/* 寒色系・白背景のすっきりとしたデザイン */
body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    margin: 0;
    padding: 0;
    background-color: #ffffff;
    color: #333;
}

header {
    background-color: #2980b9; /* 寒色系のメインカラー */
    color: white;
    padding: 15px 30px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.header-left {
    flex: 1;
}

.header-center {
    flex: 1;
    text-align: center;
    font-size: 1.5em;
    font-weight: bold;
}

.header-right {
    flex: 1;
    text-align: right;
}

.header-right a {
    background-color: #3498db;
    color: white;
    text-decoration: none;
    padding: 8px 16px;
    border-radius: 4px;
    transition: background-color 0.3s;
    font-weight: bold;
}

.header-right a:hover {
    background-color: #1f6391;
}

.container {
    max-width: 1000px;
    margin: 40px auto;
    padding: 0 20px;
}

h1.main-title {
    color: #2c3e50;
    border-bottom: 2px solid #3498db;
    padding-bottom: 10px;
    margin-bottom: 30px;
}

/* ホーム画面の投稿一覧 */
.post-list {
    list-style: none;
    padding: 0;
}

.post-item {
    background-color: #f8fbff;
    border: 1px solid #d4e6f1;
    margin-bottom: 15px;
    padding: 15px 20px;
    border-radius: 6px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: transform 0.2s, box-shadow 0.2s;
}

.post-item:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0,0,0,0.05);
}

.post-title {
    font-size: 1.2em;
    color: #2980b9;
    text-decoration: none;
    font-weight: bold;
}

.post-title:hover {
    text-decoration: underline;
}

.post-date {
    color: #7f8c8d;
    font-size: 0.9em;
}

/* デバイス画面のレイアウト */
.device-layout {
    display: flex;
    gap: 30px;
}

.sidebar {
    width: 200px;
    flex-shrink: 0;
    position: sticky;
    top: 20px;
    align-self: flex-start;
}

.category-btn {
    display: block;
    width: 100%;
    text-align: left;
    background-color: #ecf0f1;
    border: none;
    padding: 12px 15px;
    margin-bottom: 8px;
    border-radius: 4px;
    cursor: pointer;
    color: #2c3e50;
    font-weight: bold;
    transition: background-color 0.3s, color 0.3s;
}

.category-btn:hover {
    background-color: #3498db;
    color: white;
}

.content-area {
    flex-grow: 1;
}

.category-section {
    margin-bottom: 40px;
}

.category-title {
    color: #2980b9;
    border-left: 5px solid #3498db;
    padding-left: 10px;
    margin-bottom: 15px;
}

.device-list {
    list-style: none;
    padding: 0;
}

.device-item {
    background-color: #f8fbff;
    border: 1px solid #d4e6f1;
    margin-bottom: 10px;
    padding: 15px;
    border-radius: 5px;
}

.device-category-label {
    display: block;
    font-size: 0.85em;
    color: #7f8c8d;
    margin-bottom: 5px;
    font-weight: bold;
}

.device-name {
    font-size: 1.1em;
    color: #2980b9;
    text-decoration: none;
    font-weight: bold;
}

.device-name:hover {
    text-decoration: underline;
}