/* 顾老师英语 - 主样式表 */
:root {
    --primary: #4F46E5;
    --primary-dark: #3730A3;
    --primary-light: #818CF8;
    --secondary: #10B981;
    --accent: #F59E0B;
    --bg: #F8FAFC;
    --bg-card: #FFFFFF;
    --text: #1E293B;
    --text-light: #64748B;
    --border: #E2E8F0;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --radius: 16px;
    --radius-sm: 8px;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

[data-theme="dark"] {
    --bg: #0F172A;
    --bg-card: #1E293B;
    --text: #F1F5F9;
    --text-light: #94A3B8;
    --border: #334155;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.4);
}

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

body {
    font-family: 'Inter', sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
    transition: var(--transition);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* 导航栏 */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: var(--bg-card);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border);
    z-index: 1000;
    transition: var(--transition);
}

.navbar .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 70px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary);
}

.logo i {
    font-size: 1.8rem;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 5px;
}

.nav-links a {
    padding: 8px 16px;
    color: var(--text-light);
    text-decoration: none;
    border-radius: var(--radius-sm);
    font-size: 0.9rem;
    font-weight: 500;
    transition: var(--transition);
}

.nav-links a:hover,
.nav-links a.active {
    color: var(--primary);
    background: rgba(79, 70, 229, 0.1);
}

.nav-right {
    display: flex;
    align-items: center;
    gap: 15px;
}

.btn-admin {
    padding: 8px 20px;
    background: var(--primary);
    color: white;
    border-radius: var(--radius-sm);
    text-decoration: none;
    font-size: 0.9rem;
    font-weight: 500;
    transition: var(--transition);
}

.btn-admin:hover {
    background: var(--primary-dark);
    transform: translateY(-1px);
}

.theme-btn {
    background: none;
    border: 2px solid var(--border);
    color: var(--text);
    width: 40px;
    height: 40px;
    border-radius: 50%;
    cursor: pointer;
    font-size: 1.2rem;
    transition: var(--transition);
}

.theme-btn:hover {
    border-color: var(--primary);
    color: var(--primary);
}

/* Hero区域 */
.hero {
    padding: 140px 0 80px;
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    color: white;
    text-align: center;
}

.hero-content h1 {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 20px;
    animation: fadeInUp 0.6s ease;
}

.hero-content p {
    font-size: 1.2rem;
    opacity: 0.9;
    margin-bottom: 40px;
    animation: fadeInUp 0.8s ease;
}

.hero-stats {
    display: flex;
    justify-content: center;
    gap: 60px;
    animation: fadeInUp 1s ease;
}

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

.stat-number {
    display: block;
    font-size: 2.5rem;
    font-weight: 700;
}

.stat-label {
    font-size: 1rem;
    opacity: 0.8;
}

/* 通用章节 */
.section {
    padding: 80px 0;
}

.section-title {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 40px;
    display: flex;
    align-items: center;
    gap: 12px;
    color: var(--text);
}

.section-title i {
    color: var(--primary);
}

.bg-light {
    background: var(--bg-card);
}

/* 单词卡片 */
.card-container {
    max-width: 500px;
    margin: 0 auto;
}

.flashcard {
    perspective: 1000px;
    height: 350px;
    cursor: pointer;
    margin-bottom: 20px;
}

.card-inner {
    position: relative;
    width: 100%;
    height: 100%;
    transition: transform 0.8s cubic-bezier(0.4, 0, 0.2, 1);
    transform-style: preserve-3d;
}

.flashcard.flipped .card-inner {
    transform: rotateY(180deg);
}

.card-front,
.card-back {
    position: absolute;
    width: 100%;
    height: 100%;
    backface-visibility: hidden;
    border-radius: var(--radius);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 40px;
    box-shadow: var(--shadow-lg);
}

.card-front {
    background: linear-gradient(135deg, var(--primary), var(--primary-light));
    color: white;
}

