/* =============================================
   КОСМИЗМ TIMELINE — Custom Cosmic Palette
   Dark cosmic theme with golden accents
   ============================================= */

/* --- Fonts --- */
@import url('https://api.fontshare.com/v2/css?f[]=zodiak@400,500,700&f[]=general-sans@300,400,500,600,700&display=swap');

/* --- Design Tokens --- */
: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, 1.2rem + 2.5vw, 3.5rem);
  --text-3xl: clamp(2.5rem, 1rem + 4vw, 5rem);
  --text-hero: clamp(3rem, 0.5rem + 7vw, 8rem);

  /* 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: 'Zodiak', 'Georgia', serif;
  --font-body: 'General Sans', 'Helvetica Neue', sans-serif;

  /* Radius */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;

  /* Transitions */
  --transition-interactive: 180ms cubic-bezier(0.16, 1, 0.3, 1);
  --transition-slow: 600ms cubic-bezier(0.16, 1, 0.3, 1);

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

/* --- Dark Theme (default for cosmic feel) --- */
:root,
[data-theme='dark'] {
  --color-bg: #0a0b14;
  --color-surface: #10111c;
  --color-surface-2: #161828;
  --color-surface-offset: #1a1c30;
  --color-border: #2a2d48;
  --color-divider: #1e2038;
  
  --color-text: #e0dfd8;
  --color-text-muted: #8b8a82;
  --color-text-faint: #555468;
  
  /* Gold accent — cosmic/alchemical */
  --color-primary: #d4a843;
  --color-primary-hover: #e8be5a;
  --color-primary-active: #c49535;
  --color-primary-glow: rgba(212, 168, 67, 0.15);
  
  /* Teal for secondary elements */
  --color-secondary: #4f98a3;
  --color-secondary-hover: #6bb0ba;
  
  /* Era colors */
  --color-origin: #a37bdb;
  --color-science: #4f98a3;
  --color-space: #d4a843;
  --color-modern: #e06868;
  
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.3);
  --shadow-md: 0 4px 16px rgba(0,0,0,0.4);
  --shadow-lg: 0 12px 40px rgba(0,0,0,0.5);
  --shadow-glow: 0 0 30px rgba(212, 168, 67, 0.1);
}

/* --- Light Theme --- */
[data-theme='light'] {
  --color-bg: #f5f3ee;
  --color-surface: #faf8f4;
  --color-surface-2: #ffffff;
  --color-surface-offset: #edeae3;
  --color-border: #d4d0c6;
  --color-divider: #e0ddd5;
  
  --color-text: #1a1814;
  --color-text-muted: #6b695f;
  --color-text-faint: #a09d94;
  
  --color-primary: #9a7620;
  --color-primary-hover: #7d5f15;
  --color-primary-active: #634b10;
  --color-primary-glow: rgba(154, 118, 32, 0.08);
  
  --color-secondary: #1a7a86;
  --color-secondary-hover: #0f5c66;
  
  --color-origin: #7548b0;
  --color-science: #1a7a86;
  --color-space: #9a7620;
  --color-modern: #c04040;
  
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.06);
  --shadow-md: 0 4px 16px rgba(0,0,0,0.08);
  --shadow-lg: 0 12px 40px rgba(0,0,0,0.12);
  --shadow-glow: 0 0 30px rgba(154, 118, 32, 0.06);
}

/* --- 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;
  scroll-padding-top: var(--space-16);
}

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);
  overflow-x: hidden;
}

img, picture, video, canvas, svg { display: block; max-width: 100%; height: auto; }
h1, h2, h3, h4 { text-wrap: balance; line-height: 1.15; }
p, li, figcaption { text-wrap: pretty; max-width: 72ch; }
a { color: var(--color-primary); text-decoration: none; }
a:hover { color: var(--color-primary-hover); }

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

a, button, [role='button'] {
  transition: color var(--transition-interactive),
              background var(--transition-interactive),
              border-color var(--transition-interactive),
              box-shadow var(--transition-interactive),
              transform var(--transition-interactive);
}

::selection {
  background: rgba(212, 168, 67, 0.25);
  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;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

/* --- Stars Canvas --- */
#stars-canvas {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 0;
  pointer-events: none;
}

/* --- Navigation --- */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  padding: var(--space-4) var(--space-6);
  background: color-mix(in srgb, var(--color-bg) 85%, transparent);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-divider);
  transition: transform 0.3s ease;
}

