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

:root {
  --color-primary: #1e2a3b;
  --color-secondary: #4f6b9a;
  --color-accent: #f5a623;
  --color-accent-soft: rgba(245, 166, 35, 0.1);
  --color-neutral-100: #f7f8fa;
  --color-neutral-200: #edf0f5;
  --color-neutral-600: #3e4c61;
  --color-neutral-800: #111826;
  --color-success: #3fb9a2;
  --color-danger: #f05454;
  --radius-sm: 8px;
  --radius-md: 16px;
  --radius-lg: 32px;
  --shadow-soft: 0 12px 28px rgba(17, 24, 38, 0.12);
  --shadow-card: 0 24px 50px -24px rgba(30, 42, 59, 0.45);
  --transition-base: all 0.3s ease;
  --container-max: 1320px;
  --header-height: 78px;
  --font-heading: "Manrope", "Inter", system-ui, -apple-system, BlinkMacSystemFont, sans-serif;
  --font-body: "Inter", system-ui, -apple-system, BlinkMacSystemFont, sans-serif;
}

body.dark-mode {
  --color-neutral-100: #0b101b;
  --color-neutral-200: #1b2433;
  --color-neutral-600: #9aa6c0;
  --color-neutral-800: #f2f5ff;
  --shadow-soft: 0 28px 54px rgba(0, 0, 0, 0.45);
  background-color: var(--color-neutral-100);
  color: var(--color-neutral-800);
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font-body);
  font-size: 18px;
  line-height: 1.6;
  background-color: var(--color-neutral-100);
  color: var(--color-neutral-800);
}

a {
  color: inherit;
  text-decoration: none;
  transition: color 0.2s ease;
}

a:hover {
  color: var(--color-accent);
}

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

main {
  padding-top: var(--header-height);
}

.container {
  width: min(100% - 32px, var(--container-max));
  margin-inline: auto;
}

.section {
  padding: 72px 0;
}

.section__header {
  margin-bottom: 42px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.section__title {
  font-family: var(--font-heading);
  font-size: clamp(32px, 4vw, 42px);
  margin: 0;
  color: var(--color-primary);
}

.section__subtitle {
  max-width: 720px;
  color: var(--color-neutral-600);
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  padding: 14px 28px;
  border-radius: 999px;
  border: none;
  background: linear-gradient(135deg, var(--color-accent), #f8bf55);
  color: #0b101b;
  font-weight: 600;
  cursor: pointer;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.button:hover {
  transform: translateY(-2px);
  box-shadow: 0 12px 30px rgba(245, 166, 35, 0.35);
}

.button--ghost {
  background: transparent;
  color: var(--color-accent);
  border: 1px solid rgba(245, 166, 35, 0.4);
}

.button--ghost:hover {
  background: var(--color-accent-soft);
}

/* Header */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-height);
  display: flex;
  align-items: center;
  background-color: rgba(247, 248, 250, 0.92);
  backdrop-filter: blur(18px);
  border-bottom: 1px solid rgba(79, 107, 154, 0.12);
  z-index: 999;
  transition: var(--transition-base);
}

body.dark-mode .header {
  background-color: rgba(11, 16, 27, 0.9);
  border-bottom-color: rgba(79, 107, 154, 0.22);
}

.header__inner {
  width: min(100% - 32px, var(--container-max));
  margin-inline: auto;
  display: flex;
  align-items: center;
  gap: 24px;
}

.logo {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  font-family: var(--font-heading);
  font-size: 20px;
  font-weight: 700;
  color: var(--color-primary);
}

.logo img {
  width: 40px;
  height: 40px;
}

.nav {
  display: flex;
  align-items: center;
  gap: 24px;
  margin-left: auto;
}

.nav__link {
  font-weight: 500;
  color: var(--color-neutral-600);
}

.nav__link.active {
  color: var(--color-accent);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 16px;
}

.search {
  position: relative;
}

.search input {
  width: 220px;
  padding: 10px 42px 10px 16px;
  border-radius: var(--radius-sm);
  border: 1px solid rgba(79, 107, 154, 0.22);
  background-color: #fff;
  color: var(--color-neutral-800);
  font-size: 16px;
}

body.dark-mode .search input {
  background-color: var(--color-neutral-200);
  border-color: rgba(79, 107, 154, 0.32);
}

