/* Memory - Personal Language Models Website */
/* Accessible, responsive design with purple/neural theme */

/* CSS Custom Properties for theming */
:root {
  /* Colors - Memory uses purple/violet for neural/brain theme */
  --color-primary: #8b5cf6;
  --color-primary-dark: #7c3aed;
  --color-primary-light: #a78bfa;
  --color-secondary: #6366f1;
  --color-accent: #c084fc;

  --color-text: #1f2937;
  --color-text-light: #4b5563;
  --color-text-muted: #6b7280;

  --color-bg: #ffffff;
  --color-bg-alt: #f9fafb;
  --color-bg-code: #f3f4f6;
  --color-border: #e5e7eb;

  --color-success: #059669;
  --color-warning: #d97706;
  --color-error: #dc2626;

  /* Typography */
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', 'Consolas', monospace;

  /* Spacing */
  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;
  --space-2xl: 3rem;
  --space-3xl: 4rem;

  /* Container */
  --container-max: 1200px;
  --container-narrow: 800px;

  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-normal: 250ms ease;

  /* Focus ring */
  --focus-ring: 0 0 0 3px rgba(139, 92, 246, 0.5);

  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1);
}

/* Dark mode support */
@media (prefers-color-scheme: dark) {
  :root {
    --color-text: #f9fafb;
    --color-text-light: #d1d5db;
    --color-text-muted: #9ca3af;

    --color-bg: #111827;
    --color-bg-alt: #1f2937;
    --color-bg-code: #374151;
    --color-border: #374151;

    --color-primary: #a78bfa;
    --color-primary-dark: #8b5cf6;
    --color-primary-light: #c4b5fd;
  }
}

/* Reset and base styles */
*,
*::before,
*::after {
  box-sizing: border-box;
}

* {
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  font-size: 100%;
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

body {
  font-family: var(--font-sans);
  font-size: 1rem;
  line-height: 1.6;
  color: var(--color-text);
  background-color: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* Skip link for accessibility */
.skip-link {
  position: absolute;
  top: -40px;
  left: 0;
  background: var(--color-primary);
  color: white;
  padding: var(--space-sm) var(--space-md);
  z-index: 1000;
  text-decoration: none;
  font-weight: 600;
}

.skip-link:focus {
  top: 0;
}

/* Focus styles */
:focus {
  outline: none;
  box-shadow: var(--focus-ring);
}

:focus:not(:focus-visible) {
  box-shadow: none;
}

:focus-visible {
  box-shadow: var(--focus-ring);
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  line-height: 1.3;
  color: var(--color-text);
}

h1 {
  font-size: clamp(2rem, 5vw, 3rem);
  margin-bottom: var(--space-lg);
}

h2 {
  font-size: clamp(1.5rem, 4vw, 2.25rem);
  margin-bottom: var(--space-md);
}

h3 {
  font-size: clamp(1.25rem, 3vw, 1.5rem);
  margin-bottom: var(--space-sm);
}

h4 {
  font-size: 1.125rem;
  margin-bottom: var(--space-sm);
}

p {
  margin-bottom: var(--space-md);
  max-width: 70ch;
}

a {
  color: var(--color-primary);
  text-decoration: underline;
  text-underline-offset: 2px;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--color-primary-dark);
}

/* Lists */
ul, ol {
  padding-left: var(--space-lg);
  margin-bottom: var(--space-md);
}

li {
  margin-bottom: var(--space-xs);
}

/* Code */
code {
  font-family: var(--font-mono);
  font-size: 0.9em;
  background: var(--color-bg-code);
  padding: 0.125em 0.375em;
  border-radius: 4px;
}

pre {
  font-family: var(--font-mono);
  font-size: 0.875rem;
  background: var(--color-bg-code);
  padding: var(--space-md);
  border-radius: 8px;
  overflow-x: auto;
  margin-bottom: var(--space-lg);
  border: 1px solid var(--color-border);
}

pre code {
  background: none;
  padding: 0;
}

/* Container */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--space-md);
}

