/* ============================================================
   components.css — Buttons, Headings, Cards, Forms
   B.I.Y Corporate Design System
   ============================================================ */

/* ── Buttons ────────────────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  padding: 18px 36px;
  min-width: 240px;
  font-family: var(--font-sans-ja);
  font-size: var(--fs-base);
  font-weight: var(--fw-medium);
  letter-spacing: var(--tracking-wider);
  line-height: 1;
  border: 1px solid transparent;
  border-radius: var(--radius-none);
  cursor: pointer;
  position: relative;
  transition: transform var(--transition-base), background-color var(--transition-base), color var(--transition-base), border-color var(--transition-base), box-shadow var(--transition-base);
  white-space: nowrap;
  text-align: center;
}

.btn::after {
  content: "→";
  font-family: var(--font-sans-en);
  font-size: 14px;
  transition: transform var(--transition-base);
}

.btn--no-arrow::after { display: none; }

.btn:hover::after { transform: translateX(4px); }

.btn--gold {
  background-color: var(--color-gold);
  color: var(--color-white) !important;
  box-shadow: var(--shadow-gold);
}
.btn--gold:hover {
  background-color: var(--color-gold-soft);
  transform: translateY(-2px);
  box-shadow: 0 16px 32px rgba(200, 168, 74, 0.32);
}

.btn--outline {
  background-color: transparent;
  border-color: var(--color-gold);
  color: var(--color-gold) !important;
}
.btn--outline:hover {
  background-color: var(--color-gold);
  color: var(--color-white) !important;
  transform: translateY(-2px);
}

.btn--outline-white {
  background-color: transparent;
  border-color: rgba(255, 255, 255, 0.5);
  color: var(--color-white) !important;
}
.btn--outline-white:hover {
  background-color: var(--color-gold);
  border-color: var(--color-gold);
  transform: translateY(-2px);
}

.btn--ghost {
  background-color: transparent;
  color: var(--color-navy) !important;
  border-color: var(--color-navy);
  min-width: auto;
  padding: 14px 28px;
}
.btn--ghost:hover {
  background-color: var(--color-navy);
  color: var(--color-white) !important;
}

.btn--large {
  padding: 22px 44px;
  font-size: var(--fs-md);
  min-width: 280px;
}

.btn--block {
  display: flex;
  width: 100%;
  min-width: 0;
}

.btn-group {
  display: flex;
  gap: 20px;
  flex-wrap: wrap;
}

.btn-group--center { justify-content: center; }

/* ── Section Heading ────────────────────────────────────── */
.section-heading {
  text-align: center;
  margin-bottom: 80px;
}

.section-heading--left { text-align: left; }

.section-heading__eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 14px;
  font-family: var(--font-serif-en);
  font-size: var(--fs-xs);
  font-weight: var(--fw-medium);
  color: var(--color-gold);
  letter-spacing: var(--tracking-widest);
  text-transform: uppercase;
  margin-bottom: 28px;
}

.section-heading__eyebrow::before,
.section-heading__eyebrow::after {
  content: "";
  width: 32px;
  height: 1px;
  background: var(--color-gold-line);
}

.section-heading--left .section-heading__eyebrow::before { display: none; }

.section-heading__title {
  font-family: var(--font-serif-ja);
  font-size: var(--fs-h2);
  font-weight: var(--fw-bold);
  letter-spacing: 0.08em;
  line-height: var(--lh-tight);
  margin-bottom: 24px;
}

.section-heading__rule {
  width: 48px;
  height: 1px;
  background: var(--color-gold);
  margin: 24px auto 0;
}

.section-heading--left .section-heading__rule { margin-left: 0; }

.section-heading__lead {
  max-width: 640px;
  margin: 32px auto 0;
  font-size: var(--fs-md);
  color: var(--color-text-light);
  line-height: var(--lh-relaxed);
}

.section--navy .section-heading__title,
.section--navy-deep .section-heading__title {
  color: var(--color-white);
}
.section--navy .section-heading__lead,
.section--navy-deep .section-heading__lead {
  color: var(--color-text-on-navy-muted);
}

