/* =============================================
   base.css — 基础重置、字体、共享布局与组件
   ============================================= */

/* ----- 字体加载 ----- */
@font-face {
    font-family: 'Noto Sans CJK SC';
    src: url('../fonts/NotoSansCJKsc-Medium.otf') format('opentype');
    font-weight: 500;
    font-style: normal;
    font-display: swap;
}

/* ----- CSS Reset ----- */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: var(--font-family);
    background: var(--bg-gradient);
    background-attachment: fixed;
    color: var(--text-primary);
    transition: background var(--transition-speed) ease,
                color var(--transition-speed) ease;
    min-height: 100vh;
    overflow-x: hidden;
    line-height: 1.6;
}

a {
    color: var(--accent);
    text-decoration: none;
    transition: color var(--transition-speed);
}

a:hover {
    color: var(--accent-hover);
}

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

/* ----- 容器布局 ----- */
.container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 24px;
}

/* ----- Section 通用样式 ----- */
.section {
    padding: 80px 0;
    position: relative;
}

.section-title {
    font-size: 2.4rem;
    font-weight: 700;
    margin-bottom: 48px;
    position: relative;
    display: inline-block;
    text-transform: uppercase;
    letter-spacing: 4px;
    transition: all var(--transition-speed);
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -8px;
    left: 0;
    width: 60px;
    height: 4px;
    background: var(--accent);
    transition: all var(--transition-speed);
}

/* ----- Header / 导航栏 ----- */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    padding: 16px 32px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    background: var(--nav-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid rgba(255,255,255,0.08);
    transition: all var(--transition-speed);
}

.header-brand {
    display: flex;
    align-items: center;
    gap: 12px;
    cursor: pointer;
}

.brand-logo {
    font-size: 1.4rem;
    font-weight: 900;
    color: var(--accent);
    background: var(--text-primary);
    padding: 4px 10px;
    transform: skew(var(--ui-skew));
    display: inline-block;
    line-height: 1.2;
    transition: all var(--transition-speed);
}

.brand-text {
    font-size: 1.1rem;
    font-weight: 700;
    letter-spacing: 2px;
    transition: color var(--transition-speed);
}

.header-nav {
    display: flex;
    gap: 8px;
}

.nav-link {
    padding: 8px 18px;
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-secondary);
    letter-spacing: 1px;
    text-transform: uppercase;
    position: relative;
    transform: skew(var(--ui-skew));
    transition: all var(--transition-speed);
    border: 1px solid transparent;
}

.nav-link:hover {
    color: var(--accent);
    border-color: var(--accent);
    background: rgba(255,255,255,0.05);
}

/* ----- 主题切换按钮 ----- */
.theme-toggle-btn {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 10px 20px;
    font-family: var(--font-family);
    font-size: 0.85rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 1px;
    border: 1px solid var(--accent);
    background: transparent;
    color: var(--text-primary);
    cursor: pointer;
    transform: skew(var(--ui-skew));
    transition: all var(--transition-speed);
    position: relative;
    overflow: hidden;
}

.theme-toggle-btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: var(--accent);
    transition: left 0.3s ease;
    z-index: -1;
}

.theme-toggle-btn:hover::before {
    left: 0;
}

.theme-toggle-btn:hover {
    color: #fff;
}

.toggle-icon {
    font-size: 1.1rem;
    display: inline-block;
    transition: transform 0.6s ease;
}

.theme-toggle-btn:hover .toggle-icon {
    transform: rotate(180deg);
}

/* ----- Hero 区域 ----- */
.hero-section {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    padding: 120px 24px 80px;
    overflow: hidden;
}

.hero-content {
    text-align: center;
    position: relative;
    z-index: 2;
    max-width: 800px;
}

.hero-title {
    font-size: 5rem;
    font-weight: 900;
    line-height: 1.1;
    margin-bottom: 16px;
    letter-spacing: 6px;
    text-transform: uppercase;
    transition: all var(--transition-speed);
}

.hero-title .title-line {
    display: block;
    transform: skew(var(--ui-skew));
    transition: all var(--transition-speed);
}

.hero-title .title-accent {
    color: var(--accent);
    text-shadow: var(--hero-text-shadow);
    transition: all var(--transition-speed);
}

