/* 基础公共样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f8f9fa;
    padding-top: 80px;
}

.container {
    width: 90%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* 统一导航栏样式 */
header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background-color: white;
    box-shadow: 0 2px 15px rgba(0, 0, 0, 0.1);
    z-index: 1000;
    border-bottom: 1px solid #f1f1f1;
}

.header-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px 0;
}

.logo {
    font-size: 1.8rem;
    font-weight: 700;
    color: #457b9d;
    text-decoration: none;
    display: flex;
    align-items: center;
}

.logo-icon {
    margin-right: 8px;
    font-size: 1.8rem;
}

nav ul {
    display: flex;
    list-style: none;
}

nav li {
    margin-left: 25px;
}

nav a {
    color: #333;
    text-decoration: none;
    font-size: 1.05rem;
    font-weight: 500;
    position: relative;
    padding: 5px 0;
    transition: color 0.3s ease;
}

nav a:hover {
    color: #457b9d;
}

nav a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background-color: #457b9d;
    transition: width 0.3s ease;
}

nav a:hover::after,
nav a.active::after {
    width: 100%;
}

nav a.active {
    color: #1d3557;
    font-weight: 600;
}

.cta-btn {
    background-color: #457b9d;
    color: white !important;
    padding: 8px 20px;
    border-radius: 5px;
    margin-left: 20px;
    transition: background-color 0.3s ease, transform 0.3s ease;
}

.cta-btn:hover {
    background-color: #1d3557;
    transform: translateY(-2px);
}

.cta-btn::after {
    display: none;
}

/* 移动端导航 */
.menu-toggle {
    display: none;
    cursor: pointer;
    font-size: 1.8rem;
}

/* 动画定义 */
@keyframes slideDown {
    from {
        transform: translateY(-100%);
        opacity: 0;
    }

    to {
        transform: translateY(0);
        opacity: 1;
    }
}

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

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* 响应式设计 */
/* 移动端导航响应式 */
@media (max-width: 900px) {
    nav ul {
        display: none;
        position: absolute;
        top: 80px;
        left: 0;
        width: 100%;
        background-color: white;
        flex-direction: column;
        box-shadow: 0 10px 15px rgba(0, 0, 0, 0.1);
    }

    nav li {
        margin: 0;
        text-align: center;
    }

    nav a {
        display: block;
        padding: 15px 0;
        border-bottom: 1px solid #f5f5f5;
    }

    .menu-toggle {
        display: block;
    }

    .nav-active ul {
        display: flex;
    }
}

/* 页脚样式 */
footer {
    background-color: #1d3557;
    color: white;
    padding: 30px 0;
    margin-top: 80px;
}

footer p {
    text-align: center;
    font-size: 0.95rem;
    opacity: 0.8;
}

/* 通用组件样式 */
.announcement {
    background-color: #f8f9fa;
    border-left: 4px solid #457b9d;
    padding: 15px;
    margin-bottom: 30px;
    animation: slideDown 0.5s ease-out;
}

.announcement-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.announcement h2 {
    margin: 0 0 0 10px;
    font-size: 1.2rem;
    color: #1d3557;
}

.announcement p {
    margin: 0;
    flex-grow: 1;
}

.close-btn {
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: #666;
    padding: 0 10px;
}

.watermark::after {
    content: '© SummerPainting';
    position: fixed;
    opacity: 0.1;
    font-size: 40px;
    transform: rotate(-30deg);
    pointer-events: none;
    z-index: 999;
}