/* ===== CSS Variables ===== */
:root {
    /* Colors */
    --color-bg-primary: #0a0a1a;
    --color-bg-secondary: #12122a;
    --color-bg-tertiary: #1a1a3a;
    --color-bg-card: rgba(26, 26, 58, 0.6);
    --color-bg-card-hover: rgba(36, 36, 78, 0.8);
    
    --color-text-primary: #ffffff;
    --color-text-secondary: rgba(255, 255, 255, 0.8);
    --color-text-tertiary: rgba(255, 255, 255, 0.6);
    --color-text-muted: rgba(255, 255, 255, 0.4);
    
    --color-accent-cyan: #00d4ff;
    --color-accent-purple: #a855f7;
    --color-accent-pink: #ec4899;
    --color-accent-blue: #3b82f6;
    
    --gradient-primary: linear-gradient(135deg, var(--color-accent-cyan) 0%, var(--color-accent-purple) 100%);
    --gradient-secondary: linear-gradient(135deg, var(--color-accent-purple) 0%, var(--color-accent-pink) 100%);
    --gradient-bg: linear-gradient(180deg, var(--color-bg-primary) 0%, var(--color-bg-secondary) 50%, var(--color-bg-primary) 100%);
    
    /* Shadows */
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.5);
    --shadow-glow-cyan: 0 0 30px rgba(0, 212, 255, 0.3);
    --shadow-glow-purple: 0 0 30px rgba(168, 85, 247, 0.3);
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-2xl: 4rem;
    --spacing-3xl: 6rem;
    
    /* Border Radius */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    --radius-full: 9999px;
    
    /* Transitions */
    --transition-fast: 0.15s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.5s ease;
    
    /* Typography */
    --font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
    --font-size-xs: 0.75rem;
    --font-size-sm: 0.875rem;
    --font-size-base: 1rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.25rem;
    --font-size-2xl: 1.5rem;
    --font-size-3xl: 2rem;
    --font-size-4xl: 2.5rem;
    --font-size-5xl: 3.5rem;
    
    /* Container */
    --container-max-width: 1200px;
    --header-height: 72px;
}

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

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

body {
    font-family: var(--font-family);
    background: var(--color-bg-primary);
    color: var(--color-text-primary);
    line-height: 1.6;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

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

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

ul {
    list-style: none;
}

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

/* ===== Utility Classes ===== */
.container {
    width: 100%;
    max-width: var(--container-max-width);
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

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

/* ===== Header ===== */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--header-height);
    z-index: 1000;
    transition: background var(--transition-normal), box-shadow var(--transition-normal);
}

.header.scrolled {
    background: rgba(10, 10, 26, 0.95);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    box-shadow: 0 2px 20px rgba(0, 0, 0, 0.3);
}

.nav {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: var(--header-height);
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.logo-img {
    width: 40px;
    height: 40px;
    border-radius: var(--radius-sm);
}

.logo-text {
    font-size: var(--font-size-xl);
    font-weight: 700;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: var(--spacing-lg);
}

.nav-links a {
    font-size: var(--font-size-base);
    color: var(--color-text-secondary);
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--radius-sm);
    transition: all var(--transition-fast);
}

.nav-links a:hover {
    color: var(--color-text-primary);
    background: rgba(255, 255, 255, 0.1);
}

.nav-links a.nav-login {
    background: var(--gradient-primary);
    color: var(--color-bg-primary);
    padding: var(--spacing-xs) var(--spacing-md);
    border-radius: var(--radius-md);
    font-weight: 600;
}

.nav-links a.nav-login:hover {
    transform: translateY(-1px);
    box-shadow: var(--shadow-glow-cyan);
}

.mobile-menu-btn {
    display: none;
    flex-direction: column;
    gap: 5px;
    padding: var(--spacing-xs);
}

.mobile-menu-btn span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--color-text-primary);
    border-radius: 2px;
    transition: all var(--transition-fast);
}

