/* 递归爱学 - iOS 26 液态玻璃风格样式 */

/* CSS变量 */
:root {
    --primary-color: #007AFF;
    --secondary-color: #5856D6;
    --success-color: #34C759;
    --warning-color: #FF9500;
    --danger-color: #FF3B30;
    --text-primary: #FFFFFF;
    --text-secondary: rgba(255, 255, 255, 0.7);
    --text-tertiary: rgba(255, 255, 255, 0.5);
    --glass-bg: rgba(255, 255, 255, 0.12);
    --glass-border: rgba(255, 255, 255, 0.2);
    --glass-shadow: rgba(0, 0, 0, 0.1);
    --blur-amount: 20px;
    --sidebar-width: 260px;
    --sidebar-collapsed: 70px;
    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.5s cubic-bezier(0.4, 0, 0.2, 1);
}

/* 基础样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html, body {
    height: 100%;
    font-family: -apple-system, BlinkMacSystemFont, 'SF Pro Display', 'Segoe UI', Roboto, sans-serif;
    background: linear-gradient(135deg, #1a1a2e 0%, #16213e 50%, #0f3460 100%);
    background-attachment: fixed;
    color: var(--text-primary);
    overflow: hidden;
}

/* 背景动画 */
body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: 
        radial-gradient(circle at 20% 80%, rgba(120, 119, 198, 0.3) 0%, transparent 50%),
        radial-gradient(circle at 80% 20%, rgba(255, 119, 114, 0.3) 0%, transparent 50%),
        radial-gradient(circle at 40% 40%, rgba(0, 122, 255, 0.2) 0%, transparent 60%);
    pointer-events: none;
    z-index: -1;
    animation: bgFloat 20s ease-in-out infinite;
}

@keyframes bgFloat {
    0%, 100% { transform: scale(1) rotate(0deg); }
    50% { transform: scale(1.1) rotate(5deg); }
}

/* 应用容器 */
#app {
    display: flex;
    height: 100vh;
    overflow: hidden;
}

/* ============ 侧边栏 ============ */
.sidebar {
    width: var(--sidebar-width);
    height: 100vh;
    background: var(--glass-bg);
    backdrop-filter: blur(var(--blur-amount));
    -webkit-backdrop-filter: blur(var(--blur-amount));
    border-right: 1px solid var(--glass-border);
    display: flex;
    flex-direction: column;
    transition: width var(--transition-slow), transform var(--transition-slow);
    position: relative;
    z-index: 100;
    flex-shrink: 0;
}

.sidebar.collapsed {
    width: var(--sidebar-collapsed);
}

.sidebar-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    z-index: 99;
}

.sidebar-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 20px;
    border-bottom: 1px solid var(--glass-border);
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    overflow: hidden;
}

.logo-icon {
    font-size: 28px;
    flex-shrink: 0;
}

.logo-text {
    font-size: 20px;
    font-weight: 700;
    white-space: nowrap;
    opacity: 1;
    transition: opacity var(--transition-normal);
}

.sidebar.collapsed .logo-text {
    opacity: 0;
    width: 0;
}

.toggle-btn {
    background: rgba(255, 255, 255, 0.1);
    border: none;
    color: var(--text-primary);
    width: 32px;
    height: 32px;
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-normal);
    flex-shrink: 0;
}

.toggle-btn:hover {
    background: rgba(255, 255, 255, 0.2);
    transform: scale(1.1);
}

.sidebar.collapsed .toggle-btn .toggle-icon {
    transform: rotate(180deg);
}

.sidebar-nav {
    flex: 1;
    padding: 15px 10px;
    overflow-y: auto;
    overflow-x: hidden;
}

.nav-item {
    display: flex;
    align-items: center;
    gap: 15px;
    padding: 14px 16px;
    border-radius: 12px;
    color: var(--text-secondary);
    text-decoration: none;
    transition: all var(--transition-normal);
    margin-bottom: 4px;
    position: relative;
    overflow: hidden;
}

.nav-item::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, var(--primary-color), transparent);
    opacity: 0;
    transition: opacity var(--transition-normal);
    border-radius: 12px;
}

.nav-item:hover {
    color: var(--text-primary);
    background: rgba(255, 255, 255, 0.1);
}

.nav-item:hover::before {
    opacity: 0.1;
}

.nav-item.active {
    color: var(--text-primary);
    background: var(--glass-bg);
    box-shadow: 0 4px 15px rgba(0, 122, 255, 0.2);
}

