/* --- 全局样式和 Kite 风格变量 --- */
:root {
    --primary-blue: #387ed1;
    --primary-blue-darker: #316ab7;
    --text-dark: #2c3e50;
    --text-light: #5a6b7b;
    --border-color: #e0e6ed;
    --background-light: #f8f9fa;
    --background-white: #ffffff;
    --success-green: #27ae60;
    --warning-orange: #f39c12;
    --danger-red: #e74c3c;
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.05);
    --shadow-md: 0 4px 6px rgba(0,0,0,0.07), 0 1px 3px rgba(0,0,0,0.06);
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    background-image: url('background-image.jpg');
    background-size: cover;
    background-position: center center;
    background-repeat: no-repeat;
    background-attachment: fixed;
    background-color: var(--background-light);
    margin: 0;
    padding: 40px 20px;
    display: flex;
    justify-content: center;
    align-items: flex-start;
    min-height: 100vh;
    color: var(--text-dark);
}

/* --- 主容器 --- */
.container {
    background-color: rgba(255, 255, 255, 0.85);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    padding: 40px;
    border-radius: 16px;
    box-shadow: var(--shadow-md);
    width: 100%;
    max-width: 650px;
    text-align: center;
    border: 1px solid rgba(255, 255, 255, 0.4);
}

h1 { font-weight: 700; font-size: 28px; margin-bottom: 10px; }
h2 { font-size: 20px; font-weight: 500; color: var(--text-dark); text-align: left; margin: 40px 0 15px 0; padding-bottom: 10px; border-bottom: 1px solid var(--border-color); }
p { color: var(--text-light); margin-bottom: 30px; }

header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 30px; }
header h1 { margin: 0; font-size: 24px; }

input[type="text"], input[type="password"] {
    width: 100%; padding: 12px 15px; border: 1px solid var(--border-color); border-radius: 6px;
    font-size: 16px; background-color: #fafbfc; transition: border-color 0.3s, box-shadow 0.3s; margin-bottom: 15px;
}
input[type="text"]:focus { outline: none; border-color: var(--primary-blue); box-shadow: 0 0 0 3px rgba(56, 126, 209, 0.2); }

form { display: flex; gap: 10px; margin-bottom: 20px; }
form input { flex-grow: 1; }

button {
    background-color: var(--primary-blue); color: white; border: none;
    padding: 12px 20px; border-radius: 6px; cursor: pointer;
    font-size: 16px; font-weight: 500;
    transition: background-color 0.3s, transform 0.2s;
}
button:hover { background-color: var(--primary-blue-darker); transform: translateY(-1px); }

#logout-btn { background: none; color: var(--text-light); padding: 5px; font-weight: normal; }
#logout-btn:hover { background: none; color: var(--danger-red); transform: none; }

/* --- 任务列表 --- */
.lists-container { text-align: left; }
ul { list-style-type: none; padding: 0; }

li {
    background-color: var(--background-white);
    padding: 15px; border-radius: 8px; margin-bottom: 12px;
    display: flex; flex-direction: column; align-items: flex-start;
    border: 1px solid var(--border-color); box-shadow: var(--shadow-sm);
    transition: box-shadow 0.3s, transform 0.3s, border-color 0.3s;
}
li:hover { transform: translateY(-2px); box-shadow: var(--shadow-md); border-color: #c8d4e1; }
li.completed { opacity: 0.6; }
li.completed span { text-decoration: line-through; color: var(--text-light); }

li .actions {
    display: flex; gap: 8px; margin-top: 8px; align-self: flex-end;
}
li .actions button {
    background: none; border: none; cursor: pointer;
    font-size: 20px; padding: 5px; border-radius: 50%;
    width: 32px; height: 32px; display: flex; align-items: center; justify-content: center;
    transition: background-color 0.2s;
}
li .actions button:hover { background-color: #f0f2f5; }
li .actions .complete-btn { color: var(--success-green); }
li.completed .actions .complete-btn { color: var(--warning-orange); }
li .actions .delete-btn { color: var(--danger-red); }
li .actions .detail-btn { color: var(--primary-blue); }

li .time-info { font-size: 12px; color: #888; margin-top: 6px; text-align: left; }
.details-preview { font-size: 13px; color: var(--text-light); margin-top: 6px; }

/*
 * 导师提示：这是为每周分组添加的标题样式。
 */
.week-header {
    font-size: 18px;
    font-weight: 700;
    color: var(--text-dark);
    text-align: left;
    margin: 40px 0 15px 0;
    padding-bottom: 10px;
    border-bottom: 1px solid var(--border-color);
}


/* --- 弹窗 --- */
.modal {
    position: fixed; top: 0; left: 0; right: 0; bottom: 0;
    background: rgba(0,0,0,0.5);
    display: flex; justify-content: center; align-items: center;
    z-index: 999;
}
.modal-content {
    background: white; padding: 20px; border-radius: 12px; width: 400px;
    box-shadow: var(--shadow-md);
}
.modal-content textarea {
    width: 100%; height: 120px; padding: 10px; margin-bottom: 15px;
    border: 1px solid var(--border-color); border-radius: 6px; font-size: 14px;
}
.modal-actions { display: flex; justify-content: flex-end; gap: 10px; }

li .actions .edit-btn {
    color: var(--primary-blue-darker);
}