/* paulaiverse — Styles */

/* ─── Design Tokens ────────────────────────────────────────────────────── */
:root, [data-theme="light"] {
  --text-xs:   clamp(0.75rem,  0.7rem  + 0.25vw, 0.875rem);
  --text-sm:   clamp(0.875rem, 0.8rem  + 0.35vw, 1rem);
  --text-base: clamp(1rem,     0.95rem + 0.25vw, 1.125rem);
  --text-lg:   clamp(1.125rem, 1rem    + 0.75vw, 1.5rem);
  --text-xl:   clamp(1.5rem,   1.2rem  + 1.25vw, 2.25rem);
  --text-2xl:  clamp(2rem,     1.2rem  + 2.5vw,  3.5rem);
  --text-3xl:  clamp(2.5rem,   1rem    + 4vw,    5rem);

  --space-1: 0.25rem; --space-2: 0.5rem; --space-3: 0.75rem;
  --space-4: 1rem;    --space-5: 1.25rem; --space-6: 1.5rem;
  --space-8: 2rem;    --space-10: 2.5rem; --space-12: 3rem;
  --space-16: 4rem;   --space-20: 5rem;   --space-24: 6rem;

  --color-bg:              #f5f4f0;
  --color-surface:         #f9f8f5;
  --color-surface-2:       #ffffff;
  --color-surface-offset:  #edeae4;
  --color-border:          #d8d5ce;
  --color-divider:         #e3e0da;
  --color-text:            #1e1c17;
  --color-text-muted:      #726f68;
  --color-text-faint:      #b8b5af;
  --color-text-inverse:    #f5f4f0;

  /* Primary — deep indigo-violet for a research/knowledge feel */
  --color-primary:         #4c3fd4;
  --color-primary-hover:   #3a2fb8;
  --color-primary-active:  #2a208a;
  --color-primary-highlight: #e0ddf8;
  --color-primary-muted:   #dddaf7;

  /* Secondary accent — amber for both/overlap topics */
  --color-both:            #b45309;
  --color-both-bg:         #fef3c7;
  --color-both-border:     #fcd34d;

  /* PM — teal */
  --color-pm:              #0f766e;
  --color-pm-bg:           #ccfbf1;
  --color-pm-border:       #5eead4;

  /* HFR — rose */
  --color-hfr:             #be185d;
  --color-hfr-bg:          #fce7f3;
  --color-hfr-border:      #f9a8d4;

  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1.25rem;
  --radius-full: 9999px;

  --shadow-sm: 0 1px 3px rgba(0,0,0,0.07);
  --shadow-md: 0 4px 14px rgba(0,0,0,0.09);
  --shadow-lg: 0 12px 32px rgba(0,0,0,0.11);

  --content-default: 1140px;
  --transition: 180ms cubic-bezier(0.16, 1, 0.3, 1);

  --font-display: 'Cabinet Grotesk', 'Helvetica Neue', sans-serif;
  --font-body: 'Satoshi', 'Inter', sans-serif;
}

[data-theme="dark"] {
  --color-bg:              #13120f;
  --color-surface:         #1a1917;
  --color-surface-2:       #21201d;
  --color-surface-offset:  #1e1d1a;
  --color-border:          #353330;
  --color-divider:         #292826;
  --color-text:            #d4d2ce;
  --color-text-muted:      #7a7872;
  --color-text-faint:      #56544f;
  --color-text-inverse:    #1a1917;

  --color-primary:         #7b6ee8;
  --color-primary-hover:   #9485ef;
  --color-primary-active:  #a99df3;
  --color-primary-highlight: #2a2650;
  --color-primary-muted:   #231f42;

  --color-both:            #fbbf24;
  --color-both-bg:         #2d2407;
  --color-both-border:     #78490a;

  --color-pm:              #34d399;
  --color-pm-bg:           #052e22;
  --color-pm-border:       #065f46;

  --color-hfr:             #f472b6;
  --color-hfr-bg:          #2d0a1a;
  --color-hfr-border:      #831843;