/* ===== Hero Section ===== */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding-top: var(--header-height);
    overflow: hidden;
}

.hero-bg {
    position: absolute;
    inset: 0;
    z-index: 0;
}

.hero-bg-img {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    min-width: 100%;
    min-height: 100%;
    width: auto;
    height: auto;
    object-fit: cover;
    object-position: center;
    z-index: 1;
}

.hero-gradient {
    position: absolute;
    inset: 0;
    z-index: 2;
    background: 
        linear-gradient(90deg, rgba(10, 10, 26, 0.95) 0%, rgba(10, 10, 26, 0.7) 40%, rgba(10, 10, 26, 0.3) 70%, transparent 100%),
        radial-gradient(ellipse 80% 50% at 50% -20%, rgba(0, 212, 255, 0.15) 0%, transparent 50%),
        radial-gradient(ellipse 60% 40% at 80% 60%, rgba(168, 85, 247, 0.1) 0%, transparent 50%);
}

.hero-particles {
    position: absolute;
    inset: 0;
    z-index: 3;
    background-image: 
        radial-gradient(2px 2px at 20px 30px, rgba(255, 255, 255, 0.3) 0%, transparent 100%),
        radial-gradient(2px 2px at 40px 70px, rgba(255, 255, 255, 0.2) 0%, transparent 100%),
        radial-gradient(1px 1px at 90px 40px, rgba(255, 255, 255, 0.4) 0%, transparent 100%),
        radial-gradient(2px 2px at 130px 80px, rgba(255, 255, 255, 0.2) 0%, transparent 100%),
        radial-gradient(1px 1px at 160px 120px, rgba(255, 255, 255, 0.3) 0%, transparent 100%);
    background-size: 200px 200px;
    animation: particleFloat 20s linear infinite;
}

@keyframes particleFloat {
    0% { transform: translateY(0); }
    100% { transform: translateY(-200px); }
}

.hero-content {
    display: block;
    padding: var(--spacing-2xl) 0;
    position: relative;
    z-index: 10;
}

.hero-text {
    max-width: 600px;
    z-index: 10;
}

.hero-title {
    font-size: var(--font-size-5xl);
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: var(--spacing-md);
}

.hero-subtitle {
    font-size: var(--font-size-lg);
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-xl);
    line-height: 1.8;
}

.hero-subtitle strong {
    color: var(--color-accent-cyan);
}

.hero-downloads {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-md);
}

.download-btn {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--radius-md);
    font-size: var(--font-size-sm);
    font-weight: 600;
    transition: all var(--transition-normal);
}

.download-btn-primary {
    background: var(--gradient-primary);
    color: var(--color-bg-primary);
}

.download-btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-glow-cyan);
}

.download-btn-secondary {
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
    color: var(--color-text-primary);
}

.download-btn-secondary:hover {
    background: rgba(255, 255, 255, 0.15);
    border-color: rgba(255, 255, 255, 0.3);
    transform: translateY(-2px);
}

.download-icon {
    width: 24px;
    height: 24px;
}

.download-btn span {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    line-height: 1.2;
}

.download-btn small {
    font-size: var(--font-size-xs);
    font-weight: 400;
    opacity: 0.8;
}

.hero-note {
    font-size: var(--font-size-sm);
    color: var(--color-text-muted);
}

.hero-image {
    position: relative;
    display: flex;
    justify-content: center;
    align-items: center;
}

.hero-image-glow {
    position: absolute;
    width: 80%;
    height: 80%;
    background: radial-gradient(circle, rgba(0, 212, 255, 0.2) 0%, transparent 70%);
    filter: blur(60px);
    animation: pulseGlow 4s ease-in-out infinite;
}

@keyframes pulseGlow {
    0%, 100% { opacity: 0.5; transform: scale(1); }
    50% { opacity: 0.8; transform: scale(1.1); }
}

