1.05);
  transition: filter 0.15s ease;
}

.article-card:hover .article-card__media img,
.article-card:focus-visible .article-card__media img {
  filter: grayscale(0%) contrast(1);
}

.article-card::before {
  content: "";
  position: absolute;
  top: 30px;
  left: 0;
  width: 0;
  height: calc(100% - 60px);
  background: var(--color-ink);
  transition: width 0.15s ease;
}

.article-card:hover,
.article-card:focus-visible {
  border-color: var(--color-border);
  padding-left: 26px;
  outline: none;
}

.article-card:hover::before,
.article-card:focus-visible::before {
  width: 3px;
}

.article-card__eyebrow {
  display: inline-block;
  font-size: 0.7rem;
  color: var(--color-text-muted);
  background: transparent;
  border: 1px solid var(--color-tag-border);
  padding: 3px 10px;
  border-radius: var(--radius-btn);
  margin-bottom: 14px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.article-card__title {
  font-family: var(--font-heading);
  font-size: 1.2rem;
  font-weight: 800;
  letter-spacing: -0.01em;
  margin: 0 0 12px;
  color: var(--color-ink);
  line-height: 1.55;
}

.article-card__excerpt {
  margin: 0;
  color: var(--color-text-muted);
  font-size: 0.95rem;
  line-height: 1.8;
}

/* ---------- generic buttons ---------- */

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 12px 28px;
  border-radius: var(--radius-btn);
  font-size: 0.95rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-decoration: none;
  cursor: pointer;
  border: 1.5px solid var(--color-ink);
  line-height: 1.4;
  transition: background-color 0.15s ease, color 0.15s ease;
}

.button::after {
  content: "\2192";
  margin-left: 10px;
  display: inline-block;
}

@media (prefers-reduced-motion: no-preference) {
  .button::after {
    transition: transform 0.15s ease;
  }

  .button:hover::after {
    transform: translateX(3px);
  }
}

.button-primary {
  background: var(--color-ink);
  color: var(--color-bg);
}

.button-primary:hover {
  background: transparent;
  color: var(--color-ink);
}

.button-primary:focus-visible {
  outline: 2px solid var(--color-ink);
  outline-offset: 2px;
}

.button-outline {
  background: transparent;
  border-color: var(--color-ink);
  color: var(--color-ink);
}

.button-outline:hover {
  background: var(--color-ink);
  color: var(--color-bg);
}

.button-block {
  display: flex;
  width: 100%;
}

/* ---------- article body ---------- */

.article {
  padding: 40px 0 84px;
}

.article h1 {
  font-family: var(--font-heading);
  font-size: 2.125rem;
  line-height: 1.35;
  font-weight: 900;
  letter-spacing: -0.02em;
  margin: 0 0 26px;
  color: var(--color-ink);
}

.article h2 {
  position: relative;
  font-family: var(--font-heading);
  font-size: 1.25rem;
  font-weight: 800;
  letter-spacing: -0.01em;
  line-height: 1.5;
  margin: 60px 0 20px;
  padding-top: 24px;
  color: var(--color-ink);
}

.article h2::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 44px;
  height: 1px;
  border-radius: 0;
  background: var(--color-ink);
}

.article h2:first-of-type {
  margin-top: 40px;
}

.article h3 {
  font-family: var(--font-heading);
  font-size: 1.05rem;
  font-weight: 700;
  margin: 34px 0 14px;
  color: var(--color-ink);
}

.article p {
  margin: 0 0 20px;
}

.article ul,
.article ol {
  margin: 0 0 24px;
  padding-left: 1.4em;
}

.article li {
  margin-bottom: 11px;
}

.lead {
  font-size: 1.05rem;
  line-height: 1.95;
  color: var(--color-text);
  background: transparent;
  border-top: 1px solid var(--color-ink);
  border-bottom: 1px solid var(--color-ink);
  border-radius: 0;
  padding: 24px 2px;
}

.hero-figure {
  margin: 4px 0 40px;
  border: 1px solid var(--color-border);
  overflow: hidden;
}

.hero-figure img {
  width: 100%;
  height: auto;
  max-height: 360px;
  object-fit: cover;
  filter: grayscale(35%) contrast(1.05);
  margin: 0;
}

.cta-inline {
  margin: 30px 0 38px;
  text-align: center;
}

.cta-inline .button {
  width: 100%;
  max-width: 360px;
}

.cta-note {
  margin-top: 20px;
}

/* ---------- disclosure (広告表示) ---------- */

.disclosure {
  font-size: 0.78rem;
  line-height: 1.75;
  color: var(--color-text-muted);
  background: transparent;
  border-top: 1px solid var(--color-border);
  border-bottom: 1px solid var(--color-border);
  border-radius: 0;
  padding: 14px 2px;
  margin: 0 0 32px;
  letter-spacing: 0.01em;
}

