/* === Шрифты === */
@import url('https://fonts.googleapis.com/css2?family=PT+Serif:ital,wght@0,400;0,700;1,400&family=Inter:wght@400;500;600;700&display=swap');

:root {
  --font-serif: 'PT Serif', Charter, Georgia, 'Times New Roman', serif;
  --font-sans:  'Inter', -apple-system, BlinkMacSystemFont, 'SF Pro Text', 'Segoe UI', sans-serif;

  /* Светлая тема (по умолчанию) */
  --bg: #fafaf8;
  --surface: #ffffff;
  --text: #1a1a1a;
  --text-muted: #757575;
  --text-soft: #aaa;
  --border: #ececec;
  --link: #1a73e8;
  --accent: #d4351c; /* красный — китайская тема */

  --radius: 8px;
  --content-width: 720px;
  --wide-width: 1100px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #15161a;
    --surface: #1c1d22;
    --text: #ececed;
    --text-muted: #9ba1a8;
    --text-soft: #5a5e66;
    --border: #2a2c33;
    --link: #6ea8ff;
  }
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 17px;
  line-height: 1.6;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

a { color: var(--link); text-decoration: none; }
a:hover { text-decoration: underline; }

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

/* === Шапка === */
.site-header {
  border-bottom: 1px solid var(--border);
  background: var(--surface);
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  background-color: color-mix(in srgb, var(--surface) 85%, transparent);
}
.site-header__inner {
  max-width: var(--wide-width);
  margin: 0 auto;
  padding: 14px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}
.site-logo {
  font-family: var(--font-sans);
  font-weight: 700;
  font-size: 18px;
  letter-spacing: -0.01em;
  color: var(--text);
  display: flex;
  align-items: center;
  gap: 8px;
}
.site-logo:hover { text-decoration: none; }
.site-logo__mark {
  width: 28px; height: 28px;
  background: var(--accent);
  color: white;
  border-radius: 6px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 14px;
}
.site-nav {
  display: flex;
  gap: 24px;
  font-size: 14px;
}
.site-nav a {
  color: var(--text-muted);
  font-weight: 500;
}
.site-nav a:hover { color: var(--text); text-decoration: none; }

/* === Контейнеры === */
.container {
  max-width: var(--content-width);
  margin: 0 auto;
  padding: 0 24px;
}
.container--wide {
  max-width: var(--wide-width);
}

/* === Главная: герой === */
.hero {
  padding: 80px 24px 60px;
  text-align: center;
  border-bottom: 1px solid var(--border);
}
.hero h1 {
  font-family: var(--font-serif);
  font-size: clamp(36px, 6vw, 56px);
  line-height: 1.1;
  margin: 0 0 16px;
  letter-spacing: -0.02em;
  font-weight: 700;
}
.hero p {
  font-family: var(--font-serif);
  font-size: 20px;
  line-height: 1.5;
  color: var(--text-muted);
  max-width: 580px;
  margin: 0 auto;
}

/* === Сетка карточек статей === */
.cards {
  max-width: var(--wide-width);
  margin: 60px auto;
  padding: 0 24px;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 32px 28px;
}
.card {
  display: block;
  color: inherit;
  border-radius: 14px;
  overflow: hidden;
  background: var(--surface);
  border: 1px solid var(--border);
  transition: transform 0.2s, border-color 0.2s, box-shadow 0.2s;
}
.card:hover {
  text-decoration: none;
  transform: translateY(-2px);
  border-color: var(--text-muted);
  box-shadow: 0 8px 24px rgba(0,0,0,0.08);
}
.card__cover {
  width: 100%;
  aspect-ratio: 1200 / 630;
  object-fit: cover;
  display: block;
  border-bottom: 1px solid var(--border);
  margin-bottom: 18px;
}
.card .card__brand,
.card .card__title,
.card .card__excerpt,
.card .card__meta { padding: 0 18px; }
.card .card__meta { padding-bottom: 18px; }
.card .card__brand { padding-top: 4px; }
.card__brand {
  font-family: var(--font-sans);
  font-size: 12px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--accent);
  margin-bottom: 8px;
}
.card__title {
  font-family: var(--font-serif);
  font-size: 22px;
  line-height: 1.25;
  font-weight: 700;
  margin: 0 0 8px;
  color: var(--text);
  letter-spacing: -0.01em;
}
.card:hover .card__title { color: var(--link); }
.card__excerpt {
  font-family: var(--font-serif);
  font-size: 16px;
  line-height: 1.55;
  color: var(--text-muted);
  margin: 0 0 12px;
}
.card__meta {
  font-family: var(--font-sans);
  font-size: 13px;
  color: var(--text-soft);
  display: flex;
  gap: 12px;
}

/* === Бренды (главная) === */
.brands {
  max-width: var(--wide-width);
  margin: 80px auto 60px;
  padding: 0 24px;
}
.brands h2 {
  font-family: var(--font-serif);
  font-size: 32px;
  margin: 0 0 32px;
  letter-spacing: -0.01em;
}
.brands-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  gap: 12px;
}
.brand-tile {
  padding: 18px 20px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface);
  font-family: var(--font-sans);
  font-weight: 600;
  font-size: 15px;
  color: var(--text);
  transition: all 0.15s;
}
.brand-tile:hover {
  border-color: var(--text);
  text-decoration: none;
  transform: translateY(-1px);
}
.brand-tile small {
  display: block;
  color: var(--text-soft);
  font-weight: 400;
  font-size: 12px;
  margin-top: 2px;
}

