/* ============================================================
   Tim Hsieh — Portfolio shared styles
   ============================================================ */
:root{
  --ink:#16161A;
  --paper:#FAFAF7;
  --accent:#2B4EFF;
  --accent-hover:#1a3de0;
  --accent-soft:#eef0ff;
  --muted:#6B6B70;
  --hair:#E5E5E0;
  --card:#FFFFFF;
  --maxw:1200px;
  --readw:860px;
  --pad:clamp(16px,4vw,40px);
  --display:"Fraunces",Georgia,serif;
  --body:"Inter",system-ui,-apple-system,sans-serif;
  /* radius scale */
  --r-xs:6px;
  --r-sm:12px;
  --r-md:16px;
  --r-lg:24px;
  --r-pill:999px;
  /* spacing scale */
  --space-sm:24px;
  --space-md:48px;
  --space-lg:72px;
  --space-xl:96px;
  --space-2xl:128px;
}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}}
::selection{background:var(--accent);color:#fff}
body{
  background:var(--paper);
  color:var(--ink);
  font-family:var(--body);
  font-size:17px;
  line-height:1.55;
  -webkit-font-smoothing:antialiased;
  overflow-x:hidden;
}
a{color:inherit;text-decoration:none}
img{max-width:100%;height:auto;display:block}

/* ---- layout containers ---- */
.wrap{max-width:var(--maxw);margin:0 auto;padding:0 var(--pad)}
.read{max-width:var(--readw);margin:0 auto;padding:0 var(--pad)}

/* ---------- NAV ---------- */
header{position:sticky;top:0;z-index:50;background:rgba(250,250,247,.82);backdrop-filter:saturate(180%) blur(12px);border-bottom:1px solid var(--hair)}
.nav{display:flex;align-items:center;justify-content:space-between;height:68px}
.brand{font-family:var(--display);font-weight:600;font-size:19px;letter-spacing:-.01em}
.nav-links{display:flex;gap:30px;align-items:center;font-size:15px;font-weight:500}
.nav-links a{color:var(--muted);transition:color .15s}
.nav-links a:hover{color:var(--ink)}
.nav-cta{border:1px solid var(--ink);border-radius:var(--r-pill);padding:8px 18px;color:var(--ink)!important;font-weight:600;transition:background .15s,color .15s}
.nav-cta:hover{background:var(--ink);color:var(--paper)!important}
.menu-btn{display:none;background:none;border:none;cursor:pointer;color:var(--ink);padding:4px;line-height:1}

/* ---------- BUTTONS ---------- */
.btn{display:inline-flex;align-items:center;gap:9px;font-weight:600;font-size:15px;border-radius:var(--r-pill);padding:13px 26px;transition:background .15s,border-color .15s,color .15s}
.btn-primary{background:var(--accent);color:#fff}
.btn-primary:hover{background:var(--accent-hover)}
.btn-ghost{border:1px solid var(--hair);color:var(--ink);background:var(--card)}
.btn-ghost:hover{border-color:var(--ink)}

/* ---------- FOCUS STATES ---------- */
:focus-visible{outline:2px solid var(--accent);outline-offset:3px;border-radius:var(--r-xs)}
.card:focus-visible{outline-offset:2px}
.btn:focus-visible{border-radius:var(--r-pill)}

/* ---------- FOOTER ---------- */
footer{border-top:1px solid var(--hair);padding:34px 0;margin-top:0}
.foot{display:flex;justify-content:space-between;align-items:center;flex-wrap:wrap;gap:14px;font-size:14px;color:var(--muted)}
.foot a{color:var(--muted);transition:color .15s}
.foot a:hover{color:var(--ink)}
.foot-links{display:flex;gap:24px}

/* ---------- CASE STUDY HERO ---------- */
.cs-hero{padding:64px 0 34px}
.cs-back{font-size:14px;font-weight:600;color:var(--muted);display:inline-flex;gap:7px;align-items:center;margin-bottom:30px;transition:color .15s}
.cs-back:hover{color:var(--ink)}
.cs-back .ba{display:inline-block;transition:transform .15s}
.cs-back:hover .ba{transform:translateX(-4px)}
@media(prefers-reduced-motion:reduce){.cs-back .ba,.cs-back:hover .ba{transition:none;transform:none}}
.cs-kicker{font-size:13px;font-weight:600;letter-spacing:.12em;text-transform:uppercase;color:var(--muted);margin-bottom:18px}
.cs-hero h1{font-family:var(--display);font-weight:500;font-size:clamp(36px,5.5vw,64px);line-height:1.05;letter-spacing:-.03em;max-width:18ch;margin-bottom:20px}
.cs-hero .sub{font-size:clamp(17px,2vw,20px);color:var(--muted);max-width:60ch;line-height:1.5}

