/* ============================================================
   STILLSTONE VAULT — Global Stylesheet
   Monochrome: #0A0A0A background, #F0F0F0 text, #A0A0A0 muted
   Primary: Inter (body/UI), IBM Plex Sans (structural headings)
   Dark mode is the default and only mode
   ============================================================ */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600&family=IBM+Plex+Sans:wght@300;400;500;600;700&display=swap');

/* ========================================
   DESIGN TOKENS
======================================== */

:root {
  /* Typography */
  --font-body:    'Inter', system-ui, sans-serif;
  --font-display: 'IBM Plex Sans', 'Inter', system-ui, sans-serif;

  /* Type scale (fluid) */
  --text-xs:   clamp(0.75rem,  0.7rem  + 0.25vw, 0.8125rem);
  --text-sm:   clamp(0.8125rem,0.75rem + 0.3vw,  0.9375rem);
  --text-base: clamp(0.875rem, 0.8rem  + 0.35vw, 1rem);
  --text-lg:   clamp(1rem,     0.9rem  + 0.5vw,  1.25rem);
  --text-xl:   clamp(1.25rem,  1rem    + 1.25vw, 2rem);
  --text-2xl:  clamp(1.75rem,  1.2rem  + 2.75vw, 3.25rem);
  --text-3xl:  clamp(2.25rem,  1rem    + 5vw,    5rem);

  /* Spacing (4px base) */
  --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;

  /* Stillstone monochrome colour system */
  --color-bg:              #0A0A0A;
  --color-surface:         #111111;
  --color-surface-2:       #181818;
  --color-surface-offset:  #141414;
  --color-divider:         #232323;
  --color-border:          #2E2E2E;
  --color-border-subtle:   #1E1E1E;

  /* Text */
  --color-text:            #F0F0F0;
  --color-text-muted:      #A0A0A0;
  --color-text-faint:      #5A5A5A;
  --color-text-inverse:    #0A0A0A;

  /* Primary (white — for CTA outlines/fills) */
  --color-primary:         #F0F0F0;
  --color-primary-hover:   #FFFFFF;

  /* Content widths */
  --content-narrow:  640px;
  --content-default: 960px;
  --content-wide:    1200px;

  /* Radius — zero, institutional */
  --radius-sm: 0;
  --radius-md: 0;

  /* Transitions */
  --transition-ui: 180ms cubic-bezier(0.16, 1, 0.3, 1);

  /* Nav height */
  --nav-height: 64px;
}

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

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

html {
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
  scroll-behavior: smooth;
  hanging-punctuation: first last;
  scroll-padding-top: calc(var(--nav-height) + var(--space-8));
}

body {
  min-height: 100dvh;
  line-height: 1.6;
  font-family: var(--font-body);
  font-size: var(--text-base);
  color: var(--color-text);
  background-color: var(--color-bg);
}

img, picture, video, canvas, svg {
  display: block;
  max-width: 100%;
  height: auto;
}

ul[role="list"], ol[role="list"] { list-style: none; }
input, button, textarea, select { font: inherit; color: inherit; }

h1, h2, h3, h4, h5, h6 {
  text-wrap: balance;
  line-height: 1.15;
}

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

::selection {
  background: rgba(240, 240, 240, 0.15);
  color: var(--color-text);
}

:focus-visible {
  outline: 1px solid var(--color-border);
  outline-offset: 3px;
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

button { cursor: pointer; background: none; border: none; }
table { border-collapse: collapse; width: 100%; }

.sr-only {
  position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0, 0, 0, 0); white-space: nowrap; border-width: 0;
}

/* ========================================
   LOGO MARK (SVG inline — used in nav)
======================================== */

.logo-mark {
  display: inline-flex;
  flex-direction: column;
  border: 1px solid var(--color-border);
  padding: var(--space-2) var(--space-4);
  gap: 0;
  text-decoration: none;
  transition: border-color var(--transition-ui);
  flex-shrink: 0;
}

.logo-mark:hover {
  border-color: var(--color-text-muted);
}

.logo-line-1 {
  font-family: var(--font-display);
  font-size: 0.6rem;
  font-weight: 500;
  letter-spacing: 0.2em;
  color: var(--color-text);
  text-transform: uppercase;
  line-height: 1.2;
  white-space: nowrap;
}

