/* ===========================================================================
   Koso AI News Daily
   A Koso child brand: tokens and type scale from koso.ai (koso-brand skill).
   Anton display on Inter, ink on warm paper, zero radius, hairline borders.
   =========================================================================== */

:root {
  --background: oklch(0.985 0.002 90);   /* #fafaf9 warm paper */
  --foreground: oklch(0.13 0 0);         /* #070707 ink */
  --card: oklch(1 0 0);
  --muted: oklch(0.95 0.002 90);
  --muted-foreground: oklch(0.45 0 0);
  --accent: oklch(0.92 0.002 90);
  --border: oklch(0.13 0 0 / 12%);
  --grid: oklch(0.13 0 0 / 8%);
  --font-display: "Anton", "Impact", "Haettenschweiler", "Arial Narrow Bold", "Oswald", "Arial Black", sans-serif;
  --font-sans: "Inter", system-ui, sans-serif;
  --font-mono: ui-monospace, "SF Mono", Menlo, Consolas, monospace;
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
}

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--background);
  color: var(--foreground);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}
img { max-width: 100%; height: auto; }
a { color: inherit; text-underline-offset: 3px; text-decoration-thickness: 1px; }
::selection { background: var(--foreground); color: var(--background); }

/* ── Type scale ─────────────────────────────────────────────────────────── */
.h-hero, .h-section, .h-sub, .k-display {
  font-family: var(--font-display);
  font-weight: 400;
  letter-spacing: -0.02em;
  text-transform: uppercase;
  margin: 0;
}
.h-hero { font-size: clamp(3rem, 8.1vw + 2.25rem, 5.5rem); line-height: 1.02; }
.h-section { font-size: clamp(1.75rem, 8.75vw, 3.5rem); line-height: 1.05; }
.h-sub { font-size: clamp(1.25rem, 2.5vw + 0.75rem, 1.75rem); line-height: 1.1; }
.p-lead { font-size: clamp(1rem, 0.625vw + 0.875rem, 1.125rem); line-height: 1.55; margin: 0; }
@media (min-width: 640px) {
  .h-hero { font-size: 88px; }
  .h-section { font-size: 56px; }
  .h-sub { font-size: 28px; }
  .p-lead { font-size: 20px; }
}
@media (min-width: 1024px) {
  .h-hero { font-size: 112px; }
  .h-section { font-size: 80px; }
  .h-sub { font-size: 36px; }
  .p-lead { font-size: 22px; }
  body { font-size: 17px; }
}
.k-italic {
  font-family: var(--font-sans);
  font-style: italic;
  font-weight: 300;
  text-transform: none;
  letter-spacing: -0.01em;
}
.k-muted { color: var(--muted-foreground); }
.k-label {
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  opacity: 0.7;
  margin: 0 0 12px;
}

/* ── Layout ─────────────────────────────────────────────────────────────── */
.k-container { max-width: 1400px; margin: 0 auto; padding: 0 24px; }
@media (min-width: 1024px) { .k-container { padding: 0 40px; } }
.grid-bg {
  background-image:
    linear-gradient(to right, var(--grid) 1px, transparent 1px),
    linear-gradient(to bottom, var(--grid) 1px, transparent 1px);
  background-size: 80px 80px;
}

/* Eyebrow: 01 ── LABEL */
.k-eyebrow {
  display: flex;
  align-items: center;
  gap: 12px;
  margin: 0 0 20px;
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  opacity: 0.7;
}
.k-eyebrow-n { font-family: var(--font-display); font-size: 14px; letter-spacing: 0; }
.k-eyebrow-rule { width: 32px; height: 1px; background: currentColor; opacity: 0.4; }

/* Buttons: square, ink primary, hairline secondary */
.k-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 24px;
  border: 1px solid var(--border);
  font-weight: 600;
  font-size: 15px;
  text-decoration: none;
  transition: background-color 0.2s, opacity 0.2s;
}
.k-btn:hover { background: var(--accent); }
.k-btn-primary { background: var(--foreground); color: var(--background); border-color: var(--foreground); }
.k-btn-primary:hover { background: var(--foreground); opacity: 0.9; }
.k-btn span { transition: transform 0.3s var(--ease); }
.k-btn:hover span { transform: translateX(3px); }

