/* 引入儒雅的衬线字体，打造教育学院的学术感 */
@import url('https://fonts.googleapis.com/css2?family=Noto+Serif+SC:wght@400;700;900&display=swap');

:root {
    --bg-paper: #f4f1e1; /* 暖色宣纸底 */
    --ink-dark: #2c3e50; /* 深邃浓墨 */
    --ink-light: #5a6b7d; /* 淡墨 */
    --bamboo-green: #315f51; /* 竹青，主色调 */
    --bamboo-hover: #25483d; 
    --seal-red: #9e3636; /* 传统印泥红，用于警告/点缀 */
    --border-color: #e0d8c8; /* 木质边框色 */
    --card-bg: #ffffff; /* 卡片白 */
}

body {
    margin: 0; padding: 0;
    background-color: var(--bg-paper);
    color: var(--ink-dark);
    font-family: 'Noto Serif SC', serif;
    /* 淡淡的宣纸纹理 */
    background-image: url('https://www.transparenttextures.com/patterns/rice-paper-2.png');
}

/* 顶部导航栏：端庄学院风 */
header {
    display: flex; justify-content: space-between; align-items: center;
    padding: 20px 50px;
    background: #ffffff;
    border-bottom: 2px solid var(--bamboo-green);
    box-shadow: 0 4px 15px rgba(0,0,0,0.03);
}

.logo {
    font-size: 28px; color: var(--ink-dark); text-decoration: none; font-weight: 900; letter-spacing: 2px;
}
.logo span { color: var(--seal-red); }

nav a {
    color: var(--ink-light); text-decoration: none; margin-left: 40px; font-size: 16px; font-weight: 700; letter-spacing: 1px; transition: all 0.3s;
}
nav a:hover { color: var(--bamboo-green); }

/* 下拉菜单 */
.dropdown { position: relative; display: inline-block; }
.dropbtn { color: var(--bamboo-green); cursor: pointer; padding: 10px; text-decoration: none; font-weight: bold; transition: 0.3s; }
.dropdown-content {
    display: none; position: absolute; right: 0;
    background-color: var(--card-bg); min-width: 160px;
    box-shadow: 0px 8px 16px 0px rgba(0,0,0,0.1);
    z-index: 100; border: 1px solid var(--border-color); border-top: 2px solid var(--bamboo-green);
}
.dropdown-content a { color: var(--ink-dark); padding: 12px 16px; text-decoration: none; display: block; font-size: 14px; text-align: left; transition: 0.2s; }
.dropdown-content a:hover { background-color: rgba(49, 95, 81, 0.05); color: var(--bamboo-green); }
.dropdown:hover .dropdown-content { display: block; }