.hero-img {
    position: relative;
    max-width: 100%;
    border-radius: var(--radius-lg);
    animation: floatImage 6s ease-in-out infinite;
}

@keyframes floatImage {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-20px); }
}

.scroll-indicator {
    position: absolute;
    bottom: var(--spacing-lg);
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-xs);
    color: var(--color-text-muted);
    font-size: var(--font-size-sm);
    animation: fadeInUp 1s ease 1s both;
}

.scroll-arrow {
    width: 24px;
    height: 24px;
    border-right: 2px solid var(--color-text-muted);
    border-bottom: 2px solid var(--color-text-muted);
    transform: rotate(45deg);
    animation: scrollBounce 2s ease-in-out infinite;
}

@keyframes scrollBounce {
    0%, 100% { transform: rotate(45deg) translateY(0); }
    50% { transform: rotate(45deg) translateY(10px); }
}

/* ===== Section Styles ===== */
section {
    padding: var(--spacing-3xl) 0;
}

.section-header {
    text-align: center;
    margin-bottom: var(--spacing-2xl);
}

.section-title {
    font-size: var(--font-size-4xl);
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
}

.section-subtitle {
    font-size: var(--font-size-lg);
    color: var(--color-text-tertiary);
    max-width: 600px;
    margin: 0 auto;
}

/* ===== Features Section ===== */
.features {
    background: var(--color-bg-secondary);
    position: relative;
}

.features::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 1px;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.1), transparent);
}

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

.feature-card {
    background: var(--color-bg-card);
    border: 1px solid rgba(255, 255, 255, 0.05);
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl);
    text-align: center;
    transition: transform 0.3s ease, box-shadow 0.3s ease, background 0.3s ease, border-color 0.3s ease;
    backdrop-filter: blur(10px);
    cursor: pointer;
}

.feature-card:hover {
    background: rgba(36, 36, 78, 0.9);
    transform: translateY(-12px) scale(1.02);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.4), 0 0 30px rgba(0, 212, 255, 0.2);
    border-color: rgba(0, 212, 255, 0.4);
}

.feature-icon-wrapper {
    position: relative;
    width: 80px;
    height: 80px;
    margin: 0 auto var(--spacing-md);
    display: flex;
    align-items: center;
    justify-content: center;
}

.feature-icon-bg {
    position: absolute;
    inset: 0;
    background: var(--gradient-primary);
    border-radius: var(--radius-lg);
    opacity: 0.15;
    transition: opacity var(--transition-normal);
}

.feature-card:hover .feature-icon-bg {
    opacity: 0.4;
    transform: scale(1.1);
}

.feature-icon {
    width: 40px;
    height: 40px;
    color: var(--color-accent-cyan);
    position: relative;
    z-index: 1;
    transition: transform 0.3s ease, color 0.3s ease;
}

.feature-card:hover .feature-icon {
    transform: scale(1.2) rotate(5deg);
    color: #00ffff;
}

.feature-card-title {
    font-size: var(--font-size-xl);
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
}

.feature-card-desc {
    font-size: var(--font-size-base);
    color: var(--color-text-tertiary);
    line-height: 1.7;
}

/* ===== App Showcase Section ===== */
.app-showcase {
    background: var(--color-bg-primary);
    overflow: hidden;
}

.showcase-gallery {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-lg);
}

.showcase-item {
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-lg);
    transition: transform 0.4s ease, box-shadow 0.4s ease;
    cursor: pointer;
}

.showcase-item:hover {
    transform: scale(1.05) translateY(-8px);
    box-shadow: 0 25px 50px rgba(0, 0, 0, 0.4), 0 0 40px rgba(168, 85, 247, 0.3);
}

.showcase-item img {
    width: 100%;
    height: auto;
    object-fit: cover;
}

/* ===== All Features Section ===== */
.all-features {
    background: linear-gradient(180deg, var(--color-bg-primary) 0%, var(--color-bg-secondary) 50%, var(--color-bg-primary) 100%);
}

