/* ============================================================
   アートテック ウェブサイト スタイルシート
   Mobile-first / Responsive / No external dependencies
   ============================================================ */

:root {
  --color-primary:      #1a2744;
  --color-secondary:    #c9a84c;
  --color-accent-light: #e8f0f7;
  --color-text:         #333333;
  --color-text-light:   #666666;
  --color-bg:           #ffffff;
  --color-bg-alt:       #f8f8f8;
  --color-border:       #e0e0e0;
  --font-base: -apple-system, BlinkMacSystemFont, "Hiragino Kaku Gothic ProN",
               "Yu Gothic Medium", "Yu Gothic", "Meiryo", sans-serif;
  --space-xs: 0.5rem;
  --space-sm: 1rem;
  --space-md: 2rem;
  --space-lg: 4rem;
  --space-xl: 6rem;
  --radius:     4px;
  --radius-lg:  8px;
  --shadow:     0 2px 8px rgba(0,0,0,.08);
  --shadow-md:  0 4px 16px rgba(0,0,0,.13);
  --max-width:  1100px;
  --nav-height: 64px;
  --ease:       0.22s ease;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html  { scroll-behavior: smooth; font-size: 16px; }
body  {
  font-family: var(--font-base);
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.75;
  -webkit-text-size-adjust: 100%;
}
img   { max-width: 100%; height: auto; display: block; }
a     { color: var(--color-primary); text-decoration: none; }
a:hover { color: var(--color-secondary); }
ul, ol { list-style: none; }

/* ── LAYOUT ─────────────────────────────────── */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.25rem;
}
.section    { padding: var(--space-lg) 0; }
.section-sm { padding: var(--space-md) 0; }

/* ── HEADER ──────────────────────────────────── */
.site-header {
  position: sticky;
  top: 0;
  z-index: 200;
  background: var(--color-primary);
  height: var(--nav-height);
  box-shadow: 0 2px 10px rgba(0,0,0,.2);
}
.header-inner {
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.site-logo {
  color: #fff;
  font-size: 1.05rem;
  font-weight: 700;
  letter-spacing: .04em;
  line-height: 1.25;
}
.site-logo span  { color: var(--color-secondary); }
.site-logo small { display: block; font-size: .65rem; font-weight: 400; opacity: .75; }

/* hamburger */
.nav-toggle {
  display: flex;
  flex-direction: column;
  gap: 5px;
  width: 40px;
  height: 40px;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  background: none;
  border: none;
  padding: 0;
  border-radius: var(--radius);
}
.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: #fff;
  border-radius: 2px;
  transition: var(--ease);
}
.nav-toggle[aria-expanded="true"] span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] span:nth-child(2) { opacity: 0; transform: scaleX(0); }
.nav-toggle[aria-expanded="true"] span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

.site-nav {
  position: fixed;
  top: var(--nav-height);
  left: 0;
  width: 100%;
  background: var(--color-primary);
  max-height: 0;
  overflow: hidden;
  transition: max-height .3s ease;
  border-top: 1px solid rgba(255,255,255,.08);
}
.site-nav.open { max-height: 500px; }
.site-nav ul { padding: .5rem 0 1.25rem; }
.site-nav li a {
  display: block;
  padding: .75rem 1.5rem;
  color: rgba(255,255,255,.85);
  font-size: .95rem;
  border-bottom: 1px solid rgba(255,255,255,.06);
  transition: var(--ease);
}
.site-nav li a:hover,
.site-nav li a[aria-current="page"] {
  color: var(--color-secondary);
  background: rgba(255,255,255,.05);
}

@media (min-width: 768px) {
  .nav-toggle { display: none; }
  .site-nav {
    position: static;
    max-height: none;
    overflow: visible;
    background: none;
    border-top: none;
  }
  .site-nav ul {
    display: flex;
    gap: .15rem;
    padding: 0;
    align-items: center;
  }
  .site-nav li a {
    padding: .45rem .75rem;
    border-bottom: none;
    border-radius: var(--radius);
    font-size: .85rem;
    white-space: nowrap;
  }
  .site-logo { font-size: 1.2rem; }
}

