/**
 * 布局样式
 * TSF研究所 - ACG文化兴趣部落
 */

/* ==========================================
   Navigation
   ========================================== */

.navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: var(--z-navbar);
    padding: 20px 0;
    transition: all var(--transition-base);
}

.navbar.scrolled {
    background: var(--glass-bg);
    backdrop-filter: var(--glass-blur);
    -webkit-backdrop-filter: var(--glass-blur);
    border-bottom: var(--glass-border);
    padding: 12px 0;
    box-shadow: var(--shadow-sm);
}

.nav-container {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 12px;
    text-decoration: none;
}

.logo-img {
    width: 36px;
    height: 36px;
}

.logo-text {
    font-family: var(--font-family-heading);
    font-size: var(--font-size-lg);
    font-weight: var(--font-weight-heading-bold);
    color: var(--color-primary);
}

.nav-menu {
    display: flex;
    align-items: center;
    gap: 40px;
}

.nav-link {
    position: relative;
    font-size: var(--font-size-sm);
    font-weight: var(--font-weight-body-medium);
    color: var(--color-text-secondary);
    text-decoration: none;
    padding: 8px 0;
    transition: color var(--transition-fast);
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--gradient-accent);
    border-radius: var(--radius-full);
    transition: width var(--transition-base);
}

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

.nav-link:hover::after,
.nav-link.active::after {
    width: 100%;
}

/* Hamburger */
.hamburger {
    display: none;
    flex-direction: column;
    justify-content: center;
    gap: 6px;
    width: 32px;
    height: 32px;
    padding: 4px;
    cursor: pointer;
}

.hamburger span {
    display: block;
    width: 100%;
    height: 2px;
    background: var(--color-primary);
    border-radius: var(--radius-full);
    transition: all var(--transition-base);
}

.hamburger.active span:nth-child(1) {
    transform: translateY(8px) rotate(45deg);
}

.hamburger.active span:nth-child(2) {
    opacity: 0;
}

.hamburger.active span:nth-child(3) {
    transform: translateY(-8px) rotate(-45deg);
}

/* ==========================================
   Hero Section
   ========================================== */

.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding: 120px 0 80px;
    overflow: hidden;
}

.hero-shapes {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    overflow: hidden;
}

.shape {
    position: absolute;
    border-radius: 50%;
    opacity: 0.5;
}

.shape-1 {
    width: 400px;
    height: 400px;
    top: 10%;
    right: -5%;
    background: linear-gradient(135deg, var(--color-accent-soft) 0%, transparent 70%);
    animation: pulse 8s ease-in-out infinite;
}

.shape-2 {
    width: 300px;
    height: 300px;
    bottom: 20%;
    left: -5%;
    background: linear-gradient(135deg, rgba(126, 206, 193, 0.1) 0%, transparent 70%);
    animation: pulse 10s ease-in-out infinite 2s;
}

.shape-3 {
    width: 200px;
    height: 200px;
    top: 40%;
    left: 20%;
    background: linear-gradient(135deg, rgba(168, 164, 206, 0.08) 0%, transparent 70%);
    animation: pulse 12s ease-in-out infinite 4s;
}

@keyframes pulse {
    0%, 100% { transform: scale(1); opacity: 0.5; }
    50% { transform: scale(1.1); opacity: 0.3; }
}

.hero-content {
    position: relative;
    max-width: 800px;
    z-index: 1;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 8px 16px;
    background: var(--glass-bg);
    backdrop-filter: var(--glass-blur);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-full);
    font-size: var(--font-size-sm);
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-component);
}

.badge-dot {
    width: 8px;
    height: 8px;
    background: var(--color-accent);
    border-radius: 50%;
    animation: blink 2s ease-in-out infinite;
}

@keyframes blink {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.4; }
}

.hero-title {
    font-size: clamp(2.5rem, 6vw, 4rem);
    line-height: 1.15;
    margin-bottom: var(--spacing-component);
}

.title-line {
    display: block;
}

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

.hero-description {
    font-size: var(--font-size-md);
    color: var(--color-text-secondary);
    line-height: var(--line-height-relaxed);
    margin-bottom: var(--spacing-component);
    max-width: 560px;
}

.hero-buttons {
    display: flex;
    gap: var(--spacing-element);
    flex-wrap: wrap;
}

.hero-scroll-hint {
    display: none; /* PC端隐藏，保留移动端显示 */
}

.scroll-line {
    width: 1px;
    height: 40px;
    background: linear-gradient(to bottom, var(--color-accent), transparent);
    animation: scroll-down 2s ease-in-out infinite;
}

@keyframes scroll-down {
    0% { transform: scaleY(0); transform-origin: top; }
    50% { transform: scaleY(1); transform-origin: top; }
    51% { transform: scaleY(1); transform-origin: bottom; }
    100% { transform: scaleY(0); transform-origin: bottom; }
}