.features-nav {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-2xl);
}

.features-nav-btn {
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--radius-full);
    font-size: var(--font-size-sm);
    font-weight: 500;
    color: var(--color-text-tertiary);
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.1);
    transition: all var(--transition-fast);
}

.features-nav-btn:hover {
    color: var(--color-text-primary);
    background: rgba(255, 255, 255, 0.1);
}

.features-nav-btn.active {
    color: var(--color-bg-primary);
    background: var(--gradient-primary);
    border-color: transparent;
}

.feature-details-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-2xl);
}

.feature-detail {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-2xl);
    align-items: center;
    padding: var(--spacing-xl);
    background: var(--color-bg-card);
    border: 1px solid rgba(255, 255, 255, 0.05);
    border-radius: var(--radius-xl);
    transition: transform 0.4s ease, border-color 0.3s ease, box-shadow 0.4s ease;
}

.feature-detail:hover {
    transform: translateY(-6px);
    border-color: rgba(0, 212, 255, 0.3);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.3), 0 0 30px rgba(0, 212, 255, 0.15);
}

.feature-detail:nth-child(even) {
    direction: rtl;
}

.feature-detail:nth-child(even) > * {
    direction: ltr;
}

.feature-detail-header {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-md);
}

.feature-detail-icon {
    width: 64px;
    height: 64px;
    border-radius: var(--radius-md);
    background: rgba(255, 255, 255, 0.05);
    padding: 8px;
    object-fit: contain;
}

.feature-detail-title {
    font-size: var(--font-size-2xl);
    font-weight: 700;
    margin-bottom: 4px;
}

.feature-detail-subtitle {
    font-size: var(--font-size-sm);
    color: var(--color-accent-cyan);
    font-weight: 500;
}

.feature-detail-tagline {
    font-size: var(--font-size-lg);
    font-weight: 600;
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-sm);
}

.feature-detail-desc {
    font-size: var(--font-size-base);
    color: var(--color-text-tertiary);
    line-height: 1.8;
}

.feature-detail-image {
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-md);
}

.feature-detail-image img {
    width: 100%;
    height: auto;
    transition: transform var(--transition-slow);
}

.feature-detail:hover .feature-detail-image img {
    transform: scale(1.02);
}

/* Hidden state for filtering */
.feature-detail.hidden {
    display: none;
}

/* ===== Download Section ===== */
.download {
    position: relative;
    background: var(--color-bg-secondary);
    overflow: hidden;
}

.download-bg {
    position: absolute;
    inset: 0;
    z-index: 0;
}

.download-particles {
    position: absolute;
    inset: 0;
    background: 
        radial-gradient(ellipse 50% 30% at 50% 50%, rgba(0, 212, 255, 0.1) 0%, transparent 50%),
        radial-gradient(ellipse 40% 20% at 30% 70%, rgba(168, 85, 247, 0.08) 0%, transparent 50%);
}

.download .container {
    position: relative;
    z-index: 1;
}

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

.download-card {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: var(--spacing-xl);
    background: var(--color-bg-card);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-xl);
    text-align: center;
    transition: all var(--transition-normal);
}

.download-card:hover {
    background: var(--color-bg-card-hover);
    transform: translateY(-8px);
    border-color: rgba(0, 212, 255, 0.3);
    box-shadow: var(--shadow-glow-cyan);
}

.download-card-icon {
    width: 64px;
    height: 64px;
    margin-bottom: var(--spacing-md);
    color: var(--color-accent-cyan);
}

.download-card-icon svg {
    width: 100%;
    height: 100%;
}

.download-card-title {
    font-size: var(--font-size-xl);
    font-weight: 700;
    margin-bottom: var(--spacing-xs);
}

.download-card-desc {
    font-size: var(--font-size-sm);
    color: var(--color-text-tertiary);
    margin-bottom: var(--spacing-md);
}