.disclosure--footer {
  margin: 0;
}

/* ---------- tables ---------- */

.table-scroll {
  position: relative;
  overflow-x: auto;
  overflow-y: hidden;
  margin: 0 0 16px;
  -webkit-overflow-scrolling: touch;
  border: none;
  border-radius: 0;
}

@media (max-width: 699px) {
  .table-scroll::after {
    content: "";
    position: absolute;
    top: 0;
    right: 0;
    bottom: 0;
    width: 28px;
    background: linear-gradient(to right, transparent, var(--color-bg));
    pointer-events: none;
  }
}

table.compare-table {
  border-collapse: collapse;
  width: 100%;
  min-width: 560px;
  font-size: 0.92rem;
}

table.compare-table caption {
  caption-side: top;
  text-align: left;
  padding: 0 0 14px;
  font-family: var(--font-heading);
  font-weight: 800;
  font-size: 0.78rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  background: transparent;
}

table.compare-table th,
table.compare-table td {
  padding: 13px 16px;
  border-bottom: 1px solid var(--color-border);
  text-align: left;
  white-space: nowrap;
}

table.compare-table thead th {
  background: transparent;
  color: var(--color-ink);
  font-weight: 700;
  font-size: 0.82rem;
  letter-spacing: 0.04em;
  border-top: 1.5px solid var(--color-ink);
  border-bottom: 1.5px solid var(--color-ink);
}

table.compare-table tbody tr:nth-child(even) {
  background: transparent;
}

table.compare-table tbody tr:last-child td {
  border-bottom: 1.5px solid var(--color-ink);
}

.table-caption-note {
  font-size: 0.82rem;
  color: var(--color-text-muted);
  margin-top: 10px;
  margin-bottom: 22px;
}

/* ---------- FAQ ---------- */

.faq-item {
  border: none;
  border-top: 1px solid var(--color-border);
  border-radius: 0;
  padding: 22px 2px;
  margin-bottom: 0;
  background: transparent;
}

.faq-item:last-of-type {
  border-bottom: 1px solid var(--color-border);
}

.faq-item dt {
  position: relative;
  font-weight: 700;
  color: var(--color-ink);
  margin: 0 0 10px;
  padding-left: 30px;
  line-height: 1.55;
}

.faq-item dt::before {
  content: "Q";
  position: absolute;
  left: 0;
  top: 0;
  display: block;
  width: 20px;
  font-family: var(--font-heading);
  font-size: 0.85rem;
  font-weight: 900;
  color: var(--color-ink);
  background: transparent;
  border-radius: 0;
}

.faq-item dd {
  margin: 0;
  padding-left: 30px;
  color: var(--color-text-muted);
  line-height: 1.9;
}

/* ---------- diagnosis tool ---------- */

.diag-section {
  background: var(--color-bg-alt);
  border: 1px solid var(--color-border);
  border-radius: 0;
  padding: 34px 26px 38px;
  margin: 0 0 8px;
}

.diag-section h3 {
  font-family: var(--font-heading);
  margin: 0 0 26px;
  font-size: 1.15rem;
  font-weight: 800;
  color: var(--color-ink);
}

.diag-form fieldset {
  border: none;
  padding: 0;
  margin: 0 0 32px;
}

.diag-form legend {
  font-weight: 700;
  font-size: 0.98rem;
  color: var(--color-ink);
  padding: 0 0 16px;
  width: 100%;
  line-height: 1.5;
}

.diag-options {
  display: grid;
  grid-template-columns: 1fr;
  gap: 10px;
}

.diag-option {
  position: relative;
  display: flex;
  align-items: center;
  min-height: 48px;
  padding: 12px 40px 12px 16px;
  border: 1.5px solid var(--color-border);
  border-radius: 0;
  background: var(--color-bg);
  cursor: pointer;
  font-size: 0.96rem;
  transition: border-color 0.15s ease;
}

.diag-option:hover {
  border-color: var(--color-ink);
}

.diag-option input[type="radio"] {
  position: absolute;
  opacity: 0;
  width: 44px;
  height: 44px;
  margin: 0;
  left: 0;
  top: 0;
  cursor: pointer;
}

.diag-option__text {
  padding-left: 4px;
}

.diag-option:has(input:checked) {
  border-color: var(--color-primary);
  border-width: 2px;
  background: var(--color-bg);
  color: var(--color-ink);
  font-weight: 700;
}

.diag-option:has(input:checked)::after {
  content: "\2713";
  position: absolute;
  right: 14px;
  top: 50%;
  margin-top: -8px;
  width: auto;
  height: auto;
  border-radius: 0;
  background: transparent;
  color: var(--color-primary);
  font-size: 1rem;
  font-weight: 700;
  display: block;
}

.diag-option:has(input:focus-visible) {
  outline: 2px solid var(--color-ink);
  outline-offset: 2px;
}