/* ── Cards ──────────────────────────────────────────────── */
.cards-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
}

.cards-grid--4 { grid-template-columns: repeat(4, 1fr); }
.cards-grid--2 { grid-template-columns: repeat(2, 1fr); }

.card {
  background: var(--color-white);
  padding: 56px 36px;
  border: 1px solid var(--color-border-soft);
  position: relative;
  display: flex;
  flex-direction: column;
  height: 100%;
  transition: transform var(--transition-base), box-shadow var(--transition-base), border-color var(--transition-base);
}

.card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 48px;
  height: 1px;
  background: var(--color-gold);
  transition: width var(--transition-base);
}

.card:hover {
  transform: translateY(-6px);
  border-color: var(--color-border);
  box-shadow: var(--shadow-md);
}

.card:hover::before { width: 96px; }

.card__index {
  font-family: var(--font-serif-en);
  font-size: var(--fs-xs);
  color: var(--color-gold);
  letter-spacing: var(--tracking-widest);
  margin-bottom: 28px;
  font-weight: var(--fw-medium);
}

.card__icon {
  width: 52px;
  height: 52px;
  color: var(--color-gold);
  margin-bottom: 32px;
}

.card__icon svg {
  width: 100%;
  height: 100%;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.5;
}

.card__title {
  font-family: var(--font-serif-ja);
  font-size: 22px;
  margin-bottom: 20px;
  letter-spacing: 0.06em;
  font-weight: var(--fw-bold);
  color: var(--color-navy);
}

.card__text {
  font-size: var(--fs-base);
  color: var(--color-text-light);
  line-height: var(--lh-relaxed);
  margin-bottom: 32px;
  flex-grow: 1;
}

.card__link {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--color-gold);
  font-size: var(--fs-sm);
  font-weight: var(--fw-medium);
  letter-spacing: var(--tracking-wider);
  margin-top: auto;
  align-self: flex-start;
  transition: gap var(--transition-base);
}

.card__link::after {
  content: "→";
  transition: transform var(--transition-base);
}

.card__link:hover { gap: 16px; }
.card__link:hover::after { transform: translateX(4px); }

/* ── Section Mark (章番号 + 英語) ────────────────────── */
.section-mark {
  display: flex;
  align-items: baseline;
  gap: 18px;
  font-family: var(--font-serif-en);
  color: var(--color-gold);
  margin-bottom: 40px;
}

.section-mark__en {
  font-size: 17px;
  letter-spacing: 0.28em;
  text-transform: uppercase;
  font-weight: var(--fw-semibold);
}

.section-mark__num {
  font-size: 14px;
  letter-spacing: 0.18em;
  color: var(--color-text-muted);
  font-weight: var(--fw-regular);
}

.section--navy .section-mark__num,
.section--navy-deep .section-mark__num {
  color: rgba(255, 255, 255, 0.5);
}

@media screen and (max-width: 768px) {
  .section-mark { gap: 14px; margin-bottom: 28px; }
  .section-mark__en { font-size: 14px; letter-spacing: 0.22em; }
  .section-mark__num { font-size: 12px; }
}

/* ── Service Card (used on Services overview page) ────── */
.services-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
}

.service-card {
  background: var(--color-white);
  padding: 64px 40px 56px;
  position: relative;
  border: 1px solid var(--color-border-soft);
  display: flex;
  flex-direction: column;
  transition: transform var(--transition-base), box-shadow var(--transition-base), border-color var(--transition-base);
}

.service-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 56px;
  height: 1px;
  background: var(--color-gold);
  transition: width var(--transition-base);
}

.service-card:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow-md);
  border-color: var(--color-border);
}

.service-card:hover::before { width: 112px; }

.service-card__index {
  position: absolute;
  top: 32px;
  right: 36px;
  font-family: var(--font-serif-en);
  font-size: 14px;
  letter-spacing: 0.2em;
  color: var(--color-gold);
  font-weight: var(--fw-medium);
}

.service-card__icon {
  width: 56px;
  height: 56px;
  color: var(--color-gold);
  margin-bottom: 36px;
}