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

/* Header */
.header {
  position: sticky;
  top: 0;
  background: var(--color-bg);
  border-bottom: 1px solid var(--color-border);
  z-index: 100;
}

.header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.header__logo {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-text);
  text-decoration: none;
}

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

.header__logo-icon {
  width: 36px;
  height: 36px;
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-accent) 100%);
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 0.875rem;
  color: white;
}

/* Navigation */
.nav {
  display: flex;
  align-items: center;
  gap: var(--space-lg);
}

.nav__list {
  display: flex;
  list-style: none;
  gap: var(--space-md);
  padding: 0;
  margin: 0;
}

.nav__link {
  color: var(--color-text-light);
  text-decoration: none;
  font-weight: 500;
  padding: var(--space-xs) var(--space-sm);
  border-radius: 4px;
  transition: all var(--transition-fast);
}

.nav__link:hover,
.nav__link[aria-current="page"] {
  color: var(--color-primary);
  background: var(--color-bg-alt);
}

/* Mobile menu toggle */
.nav__toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--space-sm);
  color: var(--color-text);
}

.nav__toggle-icon {
  width: 24px;
  height: 24px;
}

@media (max-width: 768px) {
  .nav__toggle {
    display: block;
  }

  .nav__list {
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    flex-direction: column;
    background: var(--color-bg);
    border-bottom: 1px solid var(--color-border);
    padding: var(--space-md);
    gap: var(--space-sm);
    display: none;
  }

  .nav__list[data-open="true"] {
    display: flex;
  }

  .nav__link {
    display: block;
    padding: var(--space-sm);
  }
}

/* Hero section */
.hero {
  padding: var(--space-3xl) 0;
  background: linear-gradient(135deg, var(--color-bg-alt) 0%, var(--color-bg) 100%);
}

.hero__content {
  max-width: 800px;
}

.hero__tagline {
  display: inline-block;
  background: var(--color-primary);
  color: white;
  padding: var(--space-xs) var(--space-sm);
  border-radius: 4px;
  font-size: 0.875rem;
  font-weight: 600;
  margin-bottom: var(--space-md);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.hero__title {
  margin-bottom: var(--space-md);
}

.hero__description {
  font-size: 1.25rem;
  color: var(--color-text-light);
  margin-bottom: var(--space-xl);
}

.hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-md);
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  padding: var(--space-sm) var(--space-lg);
  font-size: 1rem;
  font-weight: 600;
  text-decoration: none;
  border-radius: 8px;
  border: 2px solid transparent;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.btn--primary {
  background: var(--color-primary);
  color: white;
}

.btn--primary:hover {
  background: var(--color-primary-dark);
  color: white;
}

.btn--secondary {
  background: transparent;
  color: var(--color-primary);
  border-color: var(--color-primary);
}

.btn--secondary:hover {
  background: var(--color-primary);
  color: white;
}

.btn--ghost {
  background: transparent;
  color: var(--color-text-light);
  border-color: var(--color-border);
}

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

.btn--large {
  padding: var(--space-md) var(--space-xl);
  font-size: 1.125rem;
}

/* Section styles */
.section {
  padding: var(--space-3xl) 0;
}

.section--alt {
  background: var(--color-bg-alt);
}

.section--dark {
  background: linear-gradient(135deg, #1f2937 0%, #111827 100%);
  color: #f9fafb;
}

.section--dark h2,
.section--dark h3 {
  color: #f9fafb;
}

.section--dark p {
  color: #d1d5db;
}

.section__header {
  text-align: center;
  margin-bottom: var(--space-2xl);
}

.section__title {
  margin-bottom: var(--space-sm);
}

.section__description {
  font-size: 1.125rem;
  color: var(--color-text-light);
  max-width: 600px;
  margin: 0 auto;
}

