.error-card{-webkit-backdrop-filter:blur(4px);backdrop-filter:blur(4px);background:#ffffffe6;border:1px solid rgba(140,160,210,.25);border-radius:20px;box-shadow:0 20px 50px #2d43791f;margin:200px auto 0;max-width:560px;padding:30px 28px;text-align:center;width:90%}.error-code{color:#3f5ea8;font-size:56px;font-weight:700;letter-spacing:2px;line-height:1;margin-bottom:10px}.error-title{color:#1f2f57;font-size:26px;margin:0 0 10px}.error-message{color:#5d6f96;font-size:15px;margin:0 0 24px}.error-btn{background:linear-gradient(135deg,#3f6ad8,#4b79ff);border:0;border-radius:10px;box-shadow:0 8px 20px #3f6ad847;color:#fff;cursor:pointer;font-size:14px;padding:10px 20px;transition:transform .15s ease,box-shadow .15s ease}.error-btn:hover{transform:translateY(-1px)}