/* ── Main container ── */
.main {
  max-width: calc(var(--content-max-width) + 80px); margin: 0 auto; padding: 20px 40px 64px;
}
.section-label {
  font-family: -apple-system, sans-serif; font-size: 10px; font-weight: 700;
  letter-spacing: .1em; text-transform: uppercase; color: var(--text3);
  margin-bottom: 16px;
}

/* ── Tool grid ── */
.tools-grid {
  display: grid; grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px; padding-top: 14px;
}

@media (max-width: 1000px) {
  .tools-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
.tool-card {
  background: white; border-radius: var(--r); overflow: hidden;
  box-shadow: 0 1px 6px rgba(0,0,0,0.07);
  text-decoration: none; color: inherit; display: flex; flex-direction: column;
  transition: box-shadow .2s, transform .2s;
}
.tool-card:hover { box-shadow: var(--shadow-h); transform: translateY(-2px); }
.tool-card.preview-enabled {
  position: relative;
  overflow: visible;
}
.tool-preview-trigger {
  position: absolute;
  top: 10px;
  right: 10px;
  display: inline-flex;
  width: 26px;
  height: 26px;
  border-radius: 999px;
  border: 1px solid var(--border2);
  background: rgba(255,255,255,0.95);
  color: var(--text2);
  align-items: center;
  justify-content: center;
  box-shadow: 0 2px 8px rgba(0,0,0,0.12);
  pointer-events: auto;
}
.tool-preview-panel {
  position: absolute;
  top: -10px;
  right: -12px;
  display: block;
  width: 300px;
  border-radius: 12px;
  border: 1px solid var(--border2);
  background: #fff;
  box-shadow: 0 16px 42px rgba(0,0,0,0.25);
  padding: 8px;
  opacity: 0;
  transform: translateY(6px) scale(.98);
  transition: opacity .18s ease, transform .18s ease;
  pointer-events: none;
  z-index: 12;
}
.tool-preview-trigger:hover + .tool-preview-panel,
.tool-preview-trigger:focus-visible + .tool-preview-panel {
  opacity: 1;
  transform: translateY(0) scale(1);
}
.tool-preview-shot {
  display: block;
  width: 100%;
  height: 180px;
  border-radius: 9px;
  overflow: hidden;
  position: relative;
  border: 1px solid rgba(0,0,0,0.08);
}
.tool-preview-shot::before {
  content: 'Preview';
  position: absolute;
  left: 50%;
  top: 50%;
  font-family: -apple-system, sans-serif;
  font-size: 32px;
  font-weight: 800;
  letter-spacing: .08em;
  text-transform: uppercase;
  color: rgba(17, 24, 39, 0.08);
  transform: translate(-50%, -50%) rotate(-35deg);
  transform-origin: center;
  text-shadow: 0 1px 2px rgba(255,255,255,0.18);
  pointer-events: none;
}
.tool-preview-shot.trees {
  background: radial-gradient(circle at 22% 24%, #B7F1E0 0%, #58BC98 36%, #0F6E56 100%);
}
.tool-preview-shot.network {
  background: radial-gradient(circle at 22% 24%, #D9E9FB 0%, #7FAEDC 36%, #2C5D90 100%);
}
.tool-preview-shot.img-cs112-bst-insert {
  background-image:
    url('../../img/tool-previews/cs112-bst-insert.png'),
    radial-gradient(circle at 22% 24%, #B7F1E0 0%, #58BC98 36%, #0F6E56 100%);
  background-size: cover, auto;
  background-position: center, center;
}
.tool-preview-shot.img-cs339-tcp-full {
  background-image:
    url('../../img/tool-previews/cs339-tcp-full.png'),
    radial-gradient(circle at 22% 24%, #D9E9FB 0%, #7FAEDC 36%, #2C5D90 100%);
  background-size: cover, auto;
  background-position: center, center;
}
.tool-preview-chip {
  display: inline-block;
  position: absolute;
  left: 12px;
  top: 12px;
  font-family: -apple-system, sans-serif;
  font-size: 9px;
  font-weight: 700;
  letter-spacing: .06em;
  text-transform: uppercase;
  color: rgba(255,255,255,0.94);
}
.tool-preview-caption {
  display: block;
  font-family: -apple-system, sans-serif;
  font-size: 10px;
  font-weight: 600;
  color: var(--text3);
  margin-top: 7px;
}
.tool-card-header {
  padding: 14px 16px 12px; display: flex; align-items: flex-start; gap: 10px;
  border-bottom: 0.5px solid var(--border);
}
.tool-icon {
  width: 34px; height: 34px; border-radius: 8px;
  display: flex; align-items: center; justify-content: center; flex-shrink: 0;
}
.tool-title {
  font-size: 13px; font-weight: 700; color: var(--text);
  font-family: -apple-system, sans-serif; margin-bottom: 2px;
}
.tool-subtitle {
  font-size: 10px; font-family: -apple-system, sans-serif; font-weight: 600;
  letter-spacing: .07em; text-transform: uppercase;
}
.tool-body { padding: 12px 16px; flex: 1; }
.tool-desc {
  font-family: -apple-system, sans-serif; font-size: 12px;
  color: var(--text2); line-height: 1.6; margin-bottom: 10px;
}
.tool-features { display: flex; flex-direction: column; gap: 4px; }
.tool-feature {
  display: flex; align-items: center; gap: 6px;
  font-family: -apple-system, sans-serif; font-size: 11px; color: var(--text2);
}
.tool-feature-dot { width: 4px; height: 4px; border-radius: 50%; flex-shrink: 0; }
.tool-footer {
  padding: 10px 16px; border-top: 0.5px solid var(--border);
  display: flex; align-items: center; justify-content: space-between; background: var(--bg2);
}
.tool-cta {
  font-family: -apple-system, sans-serif; font-size: 11px; font-weight: 600;
  display: flex; align-items: center; gap: 4px;
}
.tool-arrow { transition: transform .2s; }
.tool-card:hover .tool-arrow { transform: translateX(3px); }
.tool-tag {
  font-family: -apple-system, sans-serif; font-size: 9px; font-weight: 600;
  letter-spacing: .06em; text-transform: uppercase; padding: 2px 7px; border-radius: 20px;
}

/* ── Placeholder card ── */
.placeholder-card {
  background: white; border: 1.5px dashed #C8D0DA;
  border-radius: var(--r); padding: 20px 20px;
  display: flex; align-items: flex-start; gap: 14px;
}
.placeholder-icon {
  width: 36px; height: 36px; border-radius: 8px;
  background: #ECEEF1; display: flex; align-items: center;
  justify-content: center; flex-shrink: 0;
}
.placeholder-title {
  font-family: -apple-system, sans-serif; font-size: 13px;
  font-weight: 700; color: #3D4752; margin-bottom: 4px;
}
.placeholder-desc {
  font-family: -apple-system, sans-serif; font-size: 12px;
  color: #8A95A3; line-height: 1.6;
}
.placeholder-topics { display: flex; flex-wrap: wrap; gap: 5px; margin-top: 8px; }
.placeholder-tag {
  font-family: -apple-system, sans-serif; font-size: 10px; font-weight: 600;
  padding: 2px 8px; border-radius: 20px; background: #ECEEF1; color: #6B7685;
}

@media (max-width: 720px) {
  .tool-preview-trigger,
  .tool-preview-panel {
    display: none;
  }
}