.card-front h3 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 20px;
}

.hint {
    font-size: 1rem;
    opacity: 0.8;
}

.card-back {
    background: var(--bg-card);
    transform: rotateY(180deg);
    border: 2px solid var(--border);
}

.card-back h3 {
    font-size: 2rem;
    color: var(--primary);
    margin-bottom: 15px;
}

.example {
    font-size: 1.1rem;
    color: var(--text-light);
    text-align: center;
    margin-bottom: 20px;
    font-style: italic;
}

.btn-sound {
    padding: 10px 25px;
    background: var(--primary);
    color: white;
    border: none;
    border-radius: 25px;
    cursor: pointer;
    font-size: 1rem;
    transition: var(--transition);
}

.btn-sound:hover {
    background: var(--primary-dark);
    transform: scale(1.05);
}

.card-controls {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 20px;
}

.btn-nav {
    padding: 10px 25px;
    background: var(--bg-card);
    border: 2px solid var(--border);
    border-radius: var(--radius-sm);
    color: var(--text);
    cursor: pointer;
    font-size: 0.9rem;
    font-weight: 500;
    transition: var(--transition);
}

.btn-nav:hover {
    border-color: var(--primary);
    color: var(--primary);
}

#wordCounter {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--text-light);
}

/* 语法练习 */
.grammar-container {
    max-width: 700px;
    margin: 0 auto;
}

.grammar-tabs {
    display: flex;
    gap: 10px;
    margin-bottom: 30px;
}

.tab {
    padding: 10px 25px;
    background: var(--bg);
    border: 2px solid var(--border);
    border-radius: var(--radius-sm);
    color: var(--text-light);
    cursor: pointer;
    font-weight: 500;
    transition: var(--transition);
}

.tab.active {
    background: var(--primary);
    color: white;
    border-color: var(--primary);
}

.grammar-content {
    background: var(--bg-card);
    padding: 30px;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    margin-bottom: 20px;
}

.grammar-question {
    margin-bottom: 20px;
    padding: 20px;
    background: var(--bg);
    border-radius: var(--radius-sm);
}

.grammar-question .question-text {
    font-weight: 600;
    margin-bottom: 15px;
}

.grammar-question .options {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.grammar-question .options label {
    display: flex;
    align-items: center;
    gap: 10px;
    cursor: pointer;
    padding: 8px 12px;
    border-radius: var(--radius-sm);
    transition: var(--transition);
}

.grammar-question .options label:hover {
    background: rgba(79, 70, 229, 0.05);
}

.grammar-question input[type="text"] {
    width: 100%;
    padding: 10px;
    border: 2px solid var(--border);
    border-radius: var(--radius-sm);
    font-size: 1rem;
    transition: var(--transition);
}

.grammar-question input[type="text"]:focus {
    border-color: var(--primary);
    outline: none;
}

.btn-primary {
    padding: 12px 30px;
    background: var(--primary);
    color: white;
    border: none;
    border-radius: var(--radius-sm);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
}

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow);
}

.grammar-result {
    margin-top: 20px;
    padding: 20px;
    border-radius: var(--radius-sm);
    display: none;
}

.grammar-result.show {
    display: block;
}

/* AI口语 */
.speaking-container {
    max-width: 700px;
    margin: 0 auto;
}

.chat-box {
    height: 400px;
    overflow-y: auto;
    padding: 20px;
    background: var(--bg-card);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    margin-bottom: 20px;
}

.message {
    display: flex;
    align-items: flex-start;
    gap: 12px;
    margin-bottom: 15px;
    animation: fadeIn 0.3s ease;
}

.message i {
    font-size: 1.5rem;
    color: var(--primary);
    margin-top: 5px;
}

.message.ai i {
    color: var(--secondary);
}

.message span {
    padding: 12px 18px;
    border-radius: 18px;
    max-width: 80%;
}

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

.message.user span {
    background: var(--primary);
    color: white;
    border-bottom-right-radius: 5px;
}

