Add interactive check-in calendar

app/globals.css

@@ -131,6 +131,7 @@
 }
 
 body{margin:0;background:#f5f8ff;color:#172554;font-family:Arial,"PingFang SC","Microsoft YaHei",sans-serif}.shell{max-width:1120px;margin:auto;padding:32px 20px}header{display:flex;justify-content:space-between;align-items:end;gap:16px;margin-bottom:28px}.eyebrow{color:#2563eb;font-weight:700;letter-spacing:.14em;font-size:.8rem}h1{font-size:clamp(1.8rem,4vw,2.5rem);margin:8px 0}.sub{color:#64748b;margin:0}.sync{display:flex;gap:8px;align-items:center;background:#fff;padding:10px 14px;border-radius:999px;font-size:.85rem;color:#475569;box-shadow:0 1px 4px #bfdbfe}.stats{display:grid;grid-template-columns:repeat(4,1fr);gap:14px}.stat,.card,.side{background:#fff;border:1px solid #dbeafe;border-radius:18px;padding:18px}.stat span{float:right;color:#2563eb}.stat p,.stat small{display:block;margin:0;color:#64748b;font-size:.82rem}.stat strong{display:block;margin:12px 0 4px;font-size:1.65rem}.layout{display:grid;grid-template-columns:minmax(0,1fr) 280px;gap:24px;margin-top:24px}.card{padding:0;overflow:hidden;box-shadow:0 16px 50px #dbeafe}.hero{display:grid;grid-template-columns:44px 1fr 44px;align-items:center;text-align:center;gap:10px;padding:24px;background:linear-gradient(120deg,#eaf2ff,#fff)}.hero p{margin:0;color:#2563eb;font-weight:700;font-size:.9rem}.hero h2{margin:6px 0;font-size:1.55rem}.hero small{color:#64748b}.hero [role=progressbar]{grid-column:1/-1;margin-top:10px;height:10px;background:#dbeafe}.hero [data-slot=progress-indicator]{background:#2563eb}.round{width:40px;height:40px;border-radius:50%;border:1px solid #bfdbfe;background:#fff;color:#2563eb}.body{padding:24px}.tasks{display:grid;gap:10px}.task{display:flex;align-items:flex-start;gap:12px;border:1px solid #e2e8f0;border-radius:14px;padding:14px;cursor:pointer}.task:hover{border-color:#93c5fd;background:#f8fbff}.task.done{background:#eff6ff;color:#64748b}.task b{font-size:.78rem;background:#e2e8f0;border-radius:999px;padding:3px 8px;white-space:nowrap}.task.done b{background:#bfdbfe;color:#1d4ed8}.task span{line-height:1.5}.review{border-top:1px solid #e2e8f0;margin-top:22px;padding-top:20px}.review>p{font-weight:700}.pill{border:1px solid #cbd5e1;border-radius:999px;padding:7px 12px;background:white;margin:0 7px 10px 0}.pill.active{background:#2563eb;color:#fff;border-color:#2563eb}.review label{display:block;font-size:.9rem;font-weight:700;margin-top:12px}.review textarea{display:block;width:100%;min-height:92px;margin-top:8px;border:1px solid #cbd5e1;border-radius:12px;padding:12px;font:inherit;outline:none;background:#f8fafc}.review textarea:focus{border-color:#60a5fa;background:white}.dark{border-radius:18px;padding:22px;background:#172554;color:#fff}.dark h2{margin:8px 0}.dark p{color:#cbd5e1;line-height:1.6}.side{margin-top:14px}.side p{font-size:.85rem;color:#64748b;border-left:3px solid #dbeafe;padding-left:10px}.tip{font-size:.85rem;color:#64748b;line-height:1.6;padding:0 8px}@media(max-width:760px){header{align-items:flex-start;flex-direction:column}.stats{grid-template-columns:repeat(2,1fr)}.layout{grid-template-columns:1fr}.shell{padding:22px 14px}.body{padding:16px}}@media(max-width:420px){.stats{grid-template-columns:1fr}.task{gap:8px}.task b{display:none}}
+.calendar{margin-top:24px;padding:22px;background:#fff;border:1px solid #dbeafe;border-radius:18px;box-shadow:0 8px 25px #dbeafe}.calendar-head{display:flex;justify-content:space-between;align-items:center;gap:16px}.calendar-head h2{margin:5px 0;font-size:1.4rem}.month-tabs{display:flex;gap:6px}.month-tabs button{border:1px solid #dbeafe;background:#fff;color:#475569;border-radius:999px;padding:7px 11px}.month-tabs button.active{background:#2563eb;color:#fff;border-color:#2563eb}.weekdays,.calendar-grid{display:grid;grid-template-columns:repeat(7,1fr);gap:7px}.weekdays{margin:20px 0 8px;text-align:center;color:#94a3b8;font-size:.78rem}.calendar-day{min-height:68px;border:1px solid #e2e8f0;background:#fff;border-radius:12px;color:#334155;padding:7px;display:flex;flex-direction:column;align-items:flex-start;justify-content:space-between}.calendar-day:hover:not(:disabled){border-color:#60a5fa;background:#f8fbff}.calendar-day small{font-size:.68rem;color:#94a3b8}.calendar-day.full{background:#eff6ff;border-color:#93c5fd}.calendar-day.full small{color:#1d4ed8}.calendar-day.partial{background:#fffbeb;border-color:#fde68a}.calendar-day.partial small{color:#a16207}.calendar-day.chosen{outline:3px solid #2563eb;outline-offset:1px}.calendar-day.outside{visibility:hidden}.calendar-note{margin:15px 0 0;color:#64748b;font-size:.8rem}.calendar-note i{display:inline-block;width:9px;height:9px;border-radius:50%;margin:0 5px 0 12px}.calendar-note i:first-child{margin-left:0}.full-dot{background:#2563eb}.partial-dot{background:#f59e0b}.calendar-note span{margin-left:14px}@media(max-width:520px){.calendar{padding:16px}.calendar-head{align-items:flex-start;flex-direction:column}.calendar-day{min-height:52px;padding:5px}.calendar-day small{font-size:.6rem}.weekdays,.calendar-grid{gap:4px}.calendar-note span{display:block;margin:8px 0 0}}
 
 body {
   background: var(--background);