/* ============================================================
   MEMTEST INDUSTRIAL — Knowledge base page
   ============================================================ */

/* ---- Hero ---- */
.kb-hero {
  padding-top: 12rem;
  padding-bottom: 3rem;
  border-bottom: 1px solid var(--ink-line);
  position: relative;
  overflow: hidden;
}
.kb-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse 60% 70% at 20% 0%, var(--copper-glow) 0%, transparent 60%);
  pointer-events: none;
}
.kb-hero__inner { position: relative; z-index: 1; display: grid; grid-template-columns: 1.4fr 1fr; gap: clamp(2rem, 5vw, 5rem); align-items: end; }
.kb-hero__title { font-size: var(--fs-mega); line-height: 0.92; letter-spacing: -0.025em; max-width: 14ch; }
.kb-hero__title em { font-style: italic; color: var(--copper-bright); }
.kb-hero__title .stroke { -webkit-text-stroke: 1px var(--paper); color: transparent; }
.kb-hero__lead { color: var(--paper-dim); font-size: 1.1rem; line-height: 1.6; max-width: 46ch; }
.kb-hero__lead em { font-family: var(--font-display); font-style: italic; color: var(--copper-bright); }

.kb-search {
  margin-top: 2.5rem;
  display: flex;
  align-items: center;
  gap: 1rem;
  border: 1px solid var(--ink-line);
  background: var(--ink-raised);
  padding: 0.25rem 0.25rem 0.25rem 1.5rem;
  max-width: 540px;
}
.kb-search__icon { width: 18px; height: 18px; color: var(--paper-faint); flex-shrink: 0; }
.kb-search input {
  flex: 1;
  background: transparent;
  border: none;
  color: var(--paper);
  font-family: var(--font-mono);
  font-size: var(--fs-small);
  letter-spacing: 0.05em;
  padding: 0.9em 0;
}
.kb-search input::placeholder { color: var(--paper-faint); text-transform: uppercase; letter-spacing: 0.1em; }
.kb-search input:focus { outline: none; }
.kb-search button {
  background: var(--copper);
  color: var(--ink-void);
  font-family: var(--font-mono);
  font-size: var(--fs-micro);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  padding: 0.9em 1.4em;
}

@media (max-width: 880px) {
  .kb-hero { padding-top: 9rem; }
  .kb-hero__inner { grid-template-columns: 1fr; gap: 2rem; }
}

/* ---- Layout: sidebar + articles ---- */
.kb-layout {
  padding-block: clamp(3rem, 5vw, 4rem) var(--pad-section);
}
.kb-layout__grid {
  display: grid;
  grid-template-columns: 240px 1fr;
  gap: clamp(2rem, 4vw, 4rem);
  align-items: start;
}
.kb-sidebar {
  position: sticky;
  top: 100px;
  display: flex;
  flex-direction: column;
  gap: 2rem;
}
.kb-sidebar__group h4 {
  font-family: var(--font-mono);
  font-size: var(--fs-micro);
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--copper);
  margin-bottom: 1rem;
  font-weight: 400;
}
.kb-sidebar__group ul { display: flex; flex-direction: column; gap: 0.5rem; }
.kb-sidebar__group a {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: var(--fs-small);
  color: var(--paper-dim);
  padding: 0.5em 0;
  transition: color var(--t-fast) var(--ease-out), padding var(--t-fast) var(--ease-out);
}
.kb-sidebar__group a:hover { color: var(--paper); padding-left: 0.5rem; }
.kb-sidebar__group a.is-active { color: var(--copper-bright); }
.kb-sidebar__group a span { font-family: var(--font-mono); font-size: var(--fs-micro); color: var(--paper-faint); }

@media (max-width: 980px) {
  .kb-layout__grid { grid-template-columns: 1fr; }
  .kb-sidebar { position: static; flex-direction: row; flex-wrap: wrap; gap: 1.5rem; }
  .kb-sidebar__group { flex: 1; min-width: 200px; }
}

