*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0 }

:root {
  --ink: #0a0a0a;
  --ink2: #444;
  --ink3: #777;
  --ink4: #aaa;
  --surface: #fafaf8;
  --s2: #f2f0eb;
  --s3: #e8e5de;
  --accent: #e8562a;
  --ah: #c94420;
  --navy: #14203b;
  --border: rgba(0,0,0,0.08);
  --b2: rgba(0,0,0,0.14);
  --r: 4px;
  --rl: 10px;
  --max: 1140px;
  --serif: 'Instrument Serif', Georgia, serif;
  --sans: 'Geist', system-ui, sans-serif
}

html { scroll-behavior: smooth }
body { font-family: var(--sans); background: var(--surface); color: var(--ink); font-size: 16px; line-height: 1.6; -webkit-font-smoothing: antialiased }

/* HERO */
.cs-hero { background: var(--navy); padding: 5rem 2rem 4.5rem }
.csh-i { max-width: 720px; margin: 0 auto }
.csh-eyebrow { font-size: 0.7rem; text-transform: uppercase; letter-spacing: 0.2em; color: var(--accent); margin-bottom: 1.2rem }
.csh-h1 { font-family: var(--serif); font-size: clamp(2.2rem, 5vw, 3.2rem); color: #fff; line-height: 1.1; letter-spacing: -0.02em; margin-bottom: 1.2rem }
.csh-sub { font-size: 1rem; color: rgba(255,255,255,0.55); line-height: 1.75; font-weight: 300; max-width: 580px }
.csh-meta { display: flex; gap: 2rem; flex-wrap: wrap; margin-top: 2rem; padding-top: 1.8rem; border-top: 1px solid rgba(255,255,255,0.1) }
.csh-stat strong { display: block; font-family: var(--serif); font-size: 1.6rem; color: #fff; line-height: 1 }
.csh-stat span { font-size: 0.75rem; color: rgba(255,255,255,0.4); text-transform: uppercase; letter-spacing: 0.08em }

/* GRID */
.cs-grid { max-width: var(--max); margin: 0 auto; padding: 4rem 2rem; display: grid; grid-template-columns: repeat(auto-fill, minmax(340px, 1fr)); gap: 1.5rem }

/* CARD */
.cs-card { border: 1px solid var(--border); border-radius: var(--rl); background: #fff; display: flex; flex-direction: column; transition: box-shadow 0.2s, border-color 0.2s }
.cs-card:hover { box-shadow: 0 6px 24px rgba(0,0,0,0.08); border-color: var(--b2) }
.card-top { padding: 1.8rem 1.8rem 0 }
.card-tags { display: flex; gap: 0.5rem; flex-wrap: wrap; margin-bottom: 1rem }
.card-tag { font-size: 0.68rem; text-transform: uppercase; letter-spacing: 0.1em; background: rgba(232,86,42,0.08); color: var(--accent); padding: 0.2rem 0.6rem; border-radius: 2px }
.card-title { font-family: var(--serif); font-size: 1.1rem; color: var(--ink); line-height: 1.35; margin-bottom: 0.6rem }
.card-challenge { font-size: 0.83rem; color: var(--ink3); line-height: 1.6; margin-bottom: 1.2rem }
.card-outcome { background: var(--s2); border-radius: var(--r); padding: 1rem 1.2rem; margin: 0 1.8rem }
.co-label { font-size: 0.65rem; text-transform: uppercase; letter-spacing: 0.12em; color: var(--ink4); margin-bottom: 0.4rem }
.co-metric { font-family: var(--serif); font-size: 1.5rem; color: var(--accent); line-height: 1.1; margin-bottom: 0.25rem }
.co-desc { font-size: 0.78rem; color: var(--ink2); line-height: 1.5 }
.card-actions { padding: 1.2rem 1.8rem 1.8rem; margin-top: auto; display: flex; align-items: center; justify-content: space-between; gap: 1rem; flex-wrap: wrap }
.card-read { font-size: 0.83rem; color: var(--accent); text-decoration: none; font-weight: 500; transition: color 0.2s; white-space: nowrap }
.card-read:hover { color: var(--ah) }
.card-share { font-size: 0.75rem; border: 1px solid var(--b2); color: var(--ink3); padding: 0.4rem 0.85rem; border-radius: var(--r); text-decoration: none; transition: all 0.2s; white-space: nowrap }
.card-share:hover { border-color: var(--ink2); color: var(--ink) }