.message.ai span {
    background: var(--bg);
    border: 1px solid var(--border);
    border-bottom-left-radius: 5px;
}

.chat-input {
    display: flex;
    gap: 10px;
}

.scene-select {
    padding: 10px;
    border: 2px solid var(--border);
    border-radius: var(--radius-sm);
    background: var(--bg-card);
    color: var(--text);
    font-size: 0.9rem;
}

.chat-input input {
    flex: 1;
    padding: 12px;
    border: 2px solid var(--border);
    border-radius: var(--radius-sm);
    font-size: 1rem;
    background: var(--bg-card);
    color: var(--text);
    transition: var(--transition);
}

.chat-input input:focus {
    border-color: var(--primary);
    outline: none;
}

.btn-send {
    padding: 12px 20px;
    background: var(--primary);
    color: white;
    border: none;
    border-radius: var(--radius-sm);
    cursor: pointer;
    font-size: 1.2rem;
    transition: var(--transition);
}

.btn-send:hover {
    background: var(--primary-dark);
}

.score-display {
    text-align: center;
    margin-top: 15px;
    padding: 15px;
    background: var(--bg-card);
    border-radius: var(--radius-sm);
    border: 2px solid var(--border);
}

/* 阅读分析 */
.reading-container {
    max-width: 800px;
    margin: 0 auto;
}

.reading-input textarea {
    width: 100%;
    padding: 15px;
    border: 2px solid var(--border);
    border-radius: var(--radius);
    font-size: 1rem;
    font-family: 'Inter', sans-serif;
    resize: vertical;
    background: var(--bg-card);
    color: var(--text);
    transition: var(--transition);
}

.reading-input textarea:focus {
    border-color: var(--primary);
    outline: none;
}

.analysis-result {
    margin-top: 20px;
    padding: 20px;
    background: var(--bg-card);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
}

.analysis-result h4 {
    color: var(--primary);
    margin-bottom: 15px;
}

.analysis-result .word-tag {
    display: inline-block;
    padding: 4px 10px;
    background: rgba(79, 70, 229, 0.1);
    color: var(--primary);
    border-radius: 15px;
    margin: 3px;
    font-size: 0.85rem;
}

/* 听力训练 */
.listening-container {
    max-width: 700px;
    margin: 0 auto;
}

.listening-controls {
    display: flex;
    gap: 15px;
    margin-bottom: 20px;
    align-items: center;
}

.listening-controls select {
    padding: 10px;
    border: 2px solid var(--border);
    border-radius: var(--radius-sm);
    background: var(--bg-card);
    color: var(--text);
    font-size: 0.9rem;
}

.btn-secondary {
    padding: 12px 30px;
    background: var(--bg-card);
    border: 2px solid var(--border);
    border-radius: var(--radius-sm);
    color: var(--text);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
}

.btn-secondary:hover {
    border-color: var(--primary);
    color: var(--primary);
}

.listening-text {
    padding: 20px;
    background: var(--bg-card);
    border-radius: var(--radius);
    border: 2px solid var(--border);
    margin-bottom: 20px;
    min-height: 80px;
    font-size: 1.1rem;
    line-height: 1.8;
}

.dictation-area textarea {
    width: 100%;
    padding: 15px;
    border: 2px solid var(--border);
    border-radius: var(--radius);
    font-size: 1rem;
    font-family: 'Inter', sans-serif;
    resize: vertical;
    background: var(--bg-card);
    color: var(--text);
    margin-bottom: 15px;
    transition: var(--transition);
}

.dictation-area textarea:focus {
    border-color: var(--primary);
    outline: none;
}

.dictation-result {
    padding: 15px;
    border-radius: var(--radius-sm);
    margin-top: 15px;
}

/* 作文批改 */
.writing-container {
    max-width: 800px;
    margin: 0 auto;
}

.writing-container textarea {
    width: 100%;
    padding: 15px;
    border: 2px solid var(--border);
    border-radius: var(--radius);
    font-size: 1rem;
    font-family: 'Inter', sans-serif;
    resize: vertical;
    background: var(--bg-card);
    color: var(--text);
    margin-bottom: 15px;
    transition: var(--transition);
}