.service-card__icon svg {
  width: 100%;
  height: 100%;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.5;
}

.service-card__title {
  font-family: var(--font-serif-ja);
  font-size: 26px;
  font-weight: var(--fw-bold);
  color: var(--color-navy);
  margin-bottom: 6px;
  letter-spacing: 0.08em;
}

.service-card__subtitle {
  font-family: var(--font-serif-en);
  font-size: 13px;
  letter-spacing: 0.24em;
  text-transform: uppercase;
  color: var(--color-gold);
  margin-bottom: 28px;
  font-weight: var(--fw-medium);
}

.service-card__text {
  font-size: var(--fs-base);
  line-height: 2;
  color: var(--color-text-light);
  margin-bottom: 36px;
  flex-grow: 1;
}

.service-card__link {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  align-self: flex-start;
  font-family: var(--font-serif-en);
  font-size: 13px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--color-navy);
  padding-bottom: 6px;
  border-bottom: 1px solid var(--color-navy);
  transition: gap var(--transition-base), color var(--transition-base), border-color var(--transition-base);
}

.service-card__link::after {
  content: "→";
  font-family: var(--font-sans-en);
}

.service-card__link:hover {
  gap: 18px;
  color: var(--color-gold);
  border-color: var(--color-gold);
}

@media screen and (max-width: 992px) {
  .services-grid { grid-template-columns: 1fr; gap: 24px; }
}

/* ── Client Card (used on Top, Works) ──────────────────── */
.clients-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

.client-card {
  background: var(--color-white);
  border: 1px solid var(--color-border-soft);
  padding: 48px 32px;
  text-align: center;
  position: relative;
  transition: transform var(--transition-base), box-shadow var(--transition-base), border-color var(--transition-base);
}

.client-card::before {
  content: "";
  position: absolute;
  top: 50%;
  left: -1px;
  transform: translateY(-50%);
  width: 1px;
  height: 0;
  background: var(--color-gold);
  transition: height var(--transition-base);
}

.client-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-md);
  border-color: var(--color-border);
}

.client-card:hover::before { height: 60%; }

.client-card__index {
  display: inline-block;
  font-family: var(--font-serif-en);
  font-size: var(--fs-xs);
  letter-spacing: var(--tracking-widest);
  color: var(--color-gold);
  margin-bottom: 20px;
  font-weight: var(--fw-medium);
}

.client-card__industry {
  font-family: var(--font-serif-ja);
  font-size: 24px;
  font-weight: var(--fw-bold);
  color: var(--color-navy);
  letter-spacing: 0.12em;
  margin-bottom: 16px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--color-border-soft);
}

.client-card__scale {
  font-family: var(--font-serif-en);
  font-size: 18px;
  color: var(--color-navy);
  font-weight: var(--fw-semibold);
  margin-bottom: 6px;
  letter-spacing: 0.04em;
}

.client-card__period {
  font-size: var(--fs-xs);
  color: var(--color-text-muted);
  letter-spacing: var(--tracking-wider);
}

@media screen and (max-width: 992px) {
  .clients-grid { grid-template-columns: repeat(2, 1fr); }
}

@media screen and (max-width: 480px) {
  .clients-grid { grid-template-columns: 1fr 1fr; gap: 16px; }
  .client-card { padding: 32px 20px; }
}

/* ── Reasons (used on Top, Works) ──────────────────────── */
.reasons-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
  max-width: 1080px;
  margin: 0 auto;
}

.reason-item {
  position: relative;
  display: grid;
  grid-template-columns: 72px 1fr;
  gap: 18px 28px;
  align-items: start;
  min-height: 190px;
  padding: 36px 36px 34px;
  background: var(--color-white);
  border: 1px solid var(--color-border-soft);
  transition: transform var(--transition-base), box-shadow var(--transition-base), border-color var(--transition-base);
}

.reason-item::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 56px;
  height: 1px;
  background: var(--color-gold);
  transition: width var(--transition-base);
}

.reason-item:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
  border-color: var(--color-gold-line);
}

