* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    -webkit-tap-highlight-color: transparent;
}

:root {
    --bg-primary: #111827;
    --bg-secondary: #1f2937;
    --bg-tertiary: #374151;
    --border-color: #374151;
    --border-hover: #4b5563;
    --text-primary: #f9fafb;
    --text-secondary: #d1d5db;
    --text-muted: #9ca3af;
    --text-dim: #6b7280;
    --accent-primary: #3b82f6;
    --accent-secondary: #10b981;
    --accent-glow: rgba(59, 130, 246, 0.4);
    --accent-glow-secondary: rgba(16, 185, 129, 0.4);
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 14px;
    --radius-full: 9999px;
    --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
}

html {
    scroll-behavior: auto;
    overflow-x: hidden;
    background: url('Background.png') center center / cover fixed no-repeat;
    background-color: #111827;
}

body {
    font-family: var(--font-sans);
    color: var(--text-primary);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    /* 移动端渲染优化 */
    -webkit-overflow-scrolling: touch;
    text-rendering: optimizeSpeed;
}

/* 背景图片加载时的备用深色背景 - 已移除，直接使用 html 背景图 + 备用背景色 */

/* 3D 透视容器 */
.features-grid,
.download-grid {
    perspective: 1200px;
}

/* ========== 导航栏 ========== */
.site-header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 16px 32px;
    background: rgba(17, 24, 39, 0.4);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    border-bottom: 1px solid rgba(75, 85, 99, 0.15);
    transition: background 0.3s ease, border-color 0.3s ease, padding 0.3s ease, backdrop-filter 0.3s ease;
    overflow: hidden;
    box-sizing: border-box;
}

.site-header > * {
    flex-shrink: 1;
    min-width: 0;
}

.site-header .header-action {
    flex-shrink: 0;
}

.site-header.scrolled {
    background: rgba(17, 24, 39, 0.75);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-bottom: 1px solid rgba(75, 85, 99, 0.35);
    padding: 12px 32px;
}

.brand {
    display: flex;
    align-items: center;
    gap: 10px;
    font-weight: 700;
    font-size: 17px;
    color: var(--text-primary);
    text-decoration: none;
}

.brand-mark {
    display: flex;
    align-items: center;
    justify-content: center;
    line-height: 1;
    width: 32px;
    height: 32px;
    border-radius: 50%;
    overflow: hidden;
    flex-shrink: 0;
    box-shadow: 0 0 0 1px rgba(59, 130, 246, 0.2), 0 0 12px rgba(59, 130, 246, 0.1);
}

.brand-mark img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.nav-links {
    display: flex;
    gap: 28px;
    align-items: center;
}

.nav-links a {
    position: relative;
    color: var(--text-muted);
    text-decoration: none;
    font-size: 14px;
    font-weight: 500;
}

.nav-links a {
    --line-w: 0%;
}

.nav-links a::after {
    content: "";
    position: absolute;
    bottom: -4px;
    left: 0;
    width: var(--line-w);
    height: 2px;
    background: linear-gradient(90deg, var(--accent-primary), var(--accent-secondary));
    border-radius: 2px;
    transition: width 0.25s ease;
}

.header-action {
    padding: 8px 18px;
    background: var(--text-primary);
    color: var(--bg-primary);
    font-size: 14px;
    font-weight: 600;
    border-radius: var(--radius-full);
    text-decoration: none;
    position: relative;
    overflow: hidden;
    transform-style: preserve-3d;
    white-space: nowrap;
}

.header-action::before {
    content: "";
    position: absolute;
    inset: 0;
    background: linear-gradient(120deg, transparent 30%, rgba(59, 130, 246, 0.3) 50%, transparent 70%);
    transform: translateX(-100%);
}

main {
    padding-top: 72px;
}

/* ========== Hero 区域 ========== */
.hero {
    position: relative;
    padding: 80px 32px 100px;
    overflow: hidden;
    min-height: calc(100vh - 72px);
    display: flex;
    align-items: center;
    background: transparent;
}