.search svg {
  position: absolute;
  top: 50%;
  right: 14px;
  transform: translateY(-50%);
  width: 18px;
  height: 18px;
  stroke: var(--color-neutral-600);
}

.theme-toggle {
  width: 46px;
  height: 26px;
  border-radius: 999px;
  background: var(--color-neutral-200);
  border: 1px solid rgba(79, 107, 154, 0.24);
  position: relative;
  cursor: pointer;
  transition: var(--transition-base);
}

.theme-toggle::after {
  content: "";
  position: absolute;
  top: 2px;
  left: 2px;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: var(--color-accent);
  transition: var(--transition-base);
}

body.dark-mode .theme-toggle {
  background: rgba(245, 166, 35, 0.18);
  border-color: rgba(245, 166, 35, 0.42);
}

body.dark-mode .theme-toggle::after {
  transform: translateX(20px);
}

.burger {
  display: none;
  flex-direction: column;
  gap: 6px;
  cursor: pointer;
}

.burger span {
  width: 26px;
  height: 2px;
  background: var(--color-primary);
  transition: var(--transition-base);
}

/* Hero */
.hero {
  position: relative;
  padding: 140px 0 80px;
  background: radial-gradient(circle at top right, rgba(79, 107, 154, 0.15), transparent 55%),
    linear-gradient(135deg, rgba(30, 42, 59, 0.98), rgba(30, 42, 59, 0.82));
  color: #fff;
  overflow: hidden;
}

.hero::after {
  content: "";
  position: absolute;
  inset: 0;
  background: url("/img/hero-illustration.svg") center/cover no-repeat;
  opacity: 0.14;
}

.hero__inner {
  position: relative;
  z-index: 1;
  display: grid;
  gap: 32px;
}

.hero__title {
  font-family: var(--font-heading);
  font-size: clamp(40px, 5vw, 60px);
  margin: 0;
  line-height: 1.1;
}

.hero__subtitle {
  max-width: 680px;
  color: rgba(255, 255, 255, 0.78);
}

.hero__cta {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
}

.hero__meta {
  display: flex;
  align-items: center;
  gap: 24px;
  color: rgba(255, 255, 255, 0.65);
}

.hero__meta div {
  display: flex;
  align-items: center;
  gap: 8px;
}

.hero__meta svg {
  width: 18px;
  height: 18px;
  stroke: currentColor;
}

/* Info cards */
.cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 28px;
}

.card {
  background: #fff;
  border-radius: var(--radius-md);
  padding: 28px;
  box-shadow: var(--shadow-card);
  display: flex;
  flex-direction: column;
  gap: 16px;
  transition: transform 0.25s ease;
}

body.dark-mode .card {
  background: var(--color-neutral-200);
}

.card:hover {
  transform: translateY(-6px);
}

.card__thumb {
  aspect-ratio: 16 / 10;
  border-radius: var(--radius-sm);
  overflow: hidden;
  background: var(--color-neutral-200);
}

.card__thumb img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.card__meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  color: var(--color-neutral-600);
  font-size: 14px;
}

.card__title {
  font-family: var(--font-heading);
  font-size: 24px;
  margin: 0;
  color: var(--color-primary);
}

.card__excerpt {
  color: var(--color-neutral-600);
  margin: 0;
}

.card__tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.tag {
  padding: 6px 12px;
  border-radius: 999px;
  background: rgba(79, 107, 154, 0.12);
  color: var(--color-secondary);
  font-size: 14px;
}

/* About block */
.about-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 36px;
}

.about-highlight {
  padding: 24px;
  border-radius: var(--radius-md);
  background: #fff;
  border: 1px solid rgba(79, 107, 154, 0.1);
}

body.dark-mode .about-highlight {
  background: var(--color-neutral-200);
}

/* Infographics */
.infographic {
  background: #fff;
  border-radius: var(--radius-lg);
  padding: 40px;
  box-shadow: var(--shadow-soft);
  position: relative;
  overflow: hidden;
}

body.dark-mode .infographic {
  background: var(--color-neutral-200);
}

.infographic__title {
  font-size: 26px;
  margin: 0 0 12px;
}

.infographic__chart {
  min-height: 260px;
}

/* Interactive elements */
.bar-chart {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
  gap: 20px;
  align-items: end;
}

.bar-chart__bar {
  background: linear-gradient(180deg, rgba(79, 107, 154, 0.85), rgba(30, 42, 59, 0.98));
  border-radius: var(--radius-sm) var(--radius-sm) 8px 8px;
  position: relative;
  transition: height 0.6s ease;
}