.nav-item.active::before {
    opacity: 0.2;
}

.nav-icon {
    font-size: 22px;
    flex-shrink: 0;
    width: 28px;
    text-align: center;
}

.nav-text {
    white-space: nowrap;
    opacity: 1;
    transition: opacity var(--transition-normal);
}

.sidebar.collapsed .nav-text {
    opacity: 0;
    width: 0;
}

.sidebar-footer {
    padding: 20px;
    border-top: 1px solid var(--glass-border);
}

.user-info {
    display: flex;
    align-items: center;
    gap: 12px;
    overflow: hidden;
}

.user-avatar {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    object-fit: cover;
    border: 2px solid var(--glass-border);
    flex-shrink: 0;
}

.user-name {
    white-space: nowrap;
    font-size: 14px;
    opacity: 1;
    transition: opacity var(--transition-normal);
}

.sidebar.collapsed .user-info {
    justify-content: center;
}

.sidebar.collapsed .user-name {
    opacity: 0;
    width: 0;
}

/* ============ 主内容区 ============ */
.main-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    height: 100vh;
    overflow: hidden;
    margin-left: 0;
    transition: margin-left var(--transition-slow);
}

/* 顶部栏 */
.top-bar {
    display: flex;
    align-items: center;
    padding: 15px 25px;
    background: var(--glass-bg);
    backdrop-filter: blur(var(--blur-amount));
    -webkit-backdrop-filter: blur(var(--blur-amount));
    border-bottom: 1px solid var(--glass-border);
    gap: 20px;
    z-index: 50;
    flex-shrink: 0;
}

.mobile-menu-btn {
    display: none;
    background: none;
    border: none;
    font-size: 24px;
    color: var(--text-primary);
    cursor: pointer;
}

.top-bar-title {
    flex: 1;
}

.top-bar-title h1 {
    font-size: 24px;
    font-weight: 600;
    background: linear-gradient(135deg, #fff 0%, #a5d8ff 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.top-bar-actions {
    display: flex;
    align-items: center;
    gap: 15px;
}

.auth-buttons {
    display: flex;
    gap: 10px;
}

.btn {
    padding: 10px 20px;
    border-radius: 12px;
    border: none;
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-normal);
    position: relative;
    overflow: hidden;
}

.btn span {
    margin-right: 5px;
}

.btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
    transition: left 0.5s ease;
}

.btn:hover::before {
    left: 100%;
}

.btn-login {
    background: var(--glass-bg);
    color: var(--text-primary);
    border: 1px solid var(--glass-border);
}

.btn-login:hover {
    background: rgba(255, 255, 255, 0.2);
    transform: translateY(-2px);
}

.btn-register {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    box-shadow: 0 4px 15px rgba(0, 122, 255, 0.3);
}

.btn-register:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(0, 122, 255, 0.4);
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    box-shadow: 0 4px 15px rgba(0, 122, 255, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(0, 122, 255, 0.4);
}

.btn-secondary {
    background: var(--glass-bg);
    color: var(--text-primary);
    border: 1px solid var(--glass-border);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.2);
}

.btn-danger {
    background: linear-gradient(135deg, var(--danger-color), #ff6b6b);
    color: white;
}

.btn-admin {
    background: linear-gradient(135deg, #ffd700, #ffaa00);
    color: #333;
}

.btn-small {
    padding: 6px 12px;
    font-size: 12px;
}

.btn-full {
    width: 100%;
}

.user-menu {
    display: flex;
    align-items: center;
    gap: 10px;
    cursor: pointer;
    padding: 6px 12px;
    border-radius: 20px;
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    transition: all var(--transition-normal);
}

.user-menu:hover {
    background: rgba(255, 255, 255, 0.2);
}

.user-avatar-small {
    width: 28px;
    height: 28px;
    border-radius: 50%;
    object-fit: cover;
}

.user-name-small {
    font-size: 14px;
}

/* ============ 页面容器 ============ */
.page-container {
    flex: 1;
    overflow-y: auto;
    padding: 25px;
    scroll-behavior: smooth;
}

.page-container::-webkit-scrollbar {
    width: 6px;
}

.page-container::-webkit-scrollbar-track {
    background: transparent;
}

.page-container::-webkit-scrollbar-thumb {
    background: rgba(255, 255, 255, 0.2);
    border-radius: 3px;
}

