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

body {
    font-family: 'Microsoft YaHei', sans-serif;
    background: #f1f5f8;
    line-height: 1.5;
}

.hero {
    min-height: 100vh;
    background: url('https://images.unsplash.com/photo-1557683316-973673baf926?ixlib=rb-1.2.1&auto=format&fit=crop&w=1500&q=80') center/cover no-repeat;
    display: flex;
    justify-content: center;
    align-items: center;
}

.banner {
    background: rgba(255, 255, 255, 0.85);
    padding: 2rem;
    border-radius: 0.5rem;
    text-align: center;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
    max-width: 500px;
}

.banner h1 {
    color: #102a42;
    margin-bottom: 1.5rem;
    text-transform: uppercase;
}

.btn {
    text-transform: uppercase;
    background: #49a6e9;
    color: #fff;
    padding: 0.375rem 0.75rem;
    letter-spacing: 0.1rem;
    display: inline-block;
    transition: all 0.3s linear;
    font-size: 0.875rem;
    border: 2px solid #49a6e9;
    cursor: pointer;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.2);
    border-radius: 0.25rem;
}

.btn:hover {
    background: transparent;
    color: #49a6e9;
}

/* 模态框样式 */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(73, 166, 233, 0.5);
    display: grid;
    place-items: center;
    /* 默认隐藏 */
    visibility: hidden;
    z-index: -10;
    opacity: 0;
    transition: all 0.3s linear;
}

/* 显示模态框的类 */
.open-modal {
    visibility: visible;
    z-index: 10;
    opacity: 1;
}

.modal-container {
    background: #fff;
    border-radius: 0.5rem;
    width: 90vw;
    height: 30vh;
    max-width: 620px;
    text-align: center;
    display: grid;
    place-items: center;
    position: relative;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
}

.close-btn {
    position: absolute;
    top: 1rem;
    right: 1rem;
    font-size: 2rem;
    background: transparent;
    border-color: transparent;
    color: #bb2525;
    cursor: pointer;
    transition: all 0.3s linear;
}

.close-btn:hover {
    color: #e66b6b;
    transform: scale(1.1);
}