/* =============================================================
   shared.css — Common styles for all case study pages
   --accent and dark-mode --accent are defined inline per page.
   ============================================================= */

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

/* Base design tokens */
:root {
  --bg: #F9F8F6; --fg: #0D0D0D; --muted: #6B6B6B; --subtle: #D4D0C8;
  --surface: #EEECEA;
  --nav-bg: rgba(249,248,246,0.92);
  --font-display: Georgia, 'Times New Roman', serif;
  --font-body: 'DM Sans', system-ui, sans-serif;
  --font-mono: 'DM Mono', monospace;
  --container: 760px; --pad: clamp(1.5rem, 5vw, 3rem);
}

/* Dark mode base tokens (--accent override defined inline per page) */
html[data-theme="dark"] {
  --bg: #111110; --fg: #F0EEE9; --muted: #888884; --subtle: #2E2E2B;
  --surface: #1C1C1A; --nav-bg: rgba(17,17,16,0.92);
}

html { font-size: 16px; scroll-behavior: smooth; -webkit-font-smoothing: antialiased; overflow-x: hidden; }
body { background: var(--bg); color: var(--fg); font-family: var(--font-body); line-height: 1.6; transition: background 300ms, color 300ms; overflow-x: hidden; }
a { color: inherit; text-decoration: none; }

/* ── Navigation ──────────────────────────────────────────── */
.case-nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  padding: 1.25rem var(--pad);
  display: flex; align-items: center; justify-content: space-between;
  background: var(--nav-bg);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--subtle);
}
.case-nav__back {
  display: flex; align-items: center; gap: 0.5rem;
  font-family: var(--font-mono); font-size: 0.72rem;
  letter-spacing: 0.06em; color: var(--muted);
  transition: color 150ms;
}
.case-nav__back:hover { color: var(--fg); }
.case-nav__mark {
  font-family: var(--font-mono); font-size: 0.7rem;
  border: 1.5px solid var(--fg); padding: 4px 9px 3px;
  letter-spacing: 0.1em; transition: background 150ms, color 150ms;
}
.case-nav__mark:hover { background: var(--fg); color: var(--bg); }

/* ── Theme toggle ────────────────────────────────────────── */
.theme-toggle {
  display: flex; align-items: center; justify-content: center;
  width: 32px; height: 32px; background: none;
  border: 1.5px solid var(--subtle); border-radius: 50%;
  cursor: pointer; color: var(--muted); padding: 0;
  transition: border-color 150ms, color 150ms, background 150ms, transform 300ms;
}
.theme-toggle:hover { border-color: var(--fg); color: var(--fg); background: var(--surface); }
.theme-toggle svg { width: 14px; height: 14px; display: block; }
.theme-toggle .icon-sun  { display: none; }
.theme-toggle .icon-moon { display: block; }
html[data-theme="dark"] .theme-toggle .icon-sun  { display: block; }
html[data-theme="dark"] .theme-toggle .icon-moon { display: none; }
.theme-toggle.spinning { transform: rotate(180deg); }

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

/* ── Hero ────────────────────────────────────────────────── */
.case-hero {
  padding: calc(64px + 5rem) var(--pad) 4rem;
  border-bottom: 1px solid var(--subtle);
}
.case-hero__kicker {
  font-family: var(--font-mono); font-size: 0.7rem;
  letter-spacing: 0.1em; text-transform: uppercase;
  color: var(--accent); margin-bottom: 1.25rem;
}
.case-hero__title {
  font-family: var(--font-display);
  font-size: clamp(2.5rem, 7vw, 4.5rem);
  font-weight: 700; line-height: 1; letter-spacing: -0.025em;
  margin-bottom: 1.25rem;
}
.case-hero__sub {
  font-size: 1.0625rem; color: var(--muted); font-weight: 300;
  max-width: 560px; line-height: 1.65;
}

/* ── Meta grid ───────────────────────────────────────────── */
.case-meta {
  display: grid; grid-template-columns: repeat(4, 1fr);
  gap: 0; border: 1px solid var(--subtle);
  margin: 3rem 0 4rem;
}
.meta-cell {
  padding: 1.5rem 1.25rem;
  border-right: 1px solid var(--subtle);
}
.meta-cell:last-child { border-right: none; }
.meta-label {
  font-family: var(--font-mono); font-size: 0.65rem;
  letter-spacing: 0.1em; text-transform: uppercase;
  color: var(--muted); margin-bottom: 0.375rem;
}
.meta-value { font-size: 0.875rem; font-weight: 500; line-height: 1.4; }

/* ── Body + sections ─────────────────────────────────────── */
.case-body { padding: 0 0 6rem; }
.case-section { margin-bottom: 4rem; }
@media (max-width: 767px) {
  .case-body { padding-left: var(--pad); padding-right: var(--pad); }
}
.case-section-title {
  font-family: var(--font-display);
  font-size: 1.625rem; font-weight: 600;
  letter-spacing: -0.01em; margin-bottom: 1rem;
}
.case-body p {
  font-size: 1rem; font-weight: 300; line-height: 1.8;
  color: var(--fg); margin-bottom: 1rem;
}
.case-body p:last-child { margin-bottom: 0; }
.case-body strong { font-weight: 500; }

/* ── Impact callout ──────────────────────────────────────── */
.impact-grid {
  display: grid; grid-template-columns: repeat(2, 1fr);
  gap: 1.5px; background: var(--subtle);
  border: 1.5px solid var(--subtle);
  margin: 2rem 0;
}
.impact-cell { background: var(--bg); padding: 1.5rem; }
.impact-metric {
  font-family: var(--font-display);
  font-size: 1.75rem; font-weight: 700;
  color: var(--accent); line-height: 1; margin-bottom: 0.375rem;
}
.impact-desc { font-size: 0.8rem; color: var(--muted); font-weight: 300; line-height: 1.5; }