.logo-line-2 {
  font-family: var(--font-display);
  font-size: 0.9rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  color: var(--color-text);
  text-transform: uppercase;
  line-height: 1.2;
  white-space: nowrap;
}

/* ========================================
   NAVIGATION
======================================== */

.site-nav {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--nav-height);
  background: var(--color-bg);
  border-bottom: 1px solid var(--color-divider);
  display: flex;
  align-items: center;
  padding: 0 clamp(var(--space-4), 4vw, var(--space-12));
  gap: var(--space-8);
  transition: border-color var(--transition-ui);
}

.nav-logo {
  margin-right: var(--space-4);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: var(--space-6);
  list-style: none;
  flex: 1;
}

.nav-links a {
  font-family: var(--font-body);
  font-size: var(--text-sm);
  font-weight: 400;
  color: var(--color-text-muted);
  text-decoration: none;
  letter-spacing: 0.01em;
  transition: color var(--transition-ui);
  white-space: nowrap;
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--color-text);
}

/* Dropdown nav */
.nav-dropdown {
  position: relative;
}

.nav-dropdown > a::after {
  content: '';
  display: inline-block;
  width: 0;
  height: 0;
  border-left: 3px solid transparent;
  border-right: 3px solid transparent;
  border-top: 4px solid var(--color-text-faint);
  margin-left: var(--space-2);
  vertical-align: middle;
  transition: transform var(--transition-ui);
}

.nav-dropdown:hover > a::after {
  transform: rotate(180deg);
}

.nav-dropdown-menu {
  position: absolute;
  top: calc(100% + var(--space-3));
  left: 0;
  min-width: 240px;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  padding: var(--space-2) 0;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--transition-ui);
  z-index: 200;
}

.nav-dropdown:hover .nav-dropdown-menu,
.nav-dropdown:focus-within .nav-dropdown-menu {
  opacity: 1;
  pointer-events: auto;
}

.nav-dropdown-menu a {
  display: block;
  padding: var(--space-3) var(--space-5);
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  text-decoration: none;
  transition: color var(--transition-ui), background var(--transition-ui);
  letter-spacing: 0.01em;
}

.nav-dropdown-menu a:hover {
  color: var(--color-text);
  background: var(--color-surface-2);
}

.nav-spacer { flex: 1; }

.nav-cta {
  font-family: var(--font-body);
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--color-text);
  border: 1px solid var(--color-border);
  padding: var(--space-2) var(--space-5);
  text-decoration: none;
  letter-spacing: 0.04em;
  white-space: nowrap;
  flex-shrink: 0;
  transition: background var(--transition-ui), border-color var(--transition-ui), color var(--transition-ui);
}

.nav-cta:hover {
  background: var(--color-text);
  color: var(--color-text-inverse);
  border-color: var(--color-text);
}

/* Mobile nav toggle */
.nav-hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: var(--space-2);
  margin-left: auto;
}

.nav-hamburger span {
  display: block;
  width: 22px;
  height: 1px;
  background: var(--color-text-muted);
  transition: transform var(--transition-ui), opacity var(--transition-ui);
}

/* Mobile menu */
.nav-mobile {
  display: none;
  position: fixed;
  top: var(--nav-height);
  left: 0;
  right: 0;
  bottom: 0;
  background: var(--color-bg);
  border-top: 1px solid var(--color-divider);
  padding: var(--space-8) clamp(var(--space-4), 4vw, var(--space-12));
  z-index: 99;
  overflow-y: auto;
  flex-direction: column;
  gap: 0;
}

.nav-mobile.open {
  display: flex;
}

.nav-mobile a {
  font-size: var(--text-base);
  font-weight: 400;
  color: var(--color-text-muted);
  text-decoration: none;
  padding: var(--space-4) 0;
  border-bottom: 1px solid var(--color-divider);
  transition: color var(--transition-ui);
}

.nav-mobile a:hover { color: var(--color-text); }

.nav-mobile-sub a {
  padding-left: var(--space-4);
  font-size: var(--text-sm);
}

.nav-mobile-cta {
  margin-top: var(--space-8);
  display: inline-block;
  font-size: var(--text-base);
  font-weight: 500;
  color: var(--color-text) !important;
  border: 1px solid var(--color-border);
  padding: var(--space-4) var(--space-8);
  text-align: center;
  letter-spacing: 0.04em;
}

