:root {
    --color-primary: #3B82F6;
    --color-primary-dark: #2563EB;
    --color-primary-light: #93C5FD;
    --color-secondary: #60A5FA;
    --color-cta: #3B82F6;
    --color-background: #F8FAFC;
    --color-text: #1E293B;
    --color-text-muted: #64748B;
    --color-white: #FFFFFF;
    --color-border: #E2E8F0;
    --color-success: #22C55E;

    --space-xs: 4px;
    --space-sm: 8px;
    --space-md: 16px;
    --space-lg: 24px;
    --space-xl: 32px;
    --space-2xl: 48px;
    --space-3xl: 64px;

    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.06);
    --shadow-md: 0 2px 8px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 4px 16px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 8px 24px rgba(0, 0, 0, 0.12);

    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-full: 9999px;

    --transition-fast: 150ms ease;
    --transition-base: 200ms ease;
    --transition-slow: 300ms ease;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Work Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', sans-serif;
    color: var(--color-text);
    line-height: 1.6;
    overflow-x: hidden;
    background: var(--color-background);
}

h1, h2, h3, h4, h5, h6 {
    font-family: 'Outfit', sans-serif;
    font-weight: 600;
    line-height: 1.2;
}

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

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

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--space-lg);
}

section {
    padding: var(--space-3xl) 0;
}

.nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    transition: background-color var(--transition-base), box-shadow var(--transition-base);
    backdrop-filter: blur(12px);
    background: rgba(255, 255, 255, 0.85);
    border-bottom: 1px solid rgba(0, 0, 0, 0.05);
}

.nav.scrolled {
    background: rgba(255, 255, 255, 0.98);
    box-shadow: var(--shadow-md);
}

.nav-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--space-md) var(--space-lg);
    max-width: 1200px;
    margin: 0 auto;
}

.nav-actions {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    font-size: 22px;
    font-weight: 600;
    color: var(--color-primary);
}

.logo span {
    font-size: 16px;
    font-weight: 500;
    color: var(--color-text-muted);
}

.nav-links {
    display: flex;
    gap: var(--space-xl);
}

.nav-links a {
    color: var(--color-text-muted);
    font-weight: 500;
    font-size: 15px;
    transition: color var(--transition-base);
    position: relative;
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--color-primary);
    border-radius: 1px;
    transition: width var(--transition-slow);
}

.nav-links a:hover {
    color: var(--color-primary);
}

.nav-links a.active {
    color: var(--color-primary);
}

.nav-links a.active::after {
    width: 100%;
}

.nav-btn {
    background: var(--color-white);
    color: var(--color-primary);
    padding: 10px 20px;
    border-radius: var(--radius-sm);
    font-weight: 600;
    font-size: 14px;
    box-shadow: var(--shadow-sm), 0 2px 8px rgba(59, 130, 246, 0.15);
    transition: all var(--transition-base);
}

.nav-btn:hover {
    transform: translateY(-1px);
    box-shadow: var(--shadow-md), 0 4px 12px rgba(59, 130, 246, 0.25);
}

.lang-switch-btn {
    background: transparent;
    color: var(--color-text-muted);
    padding: 8px 14px;
    border-radius: var(--radius-sm);
    font-weight: 500;
    font-size: 13px;
    border: 1px solid var(--color-border);
    transition: all var(--transition-base);
    cursor: pointer;
}

.lang-switch-btn:hover {
    color: var(--color-primary);
    border-color: var(--color-primary);
    background: rgba(59, 130, 246, 0.04);
}

/* Hamburger Menu Button */
.hamburger-btn {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
    flex-direction: column;
    gap: 5px;
    align-items: center;
    justify-content: center;
}

.hamburger-btn span {
    display: block;
    width: 22px;
    height: 2px;
    background: var(--color-text-muted);
    border-radius: 2px;
    transition: all var(--transition-base);
    transform-origin: center;
}

.hamburger-btn:hover span {
    background: var(--color-primary);
}

.hamburger-btn.active span:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
}

