/* ============================================
   CSS変数
   ============================================ */
:root {
  --color-bg: #FAFAF7;
  --color-text: #3E2C23;
  --color-text-light: #8C7B6B;
  --color-accent: #6B4C3B;
  --color-border: #D6CEC6;
  --color-section-bg: #F3EDE7;
  --color-dark: #2C2220;
  --color-cta-bg: #5C3D2E;
  --color-white: #FFFFFF;
  --font-display: 'Cormorant Garamond', serif;
  --font-body: 'Noto Sans JP', sans-serif;
  --max-width: 800px;
}

*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
  font-family: var(--font-body);
  color: var(--color-text);
  background-color: var(--color-bg);
  line-height: 1.8;
  font-weight: 300;
  font-size: 14px;
  -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; height: auto; display: block; }
a { color: inherit; text-decoration: none; }

/* ============================================
   ヘッダー
   ============================================ */
.header {
  position: fixed;
  top: 0; left: 0;
  width: 100%;
  z-index: 1000;
  padding: 20px 40px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  background-color: rgba(250, 250, 247, 0.95);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--color-border);
}

.header__logo {
  font-family: var(--font-display);
  font-size: 16px;
  font-weight: 400;
  letter-spacing: 0.05em;
  color: var(--color-text);
}

.header__nav { display: flex; align-items: center; gap: 32px; }

.header__nav a {
  font-family: var(--font-display);
  font-size: 13px;
  letter-spacing: 0.15em;
  color: var(--color-text);
  transition: opacity 0.3s ease;
}

.header__nav a:hover { opacity: 0.6; }

.header__contact-btn {
  padding: 8px 20px;
  border: 1px solid var(--color-text);
  transition: all 0.3s ease;
}

.header__contact-btn:hover {
  background-color: var(--color-text);
  color: var(--color-white) !important;
  opacity: 1 !important;
}

/* ============================================
   ハンバーガーメニュー
   ============================================ */
.hamburger {
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 5px;
  width: 30px;
  height: 30px;
  cursor: pointer;
  z-index: 1100;
  background: none;
  border: none;
  padding: 0;
}

.hamburger span {
  display: block;
  width: 22px;
  height: 1.5px;
  background-color: var(--color-text);
  transition: all 0.3s ease;
}

.hamburger.active span:nth-child(1) { transform: rotate(45deg) translate(5px, 5px); }
.hamburger.active span:nth-child(2) { opacity: 0; }
.hamburger.active span:nth-child(3) { transform: rotate(-45deg) translate(5px, -5px); }

.mobile-menu {
  display: none;
  position: fixed;
  top: 0; left: 0;
  width: 100%;
  height: 100vh;
  background-color: var(--color-dark);
  z-index: 1050;
  justify-content: center;
  align-items: center;
  flex-direction: column;
  gap: 40px;
  opacity: 0;
  transition: opacity 0.4s ease;
}

.mobile-menu.active { display: flex; opacity: 1; }

.mobile-menu a {
  font-family: var(--font-display);
  font-size: 18px;
  letter-spacing: 0.2em;
  color: var(--color-border);
  transition: color 0.3s ease;
}

.mobile-menu a:hover { color: var(--color-white); }

/* ============================================
   ページタイトルエリア
   ============================================ */
.page-hero {
  padding-top: 140px;
  padding-bottom: 60px;
  padding-left: 40px;
  padding-right: 40px;
  max-width: var(--max-width);
  margin: 0 auto;
}

.page-hero__label {
  display: flex;
  align-items: center;
  gap: 12px;
  font-family: var(--font-display);
  font-size: 11px;
  letter-spacing: 0.2em;
  color: var(--color-text-light);
  margin-bottom: 16px;
  text-transform: uppercase;
}

.page-hero__label::before {
  content: '';
  display: block;
  width: 30px;
  height: 1px;
  background-color: var(--color-text-light);
}

.page-hero__title {
  font-family: var(--font-display);
  font-size: clamp(36px, 5vw, 56px);
  font-weight: 400;
  font-style: italic;
  line-height: 1.2;
  margin-bottom: 32px;
  color: var(--color-text);
}

