/* 全局样式 */
:root {
    --primary-color: #4f46e5;
    --primary-hover: #4338ca;
    --success-color: #10b981;
    --danger-color: #ef4444;
    --warning-color: #f59e0b;
    --bg-color: #f9fafb;
    --card-bg: #ffffff;
    --text-primary: #111827;
    --text-secondary: #6b7280;
    --border-color: #e5e7eb;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-primary);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* 加载动画 */
.loading-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(255, 255, 255, 0.95);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    z-index: 9999;
}

.loading-spinner {
    width: 48px;
    height: 48px;
    border: 4px solid var(--border-color);
    border-top-color: var(--primary-color);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

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

.loading-text {
    margin-top: 1rem;
    color: var(--text-secondary);
    font-size: 0.875rem;
}

/* 模态框 */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    padding: 1rem;
    overflow-y: auto;
}

.modal-content {
    background: var(--card-bg);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    max-width: 600px;
    width: 100%;
    max-height: 90vh;
    overflow-y: auto;
    padding: 2rem;
    animation: slideUp 0.3s ease-out;
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
}

.modal-header h2 {
    font-size: 1.5rem;
    font-weight: 600;
}

.close-btn {
    background: none;
    border: none;
    font-size: 2rem;
    color: var(--text-secondary);
    cursor: pointer;
    line-height: 1;
    padding: 0;
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius-sm);
    transition: all 0.2s;
}

.close-btn:hover {
    background: var(--bg-color);
    color: var(--text-primary);
}

/* 欢迎界面 */
.welcome-header {
    text-align: center;
    margin-bottom: 2rem;
}

.welcome-header h2 {
    font-size: 1.75rem;
    margin-bottom: 0.5rem;
}

.subtitle {
    color: var(--text-secondary);
    font-size: 0.875rem;
}

/* 选择界面 */
.choice-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
    margin-top: 2rem;
}

.choice-card {
    background: var(--bg-color);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 2rem 1.5rem;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s;
}

.choice-card:hover {
    border-color: var(--primary-color);
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.choice-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.choice-card h3 {
    font-size: 1.125rem;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.choice-card p {
    font-size: 0.875rem;
    color: var(--text-secondary);
    line-height: 1.5;
}

/* 导入表单 */
.import-form {
    margin-top: 1.5rem;
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    font-weight: 500;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.form-input {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    font-size: 0.875rem;
    font-family: 'Courier New', monospace;
    transition: all 0.2s;
}

.form-input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.1);
}

.form-hint {
    display: block;
    margin-top: 0.25rem;
    font-size: 0.75rem;
    color: var(--text-secondary);
}

.form-actions {
    display: flex;
    gap: 0.75rem;
    justify-content: flex-end;
    margin-top: 2rem;
}

.key-display {
    margin-bottom: 2rem;
}

.key-display h3 {
    font-size: 1.125rem;
    margin-bottom: 1rem;
}

.key-box {
    background: var(--bg-color);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 1rem;
    margin-bottom: 1rem;
}

.key-label {
    font-size: 0.75rem;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 0.5rem;
}

.key-value {
    font-family: 'Courier New', monospace;
    font-size: 0.875rem;
    word-break: break-all;
    background: var(--card-bg);
    padding: 0.75rem;
    border-radius: var(--radius-sm);
    margin-bottom: 0.5rem;
    border: 1px solid var(--border-color);
}

.warning-box {
    background: #fef3c7;
    border: 1px solid #fbbf24;
    border-radius: var(--radius-md);
    padding: 1rem;
    margin-bottom: 1.5rem;
}

.warning-box h4 {
    color: #92400e;
    font-size: 1rem;
    margin-bottom: 0.5rem;
}

.warning-box ul {
    list-style: none;
    padding-left: 0;
}

.warning-box li {
    color: #78350f;
    font-size: 0.875rem;
    margin-bottom: 0.25rem;
    padding-left: 1.25rem;
    position: relative;
}

.warning-box li:before {
    content: "•";
    position: absolute;
    left: 0.5rem;
}

.backup-options {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 0.75rem;
    margin-bottom: 1.5rem;
}

.modal-footer {
    border-top: 1px solid var(--border-color);
    padding-top: 1.5rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.checkbox-label {
    display: flex;
    align-items: center;
    cursor: pointer;
    user-select: none;
}

.checkbox-label input {
    margin-right: 0.5rem;
    cursor: pointer;
}

/* 按钮 */
.btn {
    padding: 0.625rem 1.25rem;
    border: none;
    border-radius: var(--radius-md);
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    white-space: nowrap;
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.btn-primary {
    background: var(--primary-color);
    color: white;
}

.btn-primary:hover:not(:disabled) {
    background: var(--primary-hover);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

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

.btn-secondary:hover:not(:disabled) {
    background: #f3f4f6;
}

.btn-success {
    background: var(--success-color);
    color: white;
}

.btn-success:hover:not(:disabled) {
    background: #059669;
}

.btn-danger {
    background: var(--danger-color);
    color: white;
}

.btn-danger:hover:not(:disabled) {
    background: #dc2626;
}

.btn-block {
    width: 100%;
    margin-bottom: 0.5rem;
}

.copy-btn {
    padding: 0.375rem 0.75rem;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: var(--radius-sm);
    font-size: 0.75rem;
    cursor: pointer;
    transition: all 0.2s;
}