.hero-subtitle {
    font-size: 1.2rem;
    color: var(--text-secondary);
    letter-spacing: 6px;
    text-transform: uppercase;
    margin-bottom: 40px;
    font-weight: 300;
    transition: color var(--transition-speed);
}

.hero-actions {
    display: flex;
    gap: 16px;
    justify-content: center;
    flex-wrap: wrap;
}

/* ----- 按钮系统 ----- */
.btn {
    display: inline-block;
    padding: 14px 36px;
    font-family: var(--font-family);
    font-size: 0.9rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 2px;
    cursor: pointer;
    transition: all 0.3s ease;
    text-decoration: none;
    position: relative;
}

.btn-primary {
    background: var(--accent);
    color: #fff;
    border: 2px solid var(--accent);
    transform: skew(var(--ui-skew));
    box-shadow: var(--button-shadow);
}

.btn-primary:hover {
    transform: skew(var(--ui-skew)) translate(-2px, -2px);
    box-shadow: calc(var(--button-shadow-x, 4px) + 2px) calc(var(--button-shadow-y, 4px) + 2px) 0px var(--button-shadow-color, var(--accent));
    background: var(--accent-hover);
}

.btn-primary:active {
    transform: skew(var(--ui-skew)) translate(2px, 2px);
    box-shadow: none;
}

.btn-secondary {
    background: transparent;
    color: var(--text-primary);
    border: 2px solid var(--text-primary);
    transform: skew(var(--ui-skew));
}

.btn-secondary:hover {
    background: var(--text-primary);
    color: var(--bg-primary, #000);
}

/* ----- About 卡片 ----- */
.about-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 32px;
    align-items: center;
}

.about-text {
    font-size: 1.05rem;
    line-height: 1.8;
    color: var(--text-secondary);
    transition: color var(--transition-speed);
}

.about-text p {
    margin-bottom: 16px;
}

.about-stats {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
}

.stat-card {
    background: var(--card-bg);
    border: var(--card-border);
    padding: 24px;
    text-align: center;
    backdrop-filter: blur(8px);
    transform: skew(var(--ui-skew));
    transition: all var(--transition-speed);
}

.stat-card:hover {
    transform: skew(var(--ui-skew)) scale(1.03);
    border-color: var(--accent);
}

.stat-card > * {
    transform: skew(calc(var(--ui-skew) * -1));
    transition: transform var(--transition-speed);
}

.stat-number {
    font-size: 2rem;
    font-weight: 900;
    color: var(--accent);
    display: block;
    transition: color var(--transition-speed);
}

.stat-label {
    font-size: 0.85rem;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-top: 4px;
    display: block;
}

/* ----- 作品集 / Gallery ----- */
.video-showcase {
    background: var(--card-bg);
    border: var(--card-border);
    padding: 32px;
    backdrop-filter: blur(8px);
    border-radius: 12px;
    transition: all var(--transition-speed);
}

.video-gallery {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 20px;
}

.video-container {
    flex: 1;
    position: relative;
    min-height: 480px;
    overflow: hidden;
}

.video-item {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    padding: 24px;
    background: var(--video-bg);
    backdrop-filter: blur(8px);
    border: 1px solid rgba(255,255,255,0.1);
    border-radius: 8px;
    box-shadow: 0 8px 32px rgba(0,0,0,0.3);
    opacity: 0;
    pointer-events: none;
    z-index: 1;
    display: flex;
    flex-direction: column;
    transition: transform 0.55s cubic-bezier(0.22, 1, 0.36, 1),
                opacity 0.55s cubic-bezier(0.22, 1, 0.36, 1);
}

/* Active: front and center */
.video-item.active {
    opacity: 1;
    transform: scale(1) translateX(0);
    z-index: 3;
    pointer-events: auto;
}

.video-item h3 {
    font-size: 1.1rem;
    margin-bottom: 12px;
    color: var(--accent);
    text-transform: uppercase;
    letter-spacing: 2px;
    text-align: center;
    flex-shrink: 0;
    transition: color var(--transition-speed);
}

.video-item video {
    width: 100%;
    min-height: 0;
    flex: 1;
    display: block;
    border-radius: 4px;
    object-fit: contain;
    background: rgba(0,0,0,0.3);
}

/* 导航按钮 */
.nav-btn {
    width: 48px;
    height: 48px;
    padding: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.4rem;
    font-weight: bold;
    cursor: pointer;
    transition: all var(--transition-speed);
    flex-shrink: 0;
}

