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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    color: #333;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    padding: 20px;
    overflow: hidden;
    opacity: 0;
    transition: opacity 0.5s ease-in-out;
}

body.loaded {
    opacity: 1;
}

.container {
    max-width: 500px;
    width: 100%;
    background-color: white;
    border-radius: 16px;
    box-shadow: 0 15px 35px rgba(0, 0, 0, 0.1), 0 5px 15px rgba(0, 0, 0, 0.05);
    padding: 40px 30px;
    text-align: center;
    animation: fadeIn 0.8s ease-in-out;
    position: relative;
    overflow: hidden;
}

@keyframes pulse {
    0% { transform: scale(1); }
    50% { transform: scale(1.03); }
    100% { transform: scale(1); }
}

.container::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 5px;
    background: linear-gradient(90deg, #3498db, #2ecc71, #3498db);
    background-size: 200% 100%;
    animation: gradientMove 3s linear infinite;
}

@keyframes gradientMove {
    0% { background-position: 0% 50%; }
    100% { background-position: 100% 50%; }
}

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

h1 {
    font-size: 26px;
    margin-bottom: 20px;
    color: #2c3e50;
    position: relative;
    display: inline-block;
    margin-top: 10px;
}

h1::after {
    content: '';
    position: absolute;
    bottom: -8px;
    left: 50%;
    transform: translateX(-50%);
    width: 50px;
    height: 3px;
    background-color: #3498db;
    border-radius: 3px;
}

p {
    font-size: 16px;
    line-height: 1.7;
    margin-bottom: 35px;
    color: #555;
    animation-delay: 0.2s;
    animation: fadeInUp 0.8s ease-in-out;
    animation-fill-mode: both;
}

@keyframes fadeInUp {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

.btn {
    display: inline-block;
    background: linear-gradient(to right, #3498db, #2980b9);
    color: white;
    text-decoration: none;
    padding: 14px 34px;
    border-radius: 50px;
    font-weight: 500;
    transition: all 0.3s ease;
    box-shadow: 0 6px 15px rgba(52, 152, 219, 0.3);
    position: relative;
    overflow: hidden;
    z-index: 1;
    animation: fadeInUp 0.8s ease-in-out 0.3s;
    animation-fill-mode: both;
}

.btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(to right, #2980b9, #3498db);
    transition: opacity 0.3s ease-in-out;
    z-index: -1;
    opacity: 0;
}

.btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 20px rgba(52, 152, 219, 0.4);
}

.btn:hover::before {
    opacity: 1;
}

.btn:active {
    transform: translateY(-1px);
    box-shadow: 0 4px 10px rgba(52, 152, 219, 0.3);
}

/* 波纹效果 */
.ripple {
    position: absolute;
    border-radius: 50%;
    background-color: rgba(255, 255, 255, 0.4);
    transform: scale(0);
    animation: ripple 0.6s linear;
    pointer-events: none;
}

@keyframes ripple {
    to {
        transform: scale(4);
        opacity: 0;
    }
}

.footer {
    margin-top: 45px;
    font-size: 14px;
    color: #999;
    animation: fadeInUp 0.8s ease-in-out 0.4s;
    animation-fill-mode: both;
}

@media (max-width: 480px) {
    .container {
        padding: 30px 20px;
        max-width: 90%;
    }
    
    h1 {
        font-size: 22px;
    }
    
    p {
        font-size: 15px;
        margin-bottom: 30px;
    }
    
    .btn {
        padding: 12px 28px;
        font-size: 15px;
    }
}

/* 背景装饰元素 */
.bg-decoration {
    position: fixed;
    width: 100%;
    height: 100%;
    top: 0;
    left: 0;
    z-index: -1;
    overflow: hidden;
}

.bg-circle {
    position: absolute;
    border-radius: 50%;
    background: rgba(52, 152, 219, 0.05);
}

.bg-circle:nth-child(1) {
    width: 300px;
    height: 300px;
    top: -150px;
    left: -150px;
}

.bg-circle:nth-child(2) {
    width: 200px;
    height: 200px;
    bottom: -100px;
    right: -100px;
}

.bg-circle:nth-child(3) {
    width: 150px;
    height: 150px;
    top: 50%;
    right: 10%;
    opacity: 0.7;
}

/* 浮动动画 */
@keyframes float {
    0% {
        transform: translateY(0) translateX(0);
    }
    50% {
        transform: translateY(-20px) translateX(10px);
    }
    100% {
        transform: translateY(0) translateX(0);
    }
}