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

.hamburger-btn.active span:nth-child(3) {
    transform: translateY(-7px) rotate(-45deg);
}

/* Mobile Menu Overlay */
.mobile-menu {
    display: none;
    position: fixed;
    top: 60px;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.98);
    backdrop-filter: blur(12px);
    padding: var(--space-lg);
    border-bottom: 1px solid var(--color-border);
    box-shadow: var(--shadow-lg);
    z-index: 999;
    transform: translateY(-10px);
    opacity: 0;
    transition: all var(--transition-base);
    pointer-events: none;
}

.mobile-menu.active {
    transform: translateY(0);
    opacity: 1;
    pointer-events: auto;
}

.mobile-menu a {
    display: block;
    padding: 12px 0;
    font-weight: 500;
    color: var(--color-text-muted);
    border-bottom: 1px solid var(--color-border);
    transition: color var(--transition-fast);
}

.mobile-menu a:last-child {
    border-bottom: none;
}

.mobile-menu a:hover {
    color: var(--color-primary);
}

.hero {
    min-height: 100vh;
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, #1E40AF 0%, #3B82F6 50%, #60A5FA 100%);
    background-size: 200% 200%;
    animation: gradientShift 15s ease infinite;
    z-index: 0;
}

@keyframes gradientShift {
    0% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
    100% { background-position: 0% 50%; }
}

.hero-bg {
    position: absolute;
    inset: 0;
    background: radial-gradient(circle at 20% 80%, rgba(255, 255, 255, 0.12) 0%, transparent 50%),
                radial-gradient(circle at 80% 20%, rgba(255, 255, 255, 0.08) 0%, transparent 50%);
}

.hero-particles {
    position: absolute;
    inset: 0;
    pointer-events: none;
}

.hero-deco-circle {
    position: absolute;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.15);
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.08);
    pointer-events: none;
}

.deco-circle-1 { animation: float-circle 20s infinite ease-in-out; }
.deco-circle-2 { animation: float-circle 25s infinite ease-in-out 3s; }
.deco-circle-3 { animation: float-circle 18s infinite ease-in-out 6s; }
.deco-circle-4 { animation: float-circle 22s infinite ease-in-out 2s; }
.deco-circle-5 { animation: float-circle 16s infinite ease-in-out 4s; }

.hero-deco-hex {
    position: absolute;
    background: rgba(255, 255, 255, 0.08);
    border: 1px solid rgba(255, 255, 255, 0.12);
    clip-path: polygon(25% 0%, 75% 0%, 100% 50%, 75% 100%, 25% 100%, 0% 50%);
    pointer-events: none;
}

.deco-hex-1 { animation: float-hex 22s infinite ease-in-out; }
.deco-hex-2 { animation: float-hex 26s infinite ease-in-out 4s; }
.deco-hex-3 { animation: float-hex 18s infinite ease-in-out 8s; }

.hero-particle-sm {
    position: absolute;
    width: 4px;
    height: 4px;
    background: rgba(255, 255, 255, 0.4);
    border-radius: 50%;
    animation: float-sm 18s infinite ease-in-out;
}

.hero-particle-md {
    position: absolute;
    width: 6px;
    height: 6px;
    background: rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    animation: float-md 22s infinite ease-in-out;
}

.hero-particle-lg {
    position: absolute;
    width: 10px;
    height: 10px;
    background: rgba(255, 255, 255, 0.2);
    border-radius: 50%;
    animation: float-lg 28s infinite ease-in-out;
}

@keyframes float-circle {
    0%, 100% { transform: translateY(0) translateX(0); opacity: 0.5; }
    50% { transform: translateY(-15px) translateX(10px); opacity: 0.7; }
}

@keyframes float-hex {
    0%, 100% { transform: translateY(0) translateX(0) rotate(0deg); opacity: 0.4; }
    50% { transform: translateY(-20px) translateX(15px) rotate(30deg); opacity: 0.6; }
}