/* ── HERO ────────────────────────────────────── */
.hero {
  background: linear-gradient(140deg, var(--color-primary) 0%, #2c3e6e 60%, #1a2744 100%);
  color: #fff;
  padding: 4.5rem 0 3.5rem;
  text-align: center;
  position: relative;
  overflow: hidden;
}
.hero-bg-pattern {
  position: absolute;
  inset: 0;
  background-image: radial-gradient(circle at 20% 80%, rgba(201,168,76,.12) 0%, transparent 50%),
                    radial-gradient(circle at 80% 20%, rgba(255,255,255,.04) 0%, transparent 50%);
  pointer-events: none;
}
.hero-eyebrow {
  display: inline-block;
  background: rgba(201,168,76,.2);
  color: var(--color-secondary);
  border: 1px solid rgba(201,168,76,.4);
  padding: .35rem 1rem;
  border-radius: 2rem;
  font-size: .8rem;
  font-weight: 600;
  letter-spacing: .06em;
  margin-bottom: 1.25rem;
}
.hero-title {
  font-size: clamp(1.6rem, 5vw, 2.75rem);
  font-weight: 700;
  line-height: 1.3;
  letter-spacing: .02em;
  margin-bottom: .75rem;
}
.hero-title em { font-style: normal; color: var(--color-secondary); }
.hero-subtitle {
  font-size: clamp(.9rem, 2.5vw, 1.1rem);
  opacity: .8;
  margin-bottom: 2.25rem;
  max-width: 540px;
  margin-left: auto;
  margin-right: auto;
}
.hero-cta-group { display: flex; flex-wrap: wrap; gap: .75rem; justify-content: center; }
.hero-cta-primary {
  display: inline-flex;
  align-items: center;
  gap: .5rem;
  background: var(--color-secondary);
  color: var(--color-primary);
  padding: .9rem 2rem;
  border-radius: 2rem;
  font-weight: 700;
  font-size: 1rem;
  transition: var(--ease);
  box-shadow: 0 4px 14px rgba(201,168,76,.45);
}
.hero-cta-primary:hover { background: #dbb85a; color: var(--color-primary); transform: translateY(-2px); }
.hero-cta-secondary {
  display: inline-flex;
  align-items: center;
  gap: .5rem;
  background: transparent;
  color: #fff;
  padding: .9rem 2rem;
  border-radius: 2rem;
  font-weight: 600;
  font-size: 1rem;
  border: 2px solid rgba(255,255,255,.4);
  transition: var(--ease);
}
.hero-cta-secondary:hover { border-color: #fff; color: #fff; background: rgba(255,255,255,.08); }

/* ── SECTION HEADING ──────────────────────────── */
.section-heading { text-align: center; margin-bottom: 2.5rem; }
.section-heading h2 {
  font-size: clamp(1.4rem, 3.5vw, 1.875rem);
  color: var(--color-primary);
  font-weight: 700;
  letter-spacing: .02em;
}
.section-heading p { font-size: .9rem; color: var(--color-text-light); margin-top: .4rem; }
.section-heading .accent-line {
  width: 48px; height: 3px;
  background: var(--color-secondary);
  margin: .75rem auto 0;
  border-radius: 2px;
}

/* ── FEATURE ICONS ───────────────────────────── */
.features-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.25rem;
}
@media (min-width: 900px) {
  .features-grid { grid-template-columns: repeat(4, 1fr); }
}
.feature-item {
  text-align: center;
  padding: 1.75rem 1rem;
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow);
}
.feature-icon  { font-size: 2.25rem; margin-bottom: .75rem; }
.feature-title { font-weight: 700; color: var(--color-primary); font-size: .95rem; margin-bottom: .3rem; }
.feature-desc  { font-size: .8rem; color: var(--color-text-light); line-height: 1.55; }

/* ── GRID CARDS ──────────────────────────────── */
.grid-3 { display: grid; grid-template-columns: 1fr; gap: 1.5rem; }
@media (min-width: 580px)  { .grid-3 { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 900px)  { .grid-3 { grid-template-columns: repeat(3, 1fr); } }

.grid-4 { display: grid; grid-template-columns: repeat(2, 1fr); gap: 1rem; }
@media (min-width: 900px)  { .grid-4 { grid-template-columns: repeat(4, 1fr); } }

.grid-2 { display: grid; grid-template-columns: 1fr; gap: 1.5rem; }
@media (min-width: 720px)  { .grid-2 { grid-template-columns: repeat(2, 1fr); } }

