/* Bitcoin Ledger Comparison - Design system */
:root {
  --color1: #061b22;
  --color2: #184970;
  --color3: #d1975b;
  --color4: #d1be59;
  --color5: #dbd97b;
  --bg-light: #f8f6f0;
  --white: #fff;
  --text: #1a1a1a;
  --text-muted: #444;
  --border: rgba(24, 73, 112, 0.2);
  --radius: 12px;
  --shadow: 0 4px 20px rgba(6, 27, 34, 0.08);
  --font-base: 1rem;
  --font-min: 16px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
  font-size: clamp(var(--font-min), 2.5vw, 18px);
  line-height: 1.6;
  color: var(--text);
  background: var(--bg-light);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

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

a {
  color: var(--color2);
  text-decoration: none;
}

a:hover {
  color: var(--color3);
  text-decoration: underline;
}

/* Header */
.site-header {
  background: var(--color1);
  color: var(--white);
  padding: 1rem 1.5rem;
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: var(--shadow);
}

.header-inner {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.logo {
  font-weight: 700;
  font-size: 1.15rem;
  color: var(--color5);
}

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

.logo a:hover {
  color: var(--color4);
  text-decoration: none;
}

/* Nav */
.nav-main {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1.25rem;
  align-items: center;
}

.nav-main a {
  color: rgba(255,255,255,0.9);
  font-size: 0.95rem;
}

.nav-main a:hover {
  color: var(--color4);
}

/* Language switcher - links */
.lang-switcher {
  display: flex;
  gap: 0.5rem;
  align-items: center;
}

.lang-switcher span {
  opacity: 0.7;
  font-size: 0.9rem;
}

.lang-switcher a {
  color: var(--color5);
  font-weight: 500;
}

.lang-switcher a:hover {
  color: var(--white);
}

.lang-switcher a.active {
  color: var(--color4);
  text-decoration: underline;
}

/* Main content */
main {
  flex: 1;
  max-width: 900px;
  margin: 0 auto;
  padding: 2rem 1.5rem;
  width: 100%;
}

/* Blocks */
.hero {
  background: linear-gradient(135deg, var(--color1) 0%, var(--color2) 100%);
  color: var(--white);
  padding: 2.5rem 1.5rem;
  border-radius: var(--radius);
  margin-bottom: 2rem;
}

.hero h1 {
  margin: 0 0 0.5rem;
  font-size: clamp(1.5rem, 4vw, 2rem);
  color: var(--color5);
}

.hero p {
  margin: 0;
  opacity: 0.95;
  max-width: 60ch;
}

.section-block {
  background: var(--white);
  padding: 2rem 1.5rem;
  border-radius: var(--radius);
  margin-bottom: 1.5rem;
  box-shadow: var(--shadow);
  border-left: 4px solid var(--color3);
}

.section-block.alt {
  border-left-color: var(--color2);
}

.section-block.highlight {
  border-left-color: var(--color4);
  background: linear-gradient(to right, rgba(209, 190, 89, 0.08), var(--white));
}

h2 {
  color: var(--color2);
  font-size: 1.4rem;
  margin: 0 0 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 2px solid var(--color3);
}

h3 {
  color: var(--color1);
  font-size: 1.15rem;
  margin: 1.25rem 0 0.5rem;
}

p {
  margin: 0 0 1rem;
}

/* Content images - not too big */
.content-img {
  max-width: 320px;
  margin: 1rem 0;
  border-radius: 8px;
  overflow: hidden;
  box-shadow: var(--shadow);
}

/* Tables */
.table-wrap {
  overflow-x: auto;
  margin: 1rem 0;
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.95rem;
}

th, td {
  padding: 0.6rem 0.8rem;
  text-align: left;
  border: 1px solid var(--border);
}

th {
  background: var(--color2);
  color: var(--white);
  font-weight: 600;
}

tr:nth-child(even) {
  background: rgba(24, 73, 112, 0.04);
}

/* Lists */
ul.list-check, .section-block ul {
  margin: 0.5rem 0 1rem;
  padding-left: 1.5rem;
}

ul.list-check li {
  margin: 0.35rem 0;
}

/* FAQ */
.faq-block {
  background: linear-gradient(to bottom, rgba(24, 73, 112, 0.03), var(--white));
  padding: 2rem 1.5rem;
  border-radius: var(--radius);
  margin-top: 2rem;
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
  border-left: 4px solid var(--color3);
}

