:root {
    --bg: #f4f5f7;
    --card: #ffffff;
    --text: #1c1e21;
    --muted: #8a9099;
    --accent: #e63946;
    --accent-dark: #c1272d;
    --line: #e4e7eb;
    --radius: 10px;
    --shadow: 0 1px 3px rgba(0, 0, 0, 0.08);
}

* { box-sizing: border-box; margin: 0; padding: 0; }

html, body {
    height: 100%;
    background: var(--bg);
    color: var(--text);
    font-family: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", sans-serif;
    font-size: 15px;
}

/* ===== 顶栏 ===== */
.topbar {
    position: sticky;
    top: 0;
    z-index: 20;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    padding: 10px 16px;
    background: var(--card);
    border-bottom: 1px solid var(--line);
    box-shadow: var(--shadow);
}
.brand { display: flex; align-items: center; gap: 8px; font-weight: 700; font-size: 17px; cursor: pointer; }
.brand-icon { font-size: 20px; }
.badge {
    font-size: 11px;
    font-weight: 400;
    color: var(--muted);
    border: 1px solid var(--line);
    border-radius: 999px;
    padding: 1px 8px;
}
.topnav { display: flex; gap: 4px; }
.topnav a {
    text-decoration: none;
    color: var(--muted);
    padding: 6px 14px;
    border-radius: 999px;
    font-size: 14px;
}
.topnav a.active { color: #fff; background: var(--accent); }

/* ===== 视图切换 ===== */
.view { display: none; }
.view.active { display: block; }

/* ===== 工具栏 ===== */
.toolbar {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 8px;
    padding: 12px;
    margin: 14px auto;
    max-width: 1200px;
    background: var(--card);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
}
.toolbar h2 { font-size: 15px; margin-right: 4px; }
.toolbar input[type="text"] {
    padding: 8px 10px;
    border: 1px solid var(--line);
    border-radius: 8px;
    font-size: 14px;
    min-width: 180px;
    outline: none;
}
.toolbar input[type="text"]:focus { border-color: var(--accent); }
.toolbar select {
    padding: 8px;
    border: 1px solid var(--line);
    border-radius: 8px;
    background: var(--card);
    font-size: 14px;
    outline: none;
}
.check-label { display: flex; align-items: center; gap: 4px; font-size: 13px; color: var(--muted); cursor: pointer; }
.hint { font-size: 13px; color: var(--muted); }
.pad { padding: 24px; }

button {
    cursor: pointer;
    border: none;
    border-radius: 8px;
    font-size: 14px;
}
button.primary { background: var(--accent); color: #fff; padding: 8px 16px; }
button.primary:hover { background: var(--accent-dark); }
button.sm { background: var(--card); color: var(--text); border: 1px solid var(--line); padding: 5px 10px; font-size: 13px; }
button.sm:hover { border-color: var(--accent); color: var(--accent); }

/* ===== 书籍网格 ===== */
.grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
    gap: 14px;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 12px 24px;
}
.card {
    background: var(--card);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    overflow: hidden;
    display: flex;
    flex-direction: column;
    transition: transform 0.12s ease, box-shadow 0.12s ease;
}
.card:hover { transform: translateY(-2px); box-shadow: 0 6px 16px rgba(0, 0, 0, 0.12); }
.cover-wrap { position: relative; aspect-ratio: 3 / 4; background: #eceef1; overflow: hidden; }
.cover-img { width: 100%; height: 100%; object-fit: cover; display: block; }
.cover-ph {
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 42px;
    font-weight: 700;
    color: #fff;
    background: linear-gradient(135deg, #e63946, #f4a261);
    user-select: none;
}
.badge-done {
    position: absolute;
    top: 6px;
    right: 6px;
    background: rgba(0, 0, 0, 0.65);
    color: #fff;
    font-size: 11px;
    padding: 2px 8px;
    border-radius: 999px;
}
.card-body { padding: 8px 10px 10px; display: flex; flex-direction: column; gap: 2px; flex: 1; }
.card-title {
    font-size: 14px;
    font-weight: 600;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}
.card-meta { font-size: 12px; color: var(--muted); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.card-sub { font-size: 12px; color: var(--muted); }
.card-actions { display: flex; gap: 8px; margin-top: auto; padding-top: 6px; }
.shelf-btn {
    width: 34px;
    background: var(--card);
    border: 1px solid var(--line);
    border-radius: 8px;
    font-size: 15px;
}
.shelf-btn:hover { border-color: #f0b429; color: #f0b429; }
.share-book-btn {
    flex: 1;
    background: var(--card);
    border: 1px solid var(--line);
    border-radius: 8px;
    padding: 6px 0;
    font-size: 13px;
    color: var(--muted);
}
.share-book-btn:hover { border-color: var(--accent); color: var(--accent); }
.read-btn {
    flex: 1;
    background: var(--accent);
    color: #fff;
    border-radius: 8px;
    padding: 6px 0;
    font-size: 13px;
}
.read-btn:hover { background: var(--accent-dark); }