.card {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow);
  transition: var(--ease);
}
.card:hover { box-shadow: var(--shadow-md); transform: translateY(-3px); }
.card-img {
  aspect-ratio: 4 / 3;
  background: var(--color-bg-alt);
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}
.card-img img { width: 100%; height: 100%; object-fit: cover; }
.card-placeholder {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: .5rem;
  color: var(--color-text-light);
  font-size: .8rem;
  text-align: center;
  padding: 1rem;
}
.card-placeholder .icon { font-size: 2rem; opacity: .35; }
.card-body  { padding: 1.25rem; }
.card-badge {
  display: inline-block;
  background: var(--color-accent-light);
  color: var(--color-primary);
  font-size: .7rem;
  font-weight: 700;
  padding: .2rem .6rem;
  border-radius: 2rem;
  margin-bottom: .5rem;
  letter-spacing: .04em;
}
.card-badge-gold { background: rgba(201,168,76,.15); color: #8a6e1e; }
.card-title { font-size: 1rem; font-weight: 700; color: var(--color-primary); margin-bottom: .4rem; }
.card-desc  { font-size: .85rem; color: var(--color-text-light); line-height: 1.55; }
.card-price { margin-top: .75rem; font-size: .85rem; color: var(--color-secondary); font-weight: 700; }
.card-link  {
  display: inline-flex;
  align-items: center;
  gap: .3rem;
  margin-top: .9rem;
  font-size: .85rem;
  font-weight: 600;
  color: var(--color-primary);
}
.card-link:hover { color: var(--color-secondary); }

/* ── BUTTONS ─────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: .4rem;
  padding: .75rem 1.75rem;
  border-radius: var(--radius);
  font-weight: 600;
  font-size: .95rem;
  cursor: pointer;
  border: 2px solid transparent;
  font-family: var(--font-base);
  transition: var(--ease);
  text-decoration: none;
}
.btn-primary  { background: var(--color-primary); color: #fff; }
.btn-primary:hover  { background: #253560; color: #fff; }
.btn-outline  { background: transparent; color: var(--color-primary); border-color: var(--color-primary); }
.btn-outline:hover  { background: var(--color-primary); color: #fff; }
.btn-gold     { background: var(--color-secondary); color: var(--color-primary); }
.btn-gold:hover     { background: #dbb85a; color: var(--color-primary); }
.btn-lg { padding: .9rem 2.25rem; font-size: 1rem; }
.btn-sm { padding: .5rem 1.1rem; font-size: .85rem; }
.btn-block { width: 100%; }

/* ── CTA STRIP ───────────────────────────────── */
.cta-strip {
  background: var(--color-primary);
  color: #fff;
  padding: 3.5rem 0;
  text-align: center;
}
.cta-strip h2 { font-size: clamp(1.2rem, 3vw, 1.75rem); margin-bottom: .75rem; }
.cta-strip p  { opacity: .8; margin-bottom: 1.75rem; font-size: .95rem; max-width: 520px; margin-left: auto; margin-right: auto; }

/* ── MALL LINKS ──────────────────────────────── */
.mall-links {
  display: flex;
  flex-wrap: wrap;
  gap: .75rem;
  align-items: center;
}
.mall-link {
  display: inline-flex;
  align-items: center;
  gap: .45rem;
  padding: .625rem 1.25rem;
  border-radius: var(--radius);
  font-size: .875rem;
  font-weight: 700;
  transition: var(--ease);
  white-space: nowrap;
}
.mall-link-rakuten { background: #bf0000; color: #fff; }
.mall-link-rakuten:hover { background: #990000; color: #fff; }
.mall-link-yahoo   { background: #ff0033; color: #fff; }
.mall-link-yahoo:hover   { background: #cc0029; color: #fff; }
.mall-link-amazon  { background: #ff9900; color: #111; }
.mall-link-amazon:hover  { background: #e68900; color: #111; }
.mall-link-own     { background: var(--color-primary); color: #fff; border: 2px solid var(--color-primary); }
.mall-link-own:hover     { background: #253560; color: #fff; }

