:root{--deep:#09182d;--blue:#2257cb;--teal:#087f7b;--body:#283147;--muted:#5e6981;--line:#dce4ee}
.v21-learning-meta{display:flex;gap:10px;flex-wrap:wrap;align-items:center;margin:18px 0 28px}.v21-pill{display:inline-block;font-weight:750;font-size:.76rem;letter-spacing:.04em;color:#0c605c;background:#e7f6f3;border:1px solid #c8eae5;border-radius:999px;padding:7px 12px}
.v21-article{font-size:1.03rem;line-height:1.82;color:var(--body);max-width:850px}
.v21-article h2{font-size:clamp(1.35rem,2.7vw,1.8rem);letter-spacing:-.025em;color:#1f2850;margin:2.2rem 0 1rem}
.v21-article h3{font-size:1.11rem;color:#193453;margin:0 0 .5rem}.v21-article p{margin:.55rem 0 1.15rem}
.v21-example{border:1px solid #cdd9e9;border-radius:18px;background:#f6f9fd;padding:1.3rem 1.45rem;margin:1.4rem 0}.v21-example ul{margin:0;padding-left:1.15rem}.v21-example li{margin:.5rem 0}
.v21-steps{counter-reset:step;display:grid;gap:16px}.v21-step{position:relative;padding:20px 21px 20px 64px;border:1px solid var(--line);border-radius:18px;background:#fff}.v21-step:before{counter-increment:step;content:counter(step,decimal-leading-zero);font-weight:850;color:#0c6c67;position:absolute;left:20px;top:19px;font-size:1.05rem}.v21-step p:last-child{margin-bottom:0}
.v21-note{border-left:4px solid #19a49d;border-radius:0 12px 12px 0;background:#edf8f5;padding:17px 21px;margin:22px 0}.v21-note p:last-child{margin-bottom:0}
.v21-article details{border:1px solid #d5deec;background:#fafcff;border-radius:15px;padding:16px 20px;margin:14px 0 23px}.v21-article summary{font-weight:800;cursor:pointer;color:#243a71}.v21-article details p{margin-top:12px}
.v21-next-links{display:flex;flex-wrap:wrap;gap:12px;margin:24px 0}.v21-next-links a{display:inline-flex;padding:11px 16px;border-radius:10px;background:#e8efff;color:#173d89;font-weight:750;text-decoration:none}
.v21-hub-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:18px;margin:25px 0}.v21-hub-grid article{background:white;border:1px solid #dce4ef;padding:23px;border-radius:17px;box-shadow:0 8px 25px rgba(15,30,60,.04)}.v21-hub-grid article h3{font-size:1.1rem;margin:.55rem 0}.v21-hub-grid article p{font-size:.93rem;color:#556077;line-height:1.65}.v21-hub-grid article a{color:#1d4d9e;font-weight:800}
.v21-subject-panel{margin:28px 0;border-radius:18px;background:#edf7f5;border:1px solid #cae6e1;padding:23px}.v21-subject-panel h3{margin:6px 0;color:#163d46;font-size:1.2rem}.v21-subject-panel p{color:#445866;line-height:1.7}.v21-subject-panel a{color:#126a66;font-weight:800}
@media(max-width:680px){.v21-hub-grid{grid-template-columns:1fr}.v21-step{padding:17px 17px 17px 54px}.v21-step:before{left:16px;top:18px}.v21-example{padding:16px}}