/* === Страница статьи === */
.article {
  max-width: var(--content-width);
  margin: 60px auto 100px;
  padding: 0 24px;
}
.article__breadcrumbs {
  font-family: var(--font-sans);
  font-size: 13px;
  color: var(--text-muted);
  margin-bottom: 24px;
}
.article__breadcrumbs a { color: var(--text-muted); }
.article__brand {
  font-family: var(--font-sans);
  font-size: 13px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--accent);
  margin-bottom: 16px;
}
.article h1 {
  font-family: var(--font-serif);
  font-size: clamp(32px, 5vw, 44px);
  line-height: 1.15;
  letter-spacing: -0.02em;
  margin: 0 0 24px;
  font-weight: 700;
}
.article__meta {
  font-family: var(--font-sans);
  font-size: 14px;
  color: var(--text-muted);
  margin-bottom: 40px;
  padding-bottom: 24px;
  border-bottom: 1px solid var(--border);
  display: flex;
  gap: 16px;
}

.article__cover {
  width: 100%;
  aspect-ratio: 1200 / 630;
  object-fit: cover;
  border-radius: 14px;
  margin: 0 0 40px;
}

/* Контент статьи */
.article__body {
  font-family: var(--font-serif);
  font-size: 19px;
  line-height: 1.65;
  color: var(--text);
}
.article__body p {
  margin: 0 0 24px;
}
.article__body h2 {
  font-family: var(--font-serif);
  font-size: 30px;
  line-height: 1.25;
  margin: 56px 0 16px;
  letter-spacing: -0.01em;
  font-weight: 700;
}
.article__body h3 {
  font-family: var(--font-serif);
  font-size: 22px;
  line-height: 1.3;
  margin: 36px 0 12px;
  font-weight: 700;
}
.article__body ul, .article__body ol {
  padding-left: 24px;
  margin: 0 0 24px;
}
.article__body li { margin-bottom: 8px; }
.article__body blockquote {
  border-left: 3px solid var(--accent);
  padding: 4px 0 4px 20px;
  margin: 32px 0;
  color: var(--text-muted);
  font-style: italic;
}
.article__body table {
  width: 100%;
  border-collapse: collapse;
  font-family: var(--font-sans);
  font-size: 15px;
  margin: 32px 0;
}
.article__body th, .article__body td {
  text-align: left;
  padding: 12px 16px;
  border-bottom: 1px solid var(--border);
}
.article__body th { font-weight: 600; background: var(--surface); }
.article__body code {
  font-family: 'JetBrains Mono', ui-monospace, monospace;
  font-size: 0.9em;
  background: var(--surface);
  padding: 2px 6px;
  border-radius: 4px;
  border: 1px solid var(--border);
}
.article__body img {
  border-radius: var(--radius);
  margin: 32px auto;
}
.article__body hr {
  border: none;
  border-top: 1px solid var(--border);
  margin: 48px auto;
  width: 80px;
}

/* Похожие статьи */
.related {
  max-width: var(--content-width);
  margin: 60px auto;
  padding: 40px 24px;
  border-top: 1px solid var(--border);
}
.related h3 {
  font-family: var(--font-sans);
  font-size: 13px;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--text-muted);
  font-weight: 600;
  margin: 0 0 24px;
}
.related-list {
  display: flex;
  flex-direction: column;
  gap: 20px;
}
.related-item {
  display: block;
  color: inherit;
}
.related-item:hover { text-decoration: none; }
.related-item__title {
  font-family: var(--font-serif);
  font-size: 19px;
  line-height: 1.3;
  font-weight: 700;
  margin: 0 0 4px;
}
.related-item:hover .related-item__title { color: var(--link); }
.related-item__brand {
  font-family: var(--font-sans);
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--accent);
  font-weight: 600;
}

/* === Калькуляторы === */
.calc-widget {
  background: linear-gradient(180deg, var(--surface) 0%, var(--bg) 100%);
  border: 1px solid var(--border);
  border-radius: 20px;
  padding: 32px;
  margin: 36px 0 56px;
  font-family: var(--font-sans);
  box-shadow: 0 1px 3px rgba(0,0,0,0.04);
}
@media (max-width: 600px) {
  .calc-widget { padding: 20px; border-radius: 16px; }
}

.calc-widget__section-title {
  font-size: 11px;
  font-weight: 700;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: 14px;
}
.calc-widget__section-title:not(:first-child) { margin-top: 28px; }

.calc-widget__form {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
  margin-bottom: 0;
}
@media (max-width: 600px) {
  .calc-widget__form { grid-template-columns: 1fr; gap: 12px; }
}

.calc-field {
  display: block;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 14px 16px;
  transition: border-color 0.15s, background 0.15s;
}
.calc-field:hover { border-color: var(--text-muted); }
.calc-field:focus-within {
  border-color: var(--accent);
  background: var(--surface);
}