@keyframes float-sm {
    0%, 100% { transform: translateY(0) translateX(0); opacity: 0; }
    10% { opacity: 0.4; }
    90% { opacity: 0.4; }
    100% { transform: translateY(-80vh) translateX(50px); opacity: 0; }
}

@keyframes float-md {
    0%, 100% { transform: translateY(0) translateX(0); opacity: 0; }
    10% { opacity: 0.3; }
    90% { opacity: 0.3; }
    100% { transform: translateY(-80vh) translateX(80px); opacity: 0; }
}

@keyframes float-lg {
    0%, 100% { transform: translateY(0) translateX(0); opacity: 0; }
    10% { opacity: 0.2; }
    90% { opacity: 0.2; }
    100% { transform: translateY(-80vh) translateX(120px); opacity: 0; }
}

.hero-content {
    position: relative;
    z-index: 1;
    text-align: center;
    padding: 0 var(--space-lg);
    max-width: 900px;
}

/* Hero staggered entrance animation */
.hero-badge {
    animation: heroFadeInUp 0.6s ease 0.1s both;
}

.hero-title {
    animation: heroFadeInUp 0.6s ease 0.25s both;
}

.hero-subtitle {
    animation: heroFadeInUp 0.6s ease 0.4s both;
}

.hero-cta {
    animation: heroFadeInUp 0.6s ease 0.55s both;
}

.hero-stats {
    animation: heroFadeInUp 0.6s ease 0.7s both;
}

@keyframes heroFadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.hero-badge {
    display: inline-block;
    background: rgba(255, 255, 255, 0.15);
    backdrop-filter: blur(8px);
    padding: 8px 16px;
    border-radius: var(--radius-full);
    color: var(--color-white);
    font-size: 13px;
    font-weight: 500;
    margin-bottom: var(--space-lg);
    border: 1px solid rgba(255, 255, 255, 0.25);
    transition: all var(--transition-base);
}

.hero-badge:hover {
    background: rgba(255, 255, 255, 0.2);
    transform: translateY(-1px);
}

.hero-title {
    font-size: 56px;
    color: var(--color-white);
    margin-bottom: var(--space-lg);
    letter-spacing: -0.02em;
}

.hero-subtitle {
    font-size: 18px;
    color: rgba(255, 255, 255, 0.9);
    margin-bottom: var(--space-2xl);
    line-height: 1.8;
}

.hero-cta {
    display: flex;
    gap: var(--space-md);
    justify-content: center;
    align-items: center;
    flex-wrap: wrap;
    margin-bottom: var(--space-2xl);
}

.hero-btn-primary {
    background: var(--color-white);
    color: var(--color-primary);
    padding: 14px 28px;
    border-radius: var(--radius-md);
    font-size: 16px;
    font-weight: 600;
    box-shadow: 0 4px 12px rgba(59, 130, 246, 0.25);
    transition: all var(--transition-slow);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-sm);
}

.hero-btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(59, 130, 246, 0.35);
}

.hero-btn-primary.pulse {
    animation: btnPulse 2s ease-in-out infinite;
}

@keyframes btnPulse {
    0%, 100% { box-shadow: 0 4px 12px rgba(59, 130, 246, 0.25); }
    50% { box-shadow: 0 4px 24px rgba(59, 130, 246, 0.45), 0 0 0 8px rgba(59, 130, 246, 0.08); }
}

.hero-btn-secondary {
    background: rgba(255, 255, 255, 0.15);
    backdrop-filter: blur(8px);
    color: var(--color-white);
    border: 1px solid rgba(255, 255, 255, 0.3);
    padding: 14px 28px;
    border-radius: var(--radius-md);
    font-size: 16px;
    font-weight: 600;
    transition: all var(--transition-slow);
    display: flex;
    align-items: center;
    gap: var(--space-sm);
}

.hero-btn-secondary:hover {
    background: rgba(255, 255, 255, 0.25);
    transform: translateY(-2px);
}

.hero-stats {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--space-md);
    max-width: 400px;
    margin: 0 auto;
}

