/* 文件：style.css */
/* 全局样式与重置 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', sans-serif;
    background: #f9fafc;
    color: #1e293b;
    line-height: 1.5;
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

/* 内容区域自动撑开 footer 靠底 */
main {
    flex: 1;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

/* 头部导航 */
header {
    background: white;
    box-shadow: 0 1px 4px rgba(0,0,0,0.05);
    position: sticky;
    top: 0;
    z-index: 10;
}

.nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    padding: 1rem 1.5rem;
}

.logo a {
    font-size: 1.6rem;
    font-weight: 700;
    text-decoration: none;
    background: linear-gradient(135deg, #2b6e4f, #1e4a6e);
    background-clip: text;
    -webkit-background-clip: text;
    color: transparent;
}

.logo-en {
    display: block;
    font-size: 0.75rem;
    color: #5b6e8c;
    letter-spacing: 0.5px;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 1.8rem;
}

.nav-menu a {
    text-decoration: none;
    font-weight: 500;
    color: #334155;
    transition: color 0.2s;
    font-size: 1rem;
}

.nav-menu a:hover,
.nav-menu a.active {
    color: #2b6e4f;
    border-bottom: 2px solid #2b6e4f;
    padding-bottom: 4px;
}

.mobile-toggle {
    display: none;
    font-size: 1.8rem;
    cursor: pointer;
    user-select: none;
}

/* 按钮/卡片公用 */
.btn-primary {
    display: inline-block;
    background: #2b6e4f;
    color: white;
    padding: 0.75rem 1.8rem;
    border-radius: 40px;
    text-decoration: none;
    font-weight: 600;
    transition: 0.2s;
    border: none;
    cursor: pointer;
}

.btn-primary:hover {
    background: #1f5a41;
    transform: translateY(-2px);
}

.section-title {
    font-size: 2rem;
    margin-bottom: 2rem;
    border-left: 6px solid #2b6e4f;
    padding-left: 1rem;
    color: #0f2b2b;
}

/* hero区域 */
.hero {
    background: linear-gradient(145deg, #eef2f3, #e0e8ed);
    padding: 4rem 0;
    text-align: center;
    margin-bottom: 2rem;
}

.hero h1 {
    font-size: 2.8rem;
    margin-bottom: 1rem;
    color: #1f3b3a;
}

.hero p {
    font-size: 1.2rem;
    max-width: 700px;
    margin: 0 auto 2rem;
    color: #2c4c4b;
}

/* 卡片网格 */
.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 2rem;
    margin: 2rem 0;
}

.card {
    background: white;
    border-radius: 24px;
    padding: 1.8rem;
    box-shadow: 0 8px 20px rgba(0,0,0,0.03);
    transition: 0.2s;
    border: 1px solid #e9edf2;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 20px 30px -12px rgba(0,0,0,0.1);
}

.card-icon {
    font-size: 2.8rem;
    margin-bottom: 1rem;
}

.card h3 {
    font-size: 1.5rem;
    margin-bottom: 0.75rem;
}

.card p {
    color: #475569;
    margin-bottom: 1rem;
}

.card-link {
    font-weight: 600;
    text-decoration: none;
    color: #2b6e4f;
    display: inline-flex;
    align-items: center;
    gap: 6px;
}

.card-link:hover {
    text-decoration: underline;
}

/* 内容展示区通用 */
.content-block {
    background: white;
    border-radius: 28px;
    padding: 2rem;
    margin: 2rem 0;
    box-shadow: 0 4px 12px rgba(0,0,0,0.03);
    border: 1px solid #eef2f8;
}

.content-block h2 {
    font-size: 1.8rem;
    margin: 1rem 0 1rem 0;
    color: #1e3a3a;
}

.content-block h3 {
    font-size: 1.4rem;
    margin: 1.2rem 0 0.6rem;
    color: #2b6e4f;
}

.content-block p, .content-block li {
    color: #2d3a4b;
    margin-bottom: 0.75rem;
}

.content-block ul, .content-block ol {
    margin-left: 1.8rem;
    margin-bottom: 1rem;
}

.tip-card {
    background: #eaf7f0;
    border-left: 4px solid #2b6e4f;
    padding: 1rem 1.5rem;
    border-radius: 20px;

    margin: 1.5rem 0;
}

/* 资源列表样式 */
.resource-list {
    list-style: none;
    background: white;
    border-radius: 24px;
    padding: 1rem;
}

.resource-list li {
    padding: 0.8rem 1rem;
    border-bottom: 1px solid #edf2f7;
    display: flex;
    justify-content: space-between;
    flex-wrap: wrap;
}

.resource-list a {
    text-decoration: none;
    font-weight: 500;
    color: #1f4e3d;
}

/* 底部 */
footer {
    background: #0f1e1c;
    color: #b9cfcb;
    text-align: center;
    padding: 2rem 0;
    margin-top: 3rem;
    font-size: 0.85rem;
}

footer p {
    margin: 0.4rem 0;
}

.beian {
    display: flex;
    justify-content: center;
    gap: 2rem;
    flex-wrap: wrap;
    margin-top: 0.5rem;
}

/* 响应式 */
@media (max-width: 850px) {
    .nav-menu {
        display: none;
        width: 100%;
        flex-direction: column;
        background: white;
        padding: 1rem;
        gap: 1rem;
        margin-top: 0.5rem;
        border-radius: 20px;
    }
    .nav-menu.show {
        display: flex;
    }
    .mobile-toggle {
        display: block;
    }
    .nav-container {
        flex-wrap: wrap;
    }
    .hero h1 {
        font-size: 2rem;
    }
    .section-title {
        font-size: 1.6rem;
    }
}

@media (max-width: 500px) {
    .container {
        padding: 0 1rem;
    }
    .card-grid {
        grid-template-columns: 1fr;
    }
}