/* ═══════════════════════════════════════
   Kuro Portfolio — Shared Styles
   Single source of truth for all pages.
   Page-specific overrides go in each HTML.
   ═══════════════════════════════════════ */

:root {
  --bg: #050507;
  --bg-card: #09090d;
  --bg-card-hover: #0d0d13;
  --border: #111118;
  --border-hover: #1c1c28;
  --text: #a8a8b8;
  --text-dim: #4a4a58;
  --text-bright: #dcdce8;
  --text-white: #f0f0f8;
  --teal: #3dd9ad;
  --teal-dim: rgba(61, 217, 173, 0.12);
  --magenta: #c94090;
  --magenta-dim: rgba(201, 64, 144, 0.12);
  --gold: #d4a040;
  --gold-dim: rgba(212, 160, 64, 0.12);
  --blue: #4a7aef;
  --serif: 'DM Serif Display', Georgia, serif;
  --mono: 'JetBrains Mono', 'SF Mono', 'Fira Code', monospace;
  --jp: 'Noto Serif JP', serif;
  --content-w: 780px;
}

/* ═══ Reset ═══ */
* { margin: 0; padding: 0; box-sizing: border-box; }
::selection { background: var(--teal); color: var(--bg); }

html {
  scroll-behavior: smooth;
  scrollbar-width: thin;
  scrollbar-color: #16161e var(--bg);
}

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--mono);
  font-size: 14px;
  line-height: 1.75;
  font-weight: 300;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

/* ═══ Film Grain ═══ */
body::after {
  content: '';
  position: fixed;
  inset: 0;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 512 512' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.75' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='0.035'/%3E%3C/svg%3E");
  pointer-events: none;
  z-index: 1;
}

/* ═══ Header ═══ */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  padding: 20px clamp(20px, 5vw, 40px);
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: rgba(5, 5, 7, 0.85);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}

.header-name {
  font-family: var(--serif);
  font-size: 18px;
  color: var(--text-white);
  text-decoration: none;
  transition: color 0.2s;
}
.header-name:hover { color: var(--teal); }

.header-nav {
  display: flex;
  gap: 24px;
  font-size: 14px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  align-items: center;
}

.header-nav a {
  color: var(--text-dim);
  text-decoration: none;
  transition: color 0.2s;
}
.header-nav a:hover,
.header-nav a.active { color: var(--teal); }

/* ═══ Language Switcher ═══ */
.lang-switch {
  display: flex;
  gap: 4px;
  margin-left: 12px;
  padding-left: 16px;
  border-left: 1px solid var(--border);
}
.lang-btn {
  background: none;
  border: 1px solid transparent;
  color: var(--text-dim);
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  padding: 2px 6px;
  cursor: pointer;
  border-radius: 3px;
  transition: all 0.2s;
  text-transform: none;
}
.lang-btn:hover { color: var(--text-bright); border-color: var(--border); }
.lang-btn.active { color: var(--teal); border-color: var(--teal-dim); }

/* ═══ Mobile Nav ═══ */
.menu-toggle {
  display: none;
  background: none;
  border: none;
  color: var(--text-dim);
  font-size: 20px;
  cursor: pointer;
  padding: 4px 8px;
  line-height: 1;
  transition: color 0.2s;
}
.menu-toggle:hover { color: var(--text); }

@media (max-width: 640px) {
  .menu-toggle { display: block; }
  .header-nav {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: rgba(5, 5, 7, 0.95);
    backdrop-filter: blur(16px);
    border-bottom: 1px solid var(--border);
    flex-direction: column;
    padding: 20px clamp(20px, 5vw, 40px);
    gap: 20px;
    font-size: 14px;
  }
  .header-nav.open { display: flex; }
  .lang-switch {
    margin-left: 0;
    padding-left: 0;
    border-left: none;
    padding-top: 12px;
    border-top: 1px solid var(--border);
  }
}

/* ═══ Content Layout ═══ */
.content {
  position: relative;
  z-index: 2;
  max-width: var(--content-w);
  margin: 0 auto;
  padding: 100px clamp(20px, 5vw, 40px) 80px;
}

.page-title {
  font-family: var(--serif);
  font-size: clamp(36px, 6vw, 52px);
  color: var(--text-white);
  margin-bottom: 12px;
  letter-spacing: -0.02em;
}

.page-desc {
  color: var(--text-dim);
  font-size: 14px;
  margin-bottom: 48px;
  max-width: 520px;
}

/* ═══ Section Label ═══ */
.label {
  font-size: 11px;
  letter-spacing: 0.25em;
  text-transform: uppercase;
  color: var(--text-dim);
  margin-bottom: 48px;
  display: flex;
  align-items: center;
  gap: 16px;
}
.label::after {
  content: '';
  flex: 1;
  height: 1px;
  background: linear-gradient(to right, var(--border), transparent);
}
.label .num {
  color: var(--teal);
  font-weight: 500;
}

/* ═══ Page Guide ═══ */
.page-guide {
  max-width: var(--content-w);
  margin: 0 auto;
  padding: 0 clamp(20px, 5vw, 40px) 32px;
}
.page-guide-inner {
  border-top: 1px solid var(--border);
  padding-top: 28px;
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 24px;
  font-size: 12px;
  letter-spacing: 0.06em;
}
.page-guide-back a {
  color: var(--text-dim);
  text-decoration: none;
  transition: color 0.2s;
}
.page-guide-back a:hover { color: var(--teal); }
.page-guide-related {
  display: flex;
  align-items: baseline;
  gap: 16px;
  flex-wrap: wrap;
  justify-content: flex-end;
}
.page-guide-related-label {
  color: var(--text-dim);
  opacity: 0.5;
  text-transform: uppercase;
  letter-spacing: 0.15em;
  font-size: 10px;
}
.page-guide-related a {
  color: var(--text-dim);
  text-decoration: none;
  border-bottom: 1px solid var(--border);
  transition: color 0.2s, border-color 0.2s;
}
.page-guide-related a:hover { color: var(--teal); border-color: var(--teal); }

@media (max-width: 640px) {
  .page-guide-inner {
    flex-direction: column;
    gap: 16px;
  }
  .page-guide-related {
    justify-content: flex-start;
  }
}

/* ═══ Footer ═══ */
.footer {
  text-align: center;
  padding: 48px 0;
  font-size: 12px;
  color: var(--text-dim);
  letter-spacing: 0.06em;
}
.footer a {
  color: var(--text-dim);
  text-decoration: none;
  border-bottom: 1px solid var(--border);
  transition: color 0.2s, border-color 0.2s;
}
.footer a:hover { color: var(--teal); border-color: var(--teal); }

/* ═══ Footer Navigation ═══ */
.footer-nav {
  display: flex;
  justify-content: center;
  gap: 20px;
  margin-top: 16px;
  font-size: 12px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}
.footer-nav a {
  color: var(--text-dim);
  text-decoration: none;
  transition: color 0.2s;
}
.footer-nav a:hover { color: var(--teal); }

@media (max-width: 640px) {
  .footer-nav {
    flex-wrap: wrap;
    gap: 12px 16px;
  }
}