  --shadow-sm: 0 1px 3px rgba(0,0,0,0.3);
  --shadow-md: 0 4px 14px rgba(0,0,0,0.4);
  --shadow-lg: 0 12px 32px rgba(0,0,0,0.5);
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme]) {
    --color-bg:              #13120f;
    --color-surface:         #1a1917;
    --color-surface-2:       #21201d;
    --color-surface-offset:  #1e1d1a;
    --color-border:          #353330;
    --color-divider:         #292826;
    --color-text:            #d4d2ce;
    --color-text-muted:      #7a7872;
    --color-text-faint:      #56544f;
    --color-text-inverse:    #1a1917;
    --color-primary:         #7b6ee8;
    --color-primary-hover:   #9485ef;
    --color-primary-active:  #a99df3;
    --color-primary-highlight: #2a2650;
    --color-primary-muted:   #231f42;
    --color-both:            #fbbf24;
    --color-both-bg:         #2d2407;
    --color-both-border:     #78490a;
    --color-pm:              #34d399;
    --color-pm-bg:           #052e22;
    --color-pm-border:       #065f46;
    --color-hfr:             #f472b6;
    --color-hfr-bg:          #2d0a1a;
    --color-hfr-border:      #831843;
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.3);
    --shadow-md: 0 4px 14px rgba(0,0,0,0.4);
    --shadow-lg: 0 12px 32px rgba(0,0,0,0.5);
  }
}

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

html {
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  scroll-behavior: smooth;
  scroll-padding-top: var(--space-20);
}

body {
  min-height: 100dvh;
  font-family: var(--font-body);
  font-size: var(--text-base);
  color: var(--color-text);
  background-color: var(--color-bg);
  line-height: 1.65;
}

img, svg { display: block; max-width: 100%; }
h1,h2,h3,h4 { text-wrap: balance; line-height: 1.2; font-family: var(--font-display); }
p, li { text-wrap: pretty; }
a { color: inherit; text-decoration: none; }
button { cursor: pointer; background: none; border: none; font: inherit; color: inherit; }

::selection { background: var(--color-primary-muted); color: var(--color-text); }
:focus-visible { outline: 2px solid var(--color-primary); outline-offset: 3px; border-radius: var(--radius-sm); }

/* ─── Nav ───────────────────────────────────────────────────────────────── */
.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--color-bg);
  border-bottom: 1px solid var(--color-divider);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

.nav-inner {
  max-width: var(--content-default);
  margin: 0 auto;
  padding: var(--space-3) var(--space-6);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  flex-wrap: wrap;
}

.logo {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  text-decoration: none;
}

.logo-text {
  font-family: var(--font-display);
  font-size: var(--text-lg);
  font-weight: 800;
  color: var(--color-text);
  letter-spacing: -0.02em;
}

.logo-accent { color: var(--color-primary); }

.logo-gradient {
  background: linear-gradient(135deg, var(--color-primary) 0%, #a855f7 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  flex-wrap: wrap;
}

.filter-pills {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  flex-wrap: wrap;
}

.pill {
  font-size: var(--text-sm);
  font-family: var(--font-body);
  font-weight: 500;
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-full);
  border: 1.5px solid var(--color-border);
  background: transparent;
  color: var(--color-text-muted);
  transition: all var(--transition);
}

.pill:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
}

.pill.active {
  background: var(--color-primary);
  border-color: var(--color-primary);
  color: white;
}

.theme-toggle {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-full);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-text-muted);
  border: 1.5px solid var(--color-border);
  transition: all var(--transition);
}

.theme-toggle:hover {
  color: var(--color-text);
  border-color: var(--color-primary);
}

/* ─── Hero ──────────────────────────────────────────────────────────────── */
.hero {
  padding: clamp(var(--space-16), 8vw, var(--space-24)) var(--space-6) clamp(var(--space-12), 5vw, var(--space-20));
  border-bottom: 1px solid var(--color-divider);
  background: linear-gradient(160deg, var(--color-bg) 0%, var(--color-primary-muted) 100%);
}

.hero-inner {
  max-width: var(--content-default);
  margin: 0 auto;
}

.hero-eyebrow {
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--color-primary);
  letter-spacing: 0.06em;
  text-transform: uppercase;
  margin-bottom: var(--space-4);
}