/* ── INFO TABLE ──────────────────────────────── */
.info-table { width: 100%; border-collapse: collapse; font-size: .9rem; }
.info-table th,
.info-table td {
  padding: .875rem 1rem;
  border-bottom: 1px solid var(--color-border);
  text-align: left;
  vertical-align: top;
  line-height: 1.6;
}
.info-table th {
  width: 32%;
  min-width: 110px;
  background: var(--color-bg-alt);
  font-weight: 700;
  color: var(--color-primary);
  white-space: nowrap;
}
@media (max-width: 500px) {
  .info-table th,
  .info-table td { display: block; width: 100%; }
  .info-table th { border-bottom: none; padding-bottom: .25rem; white-space: normal; }
}

/* ── FAQ ACCORDION ───────────────────────────── */
.faq-category-label {
  font-size: 1rem;
  font-weight: 700;
  color: var(--color-primary);
  border-left: 4px solid var(--color-secondary);
  padding-left: .75rem;
  margin: 2.5rem 0 .75rem;
}
.faq-item { border-bottom: 1px solid var(--color-border); }
.faq-question {
  width: 100%;
  text-align: left;
  background: none;
  border: none;
  padding: 1.2rem 0;
  cursor: pointer;
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: .75rem;
  font-size: .95rem;
  font-weight: 600;
  color: var(--color-primary);
  font-family: var(--font-base);
  line-height: 1.5;
}
.faq-q-mark { color: var(--color-secondary); font-size: 1.05rem; flex-shrink: 0; margin-top: .05rem; }
.faq-q-text { flex: 1; }
.faq-toggle { font-size: 1.25rem; color: var(--color-text-light); flex-shrink: 0; transition: transform var(--ease); }
.faq-item.open .faq-toggle { transform: rotate(45deg); color: var(--color-primary); }
.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height .3s ease;
}
.faq-answer-inner {
  padding: 0 0 1.2rem 1.75rem;
  color: var(--color-text);
  font-size: .9rem;
  line-height: 1.75;
}
.faq-a-mark { color: var(--color-text-light); font-weight: 700; margin-right: .35rem; }
.faq-item.open .faq-answer { max-height: 600px; }

/* ── CONTACT FORM ────────────────────────────── */
.form-group { margin-bottom: 1.25rem; }
.form-label {
  display: block;
  font-size: .875rem;
  font-weight: 600;
  color: var(--color-primary);
  margin-bottom: .4rem;
}
.form-label .required {
  color: #c53030;
  font-size: .72rem;
  font-weight: 700;
  margin-left: .3rem;
  vertical-align: middle;
}
.form-input,
.form-select,
.form-textarea {
  width: 100%;
  padding: .75rem 1rem;
  border: 1.5px solid var(--color-border);
  border-radius: var(--radius);
  font-size: 1rem;
  font-family: var(--font-base);
  color: var(--color-text);
  background: var(--color-bg);
  transition: var(--ease);
  -webkit-appearance: none;
}
.form-input:focus,
.form-select:focus,
.form-textarea:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(26,39,68,.1);
}
.form-textarea { resize: vertical; min-height: 140px; }
.form-note { font-size: .78rem; color: var(--color-text-light); margin-top: .3rem; }

/* ── PAGE HERO (inner pages) ─────────────────── */
.page-hero {
  background: var(--color-bg-alt);
  border-bottom: 1px solid var(--color-border);
  padding: 2.25rem 0 1.75rem;
}
.page-hero h1 {
  font-size: clamp(1.4rem, 3.5vw, 2rem);
  color: var(--color-primary);
  font-weight: 700;
}
.page-hero p { color: var(--color-text-light); font-size: .9rem; margin-top: .4rem; }

/* ── BREADCRUMB ──────────────────────────────── */
.breadcrumb { font-size: .78rem; padding: .75rem 0; color: var(--color-text-light); }
.breadcrumb a { color: var(--color-text-light); }
.breadcrumb a:hover { color: var(--color-primary); }
.breadcrumb li { display: inline; }
.breadcrumb li + li::before { content: " › "; margin: 0 .3rem; }

/* ── INFO BOXES ──────────────────────────────── */
.info-box {
  background: var(--color-accent-light);
  border-left: 4px solid var(--color-primary);
  padding: 1rem 1.25rem;
  border-radius: 0 var(--radius) var(--radius) 0;
  font-size: .9rem;
  line-height: 1.7;
}
.notice-box {
  background: #fffbec;
  border-left: 4px solid var(--color-secondary);
  padding: 1rem 1.25rem;
  border-radius: 0 var(--radius) var(--radius) 0;
  font-size: .9rem;
  line-height: 1.7;
}
.info-box p + p,
.notice-box p + p { margin-top: .5rem; }

