/* ============================================
   NovelCraft - 布局系统 v2（底部导航 + 分页）
   ============================================ */
.app-shell { display: flex; height: 100%; width: 100%; overflow: hidden; position: relative; }

/* ---- 侧边栏 ---- */
.sidebar-overlay { position: fixed; inset: 0; background: rgba(0,0,0,0.3); z-index: 90; opacity: 0; visibility: hidden; pointer-events: none; transition: opacity .35s, visibility .35s; -webkit-backdrop-filter: blur(4px); backdrop-filter: blur(4px); }
.sidebar-overlay.visible { opacity: 1; visibility: visible; pointer-events: auto; }
.sidebar { position: fixed; inset: 0 auto 0 0; width: var(--sidebar-width); z-index: 100; transform: translateX(-100%); transition: transform .35s var(--ease-ios); will-change: transform; flex-shrink: 0; }
.sidebar.open { transform: translateX(0); }
.sidebar-inner { height: 100%; display: flex; flex-direction: column; background: var(--glass-bg-heavy); -webkit-backdrop-filter: saturate(180%) blur(20px); backdrop-filter: saturate(180%) blur(20px); border-right: 1px solid var(--glass-border); padding: var(--space-md); padding-top: calc(var(--safe-top) + var(--space-md)); touch-action: pan-y; }
.sidebar-header { display: flex; align-items: center; justify-content: space-between; margin-bottom: var(--space-lg); }
.sidebar-brand { display: flex; align-items: center; gap: var(--space-sm); }
.brand-icon { width: 40px; height: 40px; border-radius: var(--radius-sm); background: var(--accent-gradient); display: flex; align-items: center; justify-content: center; color: white; font-size: 20px; box-shadow: 0 4px 12px rgba(0,122,255,.3); }
.brand-title { font-size: 17px; font-weight: 700; letter-spacing: -.3px; }
.brand-subtitle { font-size: 12px; color: var(--text-tertiary); font-weight: 500; }
.sidebar-close-btn { display: none; }
@media (max-width: 768px) { .sidebar-close-btn { display: flex; } }
.sidebar-section-label { font-size: 12px; font-weight: 600; color: var(--text-tertiary); text-transform: uppercase; letter-spacing: .5px; padding: var(--space-md) var(--space-sm) var(--space-xs); }
.history-list, .chapter-list { flex: 1; overflow-y: auto; -webkit-overflow-scrolling: touch; margin: 0 calc(-1 * var(--space-md)); padding: 0 var(--space-md); }
.chapter-list { max-height: 200px; }
.sidebar-footer { padding-top: var(--space-md); border-top: 1px solid var(--separator); display: flex; flex-direction: column; gap: var(--space-xs); }

/* ---- 主内容区 ---- */
.main-content { flex: 1; display: flex; flex-direction: column; height: 100%; min-width: 0; position: relative; }

@media (min-width: 769px) {
    .sidebar { position: relative; transform: none; z-index: 1; }
    .sidebar-overlay { display: none !important; }
    .sidebar-inner { -webkit-backdrop-filter: none; backdrop-filter: none; background: var(--bg-secondary); border-right: .5px solid var(--separator); }
    .main-content { position: relative; z-index: 2; }
}

/* ---- 顶部导航栏 ---- */
.topbar { position: sticky; top: 0; z-index: 50; background: var(--glass-bg); -webkit-backdrop-filter: saturate(180%) blur(20px); backdrop-filter: saturate(180%) blur(20px); border-bottom: .5px solid var(--separator); padding-top: var(--safe-top); }
.topbar-inner { display: flex; align-items: center; justify-content: space-between; padding: var(--space-sm) var(--space-md); max-width: 100%; gap: var(--space-sm); }
.topbar-left { display: flex; align-items: center; gap: var(--space-sm); flex: 1; min-width: 0; }
.topbar-right { display: flex; align-items: center; gap: var(--space-xs); flex-shrink: 0; }
.topbar-selects { display: flex; align-items: center; gap: var(--space-sm); flex-wrap: nowrap; min-width: 0; }
.mobile-only { display: none; }
@media (max-width: 768px) { .mobile-only { display: flex; } }

/* ---- 项目上下文条 ---- */
.project-context-bar { background: var(--bg-secondary); border-bottom: .5px solid var(--separator); padding: 0 var(--space-md); }
.context-bar-inner { display: flex; align-items: center; gap: var(--space-md); padding: 8px 0; max-width: 100%; overflow: hidden; }
.context-bar-book { display: flex; align-items: center; gap: 6px; font-size: 13px; font-weight: 600; color: var(--text-primary); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.context-bar-book i { color: var(--accent); font-size: 16px; flex-shrink: 0; }
.context-bar-chapter { display: flex; align-items: center; gap: 6px; font-size: 12px; color: var(--text-secondary); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; flex: 1; min-width: 0; }
.context-bar-chapter i { font-size: 14px; flex-shrink: 0; }
.context-bar-actions { display: flex; align-items: center; gap: 2px; flex-shrink: 0; }

/* ========== 分页容器 ========== */
.page-container { flex: 1; overflow: hidden; position: relative; }
.page-content { display: none; flex-direction: column; height: 100%; overflow: hidden; }
.page-content.active { display: flex; }

