/* ============================================================
   QUANTUM BIODYNAMICS — design tokens
   Custom palette: deep ink navy accent, warm off-white surfaces
   ============================================================ */

:root {
  /* Type scale */
  --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, 1.4rem + 2.5vw, 3.5rem);
  --text-3xl: clamp(2.5rem, 1.2rem + 4vw, 4.75rem);

  /* Spacing */
  --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;
  --space-32: 8rem;

  /* Fonts */
  --font-display: 'Boska', 'Cormorant Garamond', 'Iowan Old Style', Georgia, serif;
  --font-body: 'Satoshi', 'Inter', 'Helvetica Neue', system-ui, sans-serif;

  /* Radius / transitions / shadows */
  --radius-sm: 0.25rem;
  --radius-md: 0.375rem;
  --transition-interactive: 220ms cubic-bezier(0.16, 1, 0.3, 1);
  --shadow-sm: 0 1px 2px oklch(0.2 0.02 240 / 0.06);

  /* Content widths */
  --content-narrow: 640px;
  --content-default: 960px;
  --content-wide: 1140px;
}

/* Light mode — warm off-white with deep navy ink */
:root,
[data-theme='light'] {
  --color-bg: #f6f4ee; /* warm bone */
  --color-surface: #fbfaf6;
  --color-surface-2: #eeece5;
  --color-border: #d9d5cb;
  --color-divider: #e4e0d6;

  --color-text: #1a1e28; /* deep ink, near-black with cool tone */
  --color-text-muted: #5b5e69;
  --color-text-faint: #8f9099;

  --color-primary: #1a3547; /* deep marine navy */
  --color-primary-hover: #0f2434;
  --color-primary-highlight: #dae1e6;
  --color-accent: #6c807a; /* muted sage — secondary hairline */
}

[data-theme='dark'] {
  --color-bg: #12141a;
  --color-surface: #191c24;
  --color-surface-2: #1f2330;
  --color-border: #2e323f;
  --color-divider: #23262f;

  --color-text: #e5e3dc;
  --color-text-muted: #8d8f98;
  --color-text-faint: #5c5e67;

  --color-primary: #a8c8d8;
  --color-primary-hover: #c9dfec;
  --color-primary-highlight: #253846;
  --color-accent: #8fa19b;
}

/* ============================================================
   BASE
   ============================================================ */

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

html {
  -moz-text-size-adjust: none;
  -webkit-text-size-adjust: none;
  text-size-adjust: none;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
  scroll-behavior: smooth;
  hanging-punctuation: first last;
  scroll-padding-top: 5rem;
}

body {
  min-height: 100dvh;
  line-height: 1.55;
  font-family: var(--font-body);
  font-size: var(--text-base);
  color: var(--color-text);
  background-color: var(--color-bg);
  font-feature-settings: 'ss01', 'kern';
}

a {
  color: inherit;
  text-decoration: none;
}

button {
  cursor: pointer;
  background: none;
  border: none;
  font: inherit;
  color: inherit;
}

img,
svg {
  display: block;
  max-width: 100%;
}

h1,
h2,
h3,
h4 {
  text-wrap: balance;
  line-height: 1.1;
  font-family: var(--font-display);
  font-weight: 500;
  letter-spacing: -0.015em;
}

p {
  text-wrap: pretty;
  max-width: 68ch;
}

::selection {
  background: oklch(from var(--color-primary) l c h / 0.2);
  color: var(--color-text);
}

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

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

a,
button {
  transition:
    color var(--transition-interactive),
    background var(--transition-interactive),
    border-color var(--transition-interactive);
}

/* ============================================================
   LAYOUT
   ============================================================ */

.container {
  width: 100%;
  max-width: var(--content-wide);
  margin-inline: auto;
  padding-inline: clamp(var(--space-6), 5vw, var(--space-12));
}

.section {
  padding-block: clamp(var(--space-16), 10vw, var(--space-32));
  border-top: 1px solid var(--color-divider);
}

/* ============================================================
   HEADER
   ============================================================ */

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  background: oklch(from var(--color-bg) l c h / 0.82);
  border-bottom: 1px solid transparent;
  transition: border-color var(--transition-interactive);
}
.site-header:has(+ main .hero:not(:hover)) {
  /* subtle divider only after scroll — kept minimal */
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-6);
  padding-block: var(--space-4);
}

.wordmark {
  display: inline-flex;
  align-items: center;
  gap: var(--space-3);
  font-family: var(--font-display);
  font-size: var(--text-base);
  font-weight: 500;
  letter-spacing: -0.005em;
  color: var(--color-text);
}
.wordmark svg {
  color: var(--color-primary);
}
.wordmark:hover {
  color: var(--color-primary);
}

.primary-nav {
  display: flex;
  gap: clamp(var(--space-5), 3vw, var(--space-8));
  font-size: var(--text-sm);
  color: var(--color-text-muted);
}
.primary-nav a:hover {
  color: var(--color-text);
}

.theme-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: var(--radius-sm);
  color: var(--color-text-muted);
}
.theme-toggle:hover {
  color: var(--color-text);
  background: var(--color-surface-2);
}

/* ============================================================
   HERO
   ============================================================ */

.hero {
  padding-block: clamp(var(--space-20), 14vw, var(--space-32));
}

.hero-inner {
  max-width: 62rem;
}

.eyebrow {
  display: inline-block;
  font-size: var(--text-xs);
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  margin-bottom: var(--space-8);
  padding-bottom: var(--space-3);
  border-bottom: 1px solid var(--color-border);
}

.hero-title {
  font-size: var(--text-3xl);
  font-weight: 500;
  letter-spacing: -0.02em;
  color: var(--color-text);
  margin-bottom: var(--space-8);
  max-width: 22ch;
}