/* ── STEP LIST ───────────────────────────────── */
.step-list { counter-reset: steps; display: grid; gap: 1.25rem; }
.step-item {
  display: flex;
  gap: 1rem;
  align-items: flex-start;
  counter-increment: steps;
}
.step-num {
  flex-shrink: 0;
  width: 36px; height: 36px;
  border-radius: 50%;
  background: var(--color-primary);
  color: #fff;
  font-weight: 700;
  font-size: .9rem;
  display: flex;
  align-items: center;
  justify-content: center;
}
.step-content h4 { font-weight: 700; color: var(--color-primary); margin-bottom: .25rem; }
.step-content p  { font-size: .875rem; color: var(--color-text-light); }

/* ── NEWS LIST ───────────────────────────────── */
.news-item {
  display: flex;
  gap: 1rem;
  align-items: flex-start;
  padding: 1.1rem 0;
  border-bottom: 1px solid var(--color-border);
}
.news-date {
  flex-shrink: 0;
  font-size: .8rem;
  color: var(--color-text-light);
  min-width: 90px;
  padding-top: .1rem;
}
.news-badge {
  display: inline-block;
  font-size: .7rem;
  font-weight: 700;
  padding: .1rem .5rem;
  border-radius: 2px;
  background: var(--color-accent-light);
  color: var(--color-primary);
  margin-right: .5rem;
  vertical-align: middle;
}
.news-title { font-size: .9rem; font-weight: 600; color: var(--color-text); line-height: 1.5; }
.news-title a:hover { color: var(--color-secondary); }

/* ── FOOTER ──────────────────────────────────── */
.site-footer {
  background: #0f172a;
  color: rgba(255,255,255,.65);
  padding: 3rem 0 1.5rem;
  font-size: .875rem;
}
.footer-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2rem;
  margin-bottom: 2.25rem;
}
@media (min-width: 600px)  { .footer-grid { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 900px)  { .footer-grid { grid-template-columns: 2fr 1fr 1fr; } }

.footer-brand-logo {
  font-size: 1.1rem;
  font-weight: 700;
  color: #fff;
  margin-bottom: .6rem;
}
.footer-brand-logo span { color: var(--color-secondary); }
.footer-brand p  { line-height: 1.7; font-size: .85rem; }
.footer-nav h3,
.footer-info h3  {
  color: #fff;
  font-size: .8rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .07em;
  margin-bottom: .9rem;
}
.footer-nav a {
  display: block;
  color: rgba(255,255,255,.55);
  padding: .25rem 0;
  font-size: .85rem;
  transition: var(--ease);
}
.footer-nav a:hover { color: var(--color-secondary); }
.footer-info address { font-style: normal; line-height: 2; font-size: .85rem; }
.footer-info a { color: rgba(255,255,255,.65); }
.footer-info a:hover { color: var(--color-secondary); }

.footer-bottom {
  border-top: 1px solid rgba(255,255,255,.08);
  padding-top: 1.25rem;
  display: flex;
  flex-wrap: wrap;
  gap: .5rem;
  justify-content: space-between;
  align-items: center;
}
.footer-bottom small { color: rgba(255,255,255,.35); font-size: .75rem; }
.footer-bottom .footer-links { display: flex; gap: 1rem; }
.footer-bottom .footer-links a { font-size: .75rem; color: rgba(255,255,255,.4); }
.footer-bottom .footer-links a:hover { color: rgba(255,255,255,.7); }

/* ── UTILITIES ───────────────────────────────── */
.text-center    { text-align: center; }
.text-gold      { color: var(--color-secondary); }
.text-muted     { color: var(--color-text-light); }
.mt-sm  { margin-top: 1rem; }
.mt-md  { margin-top: 2rem; }
.mt-lg  { margin-top: 3rem; }
.mb-md  { margin-bottom: 2rem; }
.bg-alt { background: var(--color-bg-alt); }
.visually-hidden {
  position: absolute; width: 1px; height: 1px;
  padding: 0; overflow: hidden;
  clip: rect(0,0,0,0); white-space: nowrap; border: 0;
}