:root {
  --bg: #f8fafc;
  --text: #0f172a;
  --muted: #475569;
  --card: #ffffff;
  --border: #e2e8f0;
  --accent: #2563eb;
  --accent-strong: #1d4ed8;
  --shadow: 0 12px 30px rgba(15, 23, 42, 0.08);
  --reader-font-size: 18px;
  --reader-line-height: 1.6;
}

body[data-theme="dark"] {
  --bg: #0b1220;
  --text: #e2e8f0;
  --muted: #94a3b8;
  --card: #111827;
  --border: #1f2937;
  --accent: #60a5fa;
  --accent-strong: #3b82f6;
  --shadow: 0 12px 30px rgba(0, 0, 0, 0.35);
}

body[data-theme="sepia"] {
  --bg: #f6f1e9;
  --text: #3b2f2f;
  --muted: #6b5e57;
  --card: #fffaf3;
  --border: #e8dcca;
  --accent: #d97706;
  --accent-strong: #b45309;
  --shadow: 0 12px 30px rgba(107, 54, 8, 0.1);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: "Inter", system-ui, -apple-system, sans-serif;
  background: var(--bg);
  color: var(--text);
}

main {
  max-width: 1100px;
  margin: 0 auto;
  padding: 24px;
}

.topbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 16px 24px;
  background: var(--card);
  border-bottom: 1px solid var(--border);
  box-shadow: var(--shadow);
  position: sticky;
  top: 0;
  z-index: 10;
}

.brand {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 12px;
  align-items: center;
}

.logo-circle {
  width: 42px;
  height: 42px;
  border-radius: 50%;
  background: var(--accent);
  color: #fff;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  letter-spacing: 0.04em;
}

.eyebrow {
  margin: 0;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-size: 12px;
  color: var(--muted);
}

h1, h2, h3 {
  margin: 4px 0 8px;
  font-weight: 700;
}

p {
  margin: 0 0 12px;
  color: var(--text);
}

.lead {
  color: var(--muted);
  font-size: 17px;
}

.top-actions {
  display: flex;
  gap: 12px;
  align-items: center;
}

button {
  border: 1px solid var(--accent);
  background: var(--accent);
  color: #fff;
  padding: 10px 16px;
  border-radius: 10px;
  font-size: 15px;
  cursor: pointer;
  transition: background 0.2s ease, transform 0.15s ease;
}

button:hover {
  background: var(--accent-strong);
  transform: translateY(-1px);
}

button:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  transform: none;
}

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

.hero {
  background: var(--card);
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
  border-radius: 16px;
  padding: 20px;
  display: flex;
  justify-content: space-between;
  gap: 18px;
  align-items: center;
}

.hero-actions {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 16px;
  margin-top: 20px;
}

.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 16px;
  box-shadow: var(--shadow);
}

.card .meta {
  color: var(--muted);
  font-size: 14px;
}

.tags {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  margin: 8px 0 0;
}

.tag {
  background: rgba(37, 99, 235, 0.1);
  color: var(--accent-strong);
  border-radius: 999px;
  padding: 6px 10px;
  font-size: 13px;
  border: 1px solid rgba(37, 99, 235, 0.25);
}

body[data-theme="dark"] .tag {
  background: rgba(96, 165, 250, 0.12);
  color: #bfdbfe;
  border-color: rgba(96, 165, 250, 0.35);
}

.view {
  display: none;
  margin-top: 20px;
}

.view.active {
  display: block;
}

.back-row {
  margin-bottom: 12px;
}

.reader-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
}

.controls {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 12px;
  margin: 16px 0;
}

.control label {
  display: block;
  margin-bottom: 6px;
  color: var(--muted);
  font-size: 14px;
}

.control select,
.control input[type="range"] {
  width: 100%;
  padding: 8px;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: var(--card);
  color: var(--text);
}

.chapter-nav {
  display: grid;
  grid-template-columns: 120px 1fr 120px;
  align-items: center;
  gap: 12px;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 12px;
  box-shadow: var(--shadow);
}

.chapter-meta {
  display: flex;
  justify-content: center;
  gap: 14px;
  color: var(--muted);
  font-size: 14px;
}

.reader {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 18px;
  box-shadow: var(--shadow);
  font-size: var(--reader-font-size);
  line-height: var(--reader-line-height);
}

.reader p {
  margin: 0 0 16px;
  color: var(--text);
}

.status-pill {
  padding: 8px 12px;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: var(--card);
  color: var(--muted);
  font-size: 14px;
}

.status-pill[data-tone="alert"] {
  background: #fef2f2;
  color: #b91c1c;
  border-color: #fecdd3;
}

body[data-theme="dark"] .status-pill[data-tone="alert"] {
  background: #331414;
  color: #fecdd3;
  border-color: #7f1d1d;
}

.empty-state {
  margin-top: 18px;
  text-align: center;
  color: var(--muted);
}

.inline-alert {
  margin: 12px 0;
  padding: 12px 14px;
  border-radius: 12px;
  border: 1px solid var(--border);
  background: var(--card);
  color: var(--muted);
  box-shadow: var(--shadow);
}

.inline-alert[data-tone="alert"] {
  border-color: #fecdd3;
  background: #fff1f2;
  color: #9f1239;
}

body[data-theme="dark"] .inline-alert[data-tone="alert"] {
  background: #331414;
  border-color: #7f1d1d;
  color: #fecdd3;
}

.version-pills {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 8px 0 12px;
}

.version-pill {
  padding: 6px 10px;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: var(--card);
  color: var(--text);
  font-size: 13px;
}

.footer {
  max-width: 1100px;
  margin: 32px auto;
  padding: 0 24px 32px;
  color: var(--muted);
}

.noscript {
  text-align: center;
  padding: 20px;
  background: #fee2e2;
  color: #991b1b;
  margin: 16px;
  border-radius: 12px;
}

@media (max-width: 720px) {
  main {
    padding: 16px;
  }

  .chapter-nav {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .chapter-nav button {
    width: 100%;
  }

  .chapter-meta {
    justify-content: space-between;
  }
}