/* =========================================
   Jialidun University - Deep Blue Theme
   ========================================= */
:root {
    /* --- 核心色板 (Deep Blue Palette) --- */
    --primary: #001a33;      /* 午夜深蓝 - 用于导航栏、标题 */
    --primary-light: #003366; /* 稍亮的深蓝 - 用于悬停、卡片边框 */
    --accent: #00a8cc;       /* 亮青蓝 - 用于按钮、高亮、链接（替代原来的金色） */
    --accent-hover: #008eb3; /* 按钮悬停色 */
    
    --text-main: #1a252f;    /* 深蓝灰文本 - 比纯黑更融合 */
    --text-light: #576b80;   /* 浅蓝灰文本 - 用于副标题 */
    
    --bg: #f4f7f9;           /* 极淡的冷蓝色背景 - 替代纯白/暖灰 */
    --white: #ffffff;
    
    --card-shadow: 0 4px 20px rgba(0, 26, 51, 0.08); /* 带有蓝色倾向的阴影 */
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
    margin: 0; padding: 0;
    font-family: 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
    color: var(--text-main); background-color: var(--bg);
    line-height: 1.6;
    display: flex; flex-direction: column; min-height: 100vh;
}

a { text-decoration: none; color: inherit; transition: color 0.3s; }
a:hover { color: var(--accent); }

/* --- Navigation --- */
header {
    background-color: var(--primary); color: var(--white);
    border-bottom: 3px solid var(--accent); /* 亮蓝底边 */
    position: sticky; top: 0; z-index: 1000;
    box-shadow: 0 4px 15px rgba(0,0,0,0.2);
}

.nav-container {
    max-width: 1200px; margin: 0 auto; padding: 0 20px; height: 70px;
    display: flex; justify-content: space-between; align-items: center;
}

.logo { font-size: 1.5rem; font-weight: bold; letter-spacing: 1px; color: var(--white); }

nav ul { list-style: none; margin: 0; padding: 0; display: flex; gap: 25px; align-items: center; }

nav a {
    color: rgba(255,255,255,0.75); font-size: 0.95rem; text-transform: uppercase;
    font-weight: 500; padding: 5px 0; position: relative;
}
nav a:hover, nav a.active { color: var(--accent); }
nav a::after {
    content: ''; position: absolute; width: 0; height: 2px; bottom: 0; left: 0;
    background: var(--accent); transition: width 0.3s;
}
nav a:hover::after, nav a.active::after { width: 100%; }

/* --- Layout Components --- */
.container { max-width: 1100px; width: 100%; margin: 40px auto; padding: 0 20px; flex: 1; }

.page-title {
    text-align: center; color: var(--primary); margin-bottom: 40px; font-size: 2.5rem;
    position: relative; padding-bottom: 15px;
}
.page-title::after {
    content: ''; width: 80px; height: 4px; background: var(--accent);
    position: absolute; bottom: 0; left: 50%; transform: translateX(-50%); border-radius: 2px;
}

.breadcrumb { font-size: 0.9rem; color: var(--text-light); margin-bottom: 20px; }
.breadcrumb a { color: var(--primary-light); font-weight: bold; }

/* --- Cards --- */
.grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 30px; }

.card {
    background: var(--white); padding: 30px; border-radius: 8px;
    box-shadow: var(--card-shadow); 
    border-top: 4px solid var(--primary-light); /* 默认深蓝顶边 */
    transition: transform 0.3s, box-shadow 0.3s, border-color 0.3s; 
    display: flex; flex-direction: column;
}
.card:hover { 
    transform: translateY(-5px); 
    box-shadow: 0 15px 30px rgba(0, 26, 51, 0.15); 
    border-top-color: var(--accent); /* 悬停变亮蓝 */
}
.card h3 { margin-top: 0; color: var(--primary); }
.card p { color: var(--text-light); margin-bottom: 15px; }
.card img { width: 100%; height: 200px; object-fit: cover; border-radius: 4px; margin-bottom: 15px; }

