:root {
    /* Instagram 风格品牌色 */
    --brand-gradient: linear-gradient(45deg, #833AB4 0%, #FD1D1D 50%, #FCAF45 100%);
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --bg-light: #f8fafc;
    --white: #ffffff;
    --radius-card: 16px;
    --shadow-soft: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
}

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

body {
    font-family: 'Inter', system-ui, -apple-system, sans-serif;
    color: var(--text-primary);
    background-color: var(--bg-light);
    line-height: 1.6;
}

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

/* Header */
.site-header {
    background: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(10px);
    position: sticky;
    top: 0;
    z-index: 100;
    border-bottom: 1px solid #e2e8f0;
    padding: 1rem 0;
}

.header-inner {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-weight: 800;
    font-size: 1.5rem;
    background: var(--brand-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    text-decoration: none;
}

/* 按钮样式 */
.btn-gradient {
    background: var(--brand-gradient);
    color: white;
    padding: 10px 24px;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 600;
    transition: opacity 0.3s;
    display: inline-block;
}

.btn-gradient:hover {
    opacity: 0.9;
}

/* 首页 Hero */
.hero {
    text-align: center;
    padding: 80px 0 60px;
}

.hero h1 {
    font-size: 3.5rem;
    margin-bottom: 1rem;
    line-height: 1.1;
}

.highlight {
    background: var(--brand-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

/* 卡片网格 */
.grid-section {
    padding: 40px 0;
}

.section-title {
    font-size: 1.8rem;
    margin-bottom: 2rem;
    border-left: 5px solid #FD1D1D;
    padding-left: 15px;
}

.grid-3 {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}

/* App 和 教程卡片 */
.card {
    background: var(--white);
    border-radius: var(--radius-card);
    padding: 24px;
    box-shadow: var(--shadow-soft);
    transition: transform 0.2s;
    border: 1px solid #f1f5f9;
    text-decoration: none;
    color: inherit;
    display: flex;
    flex-direction: column;
}

.card:hover {
    transform: translateY(-5px);
    border-color: #FD1D1D;
}

.app-icon-placeholder {
    width: 60px;
    height: 60px;
    border-radius: 12px;
    background: var(--brand-gradient);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 24px;
    margin-bottom: 16px;
}

.card-title {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.card-desc {
    color: var(--text-secondary);
    font-size: 0.95rem;
    margin-bottom: 1.5rem;
    flex-grow: 1;
}

.tag {
    display: inline-block;
    padding: 4px 12px;
    background: #fff0eb;
    color: #FD1D1D;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 600;
}

/* 教程详情页特定样式 */
.tutorial-article {
    max-width: 800px;
    margin: 40px auto;
    background: white;
    padding: 40px;
    border-radius: var(--radius-card);
    box-shadow: var(--shadow-soft);
}

.tutorial-meta {
    margin-bottom: 20px;
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.problem-box {
    background: #fdf2f8; /* 浅粉色背景 */
    border-left: 4px solid #FD1D1D;
    padding: 20px;
    margin: 30px 0;
    font-style: italic;
    color: #4a5568;
}

.step-item {
    display: flex;
    gap: 20px;
    margin-bottom: 40px;
}

.step-num {
    flex-shrink: 0;
    width: 40px;
    height: 40px;
    background: var(--brand-gradient);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: bold;
}

.cta-box {
    text-align: center;
    background: #f8fafc;
    padding: 40px;
    border-radius: var(--radius-card);
    margin-top: 60px;
    border: 1px solid #e2e8f0;
}

/* 响应式 */
@media (max-width: 768px) {
    .hero h1 { font-size: 2.5rem; }
    .tutorial-article { padding: 20px; }
}