@media (max-width: 900px) {
  .nav-links { display: none; }
  .nav-spacer { display: none; }
  .nav-cta { display: none; }
  .nav-hamburger { display: flex; }
}

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

.page-wrapper {
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
}

main { flex: 1; }

.container {
  max-width: var(--content-default);
  margin-inline: auto;
  padding-inline: clamp(var(--space-4), 4vw, var(--space-12));
}

.container--narrow {
  max-width: var(--content-narrow);
  margin-inline: auto;
  padding-inline: clamp(var(--space-4), 4vw, var(--space-12));
}

.container--wide {
  max-width: var(--content-wide);
  margin-inline: auto;
  padding-inline: clamp(var(--space-4), 4vw, var(--space-12));
}

/* ========================================
   SECTIONS
======================================== */

.section {
  padding-block: clamp(var(--space-12), 8vw, var(--space-24));
  border-bottom: 1px solid var(--color-divider);
}

.section:last-of-type {
  border-bottom: none;
}

.section--hero {
  padding-block: clamp(var(--space-16), 12vw, var(--space-32));
  border-bottom: 1px solid var(--color-divider);
}

.section--tight {
  padding-block: clamp(var(--space-8), 5vw, var(--space-16));
  border-bottom: 1px solid var(--color-divider);
}

/* ========================================
   TYPOGRAPHY COMPONENTS
======================================== */

.overline {
  font-family: var(--font-body);
  font-size: var(--text-xs);
  font-weight: 500;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-text-faint);
  margin-bottom: var(--space-4);
  display: block;
}

.page-title {
  font-family: var(--font-display);
  font-size: var(--text-2xl);
  font-weight: 300;
  color: var(--color-text);
  line-height: 1.1;
  letter-spacing: -0.01em;
  margin-bottom: var(--space-6);
}

.page-subtitle {
  font-family: var(--font-body);
  font-size: var(--text-base);
  font-weight: 400;
  color: var(--color-text-muted);
  max-width: 60ch;
  line-height: 1.65;
}

.section-heading {
  font-family: var(--font-display);
  font-size: var(--text-xl);
  font-weight: 400;
  color: var(--color-text);
  line-height: 1.15;
  letter-spacing: -0.005em;
  margin-bottom: var(--space-5);
}

.sub-heading {
  font-family: var(--font-display);
  font-size: var(--text-lg);
  font-weight: 500;
  color: var(--color-text);
  line-height: 1.2;
  margin-bottom: var(--space-4);
}

.body-text {
  font-family: var(--font-body);
  font-size: var(--text-base);
  color: var(--color-text-muted);
  line-height: 1.65;
  max-width: 68ch;
}

.body-text + .body-text {
  margin-top: var(--space-4);
}

.body-text--primary {
  color: var(--color-text);
}

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

.hero {
  padding-block: clamp(var(--space-20), 14vw, var(--space-32));
  border-bottom: 1px solid var(--color-divider);
}

.hero-title {
  font-family: var(--font-display);
  font-size: var(--text-2xl);
  font-weight: 300;
  color: var(--color-text);
  line-height: 1.1;
  letter-spacing: -0.02em;
  max-width: 16ch;
  margin-bottom: var(--space-8);
}

.hero-body {
  font-family: var(--font-body);
  font-size: var(--text-base);
  color: var(--color-text-muted);
  line-height: 1.7;
  max-width: 54ch;
  margin-bottom: var(--space-4);
}

.hero-note {
  font-family: var(--font-body);
  font-size: var(--text-sm);
  color: var(--color-text-faint);
  line-height: 1.6;
  max-width: 54ch;
  margin-top: var(--space-6);
}

/* ========================================
   CONTENT BLOCKS
======================================== */

/* Two-column content block */
.content-cols {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: clamp(var(--space-8), 5vw, var(--space-16));
  align-items: start;
}

@media (max-width: 768px) {
  .content-cols { grid-template-columns: 1fr; }
}

/* Section label + content */
.content-block {
  display: grid;
  grid-template-columns: 200px 1fr;
  gap: var(--space-8);
  align-items: start;
  padding: var(--space-8) 0;
  border-bottom: 1px solid var(--color-divider);
}