.bar-chart__label {
  text-align: center;
  margin-top: 12px;
  font-size: 14px;
  color: var(--color-neutral-600);
}

.bar-chart__value {
  position: absolute;
  bottom: calc(100% + 8px);
  left: 50%;
  transform: translateX(-50%);
  background: rgba(17, 24, 38, 0.88);
  color: #fff;
  padding: 6px 12px;
  border-radius: 999px;
  font-size: 14px;
  white-space: nowrap;
}

body.dark-mode .bar-chart__value {
  background: rgba(247, 248, 250, 0.86);
  color: var(--color-primary);
}

.quiz {
  background: #fff;
  border-radius: var(--radius-md);
  border: 1px solid rgba(79, 107, 154, 0.14);
  padding: 28px;
  display: flex;
  flex-direction: column;
  gap: 18px;
}

body.dark-mode .quiz {
  background: var(--color-neutral-200);
}

.quiz__question {
  font-weight: 600;
  color: var(--color-primary);
}

.quiz__answers {
  display: grid;
  gap: 12px;
}

.quiz__answers button {
  padding: 12px 16px;
  border: 1px solid rgba(79, 107, 154, 0.2);
  border-radius: var(--radius-sm);
  background: transparent;
  cursor: pointer;
  text-align: left;
  transition: var(--transition-base);
}

.quiz__answers button:hover,
.quiz__answers button[aria-pressed="true"] {
  border-color: var(--color-accent);
  background: var(--color-accent-soft);
}

.quiz__result {
  background: rgba(63, 185, 162, 0.12);
  border-radius: var(--radius-sm);
  padding: 16px;
  color: #0b4e43;
  display: none;
}

.calculator {
  background: #fff;
  border-radius: var(--radius-md);
  padding: 28px;
  border: 1px solid rgba(79, 107, 154, 0.14);
  display: grid;
  gap: 18px;
}

body.dark-mode .calculator {
  background: var(--color-neutral-200);
}

.calculator__fields {
  display: grid;
  gap: 16px;
}

.calculator label {
  font-weight: 500;
  color: var(--color-neutral-600);
}

.calculator input[type="number"] {
  width: 100%;
  padding: 12px 16px;
  border-radius: var(--radius-sm);
  border: 1px solid rgba(79, 107, 154, 0.2);
  background: #fff;
  color: var(--color-neutral-800);
}

body.dark-mode .calculator input[type="number"] {
  background: #0f1623;
  border-color: rgba(79, 107, 154, 0.32);
  color: var(--color-neutral-800);
}

.calculator__result {
  background: rgba(79, 107, 154, 0.12);
  border-radius: var(--radius-sm);
  padding: 16px;
  color: var(--color-primary);
  font-weight: 600;
  display: none;
}

.timeline {
  position: relative;
  padding-left: 32px;
}

.timeline::before {
  content: "";
  position: absolute;
  top: 0;
  bottom: 0;
  left: 10px;
  width: 2px;
  background: rgba(79, 107, 154, 0.3);
}

.timeline__item {
  position: relative;
  padding: 18px 0 18px 24px;
}

.timeline__item::before {
  content: "";
  position: absolute;
  left: -26px;
  top: 22px;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--color-accent);
  box-shadow: 0 0 0 6px rgba(245, 166, 35, 0.2);
}

.timeline__title {
  margin: 0;
  font-weight: 600;
  color: var(--color-primary);
}

.timeline__meta {
  font-size: 14px;
  color: var(--color-neutral-600);
  margin-bottom: 8px;
}

/* Article layout */
.article-layout {
  display: grid;
  gap: 48px;
}

.article {
  background: #fff;
  border-radius: var(--radius-lg);
  padding: 48px;
  box-shadow: var(--shadow-soft);
}

body.dark-mode .article {
  background: var(--color-neutral-200);
}

.article header {
  display: grid;
  gap: 12px;
  margin-bottom: 36px;
}

.article__body {
  font-size: 18px;
}

.article h1 {
  font-family: var(--font-heading);
  font-size: clamp(36px, 5vw, 48px);
  margin: 0;
}

.article-header__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 12px 24px;
  color: var(--color-neutral-600);
  font-size: 16px;
}

.article__body h2 {
  font-size: 30px;
  margin-top: 48px;
  margin-bottom: 16px;
  color: var(--color-primary);
}

