/* ===== 全局重置 ===== */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
                 "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
    min-height: 100vh;
    overflow-x: hidden;
    line-height: 1.6;
    transition: background 0.8s ease, color 0.5s ease;
}

a {
    text-decoration: none;
    color: inherit;
    transition: color 0.3s ease;
}

ul, ol, li {
    list-style: none;
}

button {
    border: none;
    background: none;
    cursor: pointer;
    font-family: inherit;
    color: inherit;
}

input, textarea {
    font-family: inherit;
    outline: none;
    border: none;
}

img {
    max-width: 100%;
    display: block;
}

/* ===== CSS 变量（默认） ===== */
:root {
    --text-primary: #ffffff;
    --text-secondary: rgba(255, 255, 255, 0.7);
    --text-muted: rgba(255, 255, 255, 0.45);
    --accent: #00d4ff;
    --accent-secondary: #7b2cbf;
    --accent-glow: rgba(0, 212, 255, 0.4);
    --border: rgba(255, 255, 255, 0.12);
    --border-hover: rgba(0, 212, 255, 0.5);
    --card-bg: rgba(255, 255, 255, 0.04);
    --card-bg-hover: rgba(255, 255, 255, 0.08);
    --navbar-bg: rgba(10, 10, 26, 0.6);
    --shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
    --radius: 12px;
    --radius-sm: 8px;
}

/* ===== 通用布局 ===== */
.main-container {
    width: calc(100% - 220px);
    margin-left: 220px;
    min-height: 100vh;
    position: relative;
    z-index: 1;
}

.page-container {
    padding: 3rem 2rem 4rem;
    max-width: 1200px;
    margin: 0 auto;
}

/* 内容页：在侧边栏右侧空间内居中，避免重叠 */
.main-container.page-container {
    margin-left: 220px;
    margin-right: 0;
    max-width: none;
    width: auto;
    padding-left: max(2rem, calc((100vw - 220px - 1200px) / 2));
    padding-right: max(2rem, calc((100vw - 220px - 1200px) / 2));
}

.index-main {
    padding-top: 0;
}

/* ===== 页面头部 ===== */
.page-header {
    text-align: center;
    margin-bottom: 3rem;
}

.page-title {
    font-size: 2.5rem;
    font-weight: 700;
    letter-spacing: 2px;
    background: linear-gradient(135deg, var(--accent), var(--accent-secondary));
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 0.5rem;
}

.page-subtitle {
    color: var(--text-muted);
    font-size: 0.95rem;
    letter-spacing: 1px;
}

/* ===== 卡片通用 ===== */
.content-card, .profile-card, .info-card, .sidebar-card {
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1.8rem;
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    transition: all 0.4s cubic-bezier(0.2, 0.8, 0.2, 1);
}

.content-card:hover, .profile-card:hover, .info-card:hover {
    border-color: var(--border-hover);
    box-shadow: 0 0 24px var(--accent-glow);
    transform: translateY(-2px);
}

.card-title {
    font-size: 1.2rem;
    font-weight: 600;
    margin-bottom: 1rem;
    padding-left: 0.8rem;
    border-left: 3px solid var(--accent);
    color: var(--text-primary);
}

.card-content {
    color: var(--text-secondary);
    font-size: 0.95rem;
    line-height: 1.8;
}

.card-content p {
    margin-bottom: 0.8rem;
}

.card-content p:last-child {
    margin-bottom: 0;
}

/* ===== 科技风按钮 ===== */
.tech-btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.8rem;
    border-radius: 30px;
    background: linear-gradient(135deg, var(--accent), var(--accent-secondary));
    color: #fff;
    font-size: 0.95rem;
    font-weight: 500;
    letter-spacing: 1px;
    cursor: pointer;
    position: relative;
    overflow: hidden;
    transition: all 0.3s cubic-bezier(0.2, 0.8, 0.2, 1);
    border: none;
}

.tech-btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
    transition: left 0.5s ease;
}

.tech-btn:hover::before {
    left: 100%;
}

.tech-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px var(--accent-glow);
}

.tech-btn.outline {
    background: transparent;
    border: 1px solid var(--accent);
    color: var(--accent);
}

.tech-btn.outline:hover {
    background: var(--accent);
    color: #fff;
}

.btn-arrow {
    transition: transform 0.3s ease;
}

.tech-btn:hover .btn-arrow {
    transform: translateX(4px);
}

/* ===== 图标按钮 ===== */
.icon-btn {
    width: 38px;
    height: 38px;
    border-radius: 50%;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    background: var(--card-bg);
    border: 1px solid var(--border);
    color: var(--text-secondary);
    font-size: 1rem;
    cursor: pointer;
    transition: all 0.3s ease;
    position: relative;
}

.icon-btn:hover {
    border-color: var(--accent);
    color: var(--accent);
    box-shadow: 0 0 12px var(--accent-glow);
    transform: scale(1.05);
}

/* ===== 页脚 ===== */
.footer {
    position: relative;
    z-index: 1;
    margin-left: 220px;
    padding: 2rem;
    text-align: center;
    border-top: 1px solid var(--border);
    background: var(--card-bg);
    backdrop-filter: blur(8px);
}

.footer-content p {
    color: var(--text-muted);
    font-size: 0.85rem;
    margin-bottom: 0.3rem;
}

.footer-link {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
}

.footer-link a {
    color: var(--accent);
}

.footer-link a:hover {
    text-shadow: 0 0 8px var(--accent-glow);
}

/* ===== 响应式 ===== */
@media (max-width: 992px) {
    html { font-size: 15px; }
    .main-container,
    .main-container.page-container {
        width: 100%;
        margin-left: 0;
        padding-left: 1.5rem;
        padding-right: 1.5rem;
    }
    .page-container { padding-top: 5rem; }
    .footer { margin-left: 0; }
}

@media (max-width: 768px) {
    html { font-size: 14px; }
    .page-title { font-size: 2rem; }
    .main-container,
    .main-container.page-container {
        padding-left: 1rem;
        padding-right: 1rem;
    }
    .content-card, .profile-card, .info-card, .sidebar-card { padding: 1.3rem; }
}

@media (max-width: 480px) {
    html { font-size: 13px; }
}