/* ==========================================
   Features Section
   ========================================== */

.features {
    position: relative;
    padding: var(--spacing-section-desktop) 0;
    background: var(--gradient-subtle);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--grid-gap);
}

.feature-card {
    position: relative;
    background: var(--color-bg-card);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--spacing-card-padding);
    transition: all var(--transition-smooth);
    overflow: hidden;
}

.feature-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 3px;
    background: var(--gradient-accent);
    transform: scaleX(0);
    transform-origin: left;
    transition: transform var(--transition-base);
}

.feature-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-card-hover);
    border-color: var(--color-border-accent);
}

.feature-card:hover::before {
    transform: scaleX(1);
}

.feature-number {
    position: absolute;
    top: var(--spacing-card-padding);
    right: var(--spacing-card-padding);
    font-family: var(--font-family-mono);
    font-size: var(--font-size-xs);
    color: var(--color-text-tertiary);
    opacity: 0.6;
}

.feature-icon {
    margin-bottom: var(--spacing-element);
}

.feature-card h3 {
    font-size: var(--font-size-lg);
    margin-bottom: var(--spacing-small);
}

.feature-card p {
    font-size: var(--font-size-sm);
    line-height: var(--line-height-relaxed);
}

.feature-line {
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 2px;
    background: var(--color-border-light);
}

/* ==========================================
   Updates Section
   ========================================== */

.updates {
    position: relative;
    padding: var(--spacing-section-desktop) 0;
}

.updates-bg {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: var(--color-bg-secondary);
    z-index: -1;
}

.updates-list {
    display: flex;
    flex-direction: column;
    gap: var(--grid-gap);
    margin-bottom: var(--spacing-component);
}

.update-card {
    display: grid;
    grid-template-columns: auto 1fr;
    gap: var(--spacing-component);
    background: var(--color-bg-card);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--spacing-card-padding);
    transition: all var(--transition-smooth);
}

.update-card:hover {
    box-shadow: var(--shadow-md);
    border-color: var(--color-border-accent);
}

.update-visual {
    display: flex;
    align-items: center;
    justify-content: center;
}

.update-icon-large {
    width: 80px;
    height: 80px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--color-bg-secondary);
    border-radius: var(--radius-md);
    transition: all var(--transition-base);
}

.update-card:hover .update-icon-large {
    transform: scale(1.05);
}

.update-meta-top {
    display: flex;
    align-items: center;
    gap: var(--spacing-element);
    margin-bottom: var(--spacing-small);
}

.update-date-text {
    font-size: var(--font-size-xs);
    color: var(--color-text-tertiary);
}

.update-content h3 {
    font-size: var(--font-size-lg);
    margin-bottom: var(--spacing-small);
}

.update-content h3 a {
    color: inherit;
    text-decoration: none;
    transition: color var(--transition-fast);
}

.update-content h3 a:hover {
    color: var(--color-accent);
}

.update-content p {
    font-size: var(--font-size-sm);
    margin-bottom: var(--spacing-element);
}

.update-footer {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.meta-author {
    font-size: var(--font-size-xs);
    color: var(--color-text-tertiary);
}

.read-more {
    font-size: var(--font-size-sm);
    font-weight: var(--font-weight-body-medium);
    color: var(--color-accent);
    display: inline-flex;
    align-items: center;
    gap: 4px;
}

.read-more:hover {
    gap: 8px;
}

/* ==========================================
   Stats Section
   ========================================== */

.stats {
    position: relative;
    padding: var(--spacing-section-desktop) 0;
    background: var(--color-primary);
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--grid-gap);
}

.stat-item {
    position: relative;
    text-align: center;
    padding: var(--spacing-card-padding);
}

.stat-number {
    font-family: var(--font-family-heading);
    font-size: var(--font-size-4xl);
    font-weight: var(--font-weight-heading-bold);
    color: var(--color-text-white);
    line-height: 1;
    margin-bottom: var(--spacing-small);
}

.stat-number::after {
    content: '+';
}

.stat-label {
    font-size: var(--font-size-sm);
    color: rgba(255, 255, 255, 0.7);
    letter-spacing: 1px;
}

.stat-decoration {
    position: absolute;
    right: 0;
    top: 50%;
    transform: translateY(-50%);
    width: 1px;
    height: 60%;
    background: rgba(255, 255, 255, 0.1);
}

.stat-item:last-child .stat-decoration {
    display: none;
}

/* ==========================================
   CTA Section
   ========================================== */

.cta {
    padding: var(--spacing-section-desktop) 0;
}

.cta-card {
    position: relative;
    background: var(--gradient-warm);
    border-radius: var(--radius-xl);
    padding: 60px 40px;
    text-align: center;
    overflow: hidden;
}