.page-container::-webkit-scrollbar-thumb:hover {
    background: rgba(255, 255, 255, 0.3);
}

.page {
    display: none;
    animation: fadeIn 0.3s ease;
}

.page.active {
    display: block;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

/* ============ 玻璃卡片 ============ */
.glass-card {
    background: var(--glass-bg);
    backdrop-filter: blur(var(--blur-amount));
    -webkit-backdrop-filter: blur(var(--blur-amount));
    border: 1px solid var(--glass-border);
    border-radius: 20px;
    padding: 24px;
    box-shadow: 0 8px 32px var(--glass-shadow);
    transition: all var(--transition-normal);
}

.glass-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 12px 40px rgba(0, 0, 0, 0.15);
    border-color: rgba(255, 255, 255, 0.25);
}

/* ============ 首页样式 ============ */
.welcome-card {
    background: linear-gradient(135deg, rgba(0, 122, 255, 0.25), rgba(88, 86, 214, 0.25));
    margin-bottom: 25px;
}

.welcome-content {
    text-align: center;
    margin-bottom: 20px;
}

.welcome-content h2 {
    font-size: 28px;
    margin-bottom: 8px;
}

.welcome-content p {
    color: var(--text-secondary);
}

.welcome-stats {
    display: flex;
    justify-content: space-around;
    padding-top: 20px;
    border-top: 1px solid var(--glass-border);
}

.stat-item {
    text-align: center;
}

.stat-value {
    display: block;
    font-size: 32px;
    font-weight: 700;
    background: linear-gradient(135deg, #fff, #a5d8ff);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.stat-label {
    font-size: 13px;
    color: var(--text-secondary);
}

.quick-actions {
    margin-bottom: 25px;
}

.quick-actions h3 {
    margin-bottom: 15px;
    font-size: 18px;
}

.action-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 15px;
}

.action-btn {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 10px;
    padding: 25px 20px;
    cursor: pointer;
    border: none;
    background: var(--glass-bg);
    color: var(--text-primary);
    transition: all var(--transition-normal);
}

.action-btn:hover {
    transform: translateY(-4px) scale(1.02);
}

.action-icon {
    font-size: 36px;
}

.action-text {
    font-size: 14px;
    font-weight: 500;
}

.today-goal h3, .recent-words h3 {
    margin-bottom: 15px;
}

.goal-progress {
    display: flex;
    align-items: center;
    gap: 15px;
}

.progress-bar {
    flex: 1;
    height: 12px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 6px;
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--primary-color), var(--success-color));
    border-radius: 6px;
    transition: width 0.5s cubic-bezier(0.4, 0, 0.2, 1);
}

.progress-text {
    font-size: 14px;
    color: var(--text-secondary);
    white-space: nowrap;
}

.recent-words {
    margin-top: 25px;
}

.recent-list {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
}

.recent-item {
    padding: 8px 16px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 20px;
    font-size: 14px;
}

.empty-tip {
    color: var(--text-tertiary);
    text-align: center;
    padding: 20px;
}

/* ============ 页面通用样式 ============ */
.page-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 25px;
    flex-wrap: wrap;
    gap: 15px;
}

.page-header h2 {
    font-size: 24px;
}

.header-actions {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
}

/* ============ 通用输入框 ============ */
.glass-input {
    width: 100%;
    padding: 14px 18px;
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid var(--glass-border);
    border-radius: 12px;
    color: var(--text-primary);
    font-size: 15px;
    transition: all var(--transition-normal);
    outline: none;
}

.glass-input::placeholder {
    color: var(--text-tertiary);
}

.glass-input:focus {
    border-color: var(--primary-color);
    background: rgba(255, 255, 255, 0.15);
    box-shadow: 0 0 0 3px rgba(0, 122, 255, 0.2);
}

select.glass-input {
    cursor: pointer;
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' fill='white' viewBox='0 0 16 16'%3E%3Cpath d='M8 11L3 6h10l-5 5z'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 15px center;
    padding-right: 40px;
}

select.glass-input option {
    background: #1a1a2e;
    color: white;
}

/* ============ 标签页 ============ */
.filter-tabs, .leaderboard-tabs {
    display: flex;
    gap: 10px;
    margin-bottom: 20px;
    flex-wrap: wrap;
}

.tab-btn {
    padding: 10px 20px;
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    border-radius: 20px;
    color: var(--text-secondary);
    cursor: pointer;
    transition: all var(--transition-normal);
}