.faq-block > h2 {
  margin-bottom: 1.5rem;
}

.faq-list {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.faq-item {
  background: var(--white);
  border-radius: 10px;
  border: 1px solid var(--border);
  box-shadow: 0 1px 3px rgba(6, 27, 34, 0.06);
  overflow: hidden;
  transition: box-shadow 0.2s ease, border-color 0.2s ease;
}

.faq-item:hover {
  border-color: rgba(24, 73, 112, 0.25);
  box-shadow: 0 2px 8px rgba(6, 27, 34, 0.08);
}

.faq-item.is-open {
  border-color: var(--color3);
  box-shadow: 0 4px 12px rgba(209, 151, 91, 0.15);
}

.faq-question {
  width: 100%;
  padding: 1rem 1.25rem 1rem 1.35rem;
  text-align: left;
  font-size: 1.02rem;
  font-weight: 600;
  color: var(--color2);
  background: none;
  border: none;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  line-height: 1.4;
  transition: color 0.2s ease, background 0.2s ease;
}

.faq-question:hover {
  background: rgba(24, 73, 112, 0.04);
  color: var(--color1);
}

.faq-question::after {
  content: '+';
  font-family: system-ui, sans-serif;
  flex-shrink: 0;
  width: 28px;
  height: 28px;
  min-width: 28px;
  border-radius: 50%;
  background: rgba(24, 73, 112, 0.1);
  color: var(--color3);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  font-weight: 700;
  line-height: 1;
  transition: background 0.2s ease, color 0.2s ease;
}

.faq-item.is-open .faq-question::after {
  content: '−';
  background: var(--color3);
  color: var(--color1);
}

.faq-answer {
  padding: 0 1.35rem;
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease-out;
}

.faq-item.is-open .faq-answer {
  max-height: 500px;
}

.faq-answer p {
  margin: 0;
  padding: 0.85rem 0 1.15rem 0;
  color: var(--text-muted);
  font-size: 0.98rem;
  line-height: 1.6;
  border-top: 1px solid rgba(24, 73, 112, 0.08);
}

/* Footer */
.site-footer {
  background: var(--color1);
  color: rgba(255,255,255,0.85);
  padding: 2rem 1.5rem;
  margin-top: 3rem;
}

.footer-inner {
  max-width: 1200px;
  margin: 0 auto;
}

.footer-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem 1.5rem;
  margin-bottom: 1rem;
}

.footer-nav a {
  color: var(--color5);
}

.footer-nav a:hover {
  color: var(--color4);
}

.footer-lang {
  margin-top: 1rem;
  padding-top: 1rem;
  border-top: 1px solid rgba(255,255,255,0.2);
}

.footer-lang a {
  color: var(--color5);
  margin-right: 0.75rem;
}

.footer-copy {
  margin-top: 1rem;
  font-size: 0.9rem;
  opacity: 0.8;
}

/* Internal links in content */
.content-links {
  margin: 1rem 0;
}

.content-links a {
  display: inline-block;
  margin: 0.25rem 0.5rem 0.25rem 0;
  padding: 0.35rem 0.75rem;
  background: rgba(24, 73, 112, 0.1);
  border-radius: 6px;
  font-weight: 500;
}

.content-links a:hover {
  background: rgba(24, 73, 112, 0.2);
}

/* Responsive */
@media (max-width: 768px) {
  .site-header {
    padding: 0.75rem 1rem;
  }
  .header-inner {
    flex-direction: column;
    align-items: flex-start;
  }
  .nav-main {
    width: 100%;
  }
  main {
    padding: 1.25rem 1rem;
  }
  .hero {
    padding: 1.5rem 1rem;
  }
  .section-block {
    padding: 1.25rem 1rem;
  }
  .content-img {
    max-width: 100%;
  }
  .faq-block {
    padding: 1.5rem 1rem;
  }
  .faq-question {
    padding: 0.9rem 1rem 0.9rem 1.15rem;
    font-size: 1rem;
  }
  .faq-answer {
    padding: 0 1.15rem;
  }
  .faq-answer p {
    padding: 0.75rem 0 1rem 0;
  }
}

@media (max-width: 480px) {
  body {
    font-size: var(--font-min);
  }
  .lang-switcher {
    flex-wrap: wrap;
  }
}