/* ===== 全站默认字体 ===== */
body {
    margin: 0;
    padding: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
    font-size: 15px;           /* PC 默认大小：你现在习惯的大小 */
    background: #f5f5f5;
    color: #222;
}

/* 通用容器 */
.page-container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 16px 20px 40px 20px;
}

/* 顶部条：书架页、编辑页、登录页都可以用这个类名 */
.top-bar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 10px 20px;
    background: #ffffff;
    border-bottom: 1px solid #ddd;
    position: sticky;
    top: 0;
    z-index: 10;
}

/* 放标题一侧 */
.top-left h1 {
    margin: 0;
    font-size: 20px;
}

/* 放按钮一侧 */
.top-right button {
    padding: 6px 12px;
    border-radius: 4px;
    border: 1px solid #ccc;
    background: #fafafa;
    cursor: pointer;
    font-size: 14px;
}
.top-right button:hover {
    background: #eee;
}

/* 书架页的卡片布局（如果有） */
.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
    gap: 16px;
}

.book-card {
    background: #fff;
    border-radius: 8px;
    padding: 12px;
    box-shadow: 0 1px 4px rgba(0,0,0,0.06);
}

/* 表单：登录 / 注册 / 创建作品用 */
.form-box {
    max-width: 420px;
    margin: 30px auto;
    background: #ffffff;
    border-radius: 8px;
    padding: 20px 18px 24px 18px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.06);
}

.form-box h1 {
    margin: 0 0 16px 0;
    font-size: 20px;
}

.form-box label {
    display: block;
    margin-bottom: 4px;
    font-weight: 500;
    font-size: 14px;
}

.form-box input[type="text"],
.form-box input[type="password"],
.form-box input[type="number"],
.form-box textarea {
    width: 100%;
    box-sizing: border-box;
    padding: 7px 9px;
    margin-bottom: 10px;
    border-radius: 4px;
    border: 1px solid #ccc;
    font-size: 14px;
}

.form-box button[type="submit"] {
    width: 100%;
    padding: 8px;
    border-radius: 4px;
    border: 1px solid #4a8af4;
    background: #4a8af4;
    color: #fff;
    cursor: pointer;
    font-size: 15px;
}

.form-box button[type="submit"]:hover {
    background: #3a78d8;
}

/* ===== 大字模式（全站通用） ===== */
body.big-font {
    font-size: 18px;
}

body.big-font .form-box input,
body.big-font .form-box textarea {
    font-size: 16px;
}

body.big-font .top-left h1 {
    font-size: 22px;
}

/* ===== 手机适配：屏幕窄的时候自动放大、重排 ===== */
@media (max-width: 768px) {
    body {
        font-size: 16px;  /* 手机基础字体大一点 */
    }

    .top-bar {
        padding: 8px 12px;
        flex-direction: column;
        align-items: flex-start;
        gap: 4px;
    }

    .page-container {
        padding: 10px 12px 24px 12px;
        max-width: 100%;
    }

    .card-grid {
        grid-template-columns: 1fr 1fr;  /* 手机上两列书本 */
        gap: 12px;
    }

    .book-card {
        padding: 10px;
    }

    .form-box {
        margin: 16px 8px;
        padding: 16px 14px 18px 14px;
        box-shadow: none;
        border-radius: 6px;
    }

    .form-box h1 {
        font-size: 18px;
    }
}

/* 夜间模式下的一点补充（如果你已经有 body.night-mode） */
body.night-mode {
    background: #111;
    color: #eee;
}

body.night-mode .form-box {
    background: #1b1b1b;
    box-shadow: none;
}

body.night-mode .form-box input,
body.night-mode .form-box textarea {
    background: #222;
    color: #eee;
    border-color: #555;
}