.tab-btn:hover {
    background: rgba(255, 255, 255, 0.15);
    color: var(--text-primary);
}

.tab-btn.active {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    border-color: transparent;
}

/* ============ 列表样式 ============ */
.word-list, .collection-list, .plan-list {
    display: grid;
    gap: 15px;
}

.word-list, .collection-list {
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
}

.plan-list {
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
}

.list-item {
    background: var(--glass-bg);
    backdrop-filter: blur(10px);
    border: 1px solid var(--glass-border);
    border-radius: 16px;
    padding: 18px;
    transition: all var(--transition-normal);
    cursor: pointer;
}

.list-item:hover {
    transform: translateX(5px);
    background: rgba(255, 255, 255, 0.15);
}

.list-item-content {
    margin-bottom: 10px;
}

.list-item-word {
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 5px;
}

.list-item-phonetic {
    font-size: 13px;
    color: var(--text-tertiary);
    margin-bottom: 5px;
}

.list-item-translation {
    font-size: 14px;
    color: var(--text-secondary);
}

.list-item-meta {
    display: flex;
    justify-content: space-between;
    font-size: 12px;
    color: var(--text-tertiary);
    margin-top: 8px;
}

.list-item-actions {
    display: flex;
    gap: 8px;
    margin-top: 12px;
}

.list-item-actions button {
    flex: 1;
    padding: 8px;
    font-size: 12px;
}

/* ============ 学习计划卡片 ============ */
.plan-card {
    padding: 20px;
}

.plan-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 15px;
}

.plan-header h3 {
    font-size: 16px;
}

.plan-status {
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 12px;
    background: rgba(255, 149, 0, 0.2);
    color: var(--warning-color);
}

.plan-status.completed {
    background: rgba(52, 199, 89, 0.2);
    color: var(--success-color);
}

.plan-stats {
    display: flex;
    gap: 30px;
    margin-bottom: 15px;
}

.plan-stat {
    text-align: center;
}

.plan-stat .stat-value {
    font-size: 24px;
}

.plan-stat .stat-label {
    font-size: 12px;
}

/* ============ 模态框 ============ */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.6);
    backdrop-filter: blur(5px);
    z-index: 1000;
    align-items: center;
    justify-content: center;
    animation: modalFadeIn 0.3s ease;
}

.modal.active {
    display: flex;
}

@keyframes modalFadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

.modal-content {
    max-width: 90%;
    max-height: 90vh;
    overflow-y: auto;
    animation: modalSlideIn 0.3s ease;
    position: relative;
}

@keyframes modalSlideIn {
    from { transform: translateY(-30px); opacity: 0; }
    to { transform: translateY(0); opacity: 1; }
}

.modal-close {
    position: absolute;
    top: 15px;
    right: 15px;
    width: 32px;
    height: 32px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.1);
    border: none;
    color: var(--text-secondary);
    font-size: 20px;
    cursor: pointer;
    transition: all var(--transition-normal);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 10;
}

.modal-close:hover {
    background: rgba(255, 255, 255, 0.2);
    color: var(--text-primary);
    transform: rotate(90deg);
}

/* ============ 认证模态框 ============ */
.auth-modal, .generate-modal, .plan-modal, .admin-modal {
    width: 400px;
    padding: 35px;
}

.auth-modal h2, .generate-modal h2, .plan-modal h2, .admin-modal h2 {
    text-align: center;
    margin-bottom: 25px;
    font-size: 24px;
}

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-size: 14px;
    color: var(--text-secondary);
}

.auth-switch {
    text-align: center;
    margin-top: 20px;
    font-size: 14px;
    color: var(--text-secondary);
}

.auth-switch a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
}

.auth-switch a:hover {
    text-decoration: underline;
}

/* ============ 拼写练习模态框 ============ */
.spelling-modal {
    width: 600px;
    padding: 30px;
}

.spelling-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 30px;
}

.spelling-header h2 {
    font-size: 22px;
}

.spelling-progress {
    background: var(--glass-bg);
    padding: 8px 16px;
    border-radius: 20px;
    font-size: 14px;
}

.spelling-content {
    text-align: center;
    padding: 20px 0;
}

.spelling-hint {
    font-size: 36px;
    font-weight: 600;
    margin-bottom: 25px;
    min-height: 50px;
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 5px;
    letter-spacing: 3px;
}