.nav__inner {
  max-width: var(--content-wide);
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav__logo {
  color: var(--color-primary);
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

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

.nav__link {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  font-weight: 500;
  letter-spacing: 0.02em;
}

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

.nav__toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: var(--radius-md);
  color: var(--color-text-muted);
}

.nav__toggle:hover {
  color: var(--color-primary);
  background: var(--color-primary-glow);
}

/* --- Hero --- */
.hero {
  position: relative;
  z-index: 1;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-20) var(--space-6);
  text-align: center;
}

.hero__content {
  max-width: 820px;
}

.hero__kicker {
  font-size: var(--text-sm);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.15em;
  color: var(--color-primary);
  margin-bottom: var(--space-6);
  opacity: 0;
  animation: fadeUp 0.8s ease forwards 0.2s;
}

.hero__title {
  font-family: var(--font-display);
  font-size: var(--text-hero);
  font-weight: 700;
  line-height: 1;
  color: var(--color-text);
  margin-bottom: var(--space-8);
  opacity: 0;
  animation: fadeUp 0.8s ease forwards 0.4s;
}

.hero__accent {
  color: var(--color-primary);
  display: block;
}

.hero__subtitle {
  font-size: var(--text-lg);
  color: var(--color-text-muted);
  line-height: 1.7;
  max-width: 650px;
  margin: 0 auto var(--space-12);
  opacity: 0;
  animation: fadeUp 0.8s ease forwards 0.6s;
}

.hero__scroll {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-2);
  color: var(--color-text-faint);
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  opacity: 0;
  animation: fadeUp 0.8s ease forwards 0.8s;
}

.hero__scroll svg {
  animation: bounce 2s ease infinite;
}

@keyframes fadeUp {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes bounce {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(6px); }
}

/* --- Filter Bar --- */
.filter-bar {
  position: relative;
  z-index: 2;
  padding: var(--space-8) var(--space-6);
  border-top: 1px solid var(--color-divider);
}

.filter-bar__inner {
  max-width: var(--content-wide);
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: var(--space-4);
}

.filter-bar__title {
  font-family: var(--font-display);
  font-size: var(--text-xl);
  font-weight: 700;
  color: var(--color-text);
}

.filter-bar__buttons {
  display: flex;
  gap: var(--space-2);
  flex-wrap: wrap;
}

.filter-btn {
  padding: var(--space-2) var(--space-4);
  border-radius: var(--radius-full);
  font-size: var(--text-xs);
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  border: 1px solid var(--color-border);
  background: transparent;
}

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

.filter-btn.active {
  color: var(--color-bg);
  background: var(--color-primary);
  border-color: var(--color-primary);
}

/* --- Timeline --- */
.timeline {
  position: relative;
  z-index: 1;
  max-width: var(--content-default);
  margin: 0 auto;
  padding: var(--space-8) var(--space-6) var(--space-20);
}

.timeline__line {
  position: absolute;
  left: 28px;
  top: 0;
  bottom: 0;
  width: 2px;
  background: linear-gradient(to bottom, 
    var(--color-origin) 0%,
    var(--color-science) 30%,
    var(--color-space) 60%,
    var(--color-modern) 100%
  );
  opacity: 0.3;
}

/* --- Timeline Item --- */
.timeline__item {
  position: relative;
  padding-left: 72px;
  margin-bottom: var(--space-10);
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.timeline__item.visible {
  opacity: 1;
  transform: translateY(0);
}

.timeline__item.hidden {
  display: none;
}

.timeline__dot {
  position: absolute;
  left: 20px;
  top: 8px;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  border: 2px solid var(--color-primary);
  background: var(--color-bg);
  z-index: 2;
  transition: all 0.3s ease;
}

.timeline__dot::after {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--color-primary);
}

.timeline__dot--major {
  width: 24px;
  height: 24px;
  left: 17px;
  top: 5px;
  border-color: var(--color-primary);
  box-shadow: 0 0 16px var(--color-primary-glow), 0 0 32px var(--color-primary-glow);
}

.timeline__dot--major::after {
  width: 10px;
  height: 10px;
  background: var(--color-primary);
}

.timeline__dot--future {
  border-style: dashed;
  border-color: var(--color-text-faint);
}

