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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 
                 'Microsoft YaHei', sans-serif;
    background-color: #f5f5f5;
    color: #333;
    line-height: 1.6;
}

/* 顶部导航栏 */
.top-navbar {
    background: white;
    box-shadow: 0 2px 12px rgba(0,0,0,0.08);
    position: sticky;
    top: 0;
    z-index: 1000;
    backdrop-filter: blur(10px);
    transition: all 0.3s ease;
}

.nav-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 15px 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-logo {
    font-size: 24px;
    font-weight: bold;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    text-decoration: none;
    cursor: pointer;
    transition: all 0.3s ease;
}

.nav-logo:hover {
    transform: scale(1.05);
}

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

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

.trial-hint {
    font-size: 14px;
    color: #666;
    background: #f0f0f0;
    padding: 6px 12px;
    border-radius: 20px;
}

.user-credits {
    font-size: 14px;
    font-weight: 600;
    color: #667eea;
    background: #f0f0ff;
    padding: 6px 12px;
    border-radius: 20px;
}

.btn-nav-login, .btn-nav-user {
    padding: 8px 20px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    text-decoration: none;
    border-radius: 20px;
    font-weight: 500;
    transition: all 0.3s ease;
}

.btn-nav-login:hover, .btn-nav-user:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(102, 126, 234, 0.4);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
    min-height: calc(100vh - 70px);
    display: flex;
    flex-direction: column;
    justify-content: center;
}

/* 页面切换 */
.page {
    display: none;
}

.page.active {
    display: block;
}

/* 标题 */
.title {
    font-size: 48px;
    font-weight: bold;
    margin-bottom: 10px;
    color: #000;
    text-align: center;
}

/* 输入页面 */
.input-section {
    position: relative;
    margin-bottom: 15px;
    flex: 1;
    display: flex;
    flex-direction: column;
}

.textarea-wrapper {
    position: relative;
}

.material-input {
    width: 100%;
    min-height: 150px;
    max-height: calc(100vh - 400px);
    height: 40vh;
    padding: 18px;
    padding-bottom: 45px;
    font-size: 16px;
    border: 2px solid #e0e0e0;
    border-radius: 12px;
    resize: none;
    overflow-y: auto;
    font-family: inherit;
    outline: none;
    transition: all 0.3s ease;
    background: white;
    line-height: 1.6;
}

.material-input:focus {
    border-color: #667eea;
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.material-input:hover {
    border-color: #b0b0b0;
}

.char-counter {
    position: absolute;
    bottom: 10px;
    right: 15px;
    font-size: 14px;
    color: #666;
    background: rgba(255, 255, 255, 0.9);
    padding: 4px 8px;
    border-radius: 4px;
}

.char-counter.warning {
    color: #ff9800;
    font-weight: bold;
}

.char-counter.error {
    color: #f44336;
    font-weight: bold;
}

.tooltip {
    position: absolute;
    bottom: -80px;
    left: 0;
    background-color: #FFD700;
    color: #333;
    padding: 10px 15px;
    border-radius: 4px;
    font-size: 14px;
    max-width: 300px;
}

.demo-hint {
    position: absolute;
    bottom: -110px;
    left: 0;
    background-color: #E3F2FD;
    color: #1976D2;
    padding: 8px 12px;
    border-radius: 4px;
    font-size: 13px;
    max-width: 500px;
    border-left: 3px solid #1976D2;
}

/* 控制区域 */
.control-section {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 20px;
    gap: 20px;
}

.generate-group {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    gap: 8px;
}

.card-count-section {
    display: flex;
    align-items: center;
    gap: 10px;
}

.card-count-section label {
    font-size: 16px;
    font-weight: 500;
}

.card-count-section input {
    width: 80px;
    padding: 10px 14px;
    font-size: 16px;
    border: 2px solid #e0e0e0;
    border-radius: 8px;
    outline: none;
    transition: all 0.3s ease;
    background: white;
}

.card-count-section input:focus {
    border-color: #667eea;
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.card-count-section input:hover {
    border-color: #b0b0b0;
}

.hint-text {
    font-size: 14px;
    color: #666;
}

.ghost-btn {
    padding: 10px 18px;
    border-radius: 10px;
    border: 1px dashed #6366f1;
    background: #f8f9ff;
    color: #4338ca;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
}

.ghost-btn:hover {
    background: #eef2ff;
    border-color: #4f46e5;
}

.ghost-btn:active {
    transform: translateY(1px);
}

.cost-hint {
    font-size: 13px;
    color: #4b5563;
    background: #eef2ff;
    border: 1px solid #e0e7ff;
    padding: 6px 10px;
    border-radius: 8px;
    line-height: 1.4;
}

/* 按钮样式 */
.primary-btn {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 14px 48px;
    font-size: 18px;
    border: none;
    border-radius: 12px;
    cursor: pointer;
    transition: all 0.3s ease;
    font-weight: 600;
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.3);
    position: relative;
    overflow: hidden;
}

.primary-btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, rgba(255,255,255,0.2) 0%, transparent 100%);
    transition: left 0.5s ease;
}

.primary-btn:hover:not(:disabled)::before {
    left: 100%;
}

.primary-btn:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(102, 126, 234, 0.4);
}