.spelling-letter {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 50px;
    background: rgba(255, 255, 255, 0.1);
    border-bottom: 3px solid var(--primary-color);
    margin: 0 2px;
    font-family: 'Courier New', monospace;
    transition: all 0.2s ease;
}

.spelling-letter.filled {
    color: var(--text-primary);
}

.spelling-letter.correct {
    border-color: var(--success-color);
    color: var(--success-color);
}

.spelling-letter.wrong {
    border-color: var(--danger-color);
    color: var(--danger-color);
}

.spelling-input-area {
    margin-bottom: 20px;
}

.spelling-input {
    text-align: center;
    font-size: 24px;
    padding: 15px;
    letter-spacing: 2px;
}

.answer-box {
    position: fixed;
    top: -200px;
    left: 50%;
    transform: translateX(-50%);
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    padding: 20px 40px;
    border-radius: 16px;
    font-size: 24px;
    font-weight: 600;
    transition: top 0.4s cubic-bezier(0.68, -0.55, 0.265, 1.55);
    box-shadow: 0 10px 40px rgba(0, 122, 255, 0.4);
    z-index: 1010;
    color: white;
}

.answer-box.show {
    top: 100px;
}

.word-info {
    margin-top: 30px;
    padding: 20px;
    background: rgba(255, 255, 255, 0.05);
    border-radius: 12px;
    display: none;
}

.word-info.show {
    display: block;
    animation: fadeIn 0.3s ease;
}

.word-info-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
    gap: 15px;
}

.word-info-item {
    text-align: center;
}

.word-info-label {
    font-size: 12px;
    color: var(--text-tertiary);
    margin-bottom: 5px;
}

.word-info-value {
    font-size: 16px;
    font-weight: 500;
}

.word-info-value.error {
    color: var(--danger-color);
}

.spelling-controls {
    margin-top: 25px;
    padding-top: 20px;
    border-top: 1px solid var(--glass-border);
}

.key-hints {
    display: flex;
    justify-content: center;
    gap: 20px;
    flex-wrap: wrap;
}

.key-hint {
    font-size: 12px;
    color: var(--text-tertiary);
}

kbd {
    background: rgba(255, 255, 255, 0.15);
    padding: 4px 8px;
    border-radius: 6px;
    font-family: monospace;
    margin-right: 5px;
}

/* ============ Toast提示 ============ */
.toast {
    position: fixed;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%) translateY(100px);
    background: var(--glass-bg);
    backdrop-filter: blur(20px);
    padding: 15px 30px;
    border-radius: 12px;
    border: 1px solid var(--glass-border);
    color: var(--text-primary);
    font-size: 14px;
    opacity: 0;
    transition: all 0.3s ease;
    z-index: 2000;
}

.toast.show {
    transform: translateX(-50%) translateY(0);
    opacity: 1;
}

.toast.success {
    border-color: var(--success-color);
    background: linear-gradient(135deg, rgba(52, 199, 89, 0.3), rgba(52, 199, 89, 0.1));
}

.toast.error {
    border-color: var(--danger-color);
    background: linear-gradient(135deg, rgba(255, 59, 48, 0.3), rgba(255, 59, 48, 0.1));
}

/* ============ 烟花特效 ============ */
.fireworks {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 3000;
}

.firework-particle {
    position: absolute;
    width: 6px;
    height: 6px;
    border-radius: 50%;
    animation: fireworkParticle 1s ease-out forwards;
}

@keyframes fireworkParticle {
    0% {
        transform: translate(0, 0) scale(1);
        opacity: 1;
    }
    100% {
        transform: translate(var(--tx), var(--ty)) scale(0);
        opacity: 0;
    }
}

/* ============ 加载动画 ============ */
.loading-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(26, 26, 46, 0.9);
    backdrop-filter: blur(10px);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 20px;
    z-index: 100;
    border-radius: 20px;
}

.loading-spinner {
    width: 50px;
    height: 50px;
    border: 3px solid rgba(255, 255, 255, 0.1);
    border-top-color: var(--primary-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* ============ 教材同步 ============ */
.textbook-select {
    margin-bottom: 25px;
}

.textbook-select label, .unit-select > label {
    display: block;
    margin-bottom: 10px;
    font-size: 14px;
    color: var(--text-secondary);
}

.unit-select {
    margin-bottom: 25px;
}

.unit-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(100px, 1fr));
    gap: 10px;
}