.section--dark .section__description {
  color: #d1d5db;
}

/* Problem cards grid */
.problem-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--space-xl);
}

.problem-card {
  background: var(--color-bg);
  padding: var(--space-xl);
  border-radius: 12px;
  border: 1px solid var(--color-border);
  text-align: center;
  transition: box-shadow var(--transition-normal);
}

.problem-card:hover {
  box-shadow: var(--shadow-lg);
}

.problem-card__icon {
  width: 48px;
  height: 48px;
  margin: 0 auto var(--space-md);
  color: var(--color-primary);
}

.problem-card__icon svg {
  width: 100%;
  height: 100%;
}

.problem-card h3 {
  margin-bottom: var(--space-sm);
}

.problem-card p {
  color: var(--color-text-light);
  margin: 0;
}

/* Vision diagram */
.vision-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-2xl);
  align-items: center;
}

@media (max-width: 900px) {
  .vision-content {
    grid-template-columns: 1fr;
  }
}

.vision-diagram {
  position: relative;
  width: 100%;
  aspect-ratio: 1;
  max-width: 400px;
  margin: 0 auto;
}

.vision-diagram__center {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 120px;
  height: 120px;
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-accent) 100%);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-weight: 700;
  font-size: 1rem;
  text-align: center;
  z-index: 2;
  box-shadow: 0 10px 40px rgba(139, 92, 246, 0.3);
}

.vision-diagram__orbit {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 90%;
  height: 90%;
  border: 2px dashed var(--color-border);
  border-radius: 50%;
  animation: rotate 30s linear infinite;
}

@keyframes rotate {
  from { transform: translate(-50%, -50%) rotate(0deg); }
  to { transform: translate(-50%, -50%) rotate(360deg); }
}

@media (prefers-reduced-motion: reduce) {
  .vision-diagram__orbit {
    animation: none;
  }
}

.vision-diagram__node {
  position: absolute;
  width: 50px;
  height: 50px;
  background: var(--color-bg);
  border: 2px solid var(--color-primary);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-primary);
  animation: counter-rotate 30s linear infinite;
}

@keyframes counter-rotate {
  from { transform: rotate(0deg); }
  to { transform: rotate(-360deg); }
}

@media (prefers-reduced-motion: reduce) {
  .vision-diagram__node {
    animation: none;
  }
}

.vision-diagram__node svg {
  width: 24px;
  height: 24px;
}

.vision-diagram__node:nth-child(1) {
  top: 0;
  left: 50%;
  transform: translateX(-50%);
}

.vision-diagram__node:nth-child(2) {
  top: 50%;
  right: 0;
  transform: translateY(-50%);
}

.vision-diagram__node:nth-child(3) {
  bottom: 0;
  left: 50%;
  transform: translateX(-50%);
}

.vision-diagram__node:nth-child(4) {
  top: 50%;
  left: 0;
  transform: translateY(-50%);
}

.vision-features {
  display: grid;
  gap: var(--space-lg);
}

.vision-feature h3 {
  color: var(--color-primary);
  margin-bottom: var(--space-xs);
  font-size: 1.125rem;
}

.vision-feature p {
  color: var(--color-text-light);
  margin: 0;
  font-size: 0.9375rem;
}

/* Comparison section */
.comparison {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  gap: var(--space-lg);
  align-items: start;
}

@media (max-width: 900px) {
  .comparison {
    grid-template-columns: 1fr;
  }
}

.comparison__item {
  background: var(--color-bg);
  border-radius: 12px;
  padding: var(--space-lg);
  border: 1px solid var(--color-border);
}

.comparison__title {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: var(--space-md);
  padding: var(--space-sm) var(--space-md);
  border-radius: 6px;
  text-align: center;
}