/* ===== 阅读器 ===== */
#view-reader { display: none; flex-direction: column; height: calc(100vh - 46px); }
#view-reader.active { display: flex; }
.reader-top {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 8px 12px;
    background: var(--card);
    border-bottom: 1px solid var(--line);
    box-shadow: var(--shadow);
}
.reader-title { flex: 1; font-weight: 600; font-size: 15px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.reader-area {
    flex: 1;
    overflow: hidden;
    background: #fff;
    position: relative;
}
.reader-area iframe { width: 100%; height: 100%; border: none; }
.reader-nav {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 8px 12px;
    background: var(--card);
    border-top: 1px solid var(--line);
}
.reader-nav .hint { flex: 1; text-align: center; }
.reader-error {
    margin: 20px;
    padding: 16px;
    background: #fdecea;
    color: #c1272d;
    border: 1px solid #f5c6cb;
    border-radius: var(--radius);
    font-size: 13px;
}

.reader-toc {
    position: fixed;
    top: 0;
    right: 0;
    bottom: 0;
    width: min(320px, 85vw);
    background: var(--card);
    box-shadow: -4px 0 20px rgba(0, 0, 0, 0.15);
    z-index: 40;
    display: flex;
    flex-direction: column;
}
.reader-toc.hidden { display: none; }
.toc-head {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 12px 14px;
    border-bottom: 1px solid var(--line);
    font-weight: 600;
}
.toc-list { flex: 1; overflow-y: auto; padding: 6px 0; }
.toc-item {
    padding: 8px 16px;
    font-size: 13px;
    cursor: pointer;
    border-left: 2px solid transparent;
}
.toc-item:hover { background: #f7f8fa; border-left-color: var(--accent); }

/* ===== 全白登录界面 ===== */
.login-screen {
    position: fixed;
    inset: 0;
    z-index: 100;
    background: #ffffff;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 16px;
}
.login-screen.hidden { display: none; }
.login-box {
    background: var(--card);
    border-radius: 14px;
    box-shadow: 0 12px 40px rgba(0, 0, 0, 0.35);
    padding: 28px 26px;
    width: min(320px, 90vw);
    display: flex;
    flex-direction: column;
    gap: 12px;
}
.login-title { font-size: 18px; font-weight: 700; text-align: center; }
.login-sub { font-size: 13px; color: var(--muted); text-align: center; margin-top: -6px; }
.login-box input[type="password"] {
    padding: 10px 12px;
    border: 1px solid var(--line);
    border-radius: 8px;
    font-size: 15px;
    outline: none;
}
.login-box input[type="password"]:focus { border-color: var(--accent); }
.login-btn { width: 100%; padding: 10px 0; font-size: 15px; }
.login-error { color: #c1272d; font-size: 13px; text-align: center; min-height: 18px; }

/* ===== 页脚 ===== */
.foot {
    padding: 12px 16px;
    text-align: center;
    font-size: 12px;
    color: var(--muted);
    border-top: 1px solid var(--line);
    background: var(--card);
    display: flex;
    flex-wrap: wrap;
    gap: 6px 16px;
    justify-content: center;
}

.hidden { display: none !important; }

/* ===== 移动端 ===== */
@media (max-width: 640px) {
    .grid { grid-template-columns: repeat(auto-fill, minmax(110px, 1fr)); gap: 10px; }
    .toolbar { margin: 10px 8px; }
    .toolbar input[type="text"] { min-width: 120px; flex: 1; }
    .topbar { padding: 8px 10px; }
    .brand { font-size: 15px; }
}