/* ============================================================
   base.css — リセット + 基底スタイル
   ============================================================ */

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-sans);
  font-size: 1rem;
  line-height: 1.8;
  color: var(--color-text);
  background-color: var(--color-cream);
  -webkit-font-smoothing: antialiased;
}

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

a {
  color: var(--color-link);
  text-decoration: none;
  transition: opacity var(--transition);
}

a:hover {
  opacity: 0.72;
}

ul, ol {
  list-style: none;
}

button {
  cursor: pointer;
  font-family: var(--font-sans);
  border: none;
  background: none;
}

h1, h2, h3, h4 {
  font-family: var(--font-serif);
  font-weight: 500;
  line-height: 1.5;
  color: var(--color-heading);
  letter-spacing: 0.04em;
}

p {
  line-height: 1.9;
}

/* Utility */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border-width: 0;
}

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 40px;
}

@media (max-width: 768px) {
  .container {
    padding: 0 20px;
  }
}

/* Scroll fade-in animation */
.fade-in {
  opacity: 0;
  transform: translateY(28px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}

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

.fade-in--delay-1 { transition-delay: 0.1s; }
.fade-in--delay-2 { transition-delay: 0.2s; }
.fade-in--delay-3 { transition-delay: 0.3s; }
.fade-in--delay-4 { transition-delay: 0.4s; }