.comparison__title--before {
  background: #fef2f2;
  color: #991b1b;
}

.comparison__title--after {
  background: #f0fdf4;
  color: #166534;
}

@media (prefers-color-scheme: dark) {
  .comparison__title--before {
    background: #450a0a;
    color: #fca5a5;
  }

  .comparison__title--after {
    background: #052e16;
    color: #86efac;
  }
}

.comparison__divider {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-2xl) var(--space-md);
}

.comparison__divider span {
  background: var(--color-primary);
  color: white;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 0.875rem;
}

@media (max-width: 900px) {
  .comparison__divider {
    padding: var(--space-md);
  }
}

/* Chat examples */
.chat-example {
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

.chat-message {
  padding: var(--space-md);
  border-radius: 8px;
  font-size: 0.9375rem;
  line-height: 1.5;
}

.chat-message--user {
  background: var(--color-bg-alt);
  border: 1px solid var(--color-border);
}

.chat-message--ai {
  background: var(--color-bg-code);
  border: 1px solid var(--color-border);
}

.chat-message--enhanced {
  border-color: var(--color-primary);
  background: rgba(139, 92, 246, 0.05);
}

.chat-message strong {
  display: block;
  margin-bottom: var(--space-xs);
  font-size: 0.8125rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.chat-message__note {
  display: block;
  margin-top: var(--space-md);
  padding-top: var(--space-sm);
  border-top: 1px dashed var(--color-border);
  font-size: 0.8125rem;
  color: var(--color-text-muted);
  font-style: italic;
}

/* Architecture preview */
.architecture-preview {
  max-width: 600px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

.arch-layer {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: 12px;
  padding: var(--space-lg);
  text-align: center;
}

.arch-layer--highlight {
  background: linear-gradient(135deg, rgba(139, 92, 246, 0.1) 0%, rgba(192, 132, 252, 0.1) 100%);
  border-color: var(--color-primary);
}

.arch-layer__header {
  margin-bottom: var(--space-md);
}

.arch-layer__label {
  font-weight: 600;
  font-size: 0.875rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-text-muted);
}

.arch-layer--highlight .arch-layer__label {
  color: var(--color-primary);
}

.arch-layer__items {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--space-sm);
}

.arch-item {
  background: var(--color-bg-alt);
  padding: var(--space-xs) var(--space-md);
  border-radius: 20px;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--color-text-light);
  border: 1px solid var(--color-border);
}

.arch-item--primary {
  background: var(--color-primary);
  color: white;
  border-color: var(--color-primary);
}

.arch-connector {
  display: flex;
  justify-content: center;
  color: var(--color-text-muted);
}

.arch-connector svg {
  width: 24px;
  height: 24px;
}

/* Stats */
.stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: var(--space-xl);
  text-align: center;
}

.stat__value {
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--color-primary);
  line-height: 1;
  margin-bottom: var(--space-xs);
}

.stat__label {
  color: var(--color-text-light);
  font-weight: 500;
}

/* Research grid */
.research-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--space-lg);
}

.research-card {
  display: block;
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: 12px;
  padding: var(--space-xl);
  text-decoration: none;
  color: inherit;
  transition: all var(--transition-normal);
}

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

.research-card h3 {
  color: var(--color-text);
  margin-bottom: var(--space-sm);
  transition: color var(--transition-fast);
}

.research-card:hover h3 {
  color: var(--color-primary);
}

.research-card p {
  color: var(--color-text-light);
  margin-bottom: var(--space-md);
  font-size: 0.9375rem;
}

.research-card__link {
  color: var(--color-primary);
  font-weight: 600;
  font-size: 0.875rem;
}

/* CTA section */
.cta-content {
  text-align: center;
  max-width: 700px;
  margin: 0 auto;
}

.cta-content h2 {
  margin-bottom: var(--space-md);
}

.cta-content p {
  margin: 0 auto var(--space-xl);
  max-width: 600px;
}

.cta-actions {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--space-md);
}