.download-card-btn {
    display: inline-block;
    padding: 12px 24px;
    min-width: 120px;
    background: var(--gradient-primary);
    color: var(--color-bg-primary);
    font-size: var(--font-size-sm);
    font-weight: 600;
    border-radius: 25px;
    transition: all var(--transition-fast);
    text-align: center;
}

.download-card:hover .download-card-btn {
    box-shadow: 0 4px 15px rgba(0, 212, 255, 0.4);
}

/* ===== Footer ===== */
.footer {
    background: var(--color-bg-primary);
    padding: var(--spacing-2xl) 0 var(--spacing-lg);
    border-top: 1px solid rgba(255, 255, 255, 0.05);
}

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

.footer-brand {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.footer-logo {
    width: 60px;
    height: 60px;
    border-radius: var(--radius-md);
}

.footer-brand h3 {
    font-size: var(--font-size-xl);
    font-weight: 700;
}

.footer-brand p {
    font-size: var(--font-size-sm);
    color: var(--color-text-tertiary);
}

.footer-links {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-lg);
}

.footer-column h4 {
    font-size: var(--font-size-base);
    font-weight: 600;
    margin-bottom: var(--spacing-md);
    color: var(--color-text-primary);
}

.footer-column ul {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.footer-column a {
    font-size: var(--font-size-sm);
    color: var(--color-text-tertiary);
    transition: color var(--transition-fast);
}

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

.footer-bottom {
    padding-top: var(--spacing-lg);
    border-top: 1px solid rgba(255, 255, 255, 0.05);
    text-align: center;
}

.footer-bottom p {
    font-size: var(--font-size-sm);
    color: var(--color-text-muted);
    margin-bottom: var(--spacing-xs);
}

.footer-icp {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: var(--spacing-sm);
    flex-wrap: wrap;
}

.footer-icp a {
    color: var(--color-text-muted);
    transition: color var(--transition-fast);
}

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

.footer-company {
    font-size: var(--font-size-sm);
    color: var(--color-text-muted);
    margin-top: var(--spacing-xs);
}

.footer-divider {
    color: var(--color-text-muted);
}

/* ===== Back to Top Button ===== */
.back-to-top {
    position: fixed;
    bottom: var(--spacing-lg);
    right: var(--spacing-lg);
    width: 48px;
    height: 48px;
    background: var(--gradient-primary);
    border-radius: var(--radius-full);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--color-bg-primary);
    box-shadow: var(--shadow-md);
    opacity: 0;
    visibility: hidden;
    transform: translateY(20px);
    transition: all var(--transition-normal);
    z-index: 999;
}

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

.back-to-top:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-glow-cyan);
}

.back-to-top svg {
    width: 24px;
    height: 24px;
}

/* ===== HarmonyOS Button Styles ===== */
.download-btn-harmony {
    background: linear-gradient(135deg, #e52828 0%, #ff6b35 100%);
    color: white;
}

.download-btn-harmony:hover {
    transform: translateY(-2px);
    box-shadow: 0 0 30px rgba(229, 40, 40, 0.4);
}

.download-card-harmony {
    border-color: rgba(229, 40, 40, 0.3);
}

.download-card-harmony:hover {
    border-color: rgba(229, 40, 40, 0.5);
    box-shadow: 0 0 30px rgba(229, 40, 40, 0.3);
}

.download-card-harmony .download-card-icon {
    color: #e52828;
}

.download-card-harmony .download-card-btn {
    background: linear-gradient(135deg, #e52828 0%, #ff6b35 100%);
}

.download-grid-5 {
    grid-template-columns: repeat(5, 1fr);
}

/* ===== Feedback Section ===== */
.feedback {
    background: var(--color-bg-primary);
    position: relative;
}

.feedback-container {
    display: grid;
    grid-template-columns: 1.5fr 1fr;
    gap: var(--spacing-xl);
    align-items: start;
}

.feedback-form {
    background: var(--color-bg-card);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-xl);
    padding: var(--spacing-xl);
}

