/* ============================================
   hair salon kiki — Quiet Science
   共通スタイルシート
   ============================================ */

/* CSS変数（デザイントークン） */
:root {
  /* Colors */
  --color-bg: #F8F6F1;
  --color-ink: #1A1F2B;
  --color-ink-soft: #4A4F5B;
  --color-deep-blue: #1E3A5F;
  --color-wood: #B89970;
  --color-moss: #7A8B5A;
  --color-rose: #C8A5A0;
  --color-line: #E8E2D6;
  --color-overlay: rgba(26, 31, 43, 0.55);

  /* Typography */
  --font-serif-jp: "Shippori Mincho B1", "Noto Serif JP", serif;
  --font-sans-jp: "Noto Sans JP", sans-serif;
  --font-serif-en: "Cormorant Garamond", serif;

  /* Spacing */
  --space-xs: 0.5rem;
  --space-sm: 1rem;
  --space-md: 2rem;
  --space-lg: 4rem;
  --space-xl: 6rem;
  --space-xxl: 8rem;

  /* Layout */
  --max-width: 1100px;
  --content-width: 720px;

  /* Transitions */
  --ease: cubic-bezier(0.4, 0, 0.2, 1);
}

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

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

body {
  font-family: var(--font-sans-jp);
  font-weight: 300;
  font-size: 1rem;
  line-height: 1.9;
  color: var(--color-ink);
  background-color: var(--color-bg);
  letter-spacing: 0.04em;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* Typography Base */
h1, h2, h3, h4 {
  font-family: var(--font-serif-jp);
  font-weight: 400;
  line-height: 1.5;
  letter-spacing: 0.06em;
}

p {
  line-height: 2.0;
}

a {
  color: var(--color-ink);
  text-decoration: none;
  transition: color 0.3s var(--ease), opacity 0.3s var(--ease);
}

a:hover {
  opacity: 0.6;
}

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

/* ============================================
   Header / Navigation
   ============================================ */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  padding: 1.25rem var(--space-md);
  background: rgba(248, 246, 241, 0.85);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--color-line);
}

.header-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.site-logo {
  font-family: var(--font-serif-en);
  font-size: 1.5rem;
  font-weight: 500;
  letter-spacing: 0.1em;
  color: var(--color-ink);
}

.site-logo .small {
  font-size: 0.7rem;
  letter-spacing: 0.25em;
  display: block;
  margin-top: -0.1rem;
  color: var(--color-ink-soft);
}

.nav-toggle {
  background: none;
  border: none;
  width: 28px;
  height: 20px;
  position: relative;
  cursor: pointer;
  padding: 0;
}

.nav-toggle span {
  display: block;
  position: absolute;
  height: 1px;
  width: 100%;
  background: var(--color-ink);
  left: 0;
  transition: all 0.3s var(--ease);
}

.nav-toggle span:nth-child(1) { top: 4px; }
.nav-toggle span:nth-child(2) { top: 10px; }
.nav-toggle span:nth-child(3) { top: 16px; }

.nav-toggle.active span:nth-child(1) { top: 10px; transform: rotate(45deg); }
.nav-toggle.active span:nth-child(2) { opacity: 0; }
.nav-toggle.active span:nth-child(3) { top: 10px; transform: rotate(-45deg); }

.site-nav {
  position: fixed;
  top: 0;
  right: 0;
  width: 100%;
  height: 100vh;
  background: var(--color-bg);
  display: flex;
  align-items: center;
  justify-content: center;
  transform: translateX(100%);
  transition: transform 0.5s var(--ease);
  z-index: 99;
}

.site-nav.active {
  transform: translateX(0);
}

.site-nav ul {
  list-style: none;
  text-align: center;
}

.site-nav li {
  margin-bottom: var(--space-md);
  opacity: 0;
  transform: translateY(10px);
  transition: all 0.5s var(--ease);
}

.site-nav.active li {
  opacity: 1;
  transform: translateY(0);
}

.site-nav.active li:nth-child(1) { transition-delay: 0.1s; }
.site-nav.active li:nth-child(2) { transition-delay: 0.15s; }
.site-nav.active li:nth-child(3) { transition-delay: 0.2s; }
.site-nav.active li:nth-child(4) { transition-delay: 0.25s; }
.site-nav.active li:nth-child(5) { transition-delay: 0.3s; }