/* summary band */
.summary{border-top:1px solid var(--hair);border-bottom:1px solid var(--hair);padding:30px 0;margin:34px 0 0}
.summary-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:26px}
.sm{display:flex;flex-direction:column;gap:5px}
.sm .k{font-size:12px;font-weight:600;letter-spacing:.08em;text-transform:uppercase;color:var(--muted)}
.sm .v{font-size:15px;font-weight:500;line-height:1.4}

/* metric row */
.metric-band{padding:46px 0;border-bottom:1px solid var(--hair)}
.metric-grid{display:flex;flex-wrap:wrap;gap:22px;justify-content:space-between}
.metric{display:flex;flex-direction:column;gap:4px}
.metric .n{font-family:var(--display);font-weight:600;font-size:clamp(30px,4vw,42px);letter-spacing:-.02em;color:var(--accent);line-height:1}
.metric .l{font-size:13.5px;color:var(--muted);font-weight:500;max-width:16ch}

/* body sections */
.cs-section{padding:54px 0}
.cs-section.tight{padding:38px 0}
.cs-section h2{font-family:var(--display);font-weight:500;font-size:clamp(26px,3.4vw,38px);letter-spacing:-.025em;margin-bottom:20px;line-height:1.15;max-width:30ch;text-wrap:balance}
.cs-section h3{font-size:19px;font-weight:600;margin:30px 0 10px;letter-spacing:-.01em}
.cs-section p{color:#33333a;font-size:17px;line-height:1.65;margin-bottom:16px}
.cs-section p .lead{font-weight:500}
.eyebrow-sm{font-size:13px;font-weight:600;letter-spacing:.1em;text-transform:uppercase;color:var(--muted);margin-bottom:14px}
.eyebrow-sm .sn{color:var(--accent);margin-right:10px;font-variant-numeric:tabular-nums}

/* case video */
.case-video{max-width:var(--maxw);padding:0 var(--pad);margin:32px auto 0}
.case-video__media{display:block;width:100%;height:auto;aspect-ratio:16/9;background:var(--ink);border-radius:var(--r-md)}

/* goal cards */
.goal-grid{display:grid;grid-template-columns:1fr 1fr;gap:32px;margin-top:28px}
.goal-card{padding-top:22px}
.goal-num{font-size:12px;font-weight:600;letter-spacing:.12em;text-transform:uppercase;color:var(--muted);margin-bottom:12px}
.goal-label{font-family:var(--display);font-size:clamp(18px,2vw,22px);font-weight:500;font-style:italic;letter-spacing:-.01em;color:var(--ink);margin-bottom:12px}
.goal-card p{font-size:15.5px;color:#44444b;line-height:1.6;margin:0}
@media(max-width:860px){.goal-grid{grid-template-columns:1fr;gap:24px}}

/* pain / win lists */
.painlist{list-style:none;display:grid;gap:12px;margin:18px 0 8px}
.painlist li{display:flex;gap:12px;align-items:flex-start;font-size:16px;color:#33333a;line-height:1.5}
.painlist li::before{content:"✕";color:#c0392b;font-weight:700;flex-shrink:0;font-size:14px;margin-top:3px}
.winlist{list-style:none;display:grid;gap:12px;margin:18px 0 8px}
.winlist li{display:flex;gap:12px;align-items:flex-start;font-size:16px;color:#33333a;line-height:1.5}
.winlist li::before{content:"→";color:var(--ink);font-weight:700;flex-shrink:0;margin-top:1px}

/* callout */
.callout{background:var(--ink);color:#eaeaef;border-radius:var(--r-md);padding:38px 40px;margin:14px 0 6px}
.callout .q{font-family:var(--display);font-size:clamp(20px,2.6vw,27px);line-height:1.3;font-weight:500;color:#fff;margin-bottom:14px;font-style:italic}
.callout p{color:#e8e8f0;font-size:16px;margin-bottom:0}