.hero-lede {
  font-size: var(--text-lg);
  line-height: 1.55;
  color: var(--color-text-muted);
  max-width: 58ch;
  font-weight: 400;
}

/* ============================================================
   SECTION HEADS
   ============================================================ */

.section-label {
  font-size: var(--text-xs);
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  margin-bottom: var(--space-5);
}

.section-title {
  font-size: var(--text-xl);
  font-weight: 500;
  color: var(--color-text);
  margin-bottom: var(--space-12);
  max-width: 24ch;
  letter-spacing: -0.015em;
}

/* ============================================================
   RESEARCH — pillars grid
   ============================================================ */

.pillars {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(100%, 260px), 1fr));
  gap: var(--space-10);
  border-top: 1px solid var(--color-border);
  padding-top: var(--space-10);
}

.pillar {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

.pillar-index {
  font-family: var(--font-display);
  font-size: var(--text-base);
  color: var(--color-primary);
  letter-spacing: 0.02em;
}

.pillar-title {
  font-size: var(--text-lg);
  font-family: var(--font-body);
  font-weight: 500;
  color: var(--color-text);
  letter-spacing: -0.01em;
}

.pillar-body {
  font-size: var(--text-base);
  color: var(--color-text-muted);
  line-height: 1.6;
  max-width: 42ch;
}

/* ============================================================
   APPROACH
   ============================================================ */

.section-approach {
  background: var(--color-surface);
}
[data-theme='dark'] .section-approach {
  background: var(--color-surface);
}

.approach-inner {
  max-width: 62rem;
}

.approach-body {
  display: grid;
  gap: var(--space-6);
  color: var(--color-text);
  font-size: var(--text-base);
  line-height: 1.7;
}
.approach-body p {
  max-width: 68ch;
  color: var(--color-text);
}
.approach-body p + p {
  color: var(--color-text-muted);
}

/* ============================================================
   CONTACT
   ============================================================ */

.contact-inner {
  max-width: 62rem;
}

.contact-title {
  font-family: var(--font-display);
  font-size: var(--text-xl);
  font-weight: 500;
  color: var(--color-text);
  line-height: 1.35;
  letter-spacing: -0.01em;
  margin-bottom: var(--space-8);
  max-width: 32ch;
}

.contact-email {
  color: var(--color-primary);
  border-bottom: 1px solid oklch(from var(--color-primary) l c h / 0.35);
  padding-bottom: 2px;
  word-break: break-all;
}
.contact-email:hover {
  color: var(--color-primary-hover);
  border-bottom-color: var(--color-primary-hover);
}

.contact-note {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  max-width: 56ch;
  line-height: 1.6;
}

/* ============================================================
   FOOTER
   ============================================================ */

.site-footer {
  border-top: 1px solid var(--color-divider);
  padding-block: var(--space-10);
}

.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-6);
  flex-wrap: wrap;
}

.footer-mark {
  display: inline-flex;
  align-items: center;
  gap: var(--space-3);
  font-family: var(--font-display);
  font-size: var(--text-sm);
  color: var(--color-text);
}
.footer-mark svg {
  color: var(--color-primary);
}

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

/* ============================================================
   RESPONSIVE
   ============================================================ */

@media (max-width: 640px) {
  .primary-nav {
    gap: var(--space-4);
  }
  .wordmark span {
    display: none;
  }
  .footer-inner {
    flex-direction: column;
    align-items: flex-start;
  }
}

/* ============================================================
   Current work — essay cards
   ============================================================ */
.section-work {
  background: var(--color-surface);
  border-top: 1px solid var(--color-divider);
  border-bottom: 1px solid var(--color-divider);
}
.section-lede {
  font-family: var(--font-body);
  font-size: var(--text-base);
  color: var(--color-text-muted);
  max-width: 62ch;
  margin: 0 0 var(--space-16) 0;
  line-height: 1.65;
}
.essays {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: var(--space-12);
}
.essay-card {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}
.essay-figure {
  aspect-ratio: 16 / 9;
  background: var(--color-surface-2);
  border: 1px solid var(--color-divider);
  overflow: hidden;
  border-radius: var(--radius-sm);
  margin-bottom: var(--space-3);
}
.essay-figure img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.essay-figure-plain {
  background:
    linear-gradient(135deg, transparent 47%, var(--color-primary) 47%, var(--color-primary) 48%, transparent 48%),
    linear-gradient(45deg, transparent 47%, var(--color-primary) 47%, var(--color-primary) 48%, transparent 48%),
    var(--color-surface-2);
  background-size: 32px 32px;
  opacity: 0.9;
}
[data-theme='dark'] .essay-figure img {
  /* light-mode svg exports become subtle in dark mode */
  filter: invert(0.92) hue-rotate(180deg) contrast(0.85);
  opacity: 0.7;
}
.essay-meta {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  font-family: var(--font-body);
  font-size: var(--text-xs);
  text-transform: uppercase;
  letter-spacing: 0.08em;
}
.essay-tag {
  color: var(--color-primary);
  font-weight: 500;
}
.essay-status {
  color: var(--color-text-faint);
  padding-left: var(--space-3);
  border-left: 1px solid var(--color-divider);
}
.essay-title {
  font-family: var(--font-display);
  font-size: var(--text-lg);
  font-weight: 500;
  color: var(--color-text);
  margin: var(--space-2) 0 0 0;
  line-height: 1.2;
  letter-spacing: -0.01em;
}
.essay-body {
  font-family: var(--font-body);
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  line-height: 1.6;
  margin: 0;
  max-width: 42ch;
}