.hero-title {
  font-size: clamp(2rem, 5vw, 5rem);
  font-weight: 800;
  letter-spacing: -0.04em;
  color: var(--color-text);
  margin-bottom: var(--space-5);
  line-height: 1.1;
  white-space: nowrap;
}

@media (max-width: 600px) {
  .hero-title { white-space: normal; }
}

.plain-text {
  color: var(--color-text);
  -webkit-text-fill-color: var(--color-text);
}

.gradient-text {
  background: linear-gradient(135deg, var(--color-primary) 0%, #a855f7 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-subtitle {
  font-size: clamp(1rem, 1.5vw, 1.35rem);
  color: var(--color-text-muted);
  max-width: 900px;
  line-height: 1.6;
  margin-bottom: var(--space-10);
  white-space: nowrap;
}

@media (max-width: 860px) {
  .hero-subtitle { white-space: normal; }
}

.hero-stats {
  display: flex;
  align-items: center;
  gap: var(--space-6);
  flex-wrap: wrap;
}

.stat {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
}

.stat-num {
  font-family: var(--font-display);
  font-size: var(--text-xl);
  font-weight: 800;
  color: var(--color-primary);
  line-height: 1;
}

.stat-label {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.stat-divider {
  width: 1px;
  height: 40px;
  background: var(--color-divider);
}

/* ─── Legend bar ────────────────────────────────────────────────────────── */
.legend-bar {
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-divider);
  padding: var(--space-3) var(--space-6);
}

.legend-inner {
  max-width: var(--content-default);
  margin: 0 auto;
  display: flex;
  align-items: center;
  gap: var(--space-6);
  flex-wrap: wrap;
}

.legend-item {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-sm);
  color: var(--color-text-muted);
}

/* ─── Badges ────────────────────────────────────────────────────────────── */
.badge {
  display: inline-flex;
  align-items: center;
  font-size: var(--text-xs);
  font-weight: 600;
  padding: 2px 8px;
  border-radius: var(--radius-full);
  border: 1.5px solid;
  white-space: nowrap;
}

.badge-both {
  color: var(--color-both);
  background: var(--color-both-bg);
  border-color: var(--color-both-border);
}

.badge-pm {
  color: var(--color-pm);
  background: var(--color-pm-bg);
  border-color: var(--color-pm-border);
}

.badge-hfr {
  color: var(--color-hfr);
  background: var(--color-hfr-bg);
  border-color: var(--color-hfr-border);
}

/* ─── Main grid ─────────────────────────────────────────────────────────── */
.main {
  max-width: var(--content-default);
  margin: 0 auto;
  padding: var(--space-10) var(--space-6) var(--space-20);
}

.topics-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(min(360px, 100%), 1fr));
  gap: var(--space-6);
  align-items: start;
}

.empty-msg {
  text-align: center;
  color: var(--color-text-muted);
  padding: var(--space-20) 0;
  font-size: var(--text-lg);
}

/* ─── Cards ─────────────────────────────────────────────────────────────── */
.card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transition: box-shadow var(--transition), transform var(--transition);
}

.card:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-2px);
}

/* Left accent stripe by category */
.card-both   { border-left: 4px solid var(--color-both-border); }
.card-pm     { border-left: 4px solid var(--color-pm-border); }
.card-hfr    { border-left: 4px solid var(--color-hfr-border); }

.card-header {
  padding: var(--space-5) var(--space-6) var(--space-4);
  border-bottom: 1px solid var(--color-divider);
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.card-title {
  font-size: var(--text-lg);
  font-weight: 800;
  color: var(--color-text);
  letter-spacing: -0.02em;
}

.card-tagline {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  font-style: italic;
}

.card-body {
  padding: var(--space-5) var(--space-6);
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
  flex: 1;
}

.card-summary {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  line-height: 1.7;
}

/* Why it matters */
.why-matters {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  background: var(--color-surface-offset);
  border-radius: var(--radius-md);
  padding: var(--space-4) var(--space-5);
}

.why-item {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
}

.why-label {
  font-size: var(--text-xs);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--color-primary);
}

.why-item p {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  line-height: 1.6;
}

/* Key terms */
.key-terms {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
}