.hero-art {
    position: absolute;
    inset: 0;
    z-index: 0;
    overflow: hidden;
}

.hero-bg-gradient {
    position: absolute;
    inset: -20%;
    background: 
        radial-gradient(ellipse at 20% 30%, rgba(59, 130, 246, 0.18) 0%, transparent 50%),
        radial-gradient(ellipse at 80% 70%, rgba(16, 185, 129, 0.12) 0%, transparent 50%);
    filter: blur(40px);
}

/* 动态光斑 */
.hero-bg-blob {
    position: absolute;
    border-radius: 50%;
    filter: blur(80px);
    opacity: 0.5;
    will-change: transform;
}

.hero-blob-1 {
    width: 500px;
    height: 500px;
    background: radial-gradient(circle, rgba(59, 130, 246, 0.45) 0%, transparent 70%);
    top: -150px;
    left: -100px;
}

.hero-blob-2 {
    width: 400px;
    height: 400px;
    background: radial-gradient(circle, rgba(139, 92, 246, 0.35) 0%, transparent 70%);
    top: 30%;
    right: -100px;
}

.hero-blob-3 {
    width: 350px;
    height: 350px;
    background: radial-gradient(circle, rgba(16, 185, 129, 0.3) 0%, transparent 70%);
    bottom: -100px;
    left: 30%;
}

.hero-bg-grid {
    position: absolute;
    inset: 0;
    background-image: 
        linear-gradient(rgba(75, 85, 99, 0.07) 1px, transparent 1px),
        linear-gradient(90deg, rgba(75, 85, 99, 0.07) 1px, transparent 1px);
    background-size: 40px 40px;
    mask-image: radial-gradient(ellipse at center, black 20%, transparent 75%);
    -webkit-mask-image: radial-gradient(ellipse at center, black 20%, transparent 75%);
    will-change: transform;
}

.hero-overlay {
    position: absolute;
    inset: 0;
    background: linear-gradient(180deg, rgba(17, 24, 39, 0.3) 0%, rgba(17, 24, 39, 0.1) 100%);
    z-index: 1;
}

.hero-content {
    position: relative;
    z-index: 2;
    max-width: 760px;
    margin: 0 auto;
    text-align: center;
    will-change: transform;
}

.eyebrow {
    font-size: 12px;
    font-weight: 600;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: var(--accent-primary);
    margin-bottom: 16px;
    display: inline-block;
    padding: 4px 12px;
    background: rgba(59, 130, 246, 0.1);
    border: 1px solid rgba(59, 130, 246, 0.2);
    border-radius: var(--radius-full);
}

.hero h1 {
    font-size: clamp(40px, 7vw, 68px);
    font-weight: 800;
    line-height: 1.08;
    letter-spacing: -0.025em;
    margin-bottom: 16px;
}

.hero-title-char {
    display: inline-block;
    will-change: transform, opacity;
    background: linear-gradient(135deg, var(--text-primary) 0%, var(--text-secondary) 50%, var(--accent-primary) 100%);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    color: var(--text-primary);
}

.hero-statement {
    font-size: clamp(18px, 2.5vw, 22px);
    font-weight: 500;
    color: var(--text-secondary);
    margin-bottom: 20px;
}

.hero-copy {
    font-size: 15px;
    color: var(--text-muted);
    max-width: 600px;
    margin: 0 auto 28px;
    line-height: 1.75;
}

.hero-pills {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    justify-content: center;
    margin-bottom: 32px;
}

.hero-pill {
    display: inline-block;
    padding: 6px 14px;
    background: rgba(31, 41, 55, 0.7);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-full);
    font-size: 12px;
    color: var(--text-secondary);
    font-weight: 500;
    backdrop-filter: blur(4px);
    -webkit-backdrop-filter: blur(4px);
    will-change: transform;
}

.hero-actions {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 12px;
    justify-content: center;
    align-items: center;
    max-width: 460px;
    margin: 0 auto;
}