/* ── Nav ────────────────────────────────────────────────────────────────── */
.k-nav {
  position: sticky;
  top: 0;
  z-index: 10;
  background: color-mix(in oklch, var(--background) 92%, transparent);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
}
.k-nav-inner { display: flex; align-items: center; justify-content: space-between; height: 64px; gap: 16px; }
.k-logo img { display: block; height: 26px; width: auto; }
.k-nav-links { display: flex; align-items: center; gap: 24px; font-size: 14px; font-weight: 500; }
.k-nav-links > a:not(.k-btn) { text-decoration: none; opacity: 0.7; transition: opacity 0.2s; }
.k-nav-links > a:not(.k-btn):hover { opacity: 1; }
.k-nav-links .k-btn { padding: 8px 16px; font-size: 14px; }
@media (max-width: 480px) { .k-nav-links > a:not(.k-btn) { display: none; } }

/* ── Hero ───────────────────────────────────────────────────────────────── */
.k-hero { position: relative; overflow: hidden; border-bottom: 1px solid var(--border); }
.k-hero-grid { position: absolute; inset: 0; pointer-events: none; }
.k-hero-inner { position: relative; padding-top: 64px; padding-bottom: 56px; display: grid; gap: 40px; }
@media (min-width: 1024px) {
  .k-hero-inner { grid-template-columns: 1.3fr 1fr; padding-top: 96px; padding-bottom: 80px; align-items: end; }
  .k-hero-inner > .k-eyebrow { grid-column: 1 / -1; margin-bottom: -16px; }
}
.k-hero-side { display: flex; flex-direction: column; gap: 32px; max-width: 480px; }
.k-hero-ctas { display: flex; flex-wrap: wrap; gap: 12px; }

/* ── Archive (home) ─────────────────────────────────────────────────────── */
.k-archive { padding: 80px 0 112px; }
.k-section-head { margin-bottom: 56px; }
.k-month { margin-bottom: 48px; }
.k-month-name {
  display: flex;
  align-items: baseline;
  gap: 16px;
  margin: 0 0 16px;
  font-family: var(--font-display);
  font-weight: 400;
  font-size: 28px;
  letter-spacing: -0.02em;
  text-transform: uppercase;
}
.k-month-n { font-family: var(--font-mono); font-size: 11px; letter-spacing: 0; opacity: 0.4; }
.k-days {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
  gap: 1px;
  background: var(--border);
  border: 1px solid var(--border);
}
.k-days li { background: var(--background); }
.k-days a {
  display: flex;
  flex-direction: column;
  gap: 4px;
  height: 100%;
  padding: 20px;
  text-decoration: none;
  transition: background-color 0.2s, color 0.2s;
  position: relative;
}
.k-days a:hover { background: var(--foreground); color: var(--background); }
.k-day-num { font-family: var(--font-display); font-size: 44px; line-height: 1; letter-spacing: -0.02em; }
.k-day-name { font-size: 12px; text-transform: uppercase; letter-spacing: 0.1em; opacity: 0.6; }
.k-day-arrow { position: absolute; top: 20px; right: 20px; opacity: 0.3; transition: transform 0.3s var(--ease), opacity 0.2s; }
.k-days a:hover .k-day-arrow { opacity: 1; transform: translateX(3px); }

/* ── Briefing (post) content ────────────────────────────────────────────── */
.main-content { padding-top: 56px; padding-bottom: 112px; }
.main-content > :not(.k-archive) { max-width: 820px; }

/* Intro line: "From 101 items, 27 ..." */
.main-content > blockquote:first-child {
  margin: 0 0 40px;
  padding: 0;
  border: 0;
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--muted-foreground);
}
.main-content > blockquote:first-child p { margin: 0; }

.main-content hr { border: 0; border-top: 1px solid var(--border); margin: 40px 0; }

/* Table of contents: numbered hairline list */
.main-content > p.toc-title {
  display: block;
  font-family: var(--font-display);
  font-weight: 400;
  font-size: 28px;
  letter-spacing: -0.02em;
  text-transform: uppercase;
}
.main-content > ol {
  list-style: none;
  counter-reset: k;
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--border);
}
.main-content > ol > li {
  counter-increment: k;
  display: flex;
  align-items: baseline;
  gap: 16px;
  padding: 14px 0;
  border-bottom: 1px solid var(--border);
}
.main-content > ol > li::before {
  content: counter(k, decimal-leading-zero);
  font-family: var(--font-mono);
  font-size: 11px;
  opacity: 0.4;
  flex: 0 0 22px;
}
.main-content > ol > li > a { flex: 1; text-decoration: none; font-weight: 500; }
.main-content > ol > li > a:hover { text-decoration: underline; }

