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

body {
    background-color: #f5f3f2;
    font-family: 'Segoe UI', 'Microsoft YaHei', sans-serif;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    padding-top: 15vh;
}

.header-container {
    text-align: center;
    width: 100%;
    margin-bottom: 60px;
}

.main-title {
    color: #12507b;
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 10px;
    letter-spacing: 2px;
}

.sub-title {
    color: #12507b;
    font-size: 1.2rem;
    font-weight: 300;
    letter-spacing: 4px;
    opacity: 0.8;
}

.search-container {
    width: 100%;
    display: flex;
    justify-content: center;
    transition: all 0.3s ease;
}

.search-input-wrapper {
    width: 40%;
    position: relative;
    display: block;
    transition: width 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

.search-box {
    width: 100%;
    padding: 18px 56px 18px 25px;
    font-size: 1.1rem;
    border: 2px solid #12507b;
    border-radius: 100px;
    outline: none;
    background-color: white;
    color: #333;
    transition: border-color 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275),
                box-shadow 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    box-shadow: 0 4px 12px rgba(18, 80, 123, 0.1);
    text-align: center;
}

.search-input-wrapper:hover,
.search-input-wrapper:focus-within {
    width: 60%;
}

.search-box:focus {
    border-color: #12507b;
    box-shadow: 0 0 0 3px rgba(18, 80, 123, 0.2);
}

.search-box::placeholder {
    color: #999;
    font-weight: 300;
    text-align: center;
    transition: opacity 0.3s ease;
}

.search-button {
    position: absolute;
    top: 50%;
    right: 18px;
    transform: translateY(-50%);
    width: 28px;
    height: 28px;
    border: none;
    background: transparent;
    color: #12507b;
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    opacity: 0.82;
    transition: opacity 0.2s ease;
}

.search-button svg {
    width: 20px;
    height: 20px;
    stroke: currentColor;
    stroke-width: 2.2;
    fill: none;
    stroke-linecap: round;
    stroke-linejoin: round;
}

.search-button:hover {
    opacity: 1;
}

.search-button:active {
    opacity: 0.7;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .main-title {
        font-size: 2.5rem;
    }

    .sub-title {
        font-size: 1rem;
        letter-spacing: 2px;
    }

    .search-input-wrapper {
        width: 70%;
    }

    .search-box {
        padding: 16px 20px;
        border-radius: 100px;
    }

    .search-input-wrapper:hover,
    .search-input-wrapper:focus-within {
        width: 85%;
    }

    body {
        padding-top: 20vh;
    }
}

@media (max-width: 480px) {
    .main-title {
        font-size: 2rem;
    }

    .sub-title {
        font-size: 0.9rem;
        letter-spacing: 1px;
    }

    .search-input-wrapper {
        width: 85%;
    }

    .search-box {
        padding: 14px 18px;
        border-radius: 100px;
    }

    .search-input-wrapper:hover,
    .search-input-wrapper:focus-within {
        width: 90%;
    }

    body {
        padding-top: 25vh;
    }
}

/* 添加一些装饰性元素 */
.decoration {
    position: absolute;
    width: 300px;
    height: 300px;
    border-radius: 50%;
    background: linear-gradient(135deg, rgba(18, 80, 123, 0.05) 0%, transparent 70%);
    z-index: -1;
}

.decoration:nth-child(1) {
    top: 10%;
    left: 5%;
}

.decoration:nth-child(2) {
    bottom: 10%;
    right: 5%;
}