* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', Tahoma, sans-serif;
}

body {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, #e63946 0%, #a4161a 50%, #660708 100%);
    padding: 20px;
}

.container { width: 100%; max-width: 420px; }

.card {
    background: #ffffff;
    border-radius: 24px;
    padding: 40px 30px;
    box-shadow: 0 25px 60px rgba(0, 0, 0, 0.4);
    text-align: center;
    animation: fadeInUp 0.6s ease;
}

@keyframes fadeInUp {
    from { opacity: 0; transform: translateY(30px); }
    to   { opacity: 1; transform: translateY(0); }
}

.logo {
    width: 80px; height: 80px;
    margin: 0 auto 20px;
    background: linear-gradient(135deg, #e63946, #a4161a);
    border-radius: 50%;
    display: flex; align-items: center; justify-content: center;
    color: white;
    box-shadow: 0 10px 25px rgba(230, 57, 70, 0.4);
}

.logo svg { width: 45px; height: 45px; }

h1 { color: #1a1a2e; font-size: 26px; margin-bottom: 8px; font-weight: 700; }

.subtitle { color: #6b7280; font-size: 14px; margin-bottom: 30px; }

.fetch-btn {
    width: 100%;
    padding: 16px;
    background: linear-gradient(135deg, #e63946, #a4161a);
    color: white;
    border: none;
    border-radius: 14px;
    font-size: 17px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex; align-items: center; justify-content: center; gap: 10px;
    box-shadow: 0 8px 20px rgba(230, 57, 70, 0.35);
}

.fetch-btn:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: 0 12px 25px rgba(230, 57, 70, 0.5);
}

.fetch-btn:disabled { opacity: 0.7; cursor: not-allowed; }

.spinner {
    display: none;
    width: 18px; height: 18px;
    border: 3px solid rgba(255,255,255,0.3);
    border-top-color: white;
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

.fetch-btn.loading .spinner { display: inline-block; }

@keyframes spin { to { transform: rotate(360deg); } }

.result { margin-top: 25px; min-height: 20px; }

.balance-box {
    background: linear-gradient(135deg, #f0fdf4, #dcfce7);
    border: 2px solid #22c55e;
    border-radius: 16px;
    padding: 20px;
    animation: popIn 0.4s ease;
}

.balance-box.error {
    background: linear-gradient(135deg, #fef2f2, #fee2e2);
    border-color: #ef4444;
}

@keyframes popIn {
    from { opacity: 0; transform: scale(0.9); }
    to   { opacity: 1; transform: scale(1); }
}

.balance-label { color: #166534; font-size: 14px; margin-bottom: 8px; font-weight: 500; }
.balance-value { color: #15803d; font-size: 36px; font-weight: 800; letter-spacing: 1px; }
.balance-box.error .balance-label,
.balance-box.error .balance-value { color: #b91c1c; }
.currency { font-size: 18px; margin-right: 6px; }