/* ========== 按钮 ========== */
.primary-button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    padding: 9px 18px;
    background: linear-gradient(135deg, var(--text-primary) 0%, #e5e7eb 100%);
    color: var(--bg-primary);
    font-size: 13px;
    font-weight: 500;
    border-radius: var(--radius-full);
    text-decoration: none;
    border: none;
    cursor: pointer;
    font-family: inherit;
    min-height: 40px;
    white-space: nowrap;
    position: relative;
    overflow: hidden;
    will-change: transform;
    box-shadow: 0 4px 14px rgba(0, 0, 0, 0.2);
}

.primary-button:hover:not(:disabled) {
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
}

.primary-button:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    filter: grayscale(0.3);
}

.hero-primary-btn {
    padding: 9px 18px;
    font-size: 13px;
    font-weight: 500;
    min-height: 40px;
    box-shadow: 
        0 6px 20px rgba(0, 0, 0, 0.25),
        0 0 0 1px rgba(255, 255, 255, 0.1) inset;
}

.secondary-button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 10px 22px;
    background: rgba(31, 41, 55, 0.5);
    color: var(--text-secondary);
    font-size: 13px;
    font-weight: 500;
    border-radius: var(--radius-full);
    text-decoration: none;
    border: 1px solid var(--border-color);
    cursor: pointer;
    font-family: inherit;
    min-height: 42px;
    backdrop-filter: blur(6px);
    -webkit-backdrop-filter: blur(6px);
    will-change: transform;
}

/* ========== Section 通用 ========== */
.section-heading {
    text-align: center;
    margin-bottom: 48px;
}

.section-heading h2 {
    font-size: clamp(24px, 3.5vw, 34px);
    font-weight: 700;
    letter-spacing: -0.015em;
    margin-bottom: 12px;
    background: linear-gradient(180deg, var(--text-primary), var(--text-secondary));
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    color: var(--text-primary);
}

.section-lede {
    font-size: 15px;
    color: var(--text-muted);
    max-width: 520px;
    margin: 0 auto;
    line-height: 1.7;
}

.section-heading .eyebrow {
    background: rgba(16, 185, 129, 0.1);
    border-color: rgba(16, 185, 129, 0.2);
    color: var(--accent-secondary);
}

/* ========== 功能区 ========== */
.features-section {
    padding: 80px 32px;
    max-width: 1040px;
    margin: 0 auto;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
}

.feature-card {
    position: relative;
    background: linear-gradient(180deg, rgba(31, 41, 55, 0.9), rgba(31, 41, 55, 0.7));
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 26px 24px;
    transform-style: preserve-3d;
    backface-visibility: hidden;
    overflow: hidden;
    will-change: transform;
}

.feature-card::before {
    content: "";
    position: absolute;
    inset: 0;
    background: radial-gradient(circle at var(--mouse-x, 50%) var(--mouse-y, 50%), rgba(59, 130, 246, 0.12), transparent 50%);
    opacity: 0;
    pointer-events: none;
}

.feature-card:hover::before {
    opacity: 1;
}

.feature-icon-wrap {
    width: 44px;
    height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 18px;
    color: var(--accent-primary);
    background: linear-gradient(135deg, rgba(59, 130, 246, 0.15), rgba(59, 130, 246, 0.05));
    border-radius: var(--radius-sm);
    border: 1px solid rgba(59, 130, 246, 0.2);
    transform: translateZ(20px);
}

.feature-card h3 {
    font-size: 16px;
    font-weight: 600;
    margin-bottom: 8px;
    transform: translateZ(15px);
}

.feature-card p {
    font-size: 13px;
    color: var(--text-muted);
    line-height: 1.7;
    transform: translateZ(10px);
}

/* ========== 下载区 ========== */
.download-section {
    padding: 80px 32px;
    background:
        radial-gradient(ellipse at 50% 0%, rgba(59, 130, 246, 0.08) 0%, transparent 50%),
        linear-gradient(180deg, transparent 0%, rgba(31, 41, 55, 0.25) 50%, transparent 100%);
}

.download-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
    max-width: 760px;
    margin: 0 auto;
}