.article__body h3 {
  font-size: 22px;
  margin-top: 28px;
  margin-bottom: 12px;
  color: var(--color-secondary);
}

.article__body p {
  margin: 0 0 18px;
}

.article__body ul,
.article__body ol {
  margin: 0 0 28px 24px;
  display: grid;
  gap: 12px;
}

.article blockquote {
  margin: 32px 0;
  padding: 24px 32px;
  border-left: 4px solid var(--color-accent);
  background: rgba(245, 166, 35, 0.12);
  border-radius: var(--radius-sm);
  color: var(--color-primary);
  font-style: italic;
}

.highlight-box {
  margin: 32px 0;
  padding: 24px;
  border-radius: var(--radius-md);
  background: rgba(63, 185, 162, 0.14);
  border: 1px solid rgba(63, 185, 162, 0.4);
  color: #0b4e43;
}

.table-scroll {
  overflow-x: auto;
  margin: 24px 0;
}

table {
  width: 100%;
  border-collapse: collapse;
  min-width: 640px;
  background: #fff;
  border-radius: var(--radius-sm);
  overflow: hidden;
}

thead {
  background: rgba(79, 107, 154, 0.08);
}

thead th {
  padding: 16px;
  text-align: left;
  font-weight: 600;
  color: var(--color-primary);
}

tbody td {
  padding: 16px;
  border-top: 1px solid rgba(79, 107, 154, 0.12);
  color: var(--color-neutral-600);
}

.article__aside {
  position: sticky;
  top: calc(var(--header-height) + 24px);
  display: grid;
  gap: 24px;
  align-self: start;
}

.toc {
  background: #fff;
  border-radius: var(--radius-md);
  padding: 24px;
  border: 1px solid rgba(79, 107, 154, 0.12);
}

body.dark-mode .toc {
  background: var(--color-neutral-200);
}

.toc__title {
  font-weight: 600;
  margin: 0 0 16px;
}

.toc ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 12px;
}

.toc a {
  font-size: 16px;
  color: var(--color-neutral-600);
}

.read-next {
  background: #fff;
  border-radius: var(--radius-md);
  padding: 24px;
  border: 1px solid rgba(79, 107, 154, 0.12);
  display: grid;
  gap: 16px;
}

body.dark-mode .read-next {
  background: var(--color-neutral-200);
}

.partner-block {
  background: linear-gradient(135deg, rgba(30, 42, 59, 0.96), rgba(30, 42, 59, 0.86));
  color: #fff;
  border-radius: var(--radius-lg);
  padding: 32px;
  display: grid;
  gap: 16px;
}

.partner-block__logo {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  font-weight: 700;
  letter-spacing: 0.04em;
}

.partner-block__logo img {
  width: 48px;
  height: 48px;
}

.partner-block__actions {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}

.tags {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 36px 0 0;
}

.share {
  margin-top: 36px;
  display: flex;
  align-items: center;
  gap: 12px;
}

.share a {
  width: 38px;
  height: 38px;
  border-radius: 50%;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: rgba(79, 107, 154, 0.14);
}

.footer {
  background: #0b101b;
  color: rgba(255, 255, 255, 0.7);
  padding: 64px 0 32px;
}

.footer__grid {
  display: grid;
  gap: 32px;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
}

.footer__logo {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 24px;
}

.footer__nav {
  display: grid;
  gap: 12px;
}

.footer__bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  margin-top: 48px;
  padding-top: 24px;
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 12px;
  font-size: 14px;
}

.badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 14px;
  border-radius: 999px;
  background: rgba(79, 107, 154, 0.12);
  color: var(--color-secondary);
  font-size: 14px;
}

/* Utility */
.hidden {
  display: none !important;
}

.sticky {
  position: sticky;
  top: calc(var(--header-height) + 16px);
}

.text-muted {
  color: var(--color-neutral-600);
}

.text-accent {
  color: var(--color-accent);
}

.bg-neutral {
  background: var(--color-neutral-100);
}

.bg-dark {
  background: #0b101b;
}

.grid {
  display: grid;
  gap: 18px;
}

.flex {
  display: flex;
  gap: 18px;
}

.flex-between {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.stat-capsule {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 10px 18px;
  border-radius: 999px;
  background: rgba(63, 185, 162, 0.16);
  color: var(--color-success);
  font-weight: 600;
}

.hero-badges {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}

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