body {
    margin: 0;
    font-family: 'Roboto', 'Microsoft YaHei', sans-serif;
    background: url('../images/background.jpg') no-repeat center center/cover, #1a1a1a;
    min-height: 100vh;
    color: #fff;
    position: relative;
}
header {
    background-color: rgba(10, 25, 47, 0.95);
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    box-shadow: 0 2px 10px rgba(0,0,0,0.08);
}
.container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 32px;
    height: 68px;
}
.logo {
    display: flex;
    align-items: center;
    font-weight: bold;
    font-size: 1.3em;
}
.logo img {
    height: 36px;
    width: 36px;
    margin-right: 10px;
    object-fit: contain;
    background: transparent;
    border-radius: 6px;
    filter: none;
}
.nav-link {
    color: #ccd6f6;
    text-decoration: none;
    font-size: 1em;
    font-weight: 500;
    transition: color 0.2s;
    display: flex;
    align-items: center;
}
.nav-link:hover {
    color: #64ffda;
    background: rgba(100,255,218,0.08);
    border-radius: 4px;
}
nav ul {
    list-style: none;
    margin: 0;
    padding: 0;
    display: flex;
    align-items: center;
}
nav ul li {
    margin-left: 28px;
}
nav ul li:first-child {
    margin-left: 0;
}
nav ul li a {
    color: #ccd6f6;
    text-decoration: none;
    font-size: 1em;
    font-weight: 500;
    transition: color 0.2s;
    padding: 6px 10px;
    border-radius: 4px;
}
nav ul li a.active,
nav ul li a:hover {
    color: #64ffda;
    background: rgba(100,255,218,0.08);
}
.btn-primary {
    background-color: #64ffda;
    color: #0a192f;
    padding: 8px 22px;
    border-radius: 24px;
    text-decoration: none;
    font-weight: 700;
    font-size: 1em;
    border: none;
    transition: background 0.2s, color 0.2s;
    margin-right: 0;
}
.btn-primary:hover {
    background-color: #52e0c4;
    color: #0a192f;
}
.free-hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    position: relative;
}
.free-hero-content {
    width: 100%;
    max-width: 900px;
    margin: 0 auto;
    padding-top: 120px;
}
.free-title {
    font-size: 4em;
    font-weight: 700;
    color: #fff;
    margin-bottom: 0.2em;
    letter-spacing: 2px;
}
.free-title-seo {
    font-size: 1.5em;
    font-weight: 900;
    color: #fff;
    margin-left: 32px;
    letter-spacing: 2px;
}
.free-desc {
    color: #fff;
    font-size: 1.1em;
    margin-bottom: 18px;
    margin-top: 32px;
    opacity: 0.85;
}
.free-desc2 {
    color: #fff;
    font-size: 1.15em;
    margin-bottom: 38px;
    opacity: 0.95;
}
.free-form {
    display: flex;
    flex-direction: column;
    align-items: center;
    margin-top: 40px;
    margin-bottom: 24px;
    width: 100%;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}
.free-input-group {
    display: flex;
    justify-content: flex-start;
    align-items: center;
    gap: 18px;
    width: 100%;
}
.free-input {
    width: 320px;
    padding: 14px 18px;
    border: none;
    border-radius: 0;
    border-bottom: 2px solid #fff;
    background: transparent;
    color: #fff;
    font-size: 1.1em;
    outline: none;
    transition: border 0.2s;
}
.free-input:focus {
    border-bottom: 2px solid #64ffda;
    background: rgba(255,255,255,0.04);
}
.free-result {
    width: 100%;
    text-align: left;
    margin-top: 18px;
    font-size: 1.1em;
    min-height: 32px;
    color: #fff;
    letter-spacing: 1px;
    padding-left: 18px;
}
.free-form .btn-primary {
    background-color: transparent;
    color: #fff;
    border: 1.5px solid #fff;
    border-radius: 32px;
    padding: 12px 38px;
    font-size: 1.2em;
    font-weight: 500;
    cursor: pointer;
    transition: background 0.2s, color 0.2s, border 0.2s;
    margin-left: 18px;
    margin-top: 0;
    outline: none;
}
.free-form .btn-primary:hover {
    background: #fff;
    color: #64ffda;
    border-color: #fff;
}
.free-form .btn-secondary {
    background-color: transparent;
    color: #fff;
    padding: 10px 20px;
    text-decoration: none;
    border: 1px solid #fff;
    border-radius: 25px;
    font-size: 1.2em;
    font-weight: 500;
    cursor: pointer;
    transition: background-color 0.3s ease, color 0.3s ease;
    margin-left: 18px;
    margin-top: 0;
    outline: none;
}
.free-form .btn-secondary:hover {
    background-color: #fff;
    color: #1a1a1a;
}
@media (max-width: 900px) {
    .free-title {
        font-size: 2.5em;
    }
    .free-title-seo {
        font-size: 1.1em;
        margin-left: 12px;
    }
    .free-hero-content {
        padding-top: 80px;
    }
    .free-input {
        width: 200px;
    }
}
@media (max-width: 600px) {
    .container {
        flex-direction: column;
        height: auto;
        padding: 0 4px;
    }
    .logo {
        margin-bottom: 8px;
    }
    nav ul {
        flex-direction: column;
        align-items: flex-start;
    }
    nav ul li {
        margin: 6px 0 0 0;
    }
    .free-title {
        font-size: 1.5em;
    }
    .free-title-seo {
        font-size: 1em;
        margin-left: 4px;
    }
    .free-input {
        width: 100%;
        margin-right: 0;
    }
    .free-form {
        flex-direction: column;
        gap: 12px;
    }
} 
footer {
    text-align: center; /* 文本居中 */
    padding: 2px 0; /* 上下内边距 */
    margin-top: 40px; /* 与上方内容的间距 */
    border-top: 1px solid #eee; /* 顶部边框线，可选 */
    font-size: 1.1em; /* 字体大小 */
    color: #ffffff; /* 字体颜色 */
}