/* design challenges */
.challenge{border:1px solid var(--hair);border-radius:var(--r-sm);padding:30px 32px;margin-bottom:18px;background:var(--card)}
.challenge p{max-width:76ch}
.challenge .num{font-family:var(--display);font-size:15px;font-weight:600;color:var(--ink);letter-spacing:.04em;margin-bottom:8px}
.challenge h3{margin:0 0 10px;font-size:20px}
.challenge p{margin-bottom:0;font-size:16px;color:#44444b}

/* challenge image pair */
.copilot-challenge-image-pair{display:flex;gap:clamp(20px,3vw,32px);margin:24px 0 72px;align-items:flex-start}
.copilot-challenge-image-pair__item{min-width:0}
.copilot-challenge-image-pair__item:first-child{flex:1463}
.copilot-challenge-image-pair__item:last-child{flex:3170}
.copilot-challenge-image-pair__media{width:100%;height:auto;display:block;border-radius:var(--r-sm)}
.copilot-challenge-image-pair .copilot-challenge-image-pair__caption{font-size:13.5px;color:var(--muted);margin-top:12px;margin-bottom:0;line-height:1.45;text-align:center;padding:0 4px}
@media(max-width:760px){
  .copilot-challenge-image-pair{flex-direction:column;margin-bottom:48px}
  .copilot-challenge-image-pair__item:first-child,
  .copilot-challenge-image-pair__item:last-child{flex:none;width:100%}
}

/* challenge evolution row */
.copilot-challenge-evolution{display:flex;gap:clamp(16px,2vw,24px);margin:24px 0 72px;align-items:center}
.copilot-challenge-evolution__item{min-width:0;align-self:flex-start}
.copilot-challenge-evolution__arrow{flex-shrink:0;font-size:20px;color:var(--muted);line-height:1;user-select:none}
.copilot-challenge-evolution__media{width:100%;height:auto;display:block;border-radius:var(--r-sm)}
.copilot-challenge-evolution .copilot-challenge-evolution__caption{font-size:13.5px;color:var(--muted);margin-top:12px;margin-bottom:0;line-height:1.45;text-align:center;padding:0 4px}
@media(max-width:760px){
  .copilot-challenge-evolution{flex-direction:column;margin-bottom:48px}
  .copilot-challenge-evolution__item{flex:none;width:100%;align-self:auto}
}
.copilot-challenge-evolution--stacked{flex-direction:column;align-items:stretch}
.copilot-challenge-evolution--stacked .copilot-challenge-evolution__arrow{align-self:center}
.copilot-challenge-evolution--stacked .copilot-challenge-evolution__item--centered-half{width:50%;align-self:center}
@media(max-width:760px){
  .copilot-challenge-evolution--stacked .copilot-challenge-evolution__item--centered-half{width:100%;align-self:stretch}
}

/* steps */
.step{display:grid;grid-template-columns:42px 1fr;gap:18px;padding:22px 0;border-bottom:1px solid var(--hair)}
.step:last-child{border-bottom:none}
.step .si{font-family:var(--display);font-size:20px;font-weight:600;color:var(--ink)}
.step h3{margin:0 0 6px;font-size:18px}
.step p{margin-bottom:0;font-size:16px;color:#44444b}

/* placeholder */
.imgph{background:linear-gradient(135deg,var(--accent-soft),#f6f4ee);border:1px dashed #c7cbe0;border-radius:var(--r-sm);min-height:260px;display:flex;align-items:center;justify-content:center;color:#8b8fa6;font-size:13px;font-weight:500;text-align:center;padding:24px;margin:22px 0}

/* icon pillar cards */
.pillars{display:grid;grid-template-columns:repeat(3,1fr);gap:18px;margin:28px 0}
.pillar{background:var(--card);border:1px solid var(--hair);border-radius:var(--r-sm);padding:32px 24px;text-align:center;display:flex;flex-direction:column;align-items:center}
.pillar img{width:64px;height:64px;object-fit:contain;margin-bottom:18px}
.pillar h3{font-size:17px;font-weight:600;margin:0 0 10px;letter-spacing:-.01em}
.pillar p{font-size:15px;color:#44444b;line-height:1.5;margin:0;text-align:left}

