/* DNA SPACE — home card grid */
.tools-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:20px;max-width:1100px;margin:0 auto}
.tool-card{display:flex;flex-direction:column;padding:28px 22px;background:rgba(7,20,40,.78);border:1px solid rgba(37,99,235,.1);border-radius:16px;text-decoration:none;color:#D1D5DB;transition:all .2s;min-height:150px;backdrop-filter:blur(14px)}
.tool-card:hover{transform:translateY(-2px);border-color:rgba(37,99,235,.3)}
.tool-card-icon{font-size:2.2rem;margin-bottom:14px}
.tool-card-name{font-size:1rem;font-weight:600;color:#F3F4F6;margin:0}
.tool-badge{display:inline-block;padding:3px 10px;margin-top:10px;background:rgba(37,99,235,.12);color:#2563eb;border-radius:20px;font-size:.75rem}
.card-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:20px;max-width:1100px;margin:0 auto}
.research-card,.tutorial-card{background:rgba(7,20,40,.78);border:1px solid rgba(37,99,235,.1);border-radius:16px;padding:20px;text-decoration:none;color:#D1D5DB;transition:all .2s;display:block;backdrop-filter:blur(14px)}
.research-card:hover,.tutorial-card:hover{transform:translateY(-2px);border-color:rgba(37,99,235,.3)}
.research-title,.tutorial-title{font-size:.95rem;font-weight:600;color:#F3F4F6;margin:0 0 8px;line-height:1.4}
.research-desc,.tutorial-desc{font-size:.82rem;color:#6B7280;line-height:1.5;margin:0 0 10px}
.research-meta,.tutorial-meta{display:flex;justify-content:space-between;font-size:.75rem;color:#4B5563}
.research-thumb,.tutorial-thumb{width:100%;height:140px;background:rgba(55,65,81,.2);border-radius:8px;margin-bottom:12px;display:flex;align-items:center;justify-content:center;font-size:2rem;overflow:hidden}
.research-thumb img,.tutorial-thumb img{width:100%;height:100%;object-fit:cover}
@media(max-width:767px){.tools-grid,.card-grid{grid-template-columns:1fr}}
/* 三大核心工具卡片（2026-08-21 首页改造） */
.core-tool-card{display:flex;flex-direction:column;align-items:center;text-align:center;padding:32px 24px;background:rgba(7,20,40,.78);border:1px solid rgba(37,99,235,.1);border-radius:16px;text-decoration:none;color:#D1D5DB;transition:all .25s;min-height:260px;backdrop-filter:blur(14px)}
.core-tool-card:hover{transform:translateY(-3px);border-color:rgba(37,99,235,.35);box-shadow:0 8px 28px rgba(37,99,235,.12)}
.core-tool-icon{width:112px;height:112px;margin-bottom:18px;border-radius:14px;overflow:hidden;border:1px solid rgba(37,99,235,.18);background:rgba(255,255,255,.05);display:flex;align-items:center;justify-content:center}
.core-tool-icon img{width:100%;height:100%;object-fit:cover;display:block}
.core-tool-name{font-size:1.12rem;font-weight:600;color:#F3F4F6;margin:0 0 10px}
.core-tool-desc{font-size:.86rem;color:#9CA3AF;margin:0 0 14px;line-height:1.55}
.core-tool-go{font-size:.88rem;font-weight:600;color:#2563eb;transition:color .2s}
.core-tool-card:hover .core-tool-go{color:#5FF7E3}
body.light .core-tool-card{background:rgba(255,255,255,.88);border-color:rgba(214,158,46,.25);color:#374151}
body.light .core-tool-card:hover{border-color:rgba(214,158,46,.5)}
body.light .core-tool-name{color:#1F2937}
body.light .core-tool-desc{color:#6B7280}
body.light .core-tool-go{color:#0D9488}
@media(max-width:767px){.core-tool-card{min-height:auto}}