.download-card {
    position: relative;
    background: linear-gradient(180deg, rgba(31, 41, 55, 0.95), rgba(31, 41, 55, 0.8));
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 30px;
    display: flex;
    flex-direction: column;
    transform-style: preserve-3d;
    backface-visibility: hidden;
    overflow: hidden;
    will-change: transform;
}

.download-card::before {
    content: "";
    position: absolute;
    inset: 0;
    border-radius: inherit;
    padding: 1px;
    background: linear-gradient(135deg, transparent 0%, var(--card-glow, transparent) 50%, transparent 100%);
    -webkit-mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
    mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
    -webkit-mask-composite: xor;
    mask-composite: exclude;
    pointer-events: none;
    opacity: 0.6;
}

.download-card-gui {
    --card-glow: rgba(59, 130, 246, 0.3);
}

.download-card-cli {
    --card-glow: rgba(16, 185, 129, 0.3);
}

.download-card::after {
    content: "";
    position: absolute;
    inset: -1px;
    background: radial-gradient(circle at var(--mouse-x, 50%) var(--mouse-y, 50%), var(--card-glow, rgba(59, 130, 246, 0.15)), transparent 55%);
    opacity: 0;
    pointer-events: none;
}

.download-card:hover::after {
    opacity: 1;
}

.download-card-top {
    margin-bottom: 18px;
    transform: translateZ(20px);
}

.download-card-top .eyebrow {
    margin-bottom: 8px;
    padding: 0;
    background: transparent;
    border: none;
}

.download-card-gui .download-card-top .eyebrow {
    color: var(--accent-primary);
}

.download-card-cli .download-card-top .eyebrow {
    color: var(--accent-secondary);
}

.download-card-top h3 {
    font-size: 22px;
    font-weight: 700;
}

.download-desc {
    font-size: 14px;
    color: var(--text-muted);
    line-height: 1.7;
    margin-bottom: 22px;
    transform: translateZ(15px);
}

.download-feature-list {
    list-style: none;
    margin-bottom: 22px;
    flex: 1;
}

.download-feature-list li {
    padding: 5px 0;
    font-size: 13px;
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    gap: 8px;
    transform: translateZ(12px);
}

.download-feature-list li::before {
    content: "";
    width: 16px;
    height: 16px;
    flex-shrink: 0;
    background: url("data:image/svg+xml,%3Csvg width='16' height='16' viewBox='0 0 24 24' fill='none' stroke='%2310b981' stroke-width='3' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='20 6 9 17 4 12'%3E%3C/polyline%3E%3C/svg%3E") center/contain no-repeat;
}

.download-version-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 11px 16px;
    background: rgba(17, 24, 39, 0.8);
    border-radius: var(--radius-sm);
    margin-bottom: 18px;
    border: 1px solid var(--border-color);
    transform: translateZ(15px);
}

.version-label {
    font-size: 12px;
    color: var(--text-dim);
}

.version-value {
    font-size: 12px;
    font-weight: 600;
    color: var(--accent-secondary);
    font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
}

.version-value.loading {
    color: var(--text-dim);
    font-weight: 400;
}

.version-value.error {
    color: #f59e0b;
}

.download-btn {
    width: 100%;
    transform: translateZ(20px);
}

.cli-btn {
    background: linear-gradient(135deg, var(--accent-secondary) 0%, #059669 100%);
    color: white;
}

/* ========== 页脚 ========== */
.site-footer {
    padding: 52px 32px 32px;
    border-top: 1px solid var(--border-color);
    background: transparent;
}

.footer-brand {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 6px;
    margin-bottom: 22px;
}

.footer-brand span:first-child {
    font-size: 17px;
    font-weight: 700;
    background: linear-gradient(135deg, var(--text-primary), var(--accent-primary));
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    color: var(--text-primary);
}

.footer-brand span:last-child {
    font-size: 13px;
    color: var(--text-muted);
}

.footer-contacts {
    display: flex;
    justify-content: center;
    gap: 24px;
    margin-bottom: 26px;
    flex-wrap: wrap;
}

.footer-contact {
    font-size: 13px;
    color: var(--text-muted);
}

.footer-bottom {
    text-align: center;
    padding-top: 22px;
    border-top: 1px solid var(--border-color);
}