/* ============================================================
   FIGURES — two tiers, both fully responsive
   .cs-fig        → standard screenshot, stays within 760px
   .cs-fig-wide   → major screenshot, stretches to --maxw
   ============================================================ */

/* shared figure base */
figure.cs-fig,
figure.cs-fig-wide{
  margin:40px auto;
  width:100%;
}
figure.cs-fig img,
figure.cs-fig-wide img{
  width:100%;
  max-width:100%;
  display:block;
  border-radius:var(--r-sm);
}
figure.cs-fig figcaption,
figure.cs-fig-wide figcaption{
  font-size:13.5px;
  color:var(--muted);
  margin-top:12px;
  line-height:1.45;
  text-align:center;
  padding:0 4px;
}

/* standard: constrained to 760px */
figure.cs-fig{
  max-width:760px;
  padding:0 var(--pad);
}

/* wide: stretches to full content width */
figure.cs-fig-wide{
  max-width:var(--maxw);
  padding:0 var(--pad);
}

figure.prediction-challenge-one-media{width:45%;max-width:45%}
@media(max-width:860px){figure.prediction-challenge-one-media{width:100%;max-width:100%}}
figure.prediction-challenge-three-media{width:80%;max-width:calc(var(--maxw) * 0.8)}
@media(max-width:860px){figure.prediction-challenge-three-media{width:100%;max-width:100%}}

.prediction-validation-results-grid{display:grid;grid-template-columns:1fr 1fr;gap:clamp(20px,3vw,48px);max-width:var(--maxw);margin:0 auto;padding:0 var(--pad);align-items:start}
@media(max-width:860px){.prediction-validation-results-grid{grid-template-columns:1fr;gap:32px}}

/* wide wrapper passthrough (HTML compatibility) */
.cs-fig-wide-wrap{
  width:100%;
  overflow-x:hidden;
}

/* ============================================================
   FEATURE ROW — paired image + copy, 7/3 split
   ============================================================ */
.feature-row{
  max-width:var(--maxw);
  margin:56px auto;
  padding:0 var(--pad);
  display:grid;
  grid-template-columns:7fr 3fr;
  gap:clamp(32px,5vw,64px);
  align-items:center;
}
.feature-row.reverse{grid-template-columns:3fr 7fr}
.feature-row.reverse .feature-media{order:2}
.feature-row.reverse .feature-copy{order:1}
.feature-media{min-width:0}
.feature-phone{
  width:100%;
  max-height:720px;
  object-fit:contain;
  border-radius:var(--r-sm);
}
.feature-copy{min-width:0}
.feature-copy .si{
  font-family:var(--display);
  font-size:20px;
  font-weight:600;
  color:var(--ink);
  margin-bottom:12px;
}
.feature-copy h3{font-size:21px;font-weight:600;margin:0 0 10px;letter-spacing:-.01em}
.feature-copy p{font-size:16px;color:#44444b;line-height:1.6;margin:0}
.feature-caption{
  font-size:13.5px;
  color:var(--muted);
  line-height:1.45;
  text-align:center;
  margin-top:12px;
}
@media(max-width:860px){
  .feature-row,
  .feature-row.reverse{grid-template-columns:1fr;margin:36px auto}
  .feature-row.reverse .feature-media,
  .feature-row.reverse .feature-copy{order:initial}
  .feature-media{order:1}
  .feature-copy{order:2}
  .feature-phone{max-height:560px}
}