/* ── Tags ────────────────────────────────────────────────── */
.tag-list { display: flex; flex-wrap: wrap; gap: 0.5rem; margin: 1.5rem 0; }
.tag {
  font-family: var(--font-mono); font-size: 0.65rem;
  letter-spacing: 0.08em; text-transform: uppercase;
  color: var(--muted); background: var(--surface);
  border: 1px solid var(--subtle); padding: 3px 10px;
}

/* ── Challenge list ──────────────────────────────────────── */
.challenge-list { list-style: none; margin: 1rem 0; }
.challenge-list li {
  font-size: 0.9rem; font-weight: 300; padding: 0.6rem 0;
  border-bottom: 1px solid var(--subtle);
  display: flex; align-items: center; gap: 0.75rem; color: var(--muted);
}
.challenge-list li::before { content: '—'; color: var(--subtle); flex-shrink: 0; }

/* ── Subproject list (DH + ML) ───────────────────────────── */
.subproject-list { list-style: none; margin: 1rem 0; }
.subproject-item { padding: 1rem 0; border-bottom: 1px solid var(--subtle); }
.subproject-name { font-weight: 500; font-size: 0.9375rem; margin-bottom: 0.2rem; }
.subproject-desc { font-size: 0.85rem; color: var(--muted); font-weight: 300; }

/* ── Case footer nav ─────────────────────────────────────── */
.case-footer-nav {
  border-top: 1px solid var(--subtle);
  padding: 3rem 0;
  display: flex; align-items: center; justify-content: space-between;
  flex-wrap: wrap; gap: 1rem;
}
.case-footer-link {
  font-size: 0.875rem; color: var(--muted);
  display: flex; align-items: center; gap: 0.5rem;
  transition: color 150ms;
}
.case-footer-link:hover { color: var(--fg); }
.case-footer-link.next { text-align: right; }
.case-footer-next-label {
  font-family: var(--font-mono); font-size: 0.65rem;
  letter-spacing: 0.1em; text-transform: uppercase;
  color: var(--muted); margin-bottom: 0.25rem;
}
.case-footer-next-name {
  font-family: var(--font-display); font-size: 1.5rem; font-weight: 600;
}

/* ── Accent bar ──────────────────────────────────────────── */
.accent-bar { height: 3px; background: var(--accent); }

/* ── Case images ─────────────────────────────────────────── */
.case-img { width: 100%; display: block; border: none; margin: 2rem 0 0.5rem; }
.case-img-row {
  display: grid; grid-template-columns: 1fr 1fr;
  gap: 1rem; margin: 2rem 0 0.5rem;
}
.case-img-row .case-img { margin: 0; }
.case-img-caption {
  font-family: var(--font-mono); font-size: 0.7rem;
  color: var(--muted); letter-spacing: 0.06em;
  margin-bottom: 2rem;
}

/* ── Password gate ───────────────────────────────────────── */
#pw-gate {
  position: fixed; inset: 0; z-index: 9999;
  background: var(--bg);
  display: flex; align-items: center; justify-content: center;
  padding: 2rem;
  transition: opacity 400ms ease, visibility 400ms ease;
}
#pw-gate.unlocked { opacity: 0; visibility: hidden; pointer-events: none; }
.pw-box { max-width: 360px; width: 100%; text-align: center; }
.pw-kicker {
  font-family: var(--font-mono); font-size: 0.68rem;
  letter-spacing: 0.1em; text-transform: uppercase;
  color: var(--accent); margin-bottom: 1.5rem;
}
.pw-title {
  font-family: var(--font-display); font-size: 1.75rem;
  font-weight: 700; margin-bottom: 0.5rem;
}
.pw-sub {
  font-size: 0.875rem; color: var(--muted);
  font-weight: 300; margin-bottom: 2rem; line-height: 1.6;
}
.pw-field { display: flex; gap: 0.5rem; margin-bottom: 0.75rem; }
.pw-input {
  flex: 1; padding: 0.625rem 1rem;
  border: 1.5px solid var(--subtle); background: var(--bg);
  color: var(--fg); font-family: var(--font-mono);
  font-size: 0.875rem; letter-spacing: 0.08em;
  outline: none; transition: border-color 150ms;
}
.pw-input:focus { border-color: var(--accent); }
.pw-btn {
  padding: 0.625rem 1.25rem;
  background: var(--fg); color: var(--bg);
  font-family: var(--font-mono); font-size: 0.75rem;
  letter-spacing: 0.08em; border: none; cursor: pointer;
  transition: opacity 150ms;
}
.pw-btn:hover { opacity: 0.8; }
.pw-error {
  font-family: var(--font-mono); font-size: 0.7rem;
  color: var(--accent); letter-spacing: 0.05em; min-height: 1rem;
}

/* ── Responsive ──────────────────────────────────────────── */
@media (max-width: 640px) {
  .case-meta { grid-template-columns: repeat(2, 1fr); }
  .meta-cell:nth-child(2) { border-right: none; }
  .meta-cell:nth-child(3), .meta-cell:nth-child(4) { border-top: 1px solid var(--subtle); }
  .impact-grid { grid-template-columns: 1fr; }
}
@media (max-width: 520px) { .case-img-row { grid-template-columns: 1fr; } }