.stat-card {
    background: rgba(255, 255, 255, 0.15);
    backdrop-filter: blur(8px);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: var(--radius-md);
    padding: 20px;
    text-align: center;
}

.stat-number {
    font-size: 36px;
    font-weight: 700;
    color: var(--color-white);
    margin-bottom: var(--space-xs);
}

.stat-label {
    font-size: 13px;
    color: rgba(255, 255, 255, 0.8);
}

.hero-wave {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 60px;
    background: linear-gradient(180deg, transparent 0%, var(--color-background) 100%);
    z-index: 1;
    pointer-events: none;
}

.features {
    background: linear-gradient(180deg, #FFFFFF 0%, var(--color-background) 100%);
    position: relative;
    overflow: hidden;
}

.section-deco {
    position: absolute;
    inset: 0;
    pointer-events: none;
}

.deco-circle {
    position: absolute;
    border-radius: 50%;
    background: rgba(59, 130, 246, 0.04);
    border: 1px solid rgba(59, 130, 246, 0.08);
}

.deco-circle-f1 { animation: float-deco 22s infinite ease-in-out; }
.deco-circle-f2 { animation: float-deco 26s infinite ease-in-out 5s; }
.deco-circle-f3 { animation: float-deco 20s infinite ease-in-out 10s; }
.deco-circle-g1 { animation: float-deco 24s infinite ease-in-out 3s; }
.deco-circle-g2 { animation: float-deco 28s infinite ease-in-out 7s; }

@keyframes float-deco {
    0%, 100% { transform: translateY(0) scale(1); opacity: 0.5; }
    50% { transform: translateY(-15px) scale(1.02); opacity: 0.7; }
}

.deco-hex {
    position: absolute;
    background: rgba(59, 130, 246, 0.03);
    border: 1px solid rgba(59, 130, 246, 0.06);
    clip-path: polygon(25% 0%, 75% 0%, 100% 50%, 75% 100%, 25% 100%, 0% 50%);
    pointer-events: none;
}

.deco-hex-a1 { animation: float-hex-deco 24s infinite ease-in-out; }
.deco-hex-a2 { animation: float-hex-deco 28s infinite ease-in-out 6s; }

@keyframes float-hex-deco {
    0%, 100% { transform: translateY(0) rotate(0deg); opacity: 0.4; }
    50% { transform: translateY(-10px) rotate(20deg); opacity: 0.6; }
}

.section-header {
    text-align: center;
    margin-bottom: var(--space-2xl);
    position: relative;
    z-index: 1;
}

.section-title {
    font-size: 40px;
    color: var(--color-text);
    margin-bottom: var(--space-md);
    letter-spacing: -0.01em;
}

.section-decoration {
    width: 48px;
    height: 3px;
    background: linear-gradient(90deg, #3B82F6, #60A5FA);
    border-radius: 2px;
    margin: var(--space-sm) auto;
}

.section-subtitle {
    font-size: 16px;
    color: var(--color-text-muted);
    max-width: 560px;
    margin: 0 auto;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--space-lg);
}

.feature-card {
    background: var(--color-white);
    padding: 32px 28px;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--color-border);
    transition: all var(--transition-slow);
}

.feature-card:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-lg);
    border-color: rgba(59, 130, 246, 0.2);
}

.feature-icon {
    width: 48px;
    height: 48px;
    background: linear-gradient(135deg, #3B82F6 0%, #2563EB 100%);
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: var(--space-md);
    color: var(--color-white);
    font-size: 20px;
    transition: transform var(--transition-slow);
}

.feature-card:hover .feature-icon {
    transform: scale(1.1) rotate(-3deg);
    border-radius: var(--radius-md);
}

.feature-title {
    font-size: 20px;
    color: var(--color-text);
    margin-bottom: var(--space-sm);
    font-weight: 600;
}

.feature-desc {
    font-size: 14px;
    color: var(--color-text-muted);
    line-height: 1.7;
}

