.case-header {
  position: sticky;
  z-index: 100;
  top: 0;
  min-height: 70px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 10px max(clamp(22px, 4vw, 68px), calc((100vw - 1440px) / 2 + 68px));
  border-bottom: 1px solid var(--line);
  background: color-mix(in srgb, var(--paper) 90%, transparent);
  backdrop-filter: blur(16px);
}
.case-brand { display: inline-flex; align-items: center; gap: 12px; white-space: nowrap; font-size: 0.88rem; font-weight: 760; }
.case-brand-mark { display: grid; place-items: center; width: 34px; height: 34px; border: 1px solid var(--ink); font-family: Georgia, serif; font-size: 0.8rem; font-weight: 400; letter-spacing: -0.08em; }
.case-header nav { display: flex; align-items: center; gap: clamp(14px, 2.5vw, 34px); font-size: 0.77rem; font-weight: 670; }
.case-header nav a { border-bottom: 1px solid transparent; padding-block: 6px; }
.case-header nav a:hover { border-color: currentColor; }
.case-header .theme-toggle { flex: none; }

.case-page { --case-color: #80d7ff; max-width: 1440px; margin: 0 auto; padding: 0 clamp(22px, 4vw, 68px) 100px; }
.case-page[data-case="hospital"] { --case-color: #72dae5; }
.case-page[data-case="sscflp"] { --case-color: #ffc45d; }
.case-page[data-case="machine"] { --case-color: #ff965b; }
.case-page[data-case="unet"] { --case-color: #b597ff; }
.case-page[data-case="numpy"] { --case-color: #8ea3ff; }
.case-page[data-case="queueing"] { --case-color: #81e2af; }
.case-page[data-case="database"] { --case-color: #c29eff; }
.case-page[data-case="mtg"] { --case-color: #71dcbc; }
.case-page[data-case="heart"] { --case-color: #ff9c94; }
.case-page[data-case="grocery"] { --case-color: #a8e091; }
.case-page[data-case="retention"] { --case-color: #79dfc8; }
.case-page[data-case="skincare"] { --case-color: #ffc194; }
.case-page[data-case="skincare"] .case-hero h1 { overflow-wrap: anywhere; }
.case-back { display: inline-block; margin-top: clamp(30px, 5vw, 65px); border-bottom: 1px solid var(--line-strong); padding-bottom: 4px; color: var(--ink-soft); font-size: 0.76rem; font-weight: 700; }
.case-back:hover { color: var(--accent); border-color: var(--accent); }
.case-hero { padding: clamp(52px, 7vw, 100px) 0 clamp(55px, 7vw, 96px); }
.case-kicker { margin: 0 0 22px; color: var(--accent); font-size: 0.68rem; font-weight: 760; letter-spacing: 0.17em; text-transform: uppercase; }
.case-hero h1 { max-width: 1120px; margin: 0; font-family: Georgia, "Times New Roman", serif; font-size: clamp(3.8rem, 8vw, 8.8rem); font-weight: 400; line-height: 0.96; letter-spacing: -0.058em; }
.case-lead { max-width: 800px; margin: 28px 0 0; color: var(--ink-soft); font-size: clamp(1.05rem, 1.45vw, 1.38rem); line-height: 1.65; }
.case-hero-actions { display: flex; align-items: center; flex-wrap: wrap; gap: 16px 30px; margin-top: 34px; }
.case-stack { display: flex; flex-wrap: wrap; gap: 8px; margin: 38px 0 0; padding: 0; list-style: none; }
.case-stack li { border: 1px solid var(--line); padding: 6px 10px; color: var(--ink-soft); font-family: ui-monospace, SFMono-Regular, Menlo, monospace; font-size: 0.67rem; }

.case-process { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 1px; padding: 1px; margin: 0; background: rgba(255,255,255,0.16); color: #fff; list-style: none; }
.case-process li { min-height: 178px; padding: 25px clamp(16px, 2.4vw, 32px); background: #171b1d; }
.case-process li:nth-child(2n) { background: #1d2225; }
.case-process small { display: block; margin-bottom: 25px; color: var(--case-color); font: 700 0.57rem ui-monospace, SFMono-Regular, Menlo, monospace; letter-spacing: 0.12em; }
.case-process strong { display: block; max-width: 220px; font-family: Georgia, serif; font-size: clamp(1.3rem, 2.2vw, 2.1rem); font-weight: 400; line-height: 1.07; letter-spacing: -0.025em; }
.case-process span { display: block; max-width: 230px; margin-top: 14px; color: rgba(255,255,255,0.56); font-size: 0.71rem; line-height: 1.45; }

.case-facts { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 1px; margin: 0; border: 1px solid var(--line); background: var(--line); }
.case-facts div { min-height: 146px; padding: 25px clamp(20px, 2vw, 31px); background: var(--paper); }
.case-facts dt { color: var(--ink-soft); font-size: 0.61rem; font-weight: 750; letter-spacing: 0.13em; text-transform: uppercase; }
.case-facts dd { margin: 11px 0 0; font-family: Georgia, serif; font-size: clamp(1.7rem, 3vw, 2.7rem); line-height: 1.05; letter-spacing: -0.04em; }
.case-facts small { display: block; margin-top: 7px; color: var(--ink-soft); font-family: Inter, sans-serif; font-size: 0.69rem; letter-spacing: normal; line-height: 1.45; }