.page-hero__client {
  font-family: var(--font-display);
  font-size: 13px;
  letter-spacing: 0.1em;
  color: var(--color-text-light);
  margin-bottom: 20px;
  text-transform: uppercase;
}

.page-hero__desc {
  font-size: 14px;
  line-height: 2;
  color: var(--color-text);
  max-width: 600px;
}

.page-hero__divider {
  width: 100%;
  height: 1px;
  background-color: var(--color-border);
  margin-top: 48px;
}

/* ============================================
   作品セクション
   ============================================ */
.work-section {
  padding: 60px 40px;
  max-width: var(--max-width);
  margin: 0 auto;
  border-bottom: 1px solid var(--color-border);
}

.work-section:last-of-type { border-bottom: none; }

.work-section__label {
  font-family: var(--font-display);
  font-size: 28px;
  letter-spacing: 0.2em;
  color: var(--color-text-light);
  margin-bottom: 12px;
}

.work-section__title {
  font-family: var(--font-display);
  font-size: clamp(22px, 3vw, 28px);
  font-weight: 400;
  font-style: italic;
  margin-bottom: 20px;
  color: var(--color-text);
}

.work-section__text {
  font-size: 13px;
  line-height: 2;
  color: var(--color-text);
  margin-bottom: 12px;
}

.work-section__tools {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 36px;
  margin-top: 16px;
}

.work-section__tool-tag {
  font-size: 11px;
  padding: 4px 12px;
  border: 1px solid var(--color-border);
  letter-spacing: 0.05em;
  color: var(--color-text-light);
}

.work-section__images {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

/* サムネイル画像（16:9の横長） */
.work-section__img {
  width: 100%;
  height: auto;
  display: block;
}

/* ============================================
   ホームに戻るセクション
   ============================================ */
.back-section {
  padding: 80px 40px 100px;
  text-align: center;
  background-color: var(--color-section-bg);
}

.back-section__text {
  font-family: var(--font-display);
  font-size: 11px;
  letter-spacing: 0.2em;
  color: var(--color-text-light);
  margin-bottom: 20px;
  text-transform: uppercase;
}

.back-section__title {
  font-family: var(--font-display);
  font-size: clamp(24px, 3vw, 32px);
  font-weight: 400;
  font-style: italic;
  color: var(--color-text);
  margin-bottom: 32px;
}

.back-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-body);
  font-size: 13px;
  letter-spacing: 0.1em;
  color: var(--color-white);
  background-color: var(--color-cta-bg);
  padding: 16px 40px;
  transition: background-color 0.3s ease;
}

.back-btn:hover { background-color: var(--color-text); }

.back-btn__arrow {
  font-size: 16px;
  transition: transform 0.3s ease;
}

.back-btn:hover .back-btn__arrow { transform: translateX(-4px); }

/* ============================================
   フッター
   ============================================ */
.footer {
  background-color: var(--color-dark);
  color: var(--color-border);
  padding: 30px 40px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.footer__logo {
  font-family: var(--font-display);
  font-size: 14px;
  letter-spacing: 0.05em;
  font-style: italic;
}

.footer__copy {
  font-size: 11px;
  letter-spacing: 0.05em;
  color: rgba(214, 206, 198, 0.6);
}

/* ============================================
   フェードインアニメーション
   ============================================ */
.fade-in {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.8s ease, transform 0.8s ease;
}

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

/* ============================================
   レスポンシブ対応（768px以下）
   ============================================ */
@media (max-width: 768px) {
  .header { padding: 16px 20px; }
  .header__nav { display: none; }
  .hamburger { display: flex; }

  .page-hero {
    padding-top: 100px;
    padding-left: 24px;
    padding-right: 24px;
  }

  .work-section { padding: 48px 24px; }
  .back-section { padding: 60px 24px 80px; }

  .footer {
    flex-direction: column;
    gap: 12px;
    text-align: center;
    padding: 24px 20px;
  }
}