.algorithms {
    background: linear-gradient(180deg, var(--color-background) 0%, #FFFFFF 100%);
    position: relative;
    overflow: hidden;
}

.algo-tabs {
    display: flex;
    justify-content: center;
    gap: var(--space-sm);
    margin-bottom: var(--space-xl);
    flex-wrap: wrap;
    background: var(--color-white);
    padding: 6px;
    border-radius: var(--radius-md);
    width: fit-content;
    margin-left: auto;
    margin-right: auto;
    border: 1px solid var(--color-border);
}

.section-header.scroll-reveal {
    transform: translateY(16px);
    transition-duration: 400ms;
}

.section-header.scroll-reveal.revealed {
    transform: translateY(0);
}

.algo-tab {
    padding: 8px 18px;
    border-radius: var(--radius-sm);
    background: transparent;
    color: var(--color-text-muted);
    font-weight: 500;
    font-size: 14px;
    transition: all var(--transition-fast);
    border: none;
}

.algo-tab.active,
.algo-tab:hover {
    background: var(--color-primary);
    color: var(--color-white);
    box-shadow: 0 2px 8px rgba(59, 130, 246, 0.25);
}

.algo-grids-wrapper {
    position: relative;
    min-height: 200px;
    transition: min-height 0.35s ease;
}

.algo-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--space-md);
    opacity: 0;
    transform: translateY(12px);
    pointer-events: none;
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    transition: opacity 0.35s ease, transform 0.35s ease;
}

.algo-grid.active {
    opacity: 1;
    transform: translateY(0);
    pointer-events: auto;
    position: relative;
}

@keyframes cardFadeIn {
    from {
        opacity: 0;
        transform: translateY(16px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.algo-card {
    background: var(--color-white);
    padding: 24px;
    border-radius: var(--radius-lg);
    transition: all var(--transition-slow);
    border: 1px solid var(--color-border);
}

.algo-card:hover {
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
    border-color: rgba(59, 130, 246, 0.2);
}

.algo-card-header {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    margin-bottom: var(--space-md);
}

.algo-card-icon {
    width: 44px;
    height: 44px;
    background: linear-gradient(135deg, #3B82F6 0%, #2563EB 100%);
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--color-white);
    font-size: 18px;
}

.algo-card-title {
    font-size: 17px;
    font-weight: 600;
    color: var(--color-text);
}

.algo-list {
    list-style: none;
}

.algo-list li {
    display: flex;
    align-items: flex-start;
    gap: var(--space-sm);
    margin-bottom: var(--space-xs);
    color: var(--color-text-muted);
    font-size: 13px;
}

.algo-list li i {
    color: var(--color-success);
    flex-shrink: 0;
    margin-top: 3px;
}

.algo-card-highlight {
    border-color: rgba(59, 130, 246, 0.3);
    background: linear-gradient(135deg, rgba(59, 130, 246, 0.03) 0%, rgba(96, 165, 250, 0.05) 100%);
}

.algo-card-highlight:hover {
    border-color: rgba(59, 130, 246, 0.5);
    box-shadow: 0 4px 16px rgba(59, 130, 246, 0.12);
}

/* ========== Modalities Section ========== */

.modalities {
    background: linear-gradient(180deg, var(--color-background) 0%, #FFFFFF 100%);
    position: relative;
    overflow: hidden;
}

.deco-circle-m1 { animation: float-deco 24s infinite ease-in-out 2s; }
.deco-circle-m2 { animation: float-deco 26s infinite ease-in-out 8s; }

.modalities-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--space-lg);
    max-width: 640px;
    margin: 0 auto var(--space-lg);
}

.modality-card {
    background: var(--color-white);
    padding: 32px 28px;
    border-radius: var(--radius-lg);
    text-align: center;
    border: 1px solid var(--color-border);
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-slow);
}

.modality-card:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-lg);
    border-color: rgba(59, 130, 246, 0.2);
}

