/* 课堂小规则：大字、大图、圆圆的 */
.rules-main{background:linear-gradient(160deg,#fdeceb 0%,#fbf6f2 45%,#eef5ea 100%);min-height:70vh;padding:28px 0 40px}
.rules-stage{display:grid;justify-items:center;gap:18px;padding:0 16px}
.rule-card{position:relative;width:min(760px,100%);min-height:min(62vh,520px);display:grid;place-content:center;justify-items:center;text-align:center;background:#fff;border-radius:40px;box-shadow:0 14px 40px rgba(83,128,71,.16);padding:32px 24px}
.rule-card.pop{animation:rule-pop .35s ease}
@keyframes rule-pop{from{transform:scale(.94);opacity:.4}to{transform:none;opacity:1}}
.rule-num{position:absolute;top:22px;left:26px;width:46px;height:46px;border-radius:50%;background:#e8737a;color:#fff;display:grid;place-items:center;font:700 1.6rem "Noto Sans SC","PingFang SC","Microsoft YaHei",sans-serif}
.rule-icon{font-size:min(28vw,170px);line-height:1.1}
.rule-card h1{margin:10px 0 6px;font:700 clamp(2.6rem,7vw,4.4rem)/1.2 "Noto Sans SC","PingFang SC","Microsoft YaHei",sans-serif;color:#2f4a28}
.rule-card p{margin:0;font:700 clamp(1.3rem,3vw,1.9rem)/1.5 "Noto Sans SC","PingFang SC","Microsoft YaHei",sans-serif;color:#cf5a64}
.rules-nav{display:flex;align-items:center;gap:16px}
.rules-btn{width:64px;height:64px;border-radius:50%;border:0;background:#fff;color:#3f6436;font-size:1.8rem;box-shadow:0 6px 18px rgba(83,128,71,.18);cursor:pointer}
.rules-btn.is-next{background:#3f6436;color:#fff}
.rules-dots{display:flex;gap:8px}
.rules-dots button{width:14px;height:14px;border-radius:50%;border:0;background:#d6dccf;padding:0;cursor:pointer}
.rules-dots button[aria-current=true]{background:#e8737a;width:30px;border-radius:999px}
.rules-back a{color:#3f6436;font-weight:600;text-decoration:none}
.rules-all{padding:36px 0 10px}
.rules-all h2{font:700 1.8rem "Noto Sans SC","PingFang SC","Microsoft YaHei",sans-serif;color:#2f4a28;margin:0 0 16px;padding-left:14px;position:relative}
.rules-all h2::before{content:"";position:absolute;left:0;top:.3em;bottom:.3em;width:4px;border-radius:2px;background:#e8737a}
.rules-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:14px}
.rule-mini{display:grid;justify-items:center;gap:4px;padding:18px 12px;border:0;border-radius:26px;background:#fff;box-shadow:0 6px 18px rgba(83,128,71,.12);cursor:pointer;color:#2f4a28}
.rule-mini-icon{font-size:56px;line-height:1.1}
.rule-mini b{font:700 1.4rem "Noto Sans SC","PingFang SC","Microsoft YaHei",sans-serif}
.rule-mini small{color:#6b7766;font-size:.95rem}
@media(max-width:760px){.rules-grid{grid-template-columns:repeat(2,minmax(0,1fr))}}
.rules-all{width:min(1160px,calc(100% - 32px));margin:0 auto;box-sizing:border-box}

/* 课堂约定插画：完整显示动作，投屏和手机都保留文字空间 */
.rule-image{display:block;width:min(100%,340px);max-height:44vh;height:auto;object-fit:contain;border-radius:20px}
.rule-mini-image{display:block;width:min(100%,220px);height:auto;aspect-ratio:1;object-fit:contain;border-radius:16px;margin-bottom:8px}
.rule-card{box-sizing:border-box}
@media(max-width:480px){.rule-card{padding:24px 16px;border-radius:28px}.rule-num{top:12px;left:12px;width:36px;height:36px;font-size:1.3rem}.rule-image{max-height:36vh}.rule-card h1{font-size:2.4rem}.rule-card p{font-size:1.2rem}.rule-mini{padding:12px 8px}}