/* ---- Featured article (lead) ---- */
.kb-feature {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: clamp(2rem, 4vw, 3.5rem);
  padding-bottom: 3rem;
  margin-bottom: 3rem;
  border-bottom: 1px solid var(--ink-line);
  align-items: center;
}
.kb-feature__media {
  aspect-ratio: 4 / 3;
  background: var(--ink-panel);
  border: 1px solid var(--ink-line);
  overflow: hidden;
  position: relative;
}
.kb-feature__media img { width: 100%; height: 100%; object-fit: cover; filter: saturate(0.8) contrast(1.05); }
.kb-feature__media .corner-label {
  position: absolute; top: 1rem; left: 1rem;
  font-family: var(--font-mono); font-size: var(--fs-micro);
  letter-spacing: 0.14em; text-transform: uppercase;
  color: var(--paper); background: rgba(8,9,10,0.7);
  backdrop-filter: blur(4px); padding: 0.4em 0.7em;
  border: 1px solid var(--ink-line);
}
.kb-feature__body { display: flex; flex-direction: column; gap: 1.25rem; }
.kb-feature__title { font-size: var(--fs-h2); line-height: 1.05; max-width: 18ch; }
.kb-feature__title em { font-style: italic; color: var(--copper-bright); }
.kb-feature__excerpt { color: var(--paper-dim); font-size: 1.05rem; line-height: 1.6; max-width: 50ch; }
.kb-feature__meta {
  display: flex; gap: 1.5rem; flex-wrap: wrap;
  font-family: var(--font-mono); font-size: var(--fs-micro);
  letter-spacing: 0.12em; text-transform: uppercase; color: var(--paper-faint);
}
@media (max-width: 880px) { .kb-feature { grid-template-columns: 1fr; } }

/* ---- Article list ---- */
.kb-list { display: flex; flex-direction: column; }
.kb-list .article-card { border-top: 1px solid var(--ink-line); }
.kb-list .article-card:last-child { border-bottom: 1px solid var(--ink-line); }

/* ---- Topic band ---- */
.kb-topics {
  padding-block: clamp(3rem, 5vw, 4rem);
  border-top: 1px solid var(--ink-line);
  background: var(--ink-void);
}
.kb-topics__grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1px;
  background: var(--ink-line-soft);
  border: 1px solid var(--ink-line-soft);
  margin-top: 2.5rem;
}
.kb-topic {
  background: var(--ink-base);
  padding: 2rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
  transition: background var(--t-med) var(--ease-out);
}
.kb-topic:hover { background: var(--ink-raised); }
.kb-topic__num {
  font-family: var(--font-mono);
  font-size: var(--fs-small);
  letter-spacing: 0.14em;
  color: var(--copper);
}
.kb-topic h3 {
  font-family: var(--font-display);
  font-size: 1.5rem;
  line-height: 1.1;
  color: var(--paper);
}
.kb-topic h3 em { font-style: italic; color: var(--copper-bright); }
.kb-topic p { color: var(--paper-dim); font-size: var(--fs-small); line-height: 1.55; }
.kb-topic__count {
  margin-top: auto;
  font-family: var(--font-mono);
  font-size: var(--fs-micro);
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--paper-faint);
}
@media (max-width: 880px) { .kb-topics__grid { grid-template-columns: 1fr; } }

/* ---- Newsletter / subscribe band ---- */
.kb-subscribe {
  padding-block: clamp(4rem, 6vw, 6rem);
  border-top: 1px solid var(--ink-line);
}
.kb-subscribe__inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: clamp(2rem, 5vw, 5rem);
  align-items: center;
}
.kb-subscribe__title { font-size: var(--fs-h2); max-width: 16ch; }
.kb-subscribe__title em { font-style: italic; color: var(--copper-bright); }
.kb-subscribe__form { display: flex; flex-direction: column; gap: 1rem; }
.kb-subscribe__form p { color: var(--paper-dim); font-size: var(--fs-small); }
@media (max-width: 880px) { .kb-subscribe__inner { grid-template-columns: 1fr; } }

/* ---- Knowledge Grid ---- */
.knowledge-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
  margin-top: 2rem;
}
.knowledge-card {
  background: var(--ink-raised);
  border: 1px solid var(--ink-line);
  padding: 1.75rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
  transition: background var(--t-fast) var(--ease-out), border-color var(--t-fast) var(--ease-out);
}
.knowledge-card:hover {
  background: var(--ink-panel);
  border-color: var(--copper);
}
.knowledge-card__tag {
  font-family: var(--font-mono);
  font-size: var(--fs-micro);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--copper);
  padding: 0.3em 0.8em;
  background: rgba(200,149,109,0.1);
  display: inline-block;
  align-self: flex-start;
}
.knowledge-card h3 {
  font-family: var(--font-display);
  font-size: var(--fs-h4);
  line-height: 1.2;
  color: var(--paper);
}
.knowledge-card p {
  color: var(--paper-dim);
  font-size: var(--fs-small);
  line-height: 1.6;
  flex: 1;
}
.knowledge-card__link {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-family: var(--font-mono);
  font-size: var(--fs-micro);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--copper-bright);
  margin-top: auto;
}
.knowledge-card__link:hover { color: var(--paper); }

@media (max-width: 880px) {
  .knowledge-grid { grid-template-columns: 1fr; }
}