/* ============================================================
   CS-ROW — two-column editorial layout
   .cs-row         text left 40% / diagram right 60%
   .cs-row.flip    phone left 40% / text right 60% (order swap)
   .cs-row.product text left 60% / phone right 40%
   ============================================================ */
.cs-row{
  display:grid;
  grid-template-columns:2fr 3fr;
  gap:clamp(32px,4vw,56px);
  max-width:var(--maxw);
  margin:48px auto;
  padding:0 var(--pad);
  align-items:start;
}
.cs-row.product{grid-template-columns:3fr 2fr;align-items:center}
.cs-row.flip .cs-row-media{order:-1}
.cs-row.flip{align-items:center}
.cs-row.cover{align-items:stretch}
.cs-row.cover .cs-row-media{display:flex;flex-direction:column}
.cs-row.cover .cs-row-media img{flex:1;object-fit:cover;min-height:200px}
.cs-row.media-70{grid-template-columns:30fr 70fr;align-items:center}
.cs-row.media-80{grid-template-columns:20fr 80fr;align-items:center}
@media(max-width:860px){.cs-row.media-70 .cs-row-media{order:1}.cs-row.media-80 .cs-row-media{order:1}.cs-row.img-right .cs-row-media{order:1}}
.cs-row-media img{width:100%;border-radius:var(--r-sm);display:block}
/* consistent device scale: phone screenshots render at one width */
.cs-row-media.phone img,.cs-row-media.phone figure{max-width:340px;margin-inline:auto}
.cs-row-media.phone figure img{max-width:100%}
/* mid-size cap for small-source assets so they stay sharp */
.cs-row-media.cap-md img{max-width:520px;margin-inline:auto}
.cs-row-media.cap-sm img{max-width:440px;margin-inline:auto}
/* h2 inside a copy column (Problem, Synthesis): tighten bottom gap before body text */
.cs-row-copy h2{margin-bottom:14px}
/* h3 as first child in copy column: remove the 30px top push */
.cs-row-copy>h3:first-child{margin-top:0}
.cs-row-copy .si{
  font-family:var(--display);
  font-size:20px;font-weight:600;
  color:var(--ink);
  margin-bottom:12px;
  display:block;
}
.cs-row-copy h3{font-size:21px;font-weight:600;margin:0 0 10px;letter-spacing:-.01em}
.cs-row-copy p{font-size:16px;color:#44444b;line-height:1.6;margin:0 0 12px}
.cs-row-copy p:last-child{margin-bottom:0}
.cs-row-copy .callout p{color:#e8e8f0}
.cs-row-copy ol{font-size:15.5px;color:#44444b;line-height:1.55;margin:0 0 14px 18px}
.cs-row-copy ul{list-style:none;font-size:15.5px;color:#44444b;line-height:1.7;margin:0 0 8px}
.cs-row-copy ul.painlist{font-size:16px;line-height:1.5;margin:18px 0 8px}
.cs-row-copy .r-label{font-size:14px;font-weight:600;color:var(--ink);margin:14px 0 8px;display:block}
@media(max-width:860px){
  .cs-row,.cs-row.product{
    grid-template-columns:1fr;
    margin:32px auto;
    gap:20px;
  }
  .cs-row .cs-row-media{order:-1}
}

/* ============================================================
   FIG-PAIR — two equal side-by-side figures
   ============================================================ */
.fig-pair{
  display:grid;
  grid-template-columns:1fr 1fr;
  gap:clamp(20px,3vw,32px);
  max-width:var(--maxw);
  margin:40px auto;
  padding:0 var(--pad);
  align-items:start;
}
.fig-pair figure{margin:0;width:100%}
.fig-pair figure img{width:100%;border-radius:var(--r-sm);display:block}
.fig-pair figcaption{font-size:13.5px;color:var(--muted);margin-top:10px;line-height:1.45}
@media(max-width:760px){.fig-pair{grid-template-columns:1fr;gap:24px}}

/* Tighten vertical rhythm between read block and following media */
.cs-section .read + .cs-row,
.cs-section .read + figure.cs-fig,
.cs-section .read + figure.cs-fig-wide,
.cs-section .read + .fig-pair{margin-top:32px}
figure.cs-fig-wide + figure.cs-fig-wide{margin-top:24px}

/* ============================================================
   CS-INTRO — section header at the same 1200px boundary as
   .cs-row and .cs-fig-wide; fixes left-edge misalignment vs .read
   ============================================================ */
.cs-intro{
  max-width:var(--maxw);
  margin:0 auto;
  padding:0 var(--pad);
}
.cs-intro p{max-width:62ch}
.cs-section .cs-intro + .cs-row,
.cs-section .cs-intro + figure.cs-fig,
.cs-section .cs-intro + figure.cs-fig-wide,
.cs-section .cs-intro + .fig-pair{margin-top:32px}
.cs-section .cs-intro + .read{margin-top:28px}