/* Category heading */
.main-content h2 {
  font-family: var(--font-display);
  font-weight: 400;
  letter-spacing: -0.02em;
  text-transform: uppercase;
  font-size: clamp(1.75rem, 6vw, 3.5rem);
  line-height: 1.05;
  margin: 64px 0 8px;
}

/* Story */
.main-content h3 {
  font-family: var(--font-display);
  font-weight: 400;
  letter-spacing: -0.01em;
  text-transform: uppercase;
  font-size: clamp(1.375rem, 2vw + 0.9rem, 2rem);
  line-height: 1.12;
  margin: 0 0 16px;
  scroll-margin-top: 88px;
}
.main-content h3 a { text-decoration: none; }
.main-content h3 a:hover { text-decoration: underline; text-decoration-thickness: 2px; }
.main-content p { margin: 0 0 16px; }
.main-content p > strong:first-child { font-weight: 600; }

/* Score badge (set by horizon.js) */
.score-badge {
  display: inline-block;
  vertical-align: middle;
  margin-left: 10px;
  padding: 3px 8px;
  font-family: var(--font-sans);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.05em;
  line-height: 1.4;
  border: 1px solid var(--foreground);
  white-space: nowrap;
}
.score-badge[data-tier="high"], .score-badge[data-tier="good"] { background: var(--foreground); color: var(--background); }
.score-badge[data-tier="mid"], .score-badge[data-tier="low"] { border-color: var(--border); color: var(--muted-foreground); }
.main-content > ol .score-badge { margin-left: auto; }

.source-line {
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--muted-foreground);
  padding-bottom: 16px;
  border-bottom: 1px solid var(--border);
}
.tag-line { font-size: 13px; color: var(--muted-foreground); }
.tag-line code {
  display: inline-block;
  margin: 2px 2px 2px 0;
  padding: 2px 8px;
  border: 1px solid var(--border);
  background: var(--card);
  font-family: var(--font-sans);
  font-size: 12px;
}

.main-content details {
  margin: 8px 0 16px;
  border: 1px solid var(--border);
  background: var(--card);
}
.main-content summary {
  padding: 12px 16px;
  font-size: 12px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  cursor: pointer;
  list-style: none;
}
.main-content summary::-webkit-details-marker { display: none; }
.main-content summary::after { content: "+"; float: right; font-weight: 400; }
.main-content details[open] summary { border-bottom: 1px solid var(--border); }
.main-content details[open] summary::after { content: "−"; }
.main-content details ul { margin: 0; padding: 12px 16px 12px 36px; font-size: 14px; }
.main-content details li { margin: 4px 0; }

.main-content code { font-family: var(--font-mono); font-size: 0.875em; background: var(--muted); padding: 1px 5px; }

/* ── Footer (ink) ───────────────────────────────────────────────────────── */
.k-footer { background: var(--foreground); color: var(--background); }
.k-footer a { color: inherit; }
.k-footer-inner {
  display: grid;
  gap: 48px;
  padding-top: 80px;
  padding-bottom: 64px;
  border-bottom: 1px solid oklch(0.985 0 0 / 10%);
}
@media (min-width: 1024px) { .k-footer-inner { grid-template-columns: 1fr 1.4fr; } }
.k-footer-logo { display: block; height: 40px; width: auto; filter: invert(1); }
.k-footer-tag { margin: 20px 0 0; font-family: var(--font-display); font-size: 28px; line-height: 1.1; text-transform: uppercase; letter-spacing: -0.02em; max-width: 14ch; }
.k-footer-cols { display: grid; grid-template-columns: repeat(auto-fit, minmax(160px, 1fr)); gap: 32px; }
.k-footer-cols a { text-decoration: none; font-weight: 500; opacity: 0.9; }
.k-footer-cols a:hover { text-decoration: underline; opacity: 1; }
.k-footer-base {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 12px;
  padding-top: 24px;
  padding-bottom: 24px;
  font-size: 13px;
  opacity: 0.6;
}

@media (prefers-reduced-motion: reduce) {
  * { transition: none !important; scroll-behavior: auto !important; }
}