.cta-decoration {
    position: absolute;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.1);
}

.cta-circle-1 {
    width: 300px;
    height: 300px;
    top: -150px;
    right: -100px;
}

.cta-circle-2 {
    width: 200px;
    height: 200px;
    bottom: -100px;
    left: -50px;
}

.cta-card h2 {
    font-size: var(--font-size-2xl);
    color: var(--color-text-white);
    margin-bottom: var(--spacing-element);
    position: relative;
}

.cta-card p {
    color: rgba(255, 255, 255, 0.9);
    margin-bottom: var(--spacing-component);
    position: relative;
}

.cta-buttons {
    position: relative;
}

/* ==========================================
   Footer
   ========================================== */

.footer {
    background: var(--color-primary);
    padding: 60px 0 30px;
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: var(--grid-gap);
    margin-bottom: 40px;
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: var(--spacing-element);
}

.footer-logo img {
    width: 32px;
    height: 32px;
}

.footer-logo span {
    font-family: var(--font-family-heading);
    font-size: var(--font-size-lg);
    font-weight: var(--font-weight-heading-bold);
    color: var(--color-text-white);
}

.footer-info p {
    color: rgba(255, 255, 255, 0.6);
    font-size: var(--font-size-sm);
}

.footer-tagline {
    margin-top: var(--spacing-small);
    font-size: var(--font-size-xs) !important;
    letter-spacing: 2px;
    text-transform: uppercase;
}

.footer-links h4,
.footer-contact h4,
.footer-social h4 {
    font-size: var(--font-size-sm);
    color: var(--color-text-white);
    margin-bottom: var(--spacing-element);
}

.footer-links ul {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.footer-links a {
    font-size: var(--font-size-sm);
    color: rgba(255, 255, 255, 0.6);
    transition: color var(--transition-fast);
}

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

.footer-contact p {
    font-size: var(--font-size-sm);
    color: rgba(255, 255, 255, 0.6);
}

.social-links {
    display: flex;
    gap: var(--spacing-small);
}

.social-link {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-sm);
    color: var(--color-text-white);
    transition: all var(--transition-fast);
}

.social-link:hover {
    background: var(--color-accent);
    transform: translateY(-2px);
}

.footer-bottom {
    padding-top: 30px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    text-align: center;
}

.footer-bottom p {
    font-size: var(--font-size-xs);
    color: rgba(255, 255, 255, 0.4);
}

/* ==========================================
   Page Header (子页面)
   ========================================== */

.page-header {
    padding: 140px 0 60px;
    background: var(--gradient-hero);
    text-align: center;
}

.page-header .page-title {
    font-size: var(--font-size-3xl);
    margin-bottom: var(--spacing-element);
}

.page-header .page-subtitle {
    font-size: var(--font-size-md);
    color: var(--color-text-secondary);
}

/* ==========================================
   About Page - Introduction
   ========================================== */

.about-intro {
    padding: var(--spacing-section-desktop) 0;
}

.about-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.about-text h2 {
    font-size: var(--font-size-2xl);
    margin-bottom: var(--spacing-component);
}

.about-text p {
    margin-bottom: var(--spacing-element);
    line-height: var(--line-height-relaxed);
}

.about-image {
    display: flex;
    justify-content: center;
}

.image-placeholder {
    width: 100%;
    max-width: 300px;
    aspect-ratio: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--color-bg-secondary);
    border-radius: var(--radius-lg);
}

/* ==========================================
   About Page - Timeline
   ========================================== */

.timeline-section {
    padding: var(--spacing-section-desktop) 0;
    background: var(--color-bg-secondary);
}

.timeline {
    position: relative;
    max-width: 700px;
    margin: 0 auto;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 50%;
    top: 0;
    bottom: 0;
    width: 2px;
    background: var(--color-border);
    transform: translateX(-50%);
}

.timeline-item {
    position: relative;
    padding: 20px 0;
    width: 50%;
}

.timeline-item:nth-child(odd) {
    padding-right: 40px;
    text-align: right;
}

.timeline-item:nth-child(even) {
    margin-left: 50%;
    padding-left: 40px;
}

.timeline-dot {
    position: absolute;
    top: 28px;
    width: 14px;
    height: 14px;
    background: var(--color-accent);
    border-radius: 50%;
    border: 3px solid var(--color-bg-secondary);
}

.timeline-item:nth-child(odd) .timeline-dot {
    right: -7px;
}

.timeline-item:nth-child(even) .timeline-dot {
    left: -7px;
}

.timeline-content h3 {
    font-size: var(--font-size-lg);
    color: var(--color-primary);
    margin-bottom: 8px;
}

.timeline-content p {
    font-size: var(--font-size-sm);
    color: var(--color-text-secondary);
}

/* ==========================================
   About Page - Team
   ========================================== */