.reason-item:hover::before {
  width: 112px;
}

.reason-item__index {
  grid-row: 1 / span 2;
  display: flex;
  align-items: flex-start;
  justify-content: flex-start;
  font-family: var(--font-serif-en);
  font-size: 42px;
  color: var(--color-gold);
  line-height: 1;
  font-weight: var(--fw-semibold);
  letter-spacing: 0.02em;
}

.reason-item__title {
  font-family: var(--font-serif-ja);
  font-size: 22px;
  font-weight: var(--fw-bold);
  color: var(--color-navy);
  margin-bottom: 0;
  letter-spacing: 0.06em;
  line-height: 1.5;
  writing-mode: horizontal-tb;
  word-break: keep-all;
}

.reason-item__text {
  grid-column: 2;
  font-size: var(--fs-sm);
  line-height: 1.95;
  color: var(--color-text-light);
  letter-spacing: 0.04em;
}

@media screen and (max-width: 992px) {
  .reasons-grid { grid-template-columns: 1fr; gap: 18px; }
  .reason-item { min-height: auto; }
}

@media screen and (max-width: 480px) {
  .reason-item {
    grid-template-columns: 52px 1fr;
    gap: 14px 18px;
    padding: 28px 24px;
  }
  .reason-item__index { font-size: 32px; }
  .reason-item__title { font-size: 18px; }
  .reason-item__text {
    grid-column: 1 / -1;
    font-size: var(--fs-sm);
  }
}

/* ── Pill / Tag ─────────────────────────────────────────── */
.pill {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 20px;
  font-family: var(--font-serif-en);
  font-size: var(--fs-xs);
  font-weight: var(--fw-medium);
  letter-spacing: var(--tracking-widest);
  text-transform: uppercase;
  color: var(--color-gold);
  border: 1px solid var(--color-gold);
  border-radius: var(--radius-full);
}

.pill--solid {
  background: var(--color-gold);
  color: var(--color-white);
}

.pill--ja {
  font-family: var(--font-sans-ja);
  font-size: var(--fs-xs);
  letter-spacing: var(--tracking-wider);
  text-transform: none;
}

/* ── Ornament ───────────────────────────────────────────── */
.ornament {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  margin: 32px 0;
}

.ornament__line {
  width: 60px;
  height: 1px;
  background: var(--color-gold-line);
}

.ornament__dot {
  width: 5px;
  height: 5px;
  background: var(--color-gold);
  transform: rotate(45deg);
}

/* ── Animate on scroll ──────────────────────────────────── */
.animate-on-scroll {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity var(--transition-slow), transform var(--transition-slow);
}

.animate-on-scroll.is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* ── Page Hero (shared) ─────────────────────────────────── */
.page-hero {
  position: relative;
  padding: 200px 0 120px;
  background-color: var(--color-navy);
  color: var(--color-white);
  text-align: center;
  overflow: hidden;
  isolation: isolate;
}

.page-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(180deg, rgba(4, 16, 35, 0.66) 0%, rgba(6, 22, 45, 0.82) 58%, rgba(4, 15, 32, 0.92) 100%),
    linear-gradient(135deg, rgba(200, 168, 74, 0.2) 0%, transparent 44%),
    radial-gradient(ellipse at top right, rgba(200, 168, 74, 0.16) 0%, transparent 58%);
  pointer-events: none;
  z-index: 1;
}

.page-hero::after {
  content: "";
  position: absolute;
  inset: 0;
  background-image: url("../images/hero-ai-field.png");
  background-size: cover;
  background-position: center;
  opacity: 0.34;
  filter: saturate(0.86) contrast(1.05);
  pointer-events: none;
  transform: scale(1.02);
  z-index: 0;
}

.page-hero__pattern {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(90deg, rgba(255, 255, 255, 0.02) 1px, transparent 1px),
    linear-gradient(180deg, rgba(255, 255, 255, 0.02) 1px, transparent 1px);
  background-size: 80px 80px;
  pointer-events: none;
  opacity: 0.6;
  z-index: 1;
}