.timeline__dot--future::after {
  background: var(--color-text-faint);
}

[data-era="origin"] .timeline__dot { border-color: var(--color-origin); }
[data-era="origin"] .timeline__dot::after { background: var(--color-origin); }
[data-era="science"] .timeline__dot { border-color: var(--color-science); }
[data-era="science"] .timeline__dot::after { background: var(--color-science); }
[data-era="space"] .timeline__dot { border-color: var(--color-space); }
[data-era="space"] .timeline__dot::after { background: var(--color-space); }
[data-era="modern"] .timeline__dot { border-color: var(--color-modern); }
[data-era="modern"] .timeline__dot::after { background: var(--color-modern); }

/* --- Timeline Card --- */
.timeline__card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
  transition: box-shadow 0.3s ease, transform 0.3s ease;
}

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

.timeline__card--highlight {
  border-color: color-mix(in srgb, var(--color-primary) 40%, var(--color-border));
  background: linear-gradient(135deg, var(--color-surface) 0%, color-mix(in srgb, var(--color-primary) 5%, var(--color-surface)) 100%);
}

.timeline__card--future {
  border-style: dashed;
  border-color: var(--color-text-faint);
  background: color-mix(in srgb, var(--color-surface) 50%, transparent);
}

.timeline__year {
  display: inline-block;
  font-family: var(--font-display);
  font-size: var(--text-lg);
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: var(--space-2);
}

.timeline__card-title {
  font-family: var(--font-display);
  font-size: var(--text-lg);
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: var(--space-3);
}

.timeline__card-text {
  font-size: var(--text-base);
  color: var(--color-text-muted);
  line-height: 1.7;
  margin-bottom: var(--space-4);
}

/* --- Quote --- */
.timeline__quote {
  border-left: 3px solid var(--color-primary);
  padding: var(--space-4) var(--space-5);
  margin: var(--space-4) 0;
  background: var(--color-primary-glow);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  font-family: var(--font-display);
  font-size: var(--text-base);
  font-style: italic;
  color: var(--color-text);
  line-height: 1.7;
}

.timeline__quote cite {
  display: block;
  margin-top: var(--space-3);
  font-size: var(--text-sm);
  font-style: normal;
  font-family: var(--font-body);
  color: var(--color-text-faint);
  font-weight: 500;
}

/* --- Tags --- */
.timeline__tag {
  display: inline-block;
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-full);
  font-size: var(--text-xs);
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  border: 1px solid var(--color-border);
  margin-top: var(--space-3);
}

.timeline__tag--key {
  color: var(--color-primary);
  border-color: var(--color-primary);
  background: var(--color-primary-glow);
}

/* --- Ideas chips --- */
.timeline__ideas {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  margin-top: var(--space-3);
}

.timeline__idea {
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-full);
  font-size: var(--text-xs);
  font-weight: 500;
  background: var(--color-surface-2);
  color: var(--color-text-muted);
  border: 1px solid var(--color-divider);
}

/* --- Connections Section --- */
.connections {
  position: relative;
  z-index: 1;
  padding: clamp(var(--space-16), 8vw, var(--space-24)) var(--space-6);
  border-top: 1px solid var(--color-divider);
}

.connections__inner {
  max-width: var(--content-wide);
  margin: 0 auto;
}

.section-title {
  font-family: var(--font-display);
  font-size: var(--text-2xl);
  font-weight: 700;
  color: var(--color-text);
  text-align: center;
  margin-bottom: var(--space-3);
}

.section-subtitle {
  font-size: var(--text-base);
  color: var(--color-text-muted);
  text-align: center;
  margin-bottom: var(--space-12);
  max-width: 560px;
  margin-left: auto;
  margin-right: auto;
}

.connections__canvas-wrap {
  width: 100%;
  max-width: 900px;
  margin: 0 auto var(--space-8);
  aspect-ratio: 16 / 10;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  background: var(--color-surface);
}

#connections-canvas {
  width: 100%;
  height: 100%;
  cursor: pointer;
}

.connections__info {
  max-width: 640px;
  margin: 0 auto;
  padding: var(--space-5) var(--space-6);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  text-align: center;
  font-size: var(--text-base);
  color: var(--color-text-muted);
  min-height: 80px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.3s ease;
}

.connections__info.active {
  border-color: var(--color-primary);
  background: linear-gradient(135deg, var(--color-surface) 0%, color-mix(in srgb, var(--color-primary) 5%, var(--color-surface)) 100%);
}