.modality-icon {
    width: 56px;
    height: 56px;
    background: linear-gradient(135deg, #3B82F6 0%, #2563EB 100%);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto var(--space-md);
    color: var(--color-white);
    font-size: 24px;
}

.modality-title {
    font-size: 18px;
    font-weight: 600;
    color: var(--color-text);
    margin-bottom: var(--space-sm);
}

.modality-formats {
    font-size: 14px;
    color: var(--color-text-muted);
    line-height: 1.6;
}

.modalities-coming {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-md);
    flex-wrap: wrap;
}

.coming-label {
    font-size: 13px;
    color: var(--color-text-muted);
    padding: 6px 14px;
    border: 1px dashed var(--color-border);
    border-radius: var(--radius-full);
    transition: all var(--transition-base);
}

.coming-label:hover {
    border-color: var(--color-primary-light);
    color: var(--color-primary);
}

.coming-badge {
    font-size: 12px;
    font-weight: 600;
    color: var(--color-primary);
    background: rgba(59, 130, 246, 0.08);
    padding: 6px 12px;
    border-radius: var(--radius-full);
    letter-spacing: 0.02em;
}

.guide {
    background: linear-gradient(180deg, #FFFFFF 0%, var(--color-background) 100%);
    position: relative;
    overflow: hidden;
}

.guide-steps {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--space-xl);
}

.guide-step {
    text-align: center;
    position: relative;
}

.guide-step-number {
    width: 52px;
    height: 52px;
    background: linear-gradient(135deg, #3B82F6 0%, #2563EB 100%);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--color-white);
    font-size: 22px;
    font-weight: 600;
    margin: 0 auto var(--space-md);
    box-shadow: 0 4px 12px rgba(59, 130, 246, 0.25);
    position: relative;
    z-index: 1;
}

.guide-step-connector {
    position: absolute;
    top: 26px;
    transform: translateY(-50%);
    width: 50px;
    height: 2px;
    background: linear-gradient(90deg, rgba(59, 130, 246, 0.3), rgba(59, 130, 246, 0.5));
    z-index: 0;
    display: none;
}

.connector-left {
    right: -25px;
}

.connector-right {
    left: -25px;
}

@media (min-width: 1024px) {
    .guide-step:not(:last-child) .guide-step-connector {
        display: block;
    }
}

.guide-step-icon {
    font-size: 42px;
    color: var(--color-primary);
    margin-bottom: var(--space-sm);
}

.guide-step-title {
    font-size: 18px;
    font-weight: 600;
    color: var(--color-text);
    margin-bottom: var(--space-xs);
}

.guide-step-desc {
    font-size: 14px;
    color: var(--color-text-muted);
    line-height: 1.7;
}

.cta {
    text-align: center;
    padding: var(--space-3xl) var(--space-lg);
    position: relative;
    overflow: hidden;
    background: linear-gradient(135deg, #1E40AF 0%, #3B82F6 50%, #60A5FA 100%);
    background-size: 200% 200%;
    animation: ctaGradient 12s ease infinite;
}

@keyframes ctaGradient {
    0% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
    100% { background-position: 0% 50%; }
}

.cta::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(255, 255, 255, 0.08) 0%, transparent 70%);
    animation: rotate 40s linear infinite;
}

.cta::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(255, 255, 255, 0.08) 0%, transparent 70%);
    animation: rotate 40s linear infinite;
}

@keyframes rotate {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

.cta-title {
    font-size: 36px;
    color: var(--color-white);
    margin-bottom: var(--space-sm);
}

.cta-subtitle {
    font-size: 16px;
    color: rgba(255, 255, 255, 0.9);
    margin-bottom: var(--space-xl);
}

.cta-note {
    margin-top: var(--space-md);
    color: rgba(255, 255, 255, 0.75);
    font-size: 13px;
}

/* ========== 平台选择模态框 ========== */
.platform-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-sm);
}

.platform-card {
    background: var(--color-white);
    border: 2px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: 16px 14px;
    text-align: center;
    cursor: pointer;
    transition: all var(--transition-base);
    position: relative;
    user-select: none;
}