.team-section {
    padding: var(--spacing-section-desktop) 0;
}

.team-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--grid-gap);
}

.team-card {
    text-align: center;
    padding: var(--spacing-card-padding);
    background: var(--color-bg-card);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    transition: all var(--transition-smooth);
}

.team-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}

.team-avatar {
    width: 80px;
    height: 80px;
    margin: 0 auto var(--spacing-element);
    border-radius: 50%;
    overflow: hidden;
}

.team-card h3 {
    font-size: var(--font-size-lg);
    margin-bottom: 4px;
}

.team-role {
    font-size: var(--font-size-xs);
    color: var(--color-accent);
    margin-bottom: var(--spacing-small);
}

.team-bio {
    font-size: var(--font-size-sm);
    color: var(--color-text-secondary);
}

/* ==========================================
   About Page - Research Directions
   ========================================== */

.research-directions {
    padding: var(--spacing-section-desktop) 0;
    background: var(--color-bg-secondary);
}

.directions-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--grid-gap);
}

.direction-card {
    padding: var(--spacing-card-padding);
    background: var(--color-bg-card);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    text-align: center;
    transition: all var(--transition-smooth);
}

.direction-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
    border-color: var(--color-border-accent);
}

.direction-icon {
    margin-bottom: var(--spacing-element);
}

.direction-card h3 {
    font-size: var(--font-size-lg);
    margin-bottom: var(--spacing-small);
}

.direction-card p {
    font-size: var(--font-size-sm);
}

/* ==========================================
   About Page - Contact
   ========================================== */

.contact-section {
    padding: var(--spacing-section-desktop) 0;
}

.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
}

.contact-info h3 {
    font-size: var(--font-size-xl);
    margin-bottom: var(--spacing-element);
}

.contact-info > p {
    margin-bottom: var(--spacing-component);
}

.contact-item {
    margin-bottom: var(--spacing-element);
}

.contact-item strong {
    color: var(--color-text-primary);
}

.contact-item p,
.contact-item a {
    font-size: var(--font-size-sm);
    color: var(--color-text-secondary);
}

.contact-form {
    background: var(--color-bg-card);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--spacing-card-padding);
}

.contact-form h3 {
    font-size: var(--font-size-xl);
    margin-bottom: var(--spacing-component);
}

/* ==========================================
   Content Page - Filter
   ========================================== */

.filter-section {
    padding: var(--spacing-component) 0;
    background: var(--color-bg-card);
    border-bottom: 1px solid var(--color-border);
    position: sticky;
    top: 70px;
    z-index: 10;
}

.filter-bar {
    display: flex;
    justify-content: center;
    gap: var(--spacing-element);
    flex-wrap: wrap;
}

.filter-btn {
    padding: 10px 20px;
    font-size: var(--font-size-sm);
    font-weight: var(--font-weight-body-medium);
    background: transparent;
    color: var(--color-text-secondary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-full);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.filter-btn:hover {
    border-color: var(--color-accent);
    color: var(--color-accent);
}

.filter-btn.active {
    background: var(--gradient-accent);
    color: var(--color-text-white);
    border-color: transparent;
}

/* ==========================================
   Content Page - Grid
   ========================================== */

.content-grid-section {
    padding: var(--spacing-section-desktop) 0;
}

.content-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--grid-gap);
    margin-bottom: var(--spacing-component);
}

.content-card {
    background: var(--color-bg-card);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    overflow: hidden;
    transition: all var(--transition-smooth);
}

.content-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}

.content-card.hidden {
    display: none;
}

.content-card .card-image {
    position: relative;
    height: 180px;
    overflow: hidden;
}

.content-card .card-image .image-placeholder {
    width: 100%;
    height: 100%;
    max-width: none;
    border-radius: 0;
}

.card-tag {
    position: absolute;
    top: 12px;
    left: 12px;
}

.content-card .card-content {
    padding: var(--spacing-card-padding);
}

.content-card .card-content h3 {
    font-size: var(--font-size-lg);
    margin-bottom: var(--spacing-small);
    line-height: 1.4;
}

.content-card .card-content p {
    font-size: var(--font-size-sm);
    margin-bottom: var(--spacing-element);
}

.content-card .card-meta {
    display: flex;
    justify-content: space-between;
    font-size: var(--font-size-xs);
    color: var(--color-text-tertiary);
}

.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--color-bg-card);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-full);
    box-shadow: var(--shadow-md);
    color: var(--color-primary);
    opacity: 0;
    visibility: hidden;
    transform: translateY(20px);
    transition: all var(--transition-base);
    z-index: var(--z-dropdown);
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.back-to-top:hover {
    background: var(--color-accent);
    border-color: var(--color-accent);
    color: var(--color-text-white);
    transform: translateY(-2px);
}