.case-layout { display: grid; grid-template-columns: 210px minmax(0, 800px); justify-content: space-between; gap: clamp(35px, 5vw, 90px); padding: clamp(70px, 9vw, 140px) 0 0; }
.case-toc { position: sticky; top: 115px; align-self: start; display: grid; gap: 13px; }
.case-toc p { margin: 0 0 7px; color: var(--ink-soft); font-size: 0.6rem; font-weight: 760; letter-spacing: 0.15em; text-transform: uppercase; }
.case-toc a { display: inline-block; width: max-content; max-width: 100%; border-bottom: 1px solid transparent; color: var(--ink-soft); font-size: 0.76rem; }
.case-toc a:hover, .case-toc a:focus-visible { color: var(--accent); border-color: var(--accent); }
.case-content { min-width: 0; }
.case-section { padding: 0 0 clamp(58px, 7vw, 95px); scroll-margin-top: 110px; }
.case-section + .case-section { border-top: 1px solid var(--line); padding-top: clamp(58px, 7vw, 95px); }
.case-section-num { display: block; margin-bottom: 20px; color: var(--accent); font: 700 0.64rem ui-monospace, SFMono-Regular, Menlo, monospace; letter-spacing: 0.12em; }
.case-section h2 { margin: 0 0 27px; font-family: Georgia, serif; font-size: clamp(2.55rem, 4.5vw, 4.8rem); font-weight: 400; line-height: 1.01; letter-spacing: -0.05em; }
.case-section h3 { margin: 33px 0 10px; font-size: 0.77rem; letter-spacing: 0.09em; text-transform: uppercase; }
.case-section p, .case-section li { color: var(--ink-soft); font-size: 0.97rem; line-height: 1.8; }
.case-section p { margin: 0 0 20px; }
.case-section ul, .case-section ol { padding-left: 22px; margin: 20px 0; }
.case-section li + li { margin-top: 10px; }
.case-section strong { color: var(--ink); }
.case-section a:not(.button) { color: var(--accent); text-decoration: underline; text-underline-offset: 3px; }
.case-note { margin-top: 25px; padding: 18px 22px; border-left: 2px solid var(--accent); background: color-mix(in srgb, var(--accent) 6%, var(--paper)); color: var(--ink-soft); line-height: 1.7; }
.case-note strong { color: var(--ink); }
.case-table-wrap { overflow-x: auto; margin: 28px 0; border-top: 1px solid var(--line-strong); }
.case-table { width: 100%; min-width: 510px; border-collapse: collapse; font-size: 0.79rem; text-align: left; }
.case-table th, .case-table td { padding: 14px 12px 14px 0; border-bottom: 1px solid var(--line); vertical-align: top; }
.case-table th { color: var(--ink-soft); font-size: 0.62rem; letter-spacing: 0.1em; text-transform: uppercase; }
.case-table td { color: var(--ink); }
.case-figure { margin: 34px 0 0; border: 1px solid var(--line); background: var(--card); }
.case-figure img { display: block; width: 100%; height: auto; }
.case-figure figcaption { padding: 12px 16px; color: var(--ink-soft); font-size: 0.7rem; line-height: 1.6; }
.case-figures { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 14px; }
.case-figures .case-figure { margin: 15px 0 0; }
.case-next { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 16px; margin-top: 10px; border-top: 1px solid var(--line); padding-top: 40px; }
.case-next a { display: block; padding: 22px; border: 1px solid var(--line); transition: border-color 180ms ease, transform 180ms ease; }
.case-next a:hover { border-color: var(--accent); transform: translateY(-3px); }
.case-next small { display: block; margin-bottom: 9px; color: var(--ink-soft); font-size: 0.6rem; font-weight: 700; letter-spacing: 0.13em; text-transform: uppercase; }
.case-next strong { font-family: Georgia, serif; font-size: clamp(1.15rem, 2vw, 1.7rem); font-weight: 400; line-height: 1.1; }
.case-footer { max-width: 1440px; display: flex; justify-content: space-between; gap: 20px; margin: 0 auto; padding: 30px clamp(22px, 4vw, 68px) 55px; border-top: 1px solid var(--line); color: var(--ink-soft); font-size: 0.7rem; }
.case-footer a { color: var(--ink); }

@media (max-width: 850px) {
  .case-layout { grid-template-columns: 1fr; }
  .case-toc { position: static; display: flex; flex-wrap: wrap; gap: 10px 17px; }
  .case-toc p { width: 100%; }
}
@media (max-width: 650px) {
  .case-header { min-height: 64px; padding-inline: 18px; }
  .case-header nav { gap: 12px; }
  .case-header nav a:not(:first-child) { display: none; }
  .case-brand { font-size: 0.75rem; }
  .case-process { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .case-process li { min-height: 150px; }
  .case-facts { grid-template-columns: 1fr; }
  .case-facts div { min-height: auto; }
  .case-figures, .case-next { grid-template-columns: 1fr; }
  .case-hero h1 { font-size: clamp(3.25rem, 14vw, 5.5rem); }
  .case-page[data-case="skincare"] .case-hero h1 { font-size: clamp(2.7rem, 11vw, 5.5rem); }
  .case-footer { flex-direction: column; }
}