.platform-card:hover {
    border-color: var(--color-primary-light);
    background: rgba(59, 130, 246, 0.03);
}

.platform-card.selected {
    border-color: var(--color-primary);
    background: rgba(59, 130, 246, 0.06);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

.platform-card .platform-check {
    position: absolute;
    top: 6px;
    right: 6px;
    width: 18px;
    height: 18px;
    border-radius: 50%;
    background: var(--color-border);
    color: var(--color-white);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 10px;
    transition: all var(--transition-base);
}

.platform-card.selected .platform-check {
    background: var(--color-primary);
}

.platform-card .platform-icon {
    font-size: 28px;
    color: var(--color-text-muted);
    margin-bottom: 6px;
    transition: color var(--transition-base);
}

.platform-card.selected .platform-icon {
    color: var(--color-primary);
}

.platform-card .platform-name {
    font-size: 13px;
    font-weight: 600;
    color: var(--color-text);
    margin-bottom: 2px;
}

.platform-card .platform-desc {
    font-size: 11px;
    color: var(--color-text-muted);
}

.platform-card .platform-badge {
    display: inline-block;
    font-size: 10px;
    font-weight: 600;
    color: var(--color-primary);
    background: rgba(59, 130, 246, 0.08);
    padding: 2px 8px;
    border-radius: var(--radius-full);
    margin-top: 4px;
}

.platform-card.na {
    opacity: 0.5;
    cursor: not-allowed;
    pointer-events: none;
}

@media (max-width: 480px) {
    .platform-grid {
        grid-template-columns: 1fr;
    }
}

.footer {
    background: #0F172A;
    color: rgba(255, 255, 255, 0.65);
    padding: 48px var(--space-lg) 32px;
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
}

.footer-top {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--space-xl);
    margin-bottom: var(--space-xl);
}

.footer-brand {
    color: var(--color-white);
}

.footer-brand h3 {
    font-size: 20px;
    margin-bottom: var(--space-sm);
}

.footer-brand p {
    font-size: 13px;
    line-height: 1.8;
    color: rgba(255, 255, 255, 0.6);
}

.footer-section h4 {
    color: var(--color-white);
    font-size: 15px;
    margin-bottom: var(--space-md);
}

.footer-links {
    list-style: none;
}

.footer-links li {
    margin-bottom: var(--space-sm);
    font-size: 13px;
}

.footer-links a {
    font-size: 13px;
    color: rgba(255, 255, 255, 0.65);
    transition: color var(--transition-fast);
}

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

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.08);
    padding-top: var(--space-lg);
    text-align: center;
    font-size: 13px;
    color: rgba(255, 255, 255, 0.5);
}

.floating-btn {
    position: fixed;
    right: 24px;
    bottom: 24px;
    z-index: 1000;
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
}

.floating-btn-main {
    background: var(--color-white);
    color: var(--color-primary);
    padding: 12px 20px;
    border-radius: var(--radius-full);
    font-weight: 600;
    font-size: 14px;
    box-shadow: var(--shadow-md), 0 4px 12px rgba(59, 130, 246, 0.25);
    transition: all var(--transition-base);
    display: flex;
    align-items: center;
    gap: var(--space-sm);
}

.floating-btn-main:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg), 0 6px 20px rgba(59, 130, 246, 0.35);
}

.floating-btn-secondary {
    background: #475569;
    color: var(--color-white);
    padding: 12px 20px;
    border-radius: var(--radius-full);
    font-weight: 600;
    font-size: 14px;
    box-shadow: var(--shadow-md);
    transition: all var(--transition-base);
    display: flex;
    align-items: center;
    gap: var(--space-sm);
}

.floating-btn-secondary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.modal {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(4px);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 2000;
    opacity: 0;
    visibility: hidden;
    transition: opacity var(--transition-base), visibility var(--transition-base);
}

