:root{--ink:#0F1218;--cyan:#00E5FF;--cyan-50:#E8FCFF;--white:#fff;--gray-500:#5B6573;--gray-100:#F2F4F7}
*{box-sizing:border-box;margin:0;padding:0}
body{font:17px/1.6 -apple-system,BlinkMacSystemFont,"Segoe UI",Inter,system-ui,sans-serif;color:var(--ink);background:var(--gray-100);min-height:100vh}

.wrap{max-width:560px;margin:0 auto;padding:48px 20px}

.top{text-align:center;margin-bottom:32px}
.top h1{font-size:36px;font-weight:800;line-height:1.1;color:var(--ink)}
.top .sub{color:var(--gray-500);font-size:16px;margin-top:8px}

.cal{background:var(--white);border-radius:16px;box-shadow:0 12px 32px rgba(15,18,24,.08);padding:24px;overflow:hidden}

.cal-head{display:flex;align-items:center;justify-content:space-between;margin-bottom:20px}
.month-name{font-size:24px;font-weight:800;text-transform:capitalize}
.arrow{border:none;background:var(--ink);color:#fff;width:42px;height:42px;border-radius:10px;font-size:20px;cursor:pointer;transition:transform .15s ease,opacity .15s ease}
.arrow:hover{transform:scale(1.06);opacity:.85}
.arrow:active{transform:scale(.95)}

.weekdays{display:grid;grid-template-columns:repeat(7,1fr);gap:6px;margin-bottom:8px}
.weekdays span{text-align:center;font-size:13px;font-weight:700;color:var(--gray-500);text-transform:uppercase;letter-spacing:.05em}

.grid{display:grid;grid-template-columns:repeat(7,1fr);gap:6px}
.day{display:flex;align-items:center;justify-content:center;height:52px;border-radius:10px;cursor:pointer;font-size:16px;font-weight:600;color:var(--ink);transition:background .15s ease,transform .15s ease}
.day:hover{background:var(--cyan-50);transform:scale(1.05)}
.day.empty{pointer-events:none}
.day.today{background:var(--ink);color:#fff;box-shadow:0 4px 12px rgba(15,18,24,.25)}
.day.today:hover{background:var(--ink)}
.day.selected{background:var(--cyan);color:var(--ink);box-shadow:0 4px 12px rgba(0,229,255,.4)}

.cal-foot{text-align:center;margin-top:18px;padding-top:18px;border-top:1px solid var(--gray-100)}
.today-btn{border:none;background:var(--cyan-50);color:var(--ink);padding:10px 24px;border-radius:10px;font-size:15px;font-weight:700;cursor:pointer;transition:background .15s ease}
.today-btn:hover{background:var(--cyan)}

.hint{text-align:center;color:var(--gray-500);font-size:15px;margin-top:20px}

@media (max-width:480px){
  .wrap{padding:32px 14px}
  .top h1{font-size:30px}
  .cal{padding:16px}
  .day{height:44px;font-size:14px}
  .month-name{font-size:20px}
}