.content-block:first-of-type { border-top: 1px solid var(--color-divider); }
.content-block:last-of-type { border-bottom: none; }

.content-block-label {
  font-family: var(--font-body);
  font-size: var(--text-xs);
  font-weight: 500;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-text-faint);
  padding-top: 0.2em;
}

@media (max-width: 640px) {
  .content-block {
    grid-template-columns: 1fr;
    gap: var(--space-3);
  }
}

/* List items */
.feature-list {
  list-style: none;
  margin: var(--space-4) 0;
}

.feature-list li {
  font-family: var(--font-body);
  font-size: var(--text-base);
  color: var(--color-text-muted);
  padding: var(--space-3) 0;
  border-bottom: 1px solid var(--color-divider);
  display: flex;
  align-items: baseline;
  gap: var(--space-3);
  max-width: 100%;
}

.feature-list li:last-child { border-bottom: none; }

.feature-list li::before {
  content: '—';
  color: var(--color-text-faint);
  flex-shrink: 0;
  font-size: var(--text-xs);
}

/* ========================================
   BUTTONS
======================================== */

.btn {
  display: inline-block;
  font-family: var(--font-body);
  font-size: var(--text-sm);
  font-weight: 500;
  letter-spacing: 0.04em;
  text-decoration: none;
  cursor: pointer;
  border: 1px solid var(--color-border);
  background: transparent;
  padding: var(--space-3) var(--space-8);
  color: var(--color-text);
  transition: background var(--transition-ui),
              color var(--transition-ui),
              border-color var(--transition-ui);
  white-space: nowrap;
}

.btn:hover {
  background: var(--color-text);
  color: var(--color-text-inverse);
  border-color: var(--color-text);
}

.btn--outline {
  border-color: var(--color-text);
}

.btn--muted {
  color: var(--color-text-muted);
  border-color: var(--color-border);
}

.btn--muted:hover {
  color: var(--color-text);
  background: transparent;
  border-color: var(--color-text-muted);
}

/* ========================================
   PRICING TABLE
======================================== */

.pricing-table {
  width: 100%;
  border-top: 1px solid var(--color-border);
  margin: var(--space-6) 0;
}

.pricing-row {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  padding: var(--space-5) 0;
  border-bottom: 1px solid var(--color-divider);
  gap: var(--space-4);
}

.pricing-item {
  font-family: var(--font-body);
  font-size: var(--text-base);
  color: var(--color-text);
  flex: 1;
}

.pricing-item-sub {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  display: block;
  margin-top: var(--space-1);
}

.pricing-amount {
  font-family: var(--font-display);
  font-size: var(--text-base);
  font-weight: 500;
  color: var(--color-text-muted);
  white-space: nowrap;
}

/* ========================================
   PAGE HEADER (inner pages)
======================================== */

.page-header {
  padding-block: clamp(var(--space-12), 8vw, var(--space-20));
  border-bottom: 1px solid var(--color-divider);
}

.page-breadcrumb {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-bottom: var(--space-6);
}

.page-breadcrumb a {
  color: var(--color-text-faint);
  text-decoration: none;
  transition: color var(--transition-ui);
}

.page-breadcrumb a:hover { color: var(--color-text-muted); }
.page-breadcrumb span { margin: 0 var(--space-2); }

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

.site-footer {
  border-top: 1px solid var(--color-divider);
  padding-block: clamp(var(--space-8), 5vw, var(--space-16));
  background: var(--color-bg);
}

.footer-inner {
  max-width: var(--content-default);
  margin-inline: auto;
  padding-inline: clamp(var(--space-4), 4vw, var(--space-12));
}

.footer-top {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: var(--space-8);
  margin-bottom: var(--space-8);
  padding-bottom: var(--space-8);
  border-bottom: 1px solid var(--color-divider);
  flex-wrap: wrap;
}

.footer-tagline {
  font-size: var(--text-sm);
  color: var(--color-text-faint);
  margin-top: var(--space-3);
  max-width: 36ch;
  line-height: 1.5;
}

.footer-cta-section {
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: var(--space-3);
}

@media (max-width: 640px) {
  .footer-cta-section { align-items: flex-start; }
}

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

.footer-links {
  display: flex;
  gap: var(--space-5);
  list-style: none;
  flex-wrap: wrap;
}