.form-group {
    margin-bottom: var(--spacing-md);
}

.form-group label {
    display: block;
    font-size: var(--font-size-sm);
    font-weight: 600;
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-xs);
}

.form-group .required {
    color: #ef4444;
}

.form-group .optional {
    font-weight: 400;
    color: var(--color-text-muted);
    font-size: var(--font-size-xs);
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: var(--spacing-sm);
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.15);
    border-radius: var(--radius-md);
    color: var(--color-text-primary);
    font-size: var(--font-size-base);
    font-family: inherit;
    transition: all var(--transition-fast);
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--color-accent-cyan);
    box-shadow: 0 0 0 3px rgba(0, 212, 255, 0.1);
}

.form-group input::placeholder,
.form-group textarea::placeholder {
    color: var(--color-text-muted);
}

.form-group select {
    cursor: pointer;
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='24' height='24' viewBox='0 0 24 24' fill='none' stroke='rgba(255,255,255,0.5)' stroke-width='2'%3E%3Cpath d='M6 9l6 6 6-6'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 12px center;
    background-size: 16px;
    padding-right: 40px;
}

.form-group select option {
    background: var(--color-bg-secondary);
    color: var(--color-text-primary);
}

.form-group textarea {
    resize: vertical;
    min-height: 120px;
}

.submit-btn {
    width: 100%;
    padding: var(--spacing-sm) var(--spacing-lg);
    background: var(--gradient-primary);
    color: var(--color-bg-primary);
    font-size: var(--font-size-base);
    font-weight: 600;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-normal);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-xs);
}

.submit-btn:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-glow-cyan);
}

.submit-btn:disabled {
    opacity: 0.7;
    cursor: not-allowed;
    transform: none;
}

.submit-btn .spinner {
    width: 20px;
    height: 20px;
    animation: spin 1s linear infinite;
}

.submit-btn .btn-loading {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
}

.contact-info-card {
    background: var(--color-bg-card);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-xl);
    padding: var(--spacing-xl);
}

.contact-info-card h3 {
    font-size: var(--font-size-lg);
    font-weight: 600;
    margin-bottom: var(--spacing-md);
    color: var(--color-text-primary);
}

.contact-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-md);
    background: rgba(255, 255, 255, 0.05);
    border-radius: var(--radius-md);
    margin-bottom: var(--spacing-md);
}

.contact-item svg {
    width: 24px;
    height: 24px;
    color: var(--color-accent-cyan);
    flex-shrink: 0;
}

.contact-item .contact-label {
    display: block;
    font-size: var(--font-size-xs);
    color: var(--color-text-muted);
    margin-bottom: 2px;
}

.contact-item .contact-value {
    font-size: var(--font-size-base);
    font-weight: 600;
    color: var(--color-accent-cyan);
}

.contact-item .contact-value:hover {
    text-decoration: underline;
}

.contact-note {
    display: flex;
    gap: var(--spacing-sm);
    padding: var(--spacing-md);
    background: rgba(0, 212, 255, 0.1);
    border-radius: var(--radius-md);
    border: 1px solid rgba(0, 212, 255, 0.2);
}

.contact-note svg {
    width: 20px;
    height: 20px;
    color: var(--color-accent-cyan);
    flex-shrink: 0;
    margin-top: 2px;
}

.contact-note p {
    font-size: var(--font-size-sm);
    color: var(--color-text-secondary);
    line-height: 1.6;
}

/* Toast Notification */
.toast {
    position: fixed;
    bottom: var(--spacing-lg);
    left: 50%;
    transform: translateX(-50%) translateY(100px);
    padding: var(--spacing-sm) var(--spacing-lg);
    background: var(--color-bg-tertiary);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-md);
    color: var(--color-text-primary);
    font-size: var(--font-size-sm);
    box-shadow: var(--shadow-lg);
    z-index: 10000;
    opacity: 0;
    transition: all var(--transition-normal);
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.toast.show {
    transform: translateX(-50%) translateY(0);
    opacity: 1;
}