/* ============================================================
   CS-BODY — wide editorial wrapper for title + copy sections
   Same 1200px boundary as .cs-row; body copy is left-anchored
   to the content grid instead of sitting in a narrow centered column.
   ============================================================ */
.cs-body{
  max-width:var(--maxw);
  margin:0 auto;
  padding:0 var(--pad);
}
/* readable measure inside wide sections */
.cs-body>p,.cs-body .painlist li,.cs-body .winlist li{max-width:68ch}
/* sub-label + figure pairing (Design process) */
.fig-label{margin-top:44px}
.fig-label h3{margin:0}
.cs-section .fig-label+figure.cs-fig,
.cs-section .fig-label+figure.cs-fig-wide{margin-top:14px}
.cs-section .cs-body + .cs-row,
.cs-section .cs-body + figure.cs-fig,
.cs-section .cs-body + figure.cs-fig-wide,
.cs-section .cs-body + .fig-pair{margin-top:32px}

/* Captions inside cs-row-media (when img is wrapped in <figure>) */
.cs-row-media figure{margin:0}
.cs-row-media figcaption{font-size:13.5px;color:var(--muted);margin-top:12px;line-height:1.45;text-align:center;padding:0 4px}
/* How It Works: anchor media column to top so captions align consistently under each image */
.how-it-works .cs-row-media{align-self:start}
/* How It Works: match caption style to Design Process cs-fig-wide figcaption exactly */
.how-it-works .cs-row-media figcaption{margin-top:12px;text-align:center;padding:0 4px}
.ctx-badge{display:flex;align-items:center;justify-content:center}
.ctx-badge img{max-width:100%;height:auto;max-height:160px;object-fit:contain}

/* goal brief — a set-apart statement between hairlines */
.goal-brief{border-top:1px solid var(--hair);border-bottom:1px solid var(--hair);padding:34px 0;max-width:940px}
.goal-brief .gq{font-family:var(--display);font-size:clamp(21px,2.6vw,29px);font-weight:500;line-height:1.4;letter-spacing:-.02em;color:var(--ink);max-width:36ch;margin:0 0 16px;text-wrap:balance}
.goal-brief p{max-width:60ch;margin-bottom:0}

/* takeaway */
.takeaway{background:var(--accent-soft);border-radius:var(--r-md);padding:38px 40px;margin:14px 0}
.takeaway .eyebrow-sm{color:var(--muted)}
.takeaway p{font-size:18px;color:#2a2a4a;margin-bottom:0;line-height:1.55}
.takeaway p+p{margin-top:16px}

/* next project */
.cs-next{border-top:1px solid var(--hair);padding:48px 0}
.cs-next a{display:flex;justify-content:space-between;align-items:center;gap:20px;flex-wrap:wrap}
.cs-next .lab{font-size:13px;font-weight:600;letter-spacing:.1em;text-transform:uppercase;color:var(--muted)}
.cs-next .ttl{font-family:var(--display);font-size:clamp(22px,3vw,30px);font-weight:500;letter-spacing:-.02em;transition:color .15s}
.cs-next a:hover .ttl{color:var(--accent)}
.cs-next .arr{display:inline-block;transition:transform .15s}
.cs-next a:hover .arr{transform:translateX(5px)}
@media(prefers-reduced-motion:reduce){.cs-next .arr,.cs-next a:hover .arr{transition:none;transform:none}}

/* ============================================================
   RESPONSIVE BREAKPOINTS
   1440 desktop  → variables handle it, no override needed
   1024 tablet landscape
    768 tablet portrait
    680 pillars collapse
    480 small tablet / large phone
    390 small phone
   ============================================================ */

/* 1024px — tablet landscape */
@media(max-width:1024px){
  .summary-grid{grid-template-columns:repeat(4,1fr)}
  .metric-grid{gap:20px}
}

/* 860px — nav collapse, layout tighten */
@media(max-width:860px){
  .nav-links{
    display:none;
    position:absolute;top:68px;left:0;right:0;
    background:var(--paper);
    flex-direction:column;gap:0;
    border-bottom:1px solid var(--hair);
    padding:8px 0;
  }
  .nav-links.open{display:flex}
  .nav-links a{padding:13px 28px;width:100%}
  .nav-links .nav-cta{margin:10px 28px;width:auto;text-align:center}
  .menu-btn{display:block}
  .summary-grid{grid-template-columns:1fr 1fr;gap:20px}
  .metric-grid{gap:18px}
  .callout,.takeaway{padding:28px 24px}
  .challenge{padding:22px 20px}
  figure.cs-fig,
  figure.cs-fig-wide{margin:28px auto}
}