.footer-bottom p {
    font-size: 12px;
    color: var(--text-dim);
}

/* ========== 支持我们 ========== */
.donate-section {
    padding: 80px 32px;
    background: transparent;
    position: relative;
    overflow: hidden;
}

.donate-section::before {
    content: "";
    position: absolute;
    top: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 600px;
    height: 600px;
    background: radial-gradient(circle, rgba(59, 130, 246, 0.08) 0%, transparent 70%);
    pointer-events: none;
}

.donate-inner {
    max-width: 720px;
    margin: 0 auto;
    position: relative;
    z-index: 1;
    text-align: center;
}

.donate-desc {
    font-size: 16px;
    color: var(--text-secondary);
    line-height: 1.7;
    margin-bottom: 32px;
    max-width: 560px;
    margin-left: auto;
    margin-right: auto;
}

.donate-tabs {
    display: inline-flex;
    gap: 8px;
    padding: 6px;
    background: var(--bg-secondary);
    border-radius: var(--radius-full);
    margin-bottom: 32px;
    border: 1px solid var(--border-color);
}

.donate-tab {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 10px 20px;
    background: transparent;
    border: none;
    border-radius: var(--radius-full);
    color: var(--text-muted);
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
    font-family: inherit;
}

.donate-tab-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 20px;
    height: 20px;
}

.donate-tab.active {
    background: var(--bg-tertiary);
    color: var(--text-primary);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
}

.donate-tab:hover:not(.active) {
    color: var(--text-secondary);
    background: rgba(55, 65, 81, 0.5);
}

.donate-qr-card {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 40px;
    position: relative;
    overflow: hidden;
    min-height: 320px;
}

.donate-qr-card::before {
    content: "";
    position: absolute;
    inset: 0;
    background: radial-gradient(circle at 50% 0%, rgba(59, 130, 246, 0.05) 0%, transparent 60%);
    pointer-events: none;
}

.donate-qr-panel {
    display: none;
    animation: fadeIn 0.4s ease;
}

.donate-qr-panel.active {
    display: block;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.donate-qr-placeholder {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 16px;
    padding: 40px;
    border: 2px dashed var(--border-color);
    border-radius: var(--radius-md);
    color: var(--text-muted);
    transition: all 0.3s ease;
}

.donate-qr-placeholder:hover {
    border-color: var(--border-hover);
    color: var(--text-secondary);
}

.donate-qr-placeholder svg {
    opacity: 0.6;
}

.donate-qr-placeholder span {
    font-size: 14px;
    font-weight: 500;
}

.donate-qr-image {
    display: flex;
    justify-content: center;
    align-items: center;
}

.donate-qr-image img {
    max-width: 280px;
    width: 100%;
    border-radius: var(--radius-md);
    box-shadow: 0 4px 24px rgba(0, 0, 0, 0.3);
    transition: transform 0.3s ease;
}

.donate-qr-image img:hover {
    transform: scale(1.02);
}

.donate-qr-hint {
    margin-top: 24px;
    font-size: 13px;
    color: var(--text-muted);
}

/* ========== 下载成功弹窗 ========== */
.modal-overlay {
    position: fixed;
    inset: 0;
    z-index: 9999;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 24px;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.35s ease, visibility 0.35s ease;
}

.modal-overlay.active {
    opacity: 1;
    visibility: visible;
}

.modal-backdrop {
    position: absolute;
    inset: 0;
    background: rgba(0, 0, 0, 0.6);
    backdrop-filter: blur(6px);
    -webkit-backdrop-filter: blur(6px);
}

.modal-content {
    position: relative;
    z-index: 1;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 40px 36px 32px;
    max-width: 480px;
    width: 100%;
    text-align: center;
    box-shadow: 0 24px 64px rgba(0, 0, 0, 0.5);
    transform: translateY(24px) scale(0.96);
    transition: transform 0.35s cubic-bezier(0.34, 1.56, 0.64, 1);
}