/* --- Buttons --- */
.btn-outline {
    border: 2px solid var(--accent); color: var(--accent); padding: 8px 25px;
    border-radius: 50px; font-weight: bold; transition: 0.3s; display: inline-block;
}
.btn-outline:hover { background: var(--accent); color: white; box-shadow: 0 5px 15px rgba(0, 168, 204, 0.3); }

.apply-btn, .btn-submit {
    background-color: var(--accent); color: var(--white); border: none;
    padding: 12px 35px; font-weight: bold; border-radius: 50px; cursor: pointer;
    font-size: 1rem; display: inline-block; transition: 0.3s;
}
.apply-btn:hover, .btn-submit:hover { background-color: var(--accent-hover); transform: translateY(-2px); box-shadow: 0 5px 15px rgba(0, 168, 204, 0.4); }

/* --- Special Sections --- */
/* About Page Stats */
.stats-section {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-light) 100%);
    color: var(--white); padding: 60px 20px; margin: 50px 0; border-radius: 8px;
    text-align: center; display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 30px;
    box-shadow: var(--card-shadow);
}
.stat-item { border-right: 1px solid rgba(255,255,255,0.1); }
.stat-item:last-child { border-right: none; }
.stat-number { font-size: 2.8rem; font-weight: bold; color: var(--accent); margin-bottom: 5px; }
.stat-label { font-size: 0.9rem; text-transform: uppercase; letter-spacing: 1.5px; opacity: 0.8; }

/* Quote Box */
.quote-box {
    background: #fff; border-left: 5px solid var(--accent);
    padding: 40px; font-style: italic; color: var(--text-light);
    margin: 40px 0; box-shadow: var(--card-shadow); position: relative; border-radius: 0 8px 8px 0;
}

/* Academics & Tables */
.program-section { padding: 60px 0; border-bottom: 1px solid #e0e6ed; }
.program-title { color: var(--primary); font-size: 2rem; margin: 0; }
.program-meta { color: var(--text-light); font-style: italic; display: block; margin-top: 5px;}

.course-item {
    background: #fff; padding: 15px; border: 1px solid #e0e6ed; border-radius: 6px;
    display: flex; align-items: center; gap: 10px; font-size: 0.95rem; color: var(--text-main);
}
.course-code {
    background: var(--primary-light); color: white; padding: 4px 10px; border-radius: 4px;
    font-weight: bold; font-size: 0.8rem;
}

table {
    width: 100%; border-collapse: collapse; margin: 20px 0; background: var(--white);
    box-shadow: var(--card-shadow); border-radius: 8px; overflow: hidden;
}
th { background-color: var(--primary-light); color: var(--white); font-weight: 600; padding: 15px; text-align: left; }
td { padding: 15px; border-bottom: 1px solid #e0e6ed; color: var(--text-main); }
tr:hover { background-color: #f0f8ff; } /* 悬停时微微发蓝 */

/* Form */
.form-group label { display: block; margin-bottom: 8px; font-weight: bold; color: var(--primary); }
.form-group input, .form-group textarea {
    width: 100%; padding: 12px; border: 1px solid #cbd5e0; border-radius: 4px;
    background: #fcfdfe; transition: 0.3s;
}
.form-group input:focus, .form-group textarea:focus {
    border-color: var(--accent); outline: none; box-shadow: 0 0 0 3px rgba(0, 168, 204, 0.1);
}

/* Footer */
footer { 
    background: var(--primary); color: rgba(255,255,255,0.6); 
    text-align: center; padding: 40px 0; margin-top: auto; 
    border-top: 5px solid var(--accent); 
}

/* Mobile */
@media (max-width: 768px) {
    .nav-container { flex-direction: column; height: auto; padding: 15px; }
    nav ul { flex-wrap: wrap; justify-content: center; gap: 15px; margin-top: 15px; }
    .stat-item { border-right: none; border-bottom: 1px solid rgba(255,255,255,0.1); padding-bottom: 20px; }
    .program-header { flex-direction: column; align-items: flex-start; gap: 15px; }
}