/* 创作页 */
#page-create .chat-container {
    flex: 1; overflow-y: auto; overflow-x: hidden;
    -webkit-overflow-scrolling: touch;
    will-change: scroll-position; transform: translateZ(0);
}
#page-create .input-area { position: sticky; bottom: 0; z-index: 40; background: var(--glass-bg); -webkit-backdrop-filter: saturate(180%) blur(20px); backdrop-filter: saturate(180%) blur(20px); border-top: .5px solid var(--separator); padding: var(--space-sm) var(--space-md) calc(var(--space-sm) + var(--safe-bottom)); }

/* 工坊/书架/我的 可滚动内容 */
.workshop-scroll, .bookshelf-scroll, .profile-scroll { flex: 1; overflow-y: auto; -webkit-overflow-scrolling: touch; padding: var(--space-md); padding-bottom: calc(80px + var(--safe-bottom)); }

/* ========== 底部导航栏 ========== */
.bottom-nav { position: sticky; bottom: 0; z-index: 60; display: flex; background: var(--glass-bg-heavy); -webkit-backdrop-filter: saturate(180%) blur(20px); backdrop-filter: saturate(180%) blur(20px); border-top: .5px solid var(--separator); padding: 6px 0 calc(6px + var(--safe-bottom)); }
.nav-item { flex: 1; display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 2px; padding: 4px 0; color: var(--text-tertiary); font-size: 10px; font-weight: 500; transition: all .2s; -webkit-tap-highlight-color: transparent; border-radius: 8px; }
.nav-item i { font-size: 22px; transition: transform .2s var(--ease-spring); }
.nav-item.active { color: var(--accent); background: var(--accent-soft); }
.nav-item.active i { transform: scale(1.1); }
.nav-item:active { opacity: .7; }

@media (min-width: 769px) {
    .bottom-nav { padding: 8px 0 calc(8px + var(--safe-bottom)); }
    .nav-item { font-size: 11px; padding: 6px 0; }
    .nav-item i { font-size: 24px; }
}

@media (max-width: 480px) {
    .workshop-scroll, .bookshelf-scroll, .profile-scroll { padding: var(--space-xs); padding-bottom: calc(80px + var(--safe-bottom)); }
    .workshop-section { padding: var(--space-sm); border-radius: 10px; }
    .workshop-section-header { margin-bottom: var(--space-sm); }
    .workshop-section-title { font-size: 15px; }
}

/* ---- 聊天区域 ---- */
.message-list { max-width: 780px; margin: 0 auto; padding: var(--space-md) var(--space-md) var(--space-xl); display: flex; flex-direction: column; gap: var(--space-md); }
@media (min-width: 1024px) { .message-list { padding: var(--space-lg) var(--space-xl) var(--space-xl); } }

.input-wrapper { max-width: 780px; margin: 0 auto; display: flex; align-items: flex-end; gap: var(--space-sm); }
.input-field-wrapper { flex: 1; position: relative; background: var(--bg-tertiary); border-radius: var(--radius-lg); border: 1px solid var(--separator); transition: border-color .2s, box-shadow .2s; }
.input-field-wrapper:focus-within { border-color: var(--accent); box-shadow: 0 0 0 3px rgba(0,122,255,.12); }
.input-field { width: 100%; padding: 12px 16px; background: transparent; border: none; outline: none; resize: none; max-height: 150px; line-height: 1.45; font-size: var(--font-size-base); color: var(--text-primary); }
.input-field::placeholder { color: var(--text-tertiary); }
.input-hint { text-align: center; font-size: 11px; color: var(--text-tertiary); padding-top: 4px; padding-bottom: 2px; }
@media (max-width: 768px) { .input-hint { display: none; } }

/* 移动端适配 */
@media (max-width: 480px) {
    .topbar-inner { padding: var(--space-xs) var(--space-xs); }
    .topbar-left { gap: 4px; }
    .topbar-right { gap: 2px; }
    .topbar-selects { gap: 4px; }
    #model-select-wrap { display: none; }
    .message-list { padding: var(--space-sm) var(--space-sm) var(--space-md); gap: var(--space-sm); }
    .input-area { padding: var(--space-xs) var(--space-xs) calc(var(--space-xs) + var(--safe-bottom)); }
    .input-wrapper { gap: 6px; }
    .input-field { padding: 10px 12px; font-size: 15px; }
    .btn-sm { padding: 6px 10px; font-size: 12px; }
    .btn-icon { width: 34px; height: 34px; font-size: 18px; }
    .custom-select-trigger { padding: 6px 10px; font-size: 12px; }
    .custom-select-trigger i { font-size: 14px; }
    .project-context-bar { padding: 0 var(--space-xs); }
    .context-bar-inner { padding: 6px 0; gap: var(--space-xs); font-size: 12px; }
    .workshop-scroll, .bookshelf-scroll, .profile-scroll { padding: var(--space-xs); padding-bottom: calc(80px + var(--safe-bottom)); }
    .workshop-section { padding: var(--space-xs); border-radius: 10px; }
    .workshop-section-header { margin-bottom: var(--space-xs); }
    .workshop-section-title { font-size: 15px; }
    .stat-card { padding: var(--space-xs); }
    .stat-card .stat-number { font-size: 20px; }
    .distill-grid { grid-template-columns: repeat(2, 1fr); gap: var(--space-xs); }
    .distill-card { padding: var(--space-xs); }
    .distill-card .distill-card-name { font-size: 13px; }
    .bookshelf-project-list { grid-template-columns: 1fr; }
    .save-chapter-list { max-height: 30vh; }
}