.primary-btn:active:not(:disabled) {
    transform: translateY(0);
}

.primary-btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none;
}

.secondary-btn {
    background-color: #f0f0f0;
    color: #333;
    padding: 10px 30px;
    font-size: 16px;
    border: 1px solid #ddd;
    border-radius: 4px;
    cursor: pointer;
    transition: all 0.3s;
}

.secondary-btn:hover {
    background-color: #e0e0e0;
}

/* 预览页面 */
.header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 30px;
    padding-bottom: 20px;
    border-bottom: 2px solid #ddd;
}

.header h2 {
    font-size: 24px;
    font-weight: 500;
}

/* 卡片容器 */
.cards-container {
    margin-bottom: 30px;
}

.card-item {
    background: #fff;
    border: 2px solid #ddd;
    border-radius: 8px;
    padding: 25px;
    margin-bottom: 20px;
}

.card-field {
    margin-bottom: 20px;
}

.card-field:last-child {
    margin-bottom: 0;
}

.card-field-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 10px;
}

.card-field-header label {
    font-size: 16px;
    font-weight: 500;
}

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

.edit-btn, .save-btn {
    padding: 6px 16px;
    font-size: 14px;
    border: 1px solid #333;
    background: #fff;
    border-radius: 4px;
    cursor: pointer;
    transition: all 0.3s;
}

.edit-btn:hover, .save-btn:hover {
    background: #333;
    color: #fff;
}

.save-btn {
    background: #4CAF50;
    color: #fff;
    border-color: #4CAF50;
}

.save-btn:hover {
    background: #45a049;
}

.card-content {
    width: 100%;
    min-height: 100px;
    padding: 12px;
    font-size: 15px;
    border: 1px solid #ddd;
    border-radius: 4px;
    background: #fafafa;
    resize: vertical;
    font-family: inherit;
    line-height: 1.6;
}

.card-content[readonly] {
    background: #fafafa;
    cursor: default;
}

.card-content:not([readonly]) {
    background: #fff;
    border-color: #4CAF50;
}

/* 分页 */
.pagination {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 10px;
    margin: 30px 0;
}

.pagination-text {
    font-size: 16px;
}

.pagination-number {
    padding: 8px 12px;
    font-size: 16px;
    border: 1px solid #ddd;
    background: #fff;
    cursor: pointer;
    border-radius: 4px;
    transition: all 0.3s;
}

.pagination-number:hover {
    background: #f0f0f0;
}

.pagination-number.active {
    background: #007bff;
    color: #fff;
    border-color: #007bff;
}

.back-section {
    text-align: center;
    margin-top: 30px;
}

/* 加载动画 */
.loading-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.7);
    z-index: 1000;
    justify-content: center;
    align-items: center;
    flex-direction: column;
}

.loading-overlay.active {
    display: flex;
}

.loading-spinner {
    border: 4px solid #f3f3f3;
    border-top: 4px solid #4CAF50;
    border-radius: 50%;
    width: 50px;
    height: 50px;
    animation: spin 1s linear infinite;
    margin-bottom: 20px;
}

.loading-overlay p {
    color: #fff;
    font-size: 18px;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* 响应式设计 */
@media (max-width: 1024px) and (min-width: 769px) {
    .material-input {
        max-height: calc(100vh - 380px);
        height: 38vh;
    }

    .title {
        font-size: 42px;
    }
}

@media (max-width: 768px) {
    .title {
        font-size: 32px;
        margin-bottom: 8px;
    }

    .subtitle {
        font-size: 0.95rem;
        margin-bottom: 1rem;
    }

    .container {
        padding: 15px;
    }

    .control-section {
        flex-direction: column;
        gap: 15px;
        align-items: stretch;
        margin-top: 15px;
    }

    .header {
        flex-direction: column;
        gap: 15px;
        align-items: stretch;
    }

    .material-input {
        min-height: 120px;
        max-height: calc(100vh - 350px);
        height: 35vh;
    }

    .card-count-section {
        justify-content: center;
    }

    .primary-btn {
        width: 100%;
        padding: 14px;
    }
}

@media (max-width: 480px) {
    .title {
        font-size: 28px;
    }

    .subtitle {
        font-size: 0.9rem;
    }

    .material-input {
        font-size: 14px;
        min-height: 100px;
        max-height: calc(100vh - 320px);
        height: 30vh;
    }

    .nav-content {
        padding: 10px 15px;
    }

    .trial-hint, .user-credits {
        font-size: 12px;
        padding: 4px 8px;
    }
}


/* 语言切换按钮 */
.language-selector {
    display: flex;
    gap: 0.5rem;
    align-items: center;
}

.lang-btn {
    padding: 0.4rem 0.8rem;
    background: rgba(102, 126, 234, 0.1);
    border: 1px solid rgba(102, 126, 234, 0.3);
    border-radius: 6px;
    color: #667eea;
    cursor: pointer;
    font-size: 0.85rem;
    font-weight: 500;
    transition: all 0.3s ease;
}

.lang-btn:hover {
    background: rgba(102, 126, 234, 0.2);
    transform: translateY(-1px);
}

.lang-btn.active {
    background: #667eea;
    color: white;
    border-color: #667eea;
    font-weight: 600;
}

.subtitle {
    text-align: center;
    color: #666;
    font-size: 1.1rem;
    margin: 0 0 1.5rem 0;
}