/* 768px — tablet portrait */
@media(max-width:768px){
  .cs-section{padding:40px 0}
  .cs-section.tight{padding:28px 0}
  .metric-grid{gap:16px}
  .summary-grid{grid-template-columns:1fr 1fr;gap:16px}
}

/* 680px — pillars stack */
@media(max-width:680px){
  .pillars{grid-template-columns:1fr}
  .pillar{flex-direction:row;text-align:left;gap:20px;padding:24px 20px}
  .pillar img{width:64px;height:64px;margin-bottom:0;flex-shrink:0}
}

/* 480px — phones */
@media(max-width:480px){
  :root{--pad:16px}
  .summary-grid{grid-template-columns:1fr 1fr}
  .metric-grid{gap:14px}
  .cs-hero{padding:44px 0 24px}
  .callout,.takeaway{padding:24px 18px;border-radius:var(--r-sm)}
  .challenge{padding:18px 16px;border-radius:var(--r-xs)}
  figure.cs-fig,
  figure.cs-fig-wide{margin:20px auto}
  figure.cs-fig img,
  figure.cs-fig-wide img{border-radius:var(--r-xs)}
  .step{grid-template-columns:32px 1fr;gap:12px}
}

/* 390px — small phones */
@media(max-width:390px){
  body{font-size:16px}
  .summary-grid{grid-template-columns:1fr 1fr;gap:12px}
  .sm .v{font-size:14px}
  .metric .n{font-size:26px}
  .pillars{gap:12px}
  .pillar img{width:52px;height:52px}
  .btn{padding:11px 20px;font-size:14px}
}

/* ============================================================
   PHONE-ONLY (max-width:767px) — collapse case-study splits
   Several .cs-row blocks (and the copilot flex pairs) carry INLINE
   grid-template-columns / flex values in the HTML, e.g.
   65fr 35fr, 3fr 7fr, 35fr 65fr, 4fr 1fr. Inline styles outrank the
   plain-selector collapse rules in the ≤860px block, so the desktop
   side-by-side split survives on phones and the text column becomes
   unreadably narrow. !important is the only way to override an inline
   style from the stylesheet; this block is scoped to ≤767px so tablet
   (≥768px) and desktop layouts are left exactly as they are today.
   ============================================================ */
@media(max-width:767px){
  /* two-column editorial rows — incl. inline-styled variants */
  .cs-row,
  .cs-row.product,
  .cs-row.flip,
  .cs-row.img-right,
  .cs-row.media-70,
  .cs-row.media-80{
    grid-template-columns:1fr !important;
  }
  .cs-row-copy,
  .cs-row-media{min-width:0;width:100%;max-width:100%}
  /* media leads the stacked copy (matches existing ≤860 behavior) */
  .cs-row .cs-row-media{order:-1}

  /* paired feature rows (7fr / 3fr) */
  .feature-row,
  .feature-row.reverse{grid-template-columns:1fr !important}
  .feature-media,
  .feature-copy{min-width:0;width:100%;max-width:100%}

  /* side-by-side figure / results grids */
  .fig-pair,
  .prediction-validation-results-grid{grid-template-columns:1fr !important}

  /* copilot flex pairs — items carry inline flex:NNN, override it */
  .copilot-challenge-image-pair,
  .copilot-challenge-evolution{flex-direction:column !important}
  .copilot-challenge-image-pair__item,
  .copilot-challenge-evolution__item{flex:none !important;width:100% !important;max-width:100%;min-width:0}
  .copilot-challenge-evolution--stacked .copilot-challenge-evolution__item--centered-half{width:100% !important;align-self:stretch}

  /* fixed-percentage figures */
  figure.prediction-challenge-one-media,
  figure.prediction-challenge-three-media{width:100% !important;max-width:100% !important}

  /* stacked media never overflows its column */
  .cs-row-media img,
  .feature-phone,
  .fig-pair img{max-width:100%;height:auto;object-fit:contain}

  /* guard against horizontal overflow on the split containers */
  .cs-row,
  .feature-row,
  .fig-pair,
  .copilot-challenge-image-pair,
  .copilot-challenge-evolution{overflow-x:hidden}
}