.unit-btn {
    padding: 15px;
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    border-radius: 12px;
    color: var(--text-primary);
    cursor: pointer;
    transition: all var(--transition-normal);
    text-align: center;
}

.unit-btn:hover {
    background: rgba(255, 255, 255, 0.15);
}

.unit-btn.active {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    border-color: transparent;
}

.sync-actions {
    display: flex;
    gap: 15px;
    flex-wrap: wrap;
}

.word-warehouse-info {
    margin-bottom: 20px;
    text-align: center;
    color: var(--text-secondary);
}

.word-warehouse-info p {
    font-size: 14px;
}

/* ============ 学习手账 - 日历 ============ */
.journal-calendar {
    margin-bottom: 25px;
}

.calendar-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
}

.calendar-nav {
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    color: var(--text-primary);
    width: 36px;
    height: 36px;
    border-radius: 50%;
    cursor: pointer;
    transition: all var(--transition-normal);
}

.calendar-nav:hover {
    background: rgba(255, 255, 255, 0.2);
}

.calendar-grid {
    display: grid;
    grid-template-columns: repeat(7, 1fr);
    gap: 8px;
}

.calendar-weekday {
    text-align: center;
    font-size: 12px;
    color: var(--text-tertiary);
    padding: 8px;
}

.calendar-day {
    aspect-ratio: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    font-size: 14px;
    cursor: pointer;
    transition: all var(--transition-normal);
    position: relative;
}

.calendar-day:hover:not(.empty) {
    background: rgba(255, 255, 255, 0.1);
}

.calendar-day.today {
    background: var(--primary-color);
    color: white;
    font-weight: 600;
}

.calendar-day.studied {
    background: var(--success-color);
    color: white;
}

.calendar-day.studied::after {
    content: '✓';
    position: absolute;
    bottom: 2px;
    font-size: 8px;
}

.calendar-day.empty {
    cursor: default;
}

.journal-records h3 {
    margin-bottom: 15px;
}

.journal-record {
    padding: 15px;
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    border-radius: 12px;
    margin-bottom: 10px;
}

.journal-record-date {
    font-size: 12px;
    color: var(--text-tertiary);
    margin-bottom: 5px;
}

.journal-record-content {
    font-size: 14px;
}

/* ============ AI创课坊 ============ */
.ai-studio-container {
    display: grid;
    grid-template-columns: 1fr 350px;
    gap: 25px;
}

.ai-chat {
    display: flex;
    flex-direction: column;
    height: 500px;
}

.chat-messages {
    flex: 1;
    overflow-y: auto;
    padding: 15px;
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.message {
    display: flex;
    gap: 10px;
    max-width: 85%;
    animation: messageSlide 0.3s ease;
}

@keyframes messageSlide {
    from { transform: translateY(10px); opacity: 0; }
    to { transform: translateY(0); opacity: 1; }
}

.message.user {
    align-self: flex-end;
    flex-direction: row-reverse;
}

.message-icon {
    font-size: 24px;
    flex-shrink: 0;
}

.message-text {
    padding: 12px 16px;
    border-radius: 16px;
    background: rgba(255, 255, 255, 0.1);
    font-size: 14px;
    line-height: 1.5;
}

.message.user .message-text {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
}

.chat-input-container {
    display: flex;
    gap: 10px;
    padding: 15px;
    border-top: 1px solid var(--glass-border);
}

.chat-input {
    flex: 1;
}

.btn-send {
    padding: 12px 24px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    border: none;
    border-radius: 12px;
    cursor: pointer;
    transition: all var(--transition-normal);
}

.btn-send:hover {
    transform: scale(1.05);
}

.ai-features h3 {
    margin-bottom: 15px;
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 15px;
}

.feature-btn {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 10px;
    padding: 20px;
    cursor: pointer;
    border: none;
    background: var(--glass-bg);
    color: var(--text-primary);
    transition: all var(--transition-normal);
}

.feature-btn:hover {
    transform: translateY(-3px);
    background: rgba(255, 255, 255, 0.15);
}

.feature-icon {
    font-size: 28px;
}

/* ============ 设置页面 ============ */
.settings-container {
    display: grid;
    gap: 20px;
    max-width: 600px;
}