.footer-links a {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  text-decoration: none;
  letter-spacing: 0.02em;
  transition: color var(--transition-ui);
}

.footer-links a:hover { color: var(--color-text-muted); }

.footer-copy {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  letter-spacing: 0.02em;
}

/* ========================================
   LEGAL PAGES
======================================== */

.legal-page {
  padding-block: clamp(var(--space-12), 8vw, var(--space-24));
}

.legal-content {
  max-width: var(--content-narrow);
}

.legal-content h2 {
  font-family: var(--font-display);
  font-size: var(--text-lg);
  font-weight: 500;
  color: var(--color-text);
  margin-top: var(--space-10);
  margin-bottom: var(--space-4);
  padding-bottom: var(--space-3);
  border-bottom: 1px solid var(--color-divider);
}

.legal-content h2:first-of-type { margin-top: var(--space-6); }

.legal-content p {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  line-height: 1.7;
  margin-bottom: var(--space-4);
}

.legal-content a {
  color: var(--color-text-muted);
  text-decoration: underline;
  text-decoration-color: var(--color-border);
  transition: color var(--transition-ui);
}

.legal-content a:hover {
  color: var(--color-text);
}

.legal-content ul {
  margin: var(--space-4) 0 var(--space-4) var(--space-4);
}

.legal-content ul li {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  line-height: 1.65;
  margin-bottom: var(--space-2);
  max-width: 100%;
}

.legal-notice {
  background: var(--color-surface);
  border: 1px solid var(--color-border-subtle);
  padding: var(--space-5) var(--space-6);
  margin-bottom: var(--space-8);
  font-size: var(--text-sm);
  color: var(--color-text-faint);
  line-height: 1.6;
}

/* ========================================
   PURCHASE PAGE
======================================== */

.purchase-panel {
  background: var(--color-surface);
  border: 1px solid var(--color-border-subtle);
  padding: clamp(var(--space-6), 4vw, var(--space-12));
  max-width: 600px;
}

.checkbox-label {
  display: flex;
  align-items: flex-start;
  gap: var(--space-3);
  cursor: pointer;
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  line-height: 1.6;
}

.checkbox-label input[type="checkbox"] {
  appearance: none;
  -webkit-appearance: none;
  width: 16px;
  height: 16px;
  min-width: 16px;
  border: 1px solid var(--color-border);
  background: transparent;
  cursor: pointer;
  margin-top: 2px;
  position: relative;
  transition: border-color var(--transition-ui), background var(--transition-ui);
}

.checkbox-label input[type="checkbox"]:checked {
  background: var(--color-text);
  border-color: var(--color-text);
}

.checkbox-label input[type="checkbox"]:checked::after {
  content: '';
  position: absolute;
  left: 4px;
  top: 1px;
  width: 5px;
  height: 9px;
  border-right: 1.5px solid var(--color-text-inverse);
  border-bottom: 1.5px solid var(--color-text-inverse);
  transform: rotate(45deg);
}

.checkbox-label a {
  color: var(--color-text-muted);
  text-decoration: underline;
  text-decoration-color: var(--color-border);
  transition: color var(--transition-ui);
}

.checkbox-label a:hover { color: var(--color-text); }

/* ========================================
   SITEMAP PAGE
======================================== */

.sitemap-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: var(--space-8);
  margin-top: var(--space-8);
}

.sitemap-section h3 {
  font-family: var(--font-display);
  font-size: var(--text-base);
  font-weight: 500;
  color: var(--color-text);
  margin-bottom: var(--space-4);
  padding-bottom: var(--space-3);
  border-bottom: 1px solid var(--color-divider);
}

.sitemap-section ul {
  list-style: none;
}

.sitemap-section ul li {
  max-width: 100%;
}

.sitemap-section ul li a {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  text-decoration: none;
  display: block;
  padding: var(--space-2) 0;
  border-bottom: 1px solid var(--color-border-subtle);
  transition: color var(--transition-ui);
}

.sitemap-section ul li a:hover { color: var(--color-text); }

/* ========================================
   SCROLL REVEAL ANIMATION (minimal)
======================================== */

.reveal {
  opacity: 0;
  transition: opacity 0.5s cubic-bezier(0.16, 1, 0.3, 1);
}

.reveal.visible {
  opacity: 1;
}