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

.icon-btn {
    background: none;
    border: none;
    padding: 0.5rem;
    cursor: pointer;
    color: var(--text-secondary);
    border-radius: var(--radius-sm);
    transition: all 0.2s;
    display: flex;
    align-items: center;
    justify-content: center;
}

.icon-btn:hover {
    background: var(--bg-color);
    color: var(--text-primary);
}

/* 应用头部 */
.app-header {
    background: var(--card-bg);
    border-bottom: 1px solid var(--border-color);
    padding: 1rem;
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: var(--shadow-sm);
}

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

.app-title {
    font-size: 1.25rem;
    font-weight: 600;
}

.header-actions {
    display: flex;
    gap: 0.5rem;
}

/* 主内容区 */
.main-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem 1rem;
}

.notes-container {
    background: var(--card-bg);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    padding: 1.5rem;
}

.notes-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
}

.notes-header h2 {
    font-size: 1.5rem;
    font-weight: 600;
}

/* 笔记列表 */
.notes-list {
    display: grid;
    gap: 1rem;
}

.note-card {
    background: var(--bg-color);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 1rem;
    cursor: pointer;
    transition: all 0.2s;
}

.note-card:hover {
    border-color: var(--primary-color);
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}

.note-card-header {
    display: flex;
    justify-content: space-between;
    align-items: start;
    margin-bottom: 0.5rem;
}

.note-title {
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: 0.25rem;
    color: var(--text-primary);
}

.note-date {
    font-size: 0.75rem;
    color: var(--text-secondary);
}

.note-preview {
    color: var(--text-secondary);
    font-size: 0.875rem;
    line-height: 1.5;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.note-actions {
    display: flex;
    gap: 0.5rem;
}

.note-actions button {
    padding: 0.25rem 0.5rem;
    font-size: 0.75rem;
}

/* 空状态 */
.empty-state {
    text-align: center;
    padding: 3rem 1rem;
    color: var(--text-secondary);
}

.empty-state svg {
    margin-bottom: 1rem;
    opacity: 0.5;
}

.empty-state h3 {
    font-size: 1.25rem;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

/* 编辑器 */
.editor-content {
    max-width: 800px;
    padding: 0;
    max-height: 90vh;
    display: flex;
    flex-direction: column;
}

.editor-header {
    padding: 1.5rem;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 1rem;
}

.note-title-input {
    flex: 1;
    border: none;
    font-size: 1.5rem;
    font-weight: 600;
    outline: none;
    padding: 0.5rem;
    border-radius: var(--radius-sm);
}

.note-title-input:focus {
    background: var(--bg-color);
}

.editor-actions {
    display: flex;
    gap: 0.5rem;
}

.note-content-input {
    flex: 1;
    border: none;
    padding: 1.5rem;
    font-size: 1rem;
    line-height: 1.6;
    resize: none;
    outline: none;
    font-family: inherit;
    min-height: 400px;
}

/* 设置面板 */
.settings-section {
    margin-bottom: 2rem;
}

.settings-section h3 {
    font-size: 1.125rem;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.info-text {
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-bottom: 0.25rem;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .modal-content {
        padding: 1.5rem;
        margin: 0.5rem;
    }

    .welcome-header h2 {
        font-size: 1.5rem;
    }

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

    .backup-options {
        grid-template-columns: 1fr;
    }

    .modal-footer {
        flex-direction: column;
        gap: 1rem;
        align-items: stretch;
    }

    .app-title {
        font-size: 1.125rem;
    }

    .main-content {
        padding: 1rem;
    }

    .notes-container {
        padding: 1rem;
    }

    .notes-header {
        flex-direction: column;
        align-items: stretch;
        gap: 1rem;
    }

    .editor-header {
        flex-direction: column;
        align-items: stretch;
    }

    .editor-actions {
        width: 100%;
    }

    .editor-actions .btn {
        flex: 1;
    }

    .key-value {
        font-size: 0.75rem;
    }
}

@media (max-width: 480px) {
    .modal-content {
        padding: 1rem;
    }

    .btn {
        padding: 0.5rem 1rem;
        font-size: 0.8125rem;
    }

    .note-title {
        font-size: 1rem;
    }

    .note-preview {
        font-size: 0.8125rem;
    }
}

/* 工具提示 */
.tooltip {
    position: relative;
    display: inline-block;
}

.tooltip .tooltiptext {
    visibility: hidden;
    background-color: var(--text-primary);
    color: white;
    text-align: center;
    border-radius: var(--radius-sm);
    padding: 0.5rem;
    position: absolute;
    z-index: 1;
    bottom: 125%;
    left: 50%;
    transform: translateX(-50%);
    opacity: 0;
    transition: opacity 0.3s;
    font-size: 0.75rem;
    white-space: nowrap;
}

.tooltip:hover .tooltiptext {
    visibility: visible;
    opacity: 1;
}

/* 动画 */
.fade-in {
    animation: fadeIn 0.3s ease-in;
}

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

.slide-in {
    animation: slideIn 0.3s ease-out;
}

@keyframes slideIn {
    from {
        transform: translateX(-20px);
        opacity: 0;
    }
    to {
        transform: translateX(0);
        opacity: 1;
    }
}