.page-hero__content {
  position: relative;
  z-index: 2;
}

.page-hero__eyebrow {
  display: inline-block;
  padding: 8px 22px;
  margin-bottom: 32px;
  font-family: var(--font-serif-en);
  font-size: var(--fs-xs);
  color: var(--color-gold);
  letter-spacing: var(--tracking-widest);
  text-transform: uppercase;
  border: 1px solid var(--color-gold);
  border-radius: var(--radius-full);
}

.page-hero__title {
  font-family: var(--font-serif-ja);
  font-size: var(--fs-h1);
  font-weight: var(--fw-bold);
  letter-spacing: 0.08em;
  margin-bottom: 24px;
  color: var(--color-white);
}

.page-hero__en {
  display: block;
  font-family: var(--font-serif-en);
  font-size: var(--fs-md);
  color: var(--color-gold);
  letter-spacing: var(--tracking-widest);
  text-transform: uppercase;
  margin-bottom: 24px;
  font-weight: var(--fw-regular);
}

.page-hero__rule {
  width: 56px;
  height: 1px;
  background: var(--color-gold);
  margin: 32px auto 0;
}

.page-hero__lead {
  margin-top: 32px;
  font-size: var(--fs-md);
  line-height: var(--lh-relaxed);
  color: var(--color-text-on-navy-muted);
  max-width: 640px;
  margin-left: auto;
  margin-right: auto;
}

/* ── Form (shared, base) ────────────────────────────────── */
.form-field {
  margin-bottom: 32px;
}

.form-field__label {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: var(--fs-sm);
  font-weight: var(--fw-medium);
  color: var(--color-navy);
  margin-bottom: 12px;
  letter-spacing: var(--tracking-wide);
}

.form-field__badge {
  display: inline-flex;
  align-items: center;
  padding: 3px 10px;
  font-size: 10px;
  font-weight: var(--fw-medium);
  letter-spacing: 0.1em;
  border-radius: var(--radius-sm);
  line-height: 1.4;
}

.form-field__badge--required {
  background-color: var(--color-gold);
  color: var(--color-white);
}

.form-field__badge--optional {
  background-color: transparent;
  color: var(--color-text-muted);
  border: 1px solid var(--color-border);
}

.form-control,
.contact-form input[type="text"],
.contact-form input[type="email"],
.contact-form input[type="tel"],
.contact-form select,
.contact-form textarea {
  width: 100%;
  padding: 16px 20px;
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  font-family: var(--font-sans-ja);
  font-size: var(--fs-base);
  color: var(--color-text);
  line-height: var(--lh-snug);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
  appearance: none;
  -webkit-appearance: none;
}

.form-control:focus,
.contact-form input:focus,
.contact-form select:focus,
.contact-form textarea:focus {
  outline: none;
  border-color: var(--color-gold);
  box-shadow: 0 0 0 3px rgba(200, 168, 74, 0.14);
}

.contact-form textarea { min-height: 160px; resize: vertical; }

.contact-form select {
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='8'%3E%3Cpath d='M1 1l5 5 5-5' stroke='%230f2547' stroke-width='1.5' fill='none' stroke-linecap='round'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 20px center;
  padding-right: 48px;
  cursor: pointer;
}

.form-row-pair {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
}

/* ── Back to Top ────────────────────────────────────────── */
.back-to-top {
  position: fixed;
  right: 32px;
  bottom: 32px;
  width: 52px;
  height: 52px;
  background: var(--color-navy);
  color: var(--color-white);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  opacity: 0;
  transform: translateY(20px);
  transition: opacity var(--transition-base), transform var(--transition-base), background-color var(--transition-base);
  z-index: var(--z-overlay);
  border: 1px solid var(--color-gold);
}

.back-to-top.is-visible {
  opacity: 1;
  transform: translateY(0);
}

.back-to-top:hover {
  background: var(--color-gold);
  transform: translateY(-4px);
}

.back-to-top svg {
  width: 22px;
  height: 22px;
  stroke: currentColor;
  stroke-width: 2;
  fill: none;
}