.connections__info p {
  max-width: none;
}

/* --- Ideas Section --- */
.ideas {
  position: relative;
  z-index: 1;
  padding: clamp(var(--space-16), 8vw, var(--space-24)) var(--space-6);
  border-top: 1px solid var(--color-divider);
}

.ideas__inner {
  max-width: var(--content-wide);
  margin: 0 auto;
}

.ideas__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-8);
}

.idea-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-8);
  transition: box-shadow 0.3s ease, transform 0.3s ease;
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease, transform 0.6s ease, box-shadow 0.3s ease;
}

.idea-card.visible {
  opacity: 1;
  transform: translateY(0);
}

.idea-card:hover {
  box-shadow: var(--shadow-glow);
}

.idea-card__icon {
  width: 56px;
  height: 56px;
  margin-bottom: var(--space-5);
  color: var(--color-primary);
}

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

.idea-card__title {
  font-family: var(--font-display);
  font-size: var(--text-xl);
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: var(--space-6);
}

.idea-card__evolution {
  display: flex;
  align-items: flex-start;
  gap: var(--space-4);
  flex-wrap: wrap;
}

.idea-card__step {
  flex: 1;
  min-width: 180px;
}

.idea-card__era {
  display: inline-block;
  font-size: var(--text-xs);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--color-primary);
  margin-bottom: var(--space-2);
  padding: var(--space-1) var(--space-2);
  background: var(--color-primary-glow);
  border-radius: var(--radius-sm);
}

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

.idea-card__arrow {
  font-size: var(--text-xl);
  color: var(--color-primary);
  font-weight: 300;
  align-self: center;
  flex-shrink: 0;
}

/* --- Footer --- */
.footer {
  position: relative;
  z-index: 1;
  padding: var(--space-12) var(--space-6);
  border-top: 1px solid var(--color-divider);
  text-align: center;
}

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

.footer__text {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  margin-bottom: var(--space-2);
}

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

/* --- Responsive --- */
@media (max-width: 768px) {
  .nav__links {
    gap: var(--space-3);
  }
  
  .nav__link {
    font-size: var(--text-xs);
  }

  .timeline__line {
    left: 16px;
  }
  
  .timeline__item {
    padding-left: 48px;
  }
  
  .timeline__dot {
    left: 8px;
    width: 16px;
    height: 16px;
  }
  
  .timeline__dot--major {
    width: 20px;
    height: 20px;
    left: 6px;
  }
  
  .timeline__card {
    padding: var(--space-4);
  }

  .idea-card__evolution {
    flex-direction: column;
    gap: var(--space-3);
  }
  
  .idea-card__arrow {
    transform: rotate(90deg);
    align-self: center;
  }
  
  .idea-card__step {
    min-width: 100%;
  }
  
  .filter-bar__inner {
    flex-direction: column;
    align-items: flex-start;
  }
  
  .connections__canvas-wrap {
    aspect-ratio: 4 / 5;
  }
}

@media (min-width: 769px) {
  .timeline__line {
    left: 50%;
    transform: translateX(-50%);
  }
  
  .timeline__item {
    padding-left: 0;
    width: 50%;
  }
  
  .timeline__item:nth-child(odd) {
    margin-left: 0;
    padding-right: 48px;
    text-align: right;
  }
  
  .timeline__item:nth-child(even) {
    margin-left: 50%;
    padding-left: 48px;
  }
  
  .timeline__dot {
    left: auto;
    right: -9px;
  }
  
  .timeline__dot--major {
    right: -12px;
  }
  
  .timeline__item:nth-child(even) .timeline__dot {
    left: -9px;
    right: auto;
  }
  
  .timeline__item:nth-child(even) .timeline__dot--major {
    left: -12px;
    right: auto;
  }
  
  .timeline__quote {
    text-align: left;
  }
  
  .timeline__ideas {
    justify-content: flex-end;
  }
  
  .timeline__item:nth-child(even) .timeline__ideas {
    justify-content: flex-start;
  }
}

/* Scrollbar styling */
::-webkit-scrollbar {
  width: 8px;
}

::-webkit-scrollbar-track {
  background: var(--color-bg);
}

::-webkit-scrollbar-thumb {
  background: var(--color-border);
  border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--color-text-faint);
}