/* ============================================
   SOL+ — Base / Reset / Global Styles
   ============================================ */

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: var(--font-body);
  font-weight: 400;
  color: var(--color-charcoal);
  background-color: var(--color-white);
  line-height: 1.8;
  letter-spacing: 0.02em;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

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

a {
  color: var(--color-teal-700);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--color-teal-900);
}

ul, ol {
  list-style: none;
}

/* ── Container ── */
.container {
  max-width: var(--content-width);
  margin: 0 auto;
  padding: 0 var(--space-lg);
}

.container--narrow {
  max-width: var(--narrow-width);
  margin: 0 auto;
  padding: 0 var(--space-lg);
}

/* ── Section Padding ── */
.section {
  padding: var(--space-4xl) 0;
}

.section--sm {
  padding: var(--space-3xl) 0;
}

/* ── Section Label (EN) ── */
.section-label {
  font-family: var(--font-ui);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-teal-700);
  display: block;
  margin-bottom: var(--space-sm);
}

/* ── Accent Line ── */
.accent-line {
  width: 40px;
  height: 2px;
  background-color: var(--color-teal-700);
  margin-bottom: var(--space-lg);
}

.accent-line--coral {
  background-color: var(--color-coral);
}

/* ── Section Heading Pattern ── */
.section-header {
  margin-bottom: var(--space-2xl);
}

.section-header__en {
  font-family: var(--font-ui);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-teal-700);
  display: block;
  margin-bottom: 12px;
}

.section-header__line {
  width: 40px;
  height: 2px;
  background-color: var(--color-teal-700);
  margin-bottom: var(--space-md);
}

.section-header__ja {
  font-family: var(--font-heading-ja);
  font-size: clamp(28px, 4vw, 40px);
  font-weight: 600;
  letter-spacing: 0.08em;
  color: var(--color-charcoal);
  line-height: 1.3;
}

/* ── Headings ── */
h1, h2, h3, h4, h5, h6 {
  line-height: 1.3;
}

.heading-en {
  font-family: var(--font-heading-en);
  font-weight: 600;
  letter-spacing: 0.04em;
}

.heading-ja {
  font-family: var(--font-heading-ja);
  font-weight: 600;
  letter-spacing: 0.08em;
}

/* ── Buttons ── */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-family: var(--font-ui);
  font-size: 16px;
  font-weight: 600;
  letter-spacing: 0.06em;
  line-height: 1;
  padding: 0 32px;
  height: 52px;
  border-radius: var(--radius-sm);
  border: 1px solid transparent;
  cursor: pointer;
  transition: background-color var(--transition-fast), color var(--transition-fast), border-color var(--transition-fast), transform var(--transition-fast);
  white-space: nowrap;
  text-decoration: none;
}

.btn--primary {
  background-color: var(--color-teal-700);
  color: #fff;
  border-color: var(--color-teal-700);
}

.btn--primary:hover {
  background-color: var(--color-teal-900);
  border-color: var(--color-teal-900);
  color: #fff;
}

.btn--secondary {
  background-color: transparent;
  color: var(--color-teal-700);
  border-color: var(--color-teal-700);
}

.btn--secondary:hover {
  background-color: var(--color-teal-700);
  color: #fff;
}

.btn--ghost {
  background-color: transparent;
  color: var(--color-teal-700);
  border-color: transparent;
}

.btn--white {
  background-color: #fff;
  color: var(--color-teal-700);
  border-color: #fff;
}

.btn--white:hover {
  background-color: var(--color-teal-100);
  border-color: var(--color-teal-100);
  color: var(--color-teal-900);
}

.btn--outline-white {
  background-color: transparent;
  color: #fff;
  border-color: rgba(255,255,255,0.7);
}

.btn--outline-white:hover {
  background-color: rgba(255,255,255,0.15);
  border-color: #fff;
  color: #fff;
}

.btn svg,
.btn .arrow {
  transition: transform var(--transition-fast);
}

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

/* ── Scroll Fade-in Animation ── */
.fade-in {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity var(--transition-normal), transform var(--transition-normal);
}

.fade-in.is-visible {
  opacity: 1;
  transform: translateY(0);
}

.fade-in--delay1 { transition-delay: 0.1s; }
.fade-in--delay2 { transition-delay: 0.2s; }
.fade-in--delay3 { transition-delay: 0.3s; }
.fade-in--delay4 { transition-delay: 0.4s; }

/* ── Background colors ── */
.bg-white    { background-color: var(--color-white); }
.bg-sand-100 { background-color: var(--color-sand-100); }
.bg-sand-300 { background-color: var(--color-sand-300); }
.bg-teal-100 { background-color: var(--color-teal-100); }
.bg-teal-700 { background-color: var(--color-teal-700); }
.bg-teal-900 { background-color: var(--color-teal-900); }

/* ── Text utilities ── */
.text-center { text-align: center; }
.text-teal   { color: var(--color-teal-700); }
.text-coral  { color: var(--color-coral); }
.text-secondary { color: var(--color-text-secondary); }
.text-white  { color: #fff; }

/* ── Responsive ── */
@media (max-width: 1023px) {
  .section {
    padding: var(--space-3xl) 0;
  }
}

@media (max-width: 767px) {
  :root {
    --header-height: 64px;
  }

  .container {
    padding: 0 20px;
  }

  .section {
    padding: 80px 0;
  }

  .section-header__ja {
    font-size: 24px;
  }

  .btn {
    height: 44px;
    font-size: 15px;
    padding: 0 24px;
  }
}