/* =========================================================
   tcm.ai — /learn/ article styles (shared)
   ========================================================= */
.art-page { max-width: 720px; margin: 0 auto; padding: 44px var(--gutter) 96px; }
.art-top { display: flex; align-items: center; justify-content: space-between; gap: 16px; margin-bottom: 36px; }
.art-back { font-family: var(--font-sans); font-size: 14px; font-weight: 600; color: var(--green); text-decoration: none; }
.art-back:hover { text-decoration: underline; }
.art-kicker { font-family: var(--font-mono); font-size: 12px; letter-spacing: .14em; text-transform: uppercase; color: var(--green-bright); margin-bottom: 12px; }
.art-page h1 { font-family: var(--font-display); font-weight: 500; font-size: clamp(30px, 5vw, 42px); line-height: 1.18; margin: 0 0 14px; }
.art-byline { font-family: var(--font-mono); font-size: 12.5px; color: var(--ink-faint); margin: 0 0 30px; }
.art-page h2 { font-family: var(--font-display); font-weight: 600; font-size: 22px; margin: 40px 0 12px; }
.art-page h3 { font-family: var(--font-sans); font-weight: 600; font-size: 16.5px; margin: 24px 0 6px; color: var(--ink); }
.art-page p, .art-page li { font-size: 16px; line-height: 1.75; color: var(--ink-soft); }
.art-page ul, .art-page ol { padding-left: 22px; margin: 10px 0; }
.art-page a { color: var(--green); }
.art-answer { background: var(--green-tint); border: 1px solid var(--sage); border-radius: var(--radius); padding: 18px 20px; margin: 0 0 30px; }
.art-answer p { margin: 0; color: var(--ink); font-size: 16.5px; }
.art-answer .lbl { font-family: var(--font-mono); font-size: 11.5px; letter-spacing: .12em; text-transform: uppercase; color: var(--green); display: block; margin-bottom: 8px; }
.art-facts { background: var(--paper-2); border: 1px solid var(--line-strong); border-radius: var(--radius); padding: 18px 20px; margin: 28px 0; }
.art-facts h2 { margin: 0 0 10px; font-size: 18px; }
.art-facts li { margin-bottom: 8px; font-size: 15px; }
.art-faq { border-top: 1px solid var(--line-strong); margin-top: 44px; padding-top: 8px; }
.art-faq details { border-bottom: 1px solid var(--line); padding: 14px 0; }
.art-faq summary { font-family: var(--font-sans); font-weight: 600; font-size: 16px; color: var(--ink); cursor: pointer; }
.art-faq details p { margin: 10px 0 0; }
.art-sources { margin-top: 44px; border-top: 1px solid var(--line-strong); padding-top: 10px; }
.art-sources li { font-size: 14px; margin-bottom: 6px; }
.art-note { background: var(--paper-3); border-radius: var(--radius-sm); padding: 14px 16px; margin: 36px 0 0; }
.art-note p { margin: 0; font-size: 13.5px; color: var(--ink-faint); line-height: 1.6; }
.art-cta { display: flex; flex-wrap: wrap; gap: 12px; align-items: center; background: var(--green); border-radius: var(--radius); padding: 22px 24px; margin: 40px 0 0; }
.art-cta p { margin: 0; color: var(--paper-2); font-size: 16px; flex: 1 1 260px; }
.art-cta a.btn { background: var(--paper); color: var(--green-deep); }

/* index page */
.learn-list { display: grid; gap: 16px; margin-top: 28px; }
.learn-card { display: block; border: 1px solid var(--line-strong); border-radius: var(--radius); padding: 20px 22px; text-decoration: none; background: var(--paper-2); transition: border-color .2s, box-shadow .2s; }
.learn-card:hover { border-color: var(--green); box-shadow: var(--shadow-sm); }
.learn-card .tag { font-family: var(--font-mono); font-size: 11.5px; letter-spacing: .12em; text-transform: uppercase; color: var(--green-bright); }
.learn-card h2 { font-family: var(--font-display); font-size: 20px; font-weight: 600; margin: 6px 0 6px; color: var(--ink); }
.learn-card p { margin: 0; font-size: 14.5px; color: var(--ink-soft); line-height: 1.6; }