/* ========================================
   投稿客 - 全局样式
   ======================================== */

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

/* 基础 */
:root {
    --primary-color: #4f46e5;
    --primary-hover: #4338ca;
    --secondary-color: #6b7280;
    --success-color: #10b981;
    --error-color: #ef4444;
    --bg-color: #f9fafb;
    --card-bg: #ffffff;
    --text-primary: #111827;
    --text-secondary: #6b7280;
    --border-color: #e5e7eb;
    --shadow: 0 1px 3px rgba(0,0,0,0.1);
    --shadow-lg: 0 10px 25px rgba(0,0,0,0.1);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background: var(--bg-color);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
}

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

/* ========================================
   头部导航
   ======================================== */
.header {
    background: var(--card-bg);
    border-bottom: 1px solid var(--border-color);
    box-shadow: var(--shadow);
}

.header .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 64px;
}

.logo a {
    font-size: 24px;
    font-weight: bold;
    color: var(--primary-color);
    text-decoration: none;
}

.ai-badge {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 2px 8px;
    border-radius: 4px;
    font-size: 12px;
    margin-left: 8px;
}

.nav {
    display: flex;
    gap: 30px;
}

.nav a {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.2s;
}

.nav a:hover,
.nav a.active {
    color: var(--primary-color);
}

.user-menu {
    display: flex;
    align-items: center;
    gap: 15px;
}

/* ========================================
   按钮
   ======================================== */
.btn-primary,
.btn-secondary,
.btn-login,
.btn-register {
    display: inline-block;
    padding: 10px 20px;
    border-radius: 6px;
    font-weight: 500;
    text-decoration: none;
    cursor: pointer;
    border: none;
    transition: all 0.2s;
}

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

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

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

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

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

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

.btn-block {
    width: 100%;
    padding: 12px;
}

button:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

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

.hero h1 {
    font-size: 48px;
    margin-bottom: 20px;
}

.hero p {
    font-size: 20px;
    opacity: 0.9;
    max-width: 600px;
    margin: 0 auto 30px;
}

.hero-actions {
    display: flex;
    gap: 15px;
    justify-content: center;
}

/* ========================================
   文章列表
   ======================================== */
.articles-section {
    padding: 60px 0;
}

.articles-section h2 {
    font-size: 28px;
    margin-bottom: 30px;
}

.article-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 30px;
}

.article-card {
    background: var(--card-bg);
    border-radius: 12px;
    padding: 24px;
    box-shadow: var(--shadow);
    transition: transform 0.2s, box-shadow 0.2s;
}

.article-card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.article-card h3 {
    font-size: 18px;
    margin-bottom: 12px;
}

.article-card h3 a {
    color: var(--text-primary);
    text-decoration: none;
}

.article-card h3 a:hover {
    color: var(--primary-color);
}

.article-card .excerpt {
    color: var(--text-secondary);
    font-size: 14px;
    margin-bottom: 16px;
    line-height: 1.5;
}

.article-card .meta {
    display: flex;
    gap: 15px;
    font-size: 13px;
    color: var(--text-secondary);
}

/* ========================================
   认证页面
   ======================================== */
.auth-page {
    min-height: calc(100vh - 64px);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 40px 20px;
}

.auth-container {
    background: var(--card-bg);
    padding: 40px;
    border-radius: 12px;
    box-shadow: var(--shadow-lg);
    width: 100%;
    max-width: 400px;
}

.auth-container h1 {
    text-align: center;
    margin-bottom: 30px;
    font-size: 24px;
}

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

.auth-form label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
    font-size: 14px;
}

.auth-form input {
    width: 100%;
    padding: 12px;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    font-size: 14px;
    transition: border-color 0.2s;
}

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

.form-error {
    color: var(--error-color);
    font-size: 14px;
    margin-bottom: 15px;
    min-height: 20px;
}

.auth-links {
    margin-top: 20px;
    text-align: center;
    font-size: 14px;
}

.auth-links a {
    color: var(--primary-color);
    text-decoration: none;
}

.auth-links p {
    margin: 8px 0;
    color: var(--text-secondary);
}

/* ========================================
   页脚
   ======================================== */
.footer {
    background: var(--card-bg);
    border-top: 1px solid var(--border-color);
    padding: 30px 0;
    text-align: center;
    color: var(--text-secondary);
}

/* ========================================
   加载和错误状态
   ======================================== */
.loading,
.empty,
.error {
    text-align: center;
    padding: 40px;
    color: var(--text-secondary);
}

.error {
    color: var(--error-color);
}

/* ========================================
   响应式
   ======================================== */
@media (max-width: 768px) {
    .hero h1 {
        font-size: 32px;
    }
    
    .hero p {
        font-size: 16px;
    }
    
    .nav {
        display: none;
    }
    
    .article-grid {
        grid-template-columns: 1fr;
    }
    
    .hero-actions {
        flex-direction: column;
        align-items: center;
    }
}