.diag-submit {
  width: 100%;
  min-height: 56px;
  font-size: 1rem;
  letter-spacing: 0.06em;
  margin-top: 4px;
}

/* result */

#diag-result {
  margin-top: 22px;
  padding: 30px 26px;
  border-radius: 0;
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-top: 2px solid var(--color-ink);
  color: var(--color-text);
  animation: diagReveal 0.35s ease;
}

@media (prefers-reduced-motion: reduce) {
  #diag-result {
    animation: none;
  }
}

@keyframes diagReveal {
  from {
    opacity: 0;
    transform: translateY(6px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.diag-shared-note {
  background: transparent;
  border-top: 1px solid var(--color-border);
  border-bottom: 1px solid var(--color-border);
  border-radius: 0;
  padding: 12px 2px;
  font-size: 0.85rem;
  margin: 0 0 20px;
  color: var(--color-text-muted);
}

.diag-shared-note a {
  color: var(--color-ink);
  font-weight: 600;
}

#diag-type {
  font-family: var(--font-heading);
  position: relative;
  font-size: 1.4rem;
  font-weight: 900;
  letter-spacing: -0.01em;
  margin: 0 0 18px;
  padding-left: 30px;
  line-height: 1.5;
  color: var(--color-ink);
}

#diag-type::before {
  content: "\2713";
  position: absolute;
  left: 0;
  top: 2px;
  width: auto;
  height: auto;
  border-radius: 0;
  background: transparent;
  color: var(--color-primary);
  font-size: 1.1rem;
  font-weight: 700;
  display: block;
}

.diag-badges {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 0 0 20px;
}

.diag-badge {
  display: inline-block;
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--color-ink);
  background: transparent;
  border: 1px solid var(--color-tag-border);
  padding: 5px 12px;
  border-radius: var(--radius-btn);
}

#diag-size {
  font-size: 1.02rem;
  font-weight: 700;
  color: var(--color-ink);
  background: transparent;
  border-top: 1px solid var(--color-ink);
  border-bottom: 1px solid var(--color-ink);
  border-radius: 0;
  padding: 14px 2px;
  margin: 0 0 20px;
}

#diag-details {
  list-style: none;
  padding: 0;
  margin: 0 0 22px;
}

#diag-details li {
  padding: 11px 0;
  border-top: 1px solid var(--color-border);
  font-size: 0.95rem;
  color: var(--color-text);
}

#diag-details li:first-child {
  border-top: none;
}

.diag-overflow-note {
  background: transparent;
  border: 1px solid var(--color-border);
  color: var(--color-text-muted);
  border-radius: 0;
  padding: 13px 15px;
  font-size: 0.88rem;
  margin: 0 0 22px;
}

.diag-result-actions {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

#diag-share {
  min-height: 48px;
  border: 1.5px solid var(--color-ink);
  border-radius: var(--radius-btn);
  background: transparent;
  color: var(--color-ink);
  font-size: 0.94rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  cursor: pointer;
  transition: background-color 0.15s ease, color 0.15s ease;
}

#diag-share:hover {
  background: var(--color-ink);
  color: var(--color-bg);
}

.diag-product-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  border-radius: var(--radius-btn);
  border: 1.5px solid var(--color-ink);
  background: var(--color-ink);
  color: var(--color-bg);
  font-weight: 700;
  letter-spacing: 0.04em;
  text-decoration: none;
  padding: 12px 16px;
  transition: background-color 0.15s ease, color 0.15s ease;
}

.diag-product-link:hover {
  background: transparent;
  color: var(--color-ink);
}

/* ---------- footer ---------- */

.site-footer {
  border-top: 1px solid var(--color-border);
  background: var(--color-bg-alt);
  padding: 44px 0 40px;
}

.site-footer p {
  margin: 0 0 14px;
  font-size: 0.82rem;
  line-height: 1.85;
  color: var(--color-text-muted);
}

.site-footer .copyright {
  margin: 0;
  font-size: 0.74rem;
  color: var(--color-text-muted);
  letter-spacing: 0.02em;
}

/* ---------- responsive ---------- */

@media (min-width: 700px) {
  body {
    font-size: 17px;
  }

  .hero {
    padding: 0 0 70px;
  }

  .hero__media img {
    height: clamp(280px, 34vw, 440px);
  }

  .hero .container {
    padding-top: 56px;
  }

  .hero h1 {
    font-size: 3rem;
    max-width: 14ch;
  }

  .hero p {
    font-size: 1.05rem;
  }

  .article h1 {
    font-size: 2.5rem;
  }

  .article h2 {
    font-size: 1.55rem;
  }

  .diag-options {
    grid-template-columns: repeat(2, 1fr);
  }

  .diag-result-actions {
    flex-direction: row;
  }

  .diag-result-actions > * {
    flex: 1;
  }
}