.nav-prev,
.nav-next {
    background: var(--accent);
    color: #fff;
    border: none;
    border-radius: 50%;
    box-shadow: var(--button-shadow);
    transition: all 0.25s ease;
}

.nav-prev:hover,
.nav-next:hover {
    transform: scale(1.12);
}

.nav-prev:active,
.nav-next:active {
    transform: scale(0.95);
    box-shadow: none;
}

.video-counter {
    text-align: center;
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin-top: 20px;
    letter-spacing: 2px;
    transition: color var(--transition-speed);
}

/* ----- Skills 区域 ----- */
.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 20px;
}

.skill-card {
    background: var(--card-bg);
    border: var(--card-border);
    padding: 28px 20px;
    text-align: center;
    backdrop-filter: blur(8px);
    transform: skew(var(--ui-skew));
    transition: all var(--transition-speed);
    cursor: default;
}

.skill-card:hover {
    transform: skew(var(--ui-skew)) translateY(-4px);
    border-color: var(--accent);
    box-shadow: 0 8px 24px var(--accent-glow);
}

.skill-card > * {
    transform: skew(calc(var(--ui-skew) * -1));
    transition: transform var(--transition-speed);
}

.skill-icon {
    font-size: 2.2rem;
    margin-bottom: 12px;
    display: block;
    color: var(--accent);
    transition: color var(--transition-speed);
}

.skill-name {
    font-size: 0.95rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 1px;
    transition: color var(--transition-speed);
}

/* ----- Contact 区域 ----- */
.contact-content {
    text-align: center;
    max-width: 600px;
    margin: 0 auto;
}

.contact-text {
    font-size: 1.1rem;
    color: var(--text-secondary);
    margin-bottom: 32px;
    transition: color var(--transition-speed);
}

.contact-links {
    display: flex;
    justify-content: center;
    gap: 24px;
    flex-wrap: wrap;
}

.contact-link {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 12px 24px;
    background: var(--card-bg);
    border: var(--card-border);
    color: var(--text-primary);
    font-weight: 600;
    transform: skew(var(--ui-skew));
    transition: all var(--transition-speed);
    font-size: 0.9rem;
}

.contact-link:hover {
    transform: skew(var(--ui-skew)) translateY(-3px);
    border-color: var(--accent);
    color: var(--accent);
    box-shadow: 0 4px 16px var(--accent-glow);
}

.contact-link .link-icon {
    font-size: 1.2rem;
}

/* ----- Footer ----- */
.footer {
    padding: 32px 24px;
    text-align: center;
    background: var(--footer-bg);
    border-top: 1px solid rgba(255,255,255,0.05);
    transition: all var(--transition-speed);
}

.footer-text {
    font-size: 0.85rem;
    color: var(--text-secondary);
    letter-spacing: 1px;
    transition: color var(--transition-speed);
}

.footer-text .highlight {
    color: var(--accent);
    transition: color var(--transition-speed);
}

/* ----- 响应式 ----- */
@media (max-width: 768px) {
    .hero-title {
        font-size: 3rem;
    }

    .hero-subtitle {
        font-size: 0.9rem;
        letter-spacing: 3px;
    }

    .header {
        padding: 12px 16px;
    }

    .header-nav {
        gap: 4px;
    }

    .nav-link {
        padding: 6px 10px;
        font-size: 0.75rem;
    }

    .brand-text {
        display: none;
    }

    .theme-toggle-btn {
        padding: 8px 12px;
        font-size: 0.75rem;
    }

    .toggle-label {
        display: none;
    }

    .about-grid {
        grid-template-columns: 1fr;
    }

    .about-stats {
        grid-template-columns: 1fr 1fr;
    }

    .video-gallery {
        gap: 8px;
    }

    .video-container {
        min-height: 280px;
    }

    .nav-btn {
        width: 40px;
        height: 40px;
        font-size: 1.1rem;
    }

    .section {
        padding: 48px 0;
    }

    .section-title {
        font-size: 1.8rem;
        margin-bottom: 32px;
    }

    .skills-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .stat-card {
        padding: 16px;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 2.2rem;
    }

    .header-nav {
        display: none;
    }

    .skills-grid {
        grid-template-columns: 1fr 1fr;
    }
}