.site-nav a {
  font-family: var(--font-serif-jp);
  font-size: 1.25rem;
  letter-spacing: 0.2em;
  display: block;
  padding: 0.5rem 1rem;
}

.site-nav a .en {
  font-family: var(--font-serif-en);
  font-size: 0.75rem;
  display: block;
  letter-spacing: 0.25em;
  color: var(--color-ink-soft);
  margin-top: 0.25rem;
}

/* ============================================
   Common Section Styles
   ============================================ */
.section {
  padding: var(--space-xl) var(--space-md);
  position: relative;
}

.section-inner {
  max-width: var(--max-width);
  margin: 0 auto;
}

.section-narrow {
  max-width: var(--content-width);
  margin: 0 auto;
}

.section-label {
  font-family: var(--font-serif-en);
  font-size: 0.75rem;
  letter-spacing: 0.35em;
  text-transform: uppercase;
  color: var(--color-deep-blue);
  margin-bottom: 1.5rem;
  display: block;
}

.section-title {
  font-size: 1.75rem;
  line-height: 1.6;
  margin-bottom: var(--space-md);
}

.section-title .accent {
  color: var(--color-deep-blue);
}

/* ============================================
   Buttons
   ============================================ */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  padding: 1rem 2rem;
  font-family: var(--font-sans-jp);
  font-size: 0.9rem;
  font-weight: 400;
  letter-spacing: 0.15em;
  border: 1px solid var(--color-ink);
  background: transparent;
  color: var(--color-ink);
  cursor: pointer;
  transition: all 0.3s var(--ease);
}

.btn:hover {
  background: var(--color-ink);
  color: var(--color-bg);
  opacity: 1;
}

.btn-primary {
  background: var(--color-deep-blue);
  color: var(--color-bg);
  border-color: var(--color-deep-blue);
}

.btn-primary:hover {
  background: var(--color-ink);
  border-color: var(--color-ink);
  color: var(--color-bg);
}

.btn .arrow {
  font-family: var(--font-serif-en);
  font-size: 1rem;
  transition: transform 0.3s var(--ease);
}

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

/* ============================================
   Footer
   ============================================ */
.site-footer {
  padding: var(--space-xl) var(--space-md) var(--space-md);
  background: var(--color-ink);
  color: var(--color-bg);
}

.footer-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  display: grid;
  gap: var(--space-md);
}

.footer-logo {
  font-family: var(--font-serif-en);
  font-size: 1.75rem;
  letter-spacing: 0.1em;
  margin-bottom: 0.5rem;
}

.footer-tagline {
  font-family: var(--font-serif-jp);
  font-size: 0.9rem;
  opacity: 0.7;
  margin-bottom: var(--space-md);
}

.footer-info {
  font-size: 0.85rem;
  line-height: 2.2;
  opacity: 0.8;
}

.footer-info a {
  color: var(--color-bg);
}

.footer-sns {
  margin-top: var(--space-sm);
  display: flex;
  gap: var(--space-md);
}

.footer-sns a {
  font-family: var(--font-serif-en);
  font-size: 0.85rem;
  letter-spacing: 0.2em;
  color: var(--color-bg);
  opacity: 0.8;
  padding-bottom: 0.25rem;
  border-bottom: 1px solid rgba(248, 246, 241, 0.3);
}

.footer-bottom {
  margin-top: var(--space-lg);
  padding-top: var(--space-md);
  border-top: 1px solid rgba(248, 246, 241, 0.15);
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.75rem;
  opacity: 0.6;
}

.footer-bottom a {
  color: var(--color-bg);
}

/* ============================================
   Fade-in Animations
   ============================================ */
.fade-in {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 1s var(--ease), transform 1s var(--ease);
}

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

/* ============================================
   Responsive
   ============================================ */
@media (min-width: 768px) {
  body {
    font-size: 1.05rem;
  }

  .section {
    padding: var(--space-xxl) var(--space-lg);
  }

  .section-title {
    font-size: 2.5rem;
  }

  .footer-inner {
    grid-template-columns: 1fr 1fr;
  }

  .footer-bottom {
    grid-column: 1 / -1;
  }
}