*,*:before,*:after{box-sizing:border-box}body{margin:0;font-family:system-ui,-apple-system,sans-serif;-webkit-font-smoothing:antialiased;background-color:#f5f5f5;color:#1a1a2e;line-height:1.4}.day-card{background:#fff;border-radius:10px;padding:1rem;display:flex;flex-direction:column;gap:.75rem;border-left:4px solid #ccc;box-shadow:0 1px 3px #00000014;transition:box-shadow .2s ease,transform .2s ease}.day-card:hover{box-shadow:0 4px 12px #0000001f;transform:translateY(-2px)}.day-card--addition{border-left-color:#2e7d32}.day-card--subtraction{border-left-color:#1565c0}.day-card__header{display:flex;justify-content:space-between;align-items:center}.day-card__day{font-weight:600;font-size:.95rem;color:#1a1a2e}.day-card__operation{font-weight:700;font-size:1.25rem;width:2rem;height:2rem;display:flex;align-items:center;justify-content:center;border-radius:50%;color:#fff}.op--addition{background-color:#2e7d32}.op--subtraction{background-color:#1565c0}.day-card__label{margin:0;font-size:.85rem;color:#444;line-height:1.4;flex-grow:1}.day-card__difficulty{display:flex;flex-direction:column;gap:.3rem}.difficulty-btn{padding:.35rem .5rem;font-size:.75rem;border:1px solid #ddd;border-radius:6px;background:#fafafa;color:#555;cursor:pointer;transition:all .15s ease;text-align:center}.difficulty-btn:hover{border-color:#999;background:#f0f0f0}.difficulty-btn--active{background:#1a1a2e;color:#fff;border-color:#1a1a2e}.day-card__generate{padding:.5rem;font-size:.85rem;font-weight:600;border:none;border-radius:8px;background:#1a1a2e;color:#fff;cursor:pointer;transition:background .15s ease}.day-card__generate:hover{background:#2a2a4e}.difficulty-btn:focus-visible{outline:2px solid #1a1a2e;outline-offset:2px}.day-card__generate:focus-visible{outline:2px solid #1a1a2e;outline-offset:2px}.week-row{margin-bottom:1.5rem}.week-row__header{display:flex;align-items:baseline;gap:.75rem;margin-bottom:.75rem;padding-bottom:.5rem;border-bottom:2px solid #e0e0e0}.week-row__number{font-weight:700;font-size:1.1rem;color:#1a1a2e}.week-row__date{font-size:.9rem;color:#888}.week-row__days{display:grid;grid-template-columns:repeat(5,1fr);gap:.75rem}.week-row__coming-soon{background:#f0f0f0;border-radius:10px;padding:1.5rem;text-align:center}.week-row__coming-soon p{margin:0;color:#999;font-size:.95rem;font-style:italic}@media(max-width:900px){.week-row__days{grid-template-columns:repeat(3,1fr)}}@media(max-width:600px){.week-row__days{grid-template-columns:1fr}}.app{max-width:1200px;margin:0 auto;padding:2rem;font-family:system-ui,-apple-system,sans-serif}.app header{margin-bottom:2rem}.app header h1{margin:0 0 .25rem;font-size:1.75rem;color:#1a1a2e}.app__subtitle{margin:0 0 .5rem;color:#666;font-size:1rem}.app__instruction{margin:0;color:#888;font-size:.9rem}