.modal-overlay.active .modal-content {
    transform: translateY(0) scale(1);
}

.modal-close {
    position: absolute;
    top: 14px;
    right: 14px;
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: transparent;
    border: 1px solid var(--border-color);
    border-radius: 50%;
    color: var(--text-dim);
    cursor: not-allowed;
    opacity: 0.5;
    transition: all 0.3s ease;
}

.modal-close.enabled {
    cursor: pointer;
    opacity: 1;
}

.modal-close.enabled:hover {
    background: var(--bg-tertiary);
    color: var(--text-primary);
    border-color: var(--border-hover);
}

.modal-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 64px;
    height: 64px;
    margin: 0 auto 20px;
    background: rgba(16, 185, 129, 0.12);
    border-radius: 50%;
    color: var(--accent-secondary);
}

.modal-title {
    font-size: 20px;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 12px;
}

.modal-desc {
    font-size: 14px;
    color: var(--text-secondary);
    line-height: 1.7;
    margin-bottom: 28px;
}

.modal-qr-row {
    display: flex;
    gap: 20px;
    justify-content: center;
    margin-bottom: 20px;
}

.modal-qr-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 10px;
}

.modal-qr-img {
    width: 160px;
    height: 160px;
    border-radius: var(--radius-md);
    overflow: hidden;
    border: 1px solid var(--border-color);
    background: var(--bg-primary);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.modal-qr-img:hover {
    transform: scale(1.04);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.3);
}

.modal-qr-img img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.modal-qr-label {
    font-size: 13px;
    font-weight: 500;
    color: var(--text-muted);
}

.modal-hint {
    font-size: 13px;
    color: var(--text-dim);
    font-style: italic;
}

/* ========== 响应式 ========== */
@media (max-width: 900px) {
    .features-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .site-header {
        padding: 14px 20px;
    }

    .site-header.scrolled {
        padding: 10px 20px;
    }
    
    .nav-links {
        display: none;
    }
    
    .hero {
        padding: 60px 20px 80px;
        min-height: auto;
    }
    
    .features-section,
    .download-section {
        padding: 60px 20px;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
    }
    
    .download-grid {
        grid-template-columns: 1fr;
    }
    
    .hero-actions {
        grid-template-columns: 1fr;
        max-width: 280px;
    }
    
    .site-footer {
        padding: 40px 20px 24px;
    }

    .donate-section {
        padding: 60px 20px;
    }

    .donate-qr-card {
        padding: 24px;
    }

    .donate-qr-image img {
        max-width: 240px;
    }

    .modal-content {
        padding: 24px 20px 20px;
        max-width: 320px;
    }

    .modal-icon {
        width: 48px;
        height: 48px;
        margin-bottom: 14px;
    }

    .modal-icon svg {
        width: 28px;
        height: 28px;
    }

    .modal-title {
        font-size: 17px;
        margin-bottom: 8px;
    }

    .modal-desc {
        font-size: 13px;
        line-height: 1.6;
        margin-bottom: 16px;
    }

    .modal-qr-row {
        flex-direction: row;
        gap: 12px;
        margin-bottom: 14px;
    }

    .modal-qr-img {
        width: 110px;
        height: 110px;
    }

    .modal-qr-label {
        font-size: 12px;
    }

    .modal-hint {
        font-size: 12px;
    }

    .modal-close {
        width: 28px;
        height: 28px;
        top: 10px;
        right: 10px;
    }

    .modal-close svg {
        width: 16px;
        height: 16px;
    }

    .hero-blob-1,
    .hero-blob-2,
    .hero-blob-3 {
        filter: blur(60px);
        opacity: 0.35;
    }
}

@media (max-width: 480px) {
    .brand span {
        font-size: 15px;
    }
    
    .header-action {
        padding: 7px 14px;
        font-size: 13px;
    }

    .feature-card {
        padding: 22px 20px;
    }

    .download-card {
        padding: 24px;
    }
}

/* 减少动画偏好 */
@media (prefers-reduced-motion: reduce) {
    .hero-bg-blob,
    .hero-bg-grid,
    .hero-title-char {
        will-change: auto;
    }
}

