/* 全局样式 - 苹果风格 */
:root {
    --primary-color: #007AFF;
    --secondary-color: #5856D6;
    --background-color: #FFFFFF;
    --surface-color: #F5F5F7;
    --text-primary: #1D1D1F;
    --text-secondary: #6E6E73;
    --border-color: #D2D2D7;
    --shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 4px 24px rgba(0, 0, 0, 0.15);
    --transition: all 0.3s ease;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", "SF Pro Text", "Segoe UI", Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    color: var(--text-primary);
    background-color: var(--background-color);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* 容器 */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

.section {
    padding: 80px 0;
}

/* 导航栏 */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: saturate(180%) blur(20px);
    border-bottom: 1px solid var(--border-color);
    z-index: 1000;
    transition: var(--transition);
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 48px;
}

.navbar-brand {
    font-size: 21px;
    font-weight: 600;
    color: var(--text-primary);
    text-decoration: none;
    letter-spacing: -0.02em;
}

.navbar-menu {
    display: flex;
    align-items: center;
    gap: 32px;
    list-style: none;
}

.navbar-menu a {
    color: var(--text-primary);
    text-decoration: none;
    font-size: 14px;
    transition: var(--transition);
    opacity: 0.8;
}

.navbar-menu a:hover {
    opacity: 1;
}

.navbar-actions {
    display: flex;
    gap: 16px;
}

/* 按钮 */
.btn {
    padding: 8px 20px;
    border: none;
    border-radius: 20px;
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
    text-decoration: none;
    display: inline-block;
}

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

.btn-primary:hover {
    background: #0056b3;
    transform: translateY(-1px);
}

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

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

.btn-lg {
    padding: 12px 32px;
    font-size: 17px;
    border-radius: 24px;
}

/* 网格布局 */
.grid {
    display: grid;
    gap: 24px;
}

.grid-2 {
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
}

.grid-3 {
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
}

.grid-4 {
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
}

/* 卡片 */
.card {
    background: var(--background-color);
    border-radius: 18px;
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

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

.card-image {
    width: 100%;
    height: 280px;
    object-fit: cover;
    background: var(--surface-color);
}

.card-body {
    padding: 20px;
}

.card-title {
    font-size: 19px;
    font-weight: 600;
    margin-bottom: 8px;
    color: var(--text-primary);
}

.card-text {
    font-size: 14px;
    color: var(--text-secondary);
    margin-bottom: 12px;
}

.card-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: 12px;
    border-top: 1px solid var(--border-color);
}

/* 表单 */
.form-group {
    margin-bottom: 24px;
}

.form-label {
    display: block;
    font-size: 14px;
    font-weight: 500;
    margin-bottom: 8px;
    color: var(--text-primary);
}

.form-control {
    width: 100%;
    padding: 12px 16px;
    font-size: 17px;
    border: 1px solid var(--border-color);
    border-radius: 12px;
    background: var(--background-color);
    transition: var(--transition);
    font-family: inherit;
}

.form-control:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 4px rgba(0, 122, 255, 0.1);
}

.form-control::placeholder {
    color: var(--text-secondary);
    opacity: 0.6;
}

textarea.form-control {
    resize: vertical;
    min-height: 120px;
}

select.form-control {
    cursor: pointer;
}

/* Hero区域 */
.hero {
    padding: 120px 0 80px;
    text-align: center;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    margin-top: 48px;
}

.hero-title {
    font-size: 56px;
    font-weight: 700;
    margin-bottom: 16px;
    letter-spacing: -0.02em;
}

.hero-subtitle {
    font-size: 24px;
    font-weight: 400;
    opacity: 0.9;
    margin-bottom: 32px;
}

/* 标签 */
.badge {
    display: inline-block;
    padding: 4px 12px;
    font-size: 12px;
    font-weight: 500;
    border-radius: 12px;
    background: var(--surface-color);
    color: var(--text-secondary);
}

/* 图标按钮 */
.icon-btn {
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
    color: var(--text-secondary);
    transition: var(--transition);
    font-size: 20px;
}

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

.icon-btn.active {
    color: #FF3B30;
}

/* 模态框 */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.4);
    backdrop-filter: blur(4px);
    z-index: 2000;
    align-items: center;
    justify-content: center;
}

.modal.active {
    display: flex;
}

.modal-content {
    background: var(--background-color);
    border-radius: 18px;
    padding: 32px;
    max-width: 500px;
    width: 90%;
    max-height: 90vh;
    overflow-y: auto;
    box-shadow: var(--shadow-lg);
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 24px;
}

.modal-title {
    font-size: 24px;
    font-weight: 600;
}

.modal-close {
    background: none;
    border: none;
    font-size: 28px;
    cursor: pointer;
    color: var(--text-secondary);
    line-height: 1;
}

/* 用户信息 */
.user-info {
    display: flex;
    align-items: center;
    gap: 12px;
}

.avatar {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: var(--surface-color);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 600;
    color: var(--primary-color);
}

.avatar img {
    width: 100%;
    height: 100%;
    border-radius: 50%;
    object-fit: cover;
}

/* 加载动画 */
.loading {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 3px solid var(--surface-color);
    border-top-color: var(--primary-color);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

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

/* 空状态 */
.empty-state {
    text-align: center;
    padding: 80px 24px;
    color: var(--text-secondary);
}

.empty-state-icon {
    font-size: 64px;
    margin-bottom: 16px;
    opacity: 0.3;
}

/* 响应式 */
@media (max-width: 768px) {
    .hero-title {
        font-size: 40px;
    }
    
    .hero-subtitle {
        font-size: 19px;
    }
    
    .navbar-menu {
        display: none;
    }
    
    .grid-2, .grid-3, .grid-4 {
        grid-template-columns: 1fr;
    }
    
    .section {
        padding: 40px 0;
    }
}

/* 工具类 */
.text-center { text-align: center; }
.text-right { text-align: right; }
.mt-1 { margin-top: 8px; }
.mt-2 { margin-top: 16px; }
.mt-3 { margin-top: 24px; }
.mb-1 { margin-bottom: 8px; }
.mb-2 { margin-bottom: 16px; }
.mb-3 { margin-bottom: 24px; }
.d-flex { display: flex; }
.align-items-center { align-items: center; }
.justify-content-between { justify-content: space-between; }
.gap-1 { gap: 8px; }
.gap-2 { gap: 16px; }