.writing-container textarea:focus {
    border-color: var(--primary);
    outline: none;
}

.essay-result {
    padding: 20px;
    background: var(--bg-card);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    margin-top: 20px;
}

/* 进度统计 */
.progress-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}

.chart-box {
    background: var(--bg-card);
    padding: 25px;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
}

.chart-box h3 {
    font-size: 1.1rem;
    color: var(--text-light);
    margin-bottom: 20px;
}

.chart-box canvas {
    max-height: 250px;
}

/* 页脚 */
.footer {
    background: var(--bg-card);
    border-top: 1px solid var(--border);
    padding: 40px 0;
    text-align: center;
}

.footer-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 10px;
}

.footer-brand {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.3rem;
    font-weight: 700;
    color: var(--primary);
}

.footer-text {
    color: var(--text-light);
    font-size: 0.9rem;
}

/* 后台样式 */
.admin-body {
    padding-top: 70px;
    background: var(--bg);
}

.admin-nav {
    background: var(--bg-card);
}

.admin-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 40px 20px;
}

.admin-section {
    background: var(--bg-card);
    padding: 30px;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    margin-bottom: 40px;
}

.admin-section h2 {
    font-size: 1.5rem;
    margin-bottom: 25px;
    color: var(--text);
    display: flex;
    align-items: center;
    gap: 10px;
}

.admin-form {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.form-repeater {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.form-row {
    display: flex;
    gap: 10px;
    align-items: center;
    flex-wrap: wrap;
    padding: 15px;
    background: var(--bg);
    border-radius: var(--radius-sm);
}

.form-row input,
.form-row select,
.form-row textarea {
    padding: 8px 12px;
    border: 2px solid var(--border);
    border-radius: var(--radius-sm);
    font-size: 0.9rem;
    background: var(--bg-card);
    color: var(--text);
    flex: 1;
    min-width: 150px;
}

.form-row textarea {
    flex: 2;
}

.btn-remove {
    padding: 8px 12px;
    background: #EF4444;
    color: white;
    border: none;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: var(--transition);
}

.btn-remove:hover {
    background: #DC2626;
}

.btn-add {
    padding: 10px 20px;
    background: var(--secondary);
    color: white;
    border: none;
    border-radius: var(--radius-sm);
    cursor: pointer;
    font-weight: 500;
    transition: var(--transition);
    align-self: flex-start;
}

.btn-add:hover {
    background: #059669;
}

.btn-save {
    padding: 12px 30px;
    background: var(--primary);
    color: white;
    border: none;
    border-radius: var(--radius-sm);
    cursor: pointer;
    font-weight: 600;
    font-size: 1rem;
    transition: var(--transition);
    align-self: flex-start;
}

.btn-save:hover {
    background: var(--primary-dark);
}

.alert {
    padding: 15px 20px;
    border-radius: var(--radius-sm);
    margin-bottom: 20px;
    font-weight: 500;
}

.alert-success {
    background: #D1FAE5;
    color: #065F46;
    border: 1px solid #A7F3D0;
}

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

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

/* 滚动条 */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: var(--bg);
}

::-webkit-scrollbar-thumb {
    background: var(--border);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--text-light);
}

/* 响应式 */
@media (max-width: 768px) {
    .navbar .container {
        flex-wrap: wrap;
        height: auto;
        padding: 10px 20px;
    }

    .nav-links {
        display: none;
    }

    .hero-content h1 {
        font-size: 2.5rem;
    }

    .hero-stats {
        flex-direction: column;
        gap: 20px;
    }

    .section-title {
        font-size: 1.5rem;
    }

    .progress-container {
        grid-template-columns: 1fr;
    }

    .form-row {
        flex-direction: column;
    }

    .form-row input,
    .form-row select,
    .form-row textarea {
        min-width: 100%;
    }
}