/* REFERRAL STRIP */
.cs-referral { background: var(--s2); border-top: 1px solid var(--border); padding: 3.5rem 2rem; text-align: center }
.csr-i { max-width: 560px; margin: 0 auto }
.csr-i h2 { font-family: var(--serif); font-size: 1.6rem; color: var(--ink); margin-bottom: 0.6rem }
.csr-i p { font-size: 0.9rem; color: var(--ink3); line-height: 1.7; margin-bottom: 1.6rem }
.csr-i a.btn { display: inline-block; background: var(--accent); color: #fff; padding: 0.78rem 1.8rem; border-radius: var(--r); font-size: 0.88rem; font-weight: 500; text-decoration: none; transition: background 0.2s }
.csr-i a.btn:hover { background: var(--ah) }

/* FILTER BAR */
.cs-filter-bar { background: var(--surface); border-bottom: 1px solid var(--border); padding: 0 2rem; overflow-x: auto }
.cfb-i { max-width: var(--max); margin: 0 auto; display: flex; gap: 0.25rem; align-items: center; height: 52px }
.cs-tab { background: none; border: none; cursor: pointer; font-family: var(--sans); font-size: 0.83rem; color: var(--ink3); padding: 0.45rem 1rem; border-radius: var(--r); transition: all 0.15s; white-space: nowrap }
.cs-tab:hover { color: var(--ink); background: var(--s2) }
.cs-tab.active { color: var(--accent); background: rgba(232,86,42,0.08); font-weight: 500 }

/* FOOTER */
footer { background: #080808; color: rgba(255,255,255,0.45); padding: 3rem 2rem }
.foot-i { max-width: var(--max); margin: 0 auto; display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 3rem }
.foot-i--wide { grid-template-columns: 1.5fr 1fr 1fr 1fr 1fr }
.foot-logo { font-family: var(--serif); font-size: 1.1rem; color: rgba(255,255,255,0.8); text-decoration: none; display: block; margin-bottom: 0.8rem }
.foot-logo span { color: var(--accent) }
.foot-tag { font-size: 0.8rem; line-height: 1.6 }
.foot-col h5 { font-size: 0.72rem; text-transform: uppercase; letter-spacing: 0.1em; color: rgba(255,255,255,0.25); margin-bottom: 1rem; font-weight: 400 }
.foot-col ul { list-style: none; display: flex; flex-direction: column; gap: 0.5rem }
.foot-col a { font-size: 0.8rem; color: rgba(255,255,255,0.4); text-decoration: none; transition: color 0.2s }
.foot-col a:hover { color: rgba(255,255,255,0.8) }
.foot-btm { max-width: var(--max); margin: 2rem auto 0; padding-top: 1.5rem; border-top: 1px solid rgba(255,255,255,0.07); display: flex; justify-content: space-between; font-size: 0.73rem; color: rgba(255,255,255,0.2); flex-wrap: wrap; gap: 0.5rem }
.foot-btm a { color: rgba(255,255,255,0.55); text-decoration: none }
.foot-btm a:hover { color: rgba(255,255,255,0.85) }

/* RESPONSIVE */
@media (max-width: 900px) {
  .foot-i--wide { grid-template-columns: 1fr 1fr }
}
@media (max-width: 640px) {
  .cs-grid { grid-template-columns: 1fr; padding: 2.5rem 1.2rem }
  .csh-meta { gap: 1.2rem }
  .foot-i, .foot-i--wide { grid-template-columns: 1fr }
}