/* ========== 移动端性能优化 ========== */
@media (max-width: 768px) {
    /* 关闭重计算的视觉效果 */
    .hero-bg-blob {
        filter: blur(40px) !important;
        animation: none !important;
        will-change: auto !important;
    }
    
    .hero-bg-grid {
        opacity: 0.3 !important;
    }
    
    /* 视差动画在移动端禁用 */
    [data-parallax] {
        transform: none !important;
        will-change: auto !important;
    }
    
    /* 减少 backdrop-filter 触发频率 */
    .site-header {
        backdrop-filter: blur(6px);
        -webkit-backdrop-filter: blur(6px);
    }
    
    .site-header.scrolled {
        backdrop-filter: blur(10px);
        -webkit-backdrop-filter: blur(10px);
    }
    
    /* 卡片 3D 效果在移动端禁用 */
    .feature-card-inner,
    .download-card {
        transform: none !important;
        transition: none !important;
    }
    
    /* 优化背景图层渲染 */
    .hero,
    .donate-section {
        background-attachment: scroll !important;
    }
    
    /* 启用 GPU 加速但限制范围 */
    .site-header,
    .modal-content {
        transform: translateZ(0);
    }
}

/* ========== B站视频弹窗 ========== */
.video-modal {
    position: fixed;
    inset: 0;
    z-index: 10000;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.35s ease, visibility 0.35s ease;
}

.video-modal.is-open {
    opacity: 1;
    visibility: visible;
}

.video-modal-backdrop {
    position: absolute;
    inset: 0;
    background: rgba(0, 0, 0, 0.7);
    backdrop-filter: blur(6px);
    -webkit-backdrop-filter: blur(6px);
}

.video-modal-container {
    position: relative;
    z-index: 1;
    width: 90%;
    max-width: 720px;
    max-height: 90vh;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 24px;
    overflow-y: auto;
    transform: translateY(30px) scale(0.95);
    transition: transform 0.4s cubic-bezier(0.16, 1, 0.3, 1), opacity 0.35s ease;
    box-shadow: 0 25px 60px rgba(0, 0, 0, 0.5), 0 0 0 1px rgba(59, 130, 246, 0.1);
}

.video-modal.is-open .video-modal-container {
    transform: translateY(0) scale(1);
}

.video-modal-close {
    position: absolute;
    top: 12px;
    right: 12px;
    z-index: 2;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    color: var(--text-muted);
    cursor: pointer;
    transition: background 0.2s ease, color 0.2s ease, border-color 0.2s ease;
}

.video-modal-close:hover {
    background: var(--border-hover);
    color: var(--text-primary);
    border-color: var(--accent-primary);
}

.video-modal-title {
    font-size: 18px;
    font-weight: 700;
    margin-bottom: 6px;
    color: var(--text-primary);
    padding-right: 40px;
}

.video-modal-desc {
    font-size: 13px;
    color: var(--text-muted);
    margin-bottom: 16px;
    line-height: 1.5;
}

.video-modal-iframe-wrap {
    position: relative;
    width: 100%;
    padding-top: 56.25%; /* 16:9 */
    border-radius: var(--radius-md);
    overflow: hidden;
    background: #000;
}

.video-modal-iframe-wrap iframe {
    position: absolute;
    inset: 0;
    width: 100%;
    height: 100%;
    border: none;
}

.video-modal-link {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    margin-top: 14px;
    padding: 8px 18px;
    background: linear-gradient(135deg, #fb72a8, #fc3aac);
    color: #fff;
    text-decoration: none;
    font-size: 14px;
    font-weight: 600;
    border-radius: var(--radius-sm);
    transition: opacity 0.2s ease, transform 0.2s ease;
}

.video-modal-link:hover {
    opacity: 0.9;
    transform: translateY(-1px);
}

@media (max-width: 640px) {
    .video-modal-container {
        width: 95%;
        padding: 16px;
    }
    
    .video-modal-title {
        font-size: 16px;
    }
    
    .video-modal-desc {
        font-size: 12px;
    }
}