.term {
  font-size: var(--text-xs);
  font-weight: 500;
  padding: 3px 10px;
  background: var(--color-primary-highlight);
  color: var(--color-primary);
  border-radius: var(--radius-full);
}

/* Card footer */
.card-footer {
  padding: var(--space-4) var(--space-6);
  border-top: 1px solid var(--color-divider);
  display: flex;
  justify-content: flex-end;
}

.learn-link {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--color-primary);
  transition: color var(--transition), gap var(--transition);
}

.learn-link:hover {
  color: var(--color-primary-hover);
  gap: var(--space-2);
}

/* ─── New / Updated freshness badges ────────────────────────────────────── */
.card-header-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-2);
}

.card-freshness {
  display: flex;
  gap: var(--space-1);
}

.badge-new {
  font-size: var(--text-xs);
  font-weight: 700;
  padding: 2px 7px;
  border-radius: var(--radius-full);
  background: var(--color-primary);
  color: white;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.badge-updated {
  font-size: var(--text-xs);
  font-weight: 700;
  padding: 2px 7px;
  border-radius: var(--radius-full);
  background: var(--color-both-bg);
  color: var(--color-both);
  border: 1px solid var(--color-both-border);
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

/* ─── Research questions ─────────────────────────────────────────────────── */
.research-qs {
  background: var(--color-primary-muted);
  border: 1px solid var(--color-primary-highlight);
  border-radius: var(--radius-md);
  padding: var(--space-4) var(--space-5);
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.rq-label {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-xs);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.07em;
  color: var(--color-primary);
}

.rq-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  padding: 0;
}

.rq-list li {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  line-height: 1.6;
  padding-left: var(--space-4);
  position: relative;
}

.rq-list li::before {
  content: '?';
  position: absolute;
  left: 0;
  color: var(--color-primary);
  font-weight: 700;
  font-size: var(--text-xs);
}

/* ─── Changelog ──────────────────────────────────────────────────────────── */
.changelog {
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-divider);
}

.changelog-inner {
  max-width: var(--content-default);
  margin: 0 auto;
  padding: 0 var(--space-6);
}

.cl-header {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-3) 0;
  cursor: pointer;
  background: none;
  border: none;
  color: var(--color-text-muted);
  font-family: var(--font-body);
  font-size: var(--text-sm);
  transition: color var(--transition);
}

.cl-header:hover { color: var(--color-text); }

.cl-title {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-weight: 500;
}

.cl-arrow {
  transition: transform var(--transition);
  flex-shrink: 0;
}

.cl-content {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease;
}

.cl-content.cl-open {
  max-height: 400px;
}

.cl-list {
  list-style: none;
  padding: 0;
  padding-bottom: var(--space-4);
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.cl-entry {
  display: flex;
  align-items: baseline;
  gap: var(--space-3);
  font-size: var(--text-sm);
}

.cl-date {
  color: var(--color-primary);
  font-weight: 600;
  white-space: nowrap;
  flex-shrink: 0;
  font-size: var(--text-xs);
}

.cl-desc {
  color: var(--color-text-muted);
}

/* ─── Footer ─────────────────────────────────────────────────────────────── */
.footer {
  border-top: 1px solid var(--color-divider);
  padding: var(--space-8) var(--space-6);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-2);
  text-align: center;
  background: var(--color-surface);
}

.footer-note {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  font-style: italic;
}

.footer-credit {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  transition: color var(--transition);
}

.footer-credit:hover { color: var(--color-primary); }

/* ─── Responsive ─────────────────────────────────────────────────────────── */
@media (max-width: 640px) {
  .nav-inner {
    padding: var(--space-3) var(--space-4);
    gap: var(--space-3);
  }

  .hero {
    padding: var(--space-12) var(--space-4) var(--space-10);
  }

  .legend-inner {
    gap: var(--space-3);
    padding: var(--space-3) var(--space-4);
  }

  .main {
    padding: var(--space-6) var(--space-4) var(--space-16);
  }

  .hero-stats {
    gap: var(--space-4);
  }

  .stat-divider { display: none; }

  .filter-pills { gap: var(--space-1); }

  .pill {
    font-size: var(--text-xs);
    padding: 2px var(--space-2);
  }
}