@import url('https://fonts.googleapis.com/css2?family=Noto+Sans+SC:wght@400;500;700&family=Inter:wght@400;500;600;700&display=swap');

:root {
    /* [修改] 纯色背景，移除了网格变量 */
    --bg-color: #0d1117;
    --bg-surface: #161b22;
    --border-color: rgba(255, 255, 255, 0.1);
    --text-color: #e6edf3;
    --text-light: #848d97;
    --primary-color: #2f81f7;
    --primary-gradient: linear-gradient(135deg, #2f81f7, #10b981);
    --shadow-color: rgba(0, 0, 0, 0.4);
    --font-family-base: 'Inter', 'Noto Sans SC', sans-serif;
}

html[data-theme='light'] {
    --bg-color: #f8fafc;
    --bg-surface: #ffffff;
    --border-color: rgba(0, 0, 0, 0.08);
    --text-color: #0f172a;
    --text-light: #64748b;
    --primary-color: #3b82f6;
    --primary-gradient: linear-gradient(135deg, #3b82f6, #10b981);
    --shadow-color: rgba(149, 157, 165, 0.15);
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { background-color: var(--bg-color); scroll-behavior: smooth; }

/* [修改] 删除了 .bg-grid 样式 */

body {
    font-family: var(--font-family-base);
    color: var(--text-color);
    background-color: var(--bg-color); /* 确保背景色应用 */
    transition: background-color 0.4s ease, color 0.4s ease;
    display: flex;
    flex-direction: column;
    align-items: center;
    min-height: 100vh;
    padding: 0 1.5rem;
    user-select: none; /* [新增] CSS层面禁止文字选择 */
    -webkit-user-select: none;
}

/* 顶部导航 */
.home-header {
    width: 100%;
    max-width: 1100px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.5rem 0;
    margin-bottom: 4rem;
    border-bottom: 1px solid var(--border-color);
    animation: fadeInDown 0.8s ease backwards;
}

.site-name {
    font-size: 1.25rem;
    font-weight: 700;
    letter-spacing: 0.5px;
    display: flex;
    align-items: center;
    gap: 10px;
}

.actions { display: flex; gap: 0.75rem; }

.icon-button {
    background: var(--bg-surface);
    border: 1px solid var(--border-color);
    cursor: pointer;
    color: var(--text-color);
    display: flex;
    justify-content: center;
    align-items: center;
    width: 42px;
    height: 42px;
    border-radius: 12px;
    transition: all 0.3s ease;
}

.icon-button:hover {
    border-color: var(--primary-color);
    color: var(--primary-color);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px var(--shadow-color);
}

/* 主体内容区 */
.home-main { width: 100%; max-width: 1100px; text-align: center; flex: 1; }
.hero-section { margin-bottom: 4rem; animation: fadeInUp 0.8s ease 0.2s backwards; }

.hero-section h1 {
    font-size: 3.5rem;
    font-weight: 800;
    margin-bottom: 1.2rem;
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    line-height: 1.2;
}

.hero-section p {
    font-size: 1.2rem;
    color: var(--text-light);
    max-width: 600px;
    margin: 0 auto;
    line-height: 1.6;
}

/* 卡片网格 */
.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.5rem;
    animation: fadeInUp 0.8s ease 0.4s backwards;
}

.feature-card {
    display: flex;
    flex-direction: column;
    background-color: var(--bg-surface);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 2rem;
    text-decoration: none;
    text-align: left;
    transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    position: relative;
    overflow: hidden;
}

.feature-card:hover {
    transform: translateY(-8px);
    border-color: var(--primary-color);
    box-shadow: 0 12px 30px var(--shadow-color);
}

.feature-card .icon {
    font-size: 36px;
    color: var(--primary-color);
    margin-bottom: 1.2rem;
    background: var(--bg-color);
    padding: 12px;
    border-radius: 12px;
    width: fit-content;
    border: 1px solid var(--border-color);
    transition: all 0.3s ease;
}

.feature-card:hover .icon {
    background: var(--primary-gradient);
    color: #fff;
    border-color: transparent;
}

.feature-card h3 { font-size: 1.3rem; color: var(--text-color); margin-bottom: 0.8rem; font-weight: 600; }
.feature-card p { font-size: 0.95rem; color: var(--text-light); line-height: 1.6; }

/* 底部 Footer */
.home-footer {
    margin-top: 4rem;
    padding: 2.5rem 0;
    width: 100%;
    text-align: center;
    font-size: 0.9rem;
    color: var(--text-light);
    border-top: 1px solid var(--border-color);
    animation: fadeIn 1s ease 0.6s backwards;
}

/* 动画定义 */
@keyframes fadeInDown { from { opacity: 0; transform: translateY(-20px); } to { opacity: 1; transform: translateY(0); } }
@keyframes fadeInUp { from { opacity: 0; transform: translateY(30px); } to { opacity: 1; transform: translateY(0); } }
@keyframes fadeIn { from { opacity: 0; } to { opacity: 1; } }

/* 响应式调整 */
@media (max-width: 768px) {
    .hero-section h1 { font-size: 2.5rem; }
    .hero-section p { font-size: 1.05rem; }
    .home-header { padding: 1rem 0; flex-direction: column; gap: 1rem; margin-bottom: 2rem; }
    .feature-grid { grid-template-columns: 1fr; }
}