.settings-section {
    padding: 25px;
}

.settings-section h3 {
    margin-bottom: 20px;
    font-size: 18px;
}

.setting-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 15px;
}

.setting-item:last-child {
    margin-bottom: 0;
}

.setting-item label {
    font-size: 14px;
}

.avatar-edit {
    display: flex;
    align-items: center;
    gap: 15px;
}

.avatar-edit img {
    width: 60px;
    height: 60px;
    border-radius: 50%;
    border: 2px solid var(--glass-border);
}

input[type="checkbox"] {
    width: 20px;
    height: 20px;
    cursor: pointer;
    accent-color: var(--primary-color);
}

/* ============ 排行榜 ============ */
.leaderboard-list {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.leaderboard-item {
    display: flex;
    align-items: center;
    gap: 15px;
    padding: 15px 20px;
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    border-radius: 16px;
    transition: all var(--transition-normal);
}

.leaderboard-item:hover {
    transform: translateX(5px);
    background: rgba(255, 255, 255, 0.15);
}

.leaderboard-item.highlight {
    border-color: var(--primary-color);
    box-shadow: 0 0 20px rgba(0, 122, 255, 0.2);
}

.leaderboard-rank {
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    font-weight: 700;
    font-size: 16px;
}

.leaderboard-rank.gold {
    background: linear-gradient(135deg, #ffd700, #ffaa00);
    color: #333;
}

.leaderboard-rank.silver {
    background: linear-gradient(135deg, #c0c0c0, #a0a0a0);
    color: #333;
}

.leaderboard-rank.bronze {
    background: linear-gradient(135deg, #cd7f32, #b06020);
    color: white;
}

.leaderboard-info {
    flex: 1;
}

.leaderboard-name {
    font-weight: 500;
    margin-bottom: 3px;
}

.leaderboard-detail {
    font-size: 12px;
    color: var(--text-tertiary);
}

.leaderboard-score {
    font-size: 20px;
    font-weight: 700;
    background: linear-gradient(135deg, #fff, #a5d8ff);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* ============ 用户管理 ============ */
.user-list {
    max-height: 400px;
    overflow-y: auto;
}

.user-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 12px;
    border-bottom: 1px solid var(--glass-border);
}

.user-item:last-child {
    border-bottom: none;
}

.user-item-info {
    display: flex;
    align-items: center;
    gap: 10px;
}

.user-item-avatar {
    width: 36px;
    height: 36px;
    border-radius: 50%;
}

.user-item-name {
    font-size: 14px;
}

.user-item-phone {
    font-size: 12px;
    color: var(--text-tertiary);
}

.user-item-actions {
    display: flex;
    gap: 8px;
}

/* ============ 响应式设计 ============ */
@media (max-width: 900px) {
    .sidebar {
        position: fixed;
        left: 0;
        top: 0;
        transform: translateX(-100%);
        width: var(--sidebar-width);
        z-index: 200;
    }
    
    .sidebar.mobile-open {
        transform: translateX(0);
    }
    
    .sidebar-overlay.active {
        display: block;
    }
    
    .mobile-menu-btn {
        display: block;
    }
    
    .ai-studio-container {
        grid-template-columns: 1fr;
    }
    
    .feature-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .top-bar {
        padding: 12px 15px;
    }
    
    .top-bar-title h1 {
        font-size: 18px;
    }
    
    .page-container {
        padding: 15px;
    }
    
    .action-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .welcome-stats {
        flex-direction: column;
        gap: 15px;
    }
    
    .stat-item {
        display: flex;
        justify-content: space-between;
        align-items: center;
        padding: 10px 0;
        border-bottom: 1px solid var(--glass-border);
    }
    
    .stat-item:last-child {
        border-bottom: none;
    }
    
    .spelling-modal {
        width: 95%;
        padding: 20px;
    }
    
    .spelling-hint {
        font-size: 28px;
    }
    
    .spelling-letter {
        width: 32px;
        height: 40px;
    }
    
    .key-hints {
        flex-direction: column;
        align-items: center;
        gap: 8px;
    }
    
    .auth-modal, .generate-modal, .plan-modal {
        width: 95%;
        padding: 25px;
    }
    
    .sync-actions {
        flex-direction: column;
    }
    
    .sync-actions .btn {
        width: 100%;
    }
    
    .plan-stats {
        flex-direction: column;
        gap: 15px;
    }
}

@media (max-width: 480px) {
    .action-grid {
        grid-template-columns: 1fr;
    }
    
    .nav-text {
        font-size: 13px;
    }
    
    .btn {
        padding: 8px 16px;
        font-size: 13px;
    }
}