* { margin: 0; padding: 0; box-sizing: border-box; }

body {
    font-family: 'Segoe UI', system-ui, sans-serif;
    background: linear-gradient(135deg, #e0f2fe 0%, #bae6fd 100%);
    color: #0f172a;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
}

.screen { 
    position: absolute; 
    width: 100%; 
    height: 100%; 
    opacity: 0; 
    transition: all 0.6s ease; 
    display: none; 
}

.screen.active { 
    opacity: 1; 
    display: flex; 
    align-items: center; 
    justify-content: center; 
}

/* 安全检测 */
.security-container { text-align: center; color: #0369a1; }
.shield-icon { font-size: 4.8rem; margin-bottom: 20px; animation: pulse 2s infinite; }
.loader {
    width: 55px; height: 55px;
    border: 5px solid #bae6fd;
    border-top: 5px solid #0369a1;
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin: 20px auto;
}
.status-text { margin-top: 15px; font-size: 1.15rem; }

/* 主页面 */
.container { width: 100%; max-width: 440px; padding: 20px; }

.header-trust { 
    display: flex; 
    align-items: center; 
    justify-content: center; 
    margin-bottom: 25px; 
    text-align: center;
}

.usdt-info {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 12px;
}

.usdt-icon { 
    width: 52px; 
    height: 52px; 
}

.trust-text {
    color: #0369a1;
    font-size: 0.95rem;
    margin-top: 4px;
}

.order-box {
    background: rgba(255,255,255,0.9);
    border: 1px solid #bae6fd;
    border-radius: 12px;
    padding: 14px 20px;
    margin-bottom: 25px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}
.order-number { font-family: monospace; color: #0369a1; font-weight: bold; }

.payment-card {
    background: white;
    border-radius: 20px;
    padding: 32px 28px;
    box-shadow: 0 15px 35px rgba(0,0,0,0.1);
    border: 1px solid #bae6fd;
}

.title { text-align: center; margin-bottom: 25px; font-size: 1.4rem; color: #0f172a; }

.input-group { position: relative; margin-bottom: 25px; }

.amount-input {
    width: 100%;
    padding: 20px 25px;
    font-size: 2.1rem;
    font-weight: bold;
    background: #f0f9ff;
    border: 2px solid #bae6fd;
    border-radius: 16px;
    color: #0f172a;
    text-align: center;
}

.unit { 
    position: absolute; 
    right: 25px; 
    top: 50%; 
    transform: translateY(-50%); 
    font-size: 1.2rem; 
    color: #64748b; 
}

.pay-button {
    width: 100%;
    padding: 18px;
    background: linear-gradient(90deg, #22c55e, #4ade80);
    color: #0f172a;
    font-size: 1.25rem;
    font-weight: bold;
    border: none;
    border-radius: 16px;
    cursor: pointer;
    margin-top: 10px;
}

.pay-button:disabled { background: #94a3b8; cursor: not-allowed; }

.tips { margin-top: 25px; font-size: 0.92rem; color: #475569; text-align: center; line-height: 1.7; }
.footer-trust { text-align: center; margin-top: 35px; font-size: 0.88rem; color: #64748b; }

@keyframes spin { to { transform: rotate(360deg); } }
@keyframes pulse { 0%,100% { opacity: 1; } 50% { opacity: 0.7; } }