.calc-field label {
  display: block;
  font-size: 12px;
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.04em;
  margin-bottom: 8px;
}

.calc-field select,
.calc-field input[type="number"] {
  width: 100%;
  padding: 10px 0 0;
  border: none;
  background: transparent;
  color: var(--text);
  font-size: 16px;
  font-family: inherit;
  font-weight: 500;
  outline: none;
  appearance: none;
  -webkit-appearance: none;
  cursor: pointer;
}
.calc-field select {
  background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='%23999'><path d='M7 10l5 5 5-5z'/></svg>");
  background-repeat: no-repeat;
  background-position: right 0 center;
  padding-right: 28px;
}
.calc-field input[type="number"] {
  cursor: text;
}

.calc-range {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-top: 4px;
}
.calc-range input[type="range"] {
  flex: 1;
  accent-color: var(--accent);
  height: 4px;
  cursor: pointer;
}
.calc-range output {
  font-weight: 700;
  font-size: 16px;
  color: var(--text);
  min-width: 80px;
  text-align: right;
}

.calc-hint {
  display: block;
  margin-top: 6px;
  color: var(--text-soft);
  font-size: 12px;
  line-height: 1.4;
}

/* Результат */
.calc-widget__result {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 22px 26px;
  min-height: 90px;
}
.calc-result-table {
  display: flex;
  flex-direction: column;
  gap: 0;
}
.calc-result-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  padding: 12px 0;
  border-bottom: 1px solid var(--border);
}
.calc-result-row:last-child { border-bottom: none; }
.calc-result-row--highlight {
  background: linear-gradient(135deg, rgba(212,53,28,0.10), rgba(212,53,28,0.04));
  border-radius: 12px;
  padding: 18px 22px;
  margin: 10px -22px;
  border: 1px solid rgba(212,53,28,0.18);
}
.calc-result-row--highlight + .calc-result-row { border-top: none; }
.calc-result-row--highlight .calc-result-label {
  color: var(--text);
  font-weight: 600;
}
.calc-result-row--highlight .calc-result-value {
  font-size: 22px;
  font-weight: 700;
  color: var(--accent);
  font-family: var(--font-serif);
  letter-spacing: -0.01em;
}
.calc-result-label {
  color: var(--text-muted);
  font-size: 14px;
}
.calc-result-value {
  font-weight: 600;
  font-size: 15px;
  color: var(--text);
  text-align: right;
  font-variant-numeric: tabular-nums;
}
.calc-result__placeholder {
  text-align: center;
  color: var(--text-soft);
  padding: 28px 12px;
  font-size: 14px;
}

/* CTA-блок */
.calc-widget__cta {
  margin-top: 24px;
  padding: 24px;
  background: linear-gradient(135deg, var(--accent) 0%, #a82817 100%);
  border-radius: 14px;
  text-align: center;
  color: white;
}
.calc-cta-btn {
  display: inline-block;
  background: white;
  color: var(--accent) !important;
  padding: 14px 32px;
  border-radius: 10px;
  font-weight: 600;
  font-size: 15px;
  margin-bottom: 10px;
  transition: transform 0.1s;
}
.calc-cta-btn:hover {
  text-decoration: none;
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(0,0,0,0.15);
}
.calc-widget__cta small {
  display: block;
  color: rgba(255,255,255,0.85);
  font-size: 12px;
}

/* FAQ калькулятора */
.calc-faq {
  margin: 0;
  border-bottom: 1px solid var(--border);
}
.calc-faq summary {
  cursor: pointer;
  padding: 16px 0;
  font-size: 17px;
  list-style: none;
  position: relative;
  padding-right: 30px;
  user-select: none;
}
.calc-faq summary::-webkit-details-marker { display: none; }
.calc-faq summary::after {
  content: '+';
  position: absolute;
  right: 4px;
  top: 50%;
  transform: translateY(-50%);
  font-size: 22px;
  color: var(--text-muted);
  font-weight: 300;
  transition: transform 0.2s;
}
.calc-faq[open] summary::after {
  content: '−';
}
.calc-faq[open] summary { color: var(--accent); }
.calc-faq p {
  padding: 0 0 16px;
  margin: 0;
  color: var(--text-muted);
  font-family: var(--font-serif);
  font-size: 16px;
  line-height: 1.6;
}

/* === Подвал === */
.site-footer {
  border-top: 1px solid var(--border);
  padding: 40px 24px 60px;
  background: var(--surface);
}
.site-footer__inner {
  max-width: var(--wide-width);
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 24px;
  font-family: var(--font-sans);
  font-size: 14px;
  color: var(--text-muted);
}
.site-footer a { color: var(--text-muted); }
.site-footer a:hover { color: var(--text); text-decoration: none; }

/* === Адаптив === */
@media (max-width: 700px) {
  .article { margin: 32px auto 60px; }
  .article__body { font-size: 18px; }
  .hero { padding: 56px 20px 40px; }
  .cards { gap: 28px 20px; }
  .site-nav { gap: 16px; }
}