.toast.success {
    border-color: rgba(34, 197, 94, 0.3);
    background: rgba(34, 197, 94, 0.1);
}

.toast.error {
    border-color: rgba(239, 68, 68, 0.3);
    background: rgba(239, 68, 68, 0.1);
}

.toast svg {
    width: 20px;
    height: 20px;
}

.toast.success svg {
    color: #22c55e;
}

.toast.error svg {
    color: #ef4444;
}

/* ===== Responsive Design ===== */
@media (max-width: 1024px) {
    :root {
        --font-size-5xl: 2.5rem;
        --font-size-4xl: 2rem;
    }
    
    .hero-gradient {
        background: 
            linear-gradient(180deg, rgba(10, 10, 26, 0.9) 0%, rgba(10, 10, 26, 0.7) 50%, rgba(10, 10, 26, 0.5) 100%),
            radial-gradient(ellipse 80% 50% at 50% -20%, rgba(0, 212, 255, 0.15) 0%, transparent 50%);
    }
    
    .hero-content {
        text-align: center;
    }
    
    .hero-text {
        max-width: 100%;
    }
    
    .hero-downloads {
        justify-content: center;
    }
    
    .features-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .feature-detail {
        grid-template-columns: 1fr;
    }
    
    .feature-detail:nth-child(even) {
        direction: ltr;
    }
    
    .download-grid,
    .download-grid-5 {
        grid-template-columns: repeat(3, 1fr);
    }
    
    .showcase-gallery {
        grid-template-columns: 1fr;
    }
    
    .feedback-container {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 768px) {
    :root {
        --font-size-5xl: 2rem;
        --font-size-4xl: 1.75rem;
        --font-size-3xl: 1.5rem;
        --spacing-3xl: 4rem;
        --spacing-2xl: 3rem;
    }
    
    .nav-links {
        display: none;
        position: absolute;
        top: var(--header-height);
        left: 0;
        right: 0;
        background: rgba(10, 10, 26, 0.98);
        backdrop-filter: blur(20px);
        flex-direction: column;
        padding: var(--spacing-md);
        border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    }
    
    .nav-links.active {
        display: flex;
    }
    
    .mobile-menu-btn {
        display: flex;
    }
    
    .mobile-menu-btn.active span:nth-child(1) {
        transform: rotate(45deg) translate(5px, 5px);
    }
    
    .mobile-menu-btn.active span:nth-child(2) {
        opacity: 0;
    }
    
    .mobile-menu-btn.active span:nth-child(3) {
        transform: rotate(-45deg) translate(5px, -5px);
    }
    
    .hero {
        min-height: auto;
        padding-top: calc(var(--header-height) + var(--spacing-lg));
        padding-bottom: var(--spacing-2xl);
    }
    
    .hero-img {
        max-width: 80%;
    }
    
    .scroll-indicator {
        display: none;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
    }
    
    .feature-detail {
        padding: var(--spacing-md);
    }
    
    .download-grid,
    .download-grid-5 {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .footer-brand {
        align-items: center;
    }
    
    .footer-links {
        grid-template-columns: 1fr;
        gap: var(--spacing-lg);
    }
    
    .footer-icp {
        flex-direction: column;
        gap: var(--spacing-xs);
    }
    
    .footer-divider {
        display: none;
    }
}

@media (max-width: 480px) {
    :root {
        --font-size-5xl: 1.75rem;
        --font-size-4xl: 1.5rem;
        --spacing-md: 1rem;
    }
    
    .hero-downloads {
        flex-direction: column;
    }
    
    .download-btn {
        width: 100%;
        justify-content: center;
    }
    
    .features-nav {
        flex-direction: column;
        align-items: stretch;
    }
    
    .features-nav-btn {
        text-align: center;
    }
    
    .download-grid,
    .download-grid-5 {
        grid-template-columns: 1fr;
    }
}