.section--dark .btn--ghost {
  color: #d1d5db;
  border-color: #4b5563;
}

.section--dark .btn--ghost:hover {
  background: rgba(255, 255, 255, 0.1);
  color: white;
  border-color: #9ca3af;
}

/* Footer */
.footer {
  background: var(--color-bg-alt);
  border-top: 1px solid var(--color-border);
  padding: var(--space-2xl) 0;
}

.footer__grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: var(--space-xl);
  margin-bottom: var(--space-xl);
}

.footer__title {
  font-size: 0.875rem;
  font-weight: 600;
  margin-bottom: var(--space-md);
}

.footer__list {
  list-style: none;
  padding: 0;
}

.footer__link {
  color: var(--color-text-light);
  text-decoration: none;
  display: block;
  padding: var(--space-xs) 0;
  font-size: 0.9375rem;
  transition: color var(--transition-fast);
}

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

.footer__bottom {
  text-align: center;
  padding-top: var(--space-xl);
  border-top: 1px solid var(--color-border);
  color: var(--color-text-muted);
  font-size: 0.875rem;
}

.footer__bottom a {
  color: var(--color-primary);
}

/* Callout boxes */
.callout {
  padding: var(--space-lg);
  border-radius: 8px;
  margin: var(--space-lg) 0;
  border-left: 4px solid;
}

.callout--info {
  background: rgba(139, 92, 246, 0.1);
  border-color: var(--color-primary);
}

.callout--success {
  background: rgba(5, 150, 105, 0.1);
  border-color: var(--color-success);
}

.callout--warning {
  background: rgba(217, 119, 6, 0.1);
  border-color: var(--color-warning);
}

.callout__title {
  font-weight: 600;
  margin-bottom: var(--space-sm);
  color: var(--color-primary);
}

/* Page content */
.page-header {
  padding: var(--space-2xl) 0;
  background: var(--color-bg-alt);
  border-bottom: 1px solid var(--color-border);
}

.page-content {
  padding: var(--space-2xl) 0;
}

.page-content h2 {
  margin-top: var(--space-2xl);
  padding-top: var(--space-xl);
  border-top: 1px solid var(--color-border);
}

.page-content h2:first-of-type {
  margin-top: 0;
  padding-top: 0;
  border-top: none;
}

/* Feature grid */
.features {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--space-xl);
}

.feature {
  background: var(--color-bg);
  padding: var(--space-xl);
  border-radius: 12px;
  border: 1px solid var(--color-border);
  transition: box-shadow var(--transition-normal);
}

.feature:hover {
  box-shadow: var(--shadow-lg);
}

.feature__icon {
  width: 48px;
  height: 48px;
  color: var(--color-primary);
  margin-bottom: var(--space-md);
}

.feature__title {
  margin-bottom: var(--space-sm);
}

.feature__description {
  color: var(--color-text-light);
  margin: 0;
}

/* Code examples */
.code-example {
  background: var(--color-bg-code);
  border-radius: 12px;
  overflow: hidden;
  border: 1px solid var(--color-border);
  margin: var(--space-lg) 0;
}

.code-example__header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-sm) var(--space-md);
  background: var(--color-border);
  font-size: 0.875rem;
  font-weight: 500;
}

.code-example__dots {
  display: flex;
  gap: 6px;
}

.code-example__dot {
  width: 12px;
  height: 12px;
  border-radius: 50%;
}

.code-example__dot--red { background: #ef4444; }
.code-example__dot--yellow { background: #eab308; }
.code-example__dot--green { background: #22c55e; }

.code-example pre {
  margin: 0;
  border: none;
  border-radius: 0;
}

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

/* Print styles */
@media print {
  .header,
  .footer,
  .nav,
  .skip-link {
    display: none;
  }

  body {
    font-size: 12pt;
    line-height: 1.5;
  }

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

  a[href]::after {
    content: " (" attr(href) ")";
    font-size: 0.8em;
  }
}