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

.modal-content {
    background: var(--color-white);
    border-radius: var(--radius-lg);
    padding: 28px;
    max-width: 440px;
    width: 90%;
    transform: scale(0.96);
    transition: transform var(--transition-slow);
    box-shadow: var(--shadow-xl);
}

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

.modal-header {
    margin-bottom: var(--space-lg);
}

.modal-title {
    font-size: 20px;
    font-weight: 600;
    color: var(--color-text);
}

.modal-subtitle {
    color: var(--color-text-muted);
    font-size: 14px;
    margin-top: var(--space-xs);
}

.modal-form {
    display: flex;
    flex-direction: column;
    gap: var(--space-md);
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.form-label {
    font-weight: 500;
    color: var(--color-text);
    font-size: 14px;
}

.form-label .required {
    color: #e53e3e;
}

.form-input,
.form-textarea {
    padding: 12px 14px;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    font-size: 15px;
    transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
    font-family: inherit;
}

.form-input:focus,
.form-textarea:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

.form-textarea {
    resize: vertical;
    min-height: 100px;
}

.form-error {
    color: #e53e3e;
    font-size: 12px;
    display: none;
}

.form-error.active {
    display: block;
}

.form-input.error {
    border-color: #e53e3e;
}

.modal-footer {
    display: flex;
    gap: var(--space-sm);
    margin-top: var(--space-lg);
}

.modal-btn {
    flex: 1;
    padding: 11px;
    border-radius: var(--radius-sm);
    font-weight: 600;
    font-size: 14px;
    transition: all var(--transition-fast);
}

.modal-btn-cancel {
    background: #E2E8F0;
    color: var(--color-text);
}

.modal-btn-cancel:hover {
    background: #CBD5E0;
}

.modal-btn-submit {
    background: linear-gradient(135deg, #3B82F6 0%, #2563EB 100%);
    color: var(--color-white);
}

.modal-btn-submit:hover {
    opacity: 0.9;
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(59, 130, 246, 0.3);
}

.scroll-reveal {
    opacity: 0;
    transform: translateY(24px);
    transition: opacity 500ms ease-out, transform 500ms ease-out;
}

.scroll-reveal.revealed {
    opacity: 1;
    transform: translateY(0);
}

.scroll-reveal-delay-1 { transition-delay: 80ms; }
.scroll-reveal-delay-2 { transition-delay: 160ms; }
.scroll-reveal-delay-3 { transition-delay: 240ms; }
.scroll-reveal-delay-4 { transition-delay: 320ms; }
.scroll-reveal-delay-5 { transition-delay: 400ms; }
.scroll-reveal-delay-6 { transition-delay: 480ms; }

/* Guide steps: independent left-to-right stagger using nth-child */
.guide-step:nth-child(1).scroll-reveal { transition-delay: 80ms; }
.guide-step:nth-child(2).scroll-reveal { transition-delay: 200ms; }
.guide-step:nth-child(3).scroll-reveal { transition-delay: 320ms; }

@media (max-width: 768px) {
    .nav-links {
        display: none;
    }

    .hamburger-btn {
        display: flex;
    }

    .mobile-menu {
        display: block;
    }

    .hero-title {
        font-size: 40px;
    }

    .hero-subtitle {
        font-size: 16px;
    }

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

    .stat-card {
        padding: 16px;
    }

    .stat-number {
        font-size: 32px;
    }

    .section-title {
        font-size: 32px;
    }

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

    .algo-tabs {
        gap: 6px;
    }

    .algo-tab {
        padding: 6px 14px;
        font-size: 13px;
    }

    .modalities-grid {
        grid-template-columns: 1fr;
        max-width: 100%;
    }

    .modalities-coming {
        gap: var(--space-sm);
    }

    .cta-title {
        font-size: 28px;
    }

    .footer-top {
        grid-template-columns: 1fr;
    }

    .lang-switch-btn {
        padding: 6px 10px;
        font-size: 12px;
    }

    .scroll-reveal {
        opacity: 0;
        transform: translateY(20px);
    }
}