/* ============================================
   Base Styles
   ============================================ */

body {
    min-height: 100vh;
    overflow: hidden;
}

/* ============================================
   Fullpage Container
   ============================================ */

.fullpage-container {
    position: relative;
    width: 100vw;
    height: 100vh;
    overflow: hidden;
}

/* ============================================
   Section Base Styles
   ============================================ */

.section {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    padding: var(--space-8);
    opacity: 0;
    visibility: hidden;
    transform: translateY(100px);
    transition: opacity var(--transition-slow), 
                transform var(--transition-slow),
                visibility var(--transition-slow);
    will-change: transform, opacity;
}

.section.active {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.section.prev {
    transform: translateY(-100px);
}

.section-content {
    position: relative;
    z-index: 2;
    width: 100%;
    max-width: 1400px;
    margin: 0 auto;
}

/* ============================================
   Section Background
   ============================================ */

.section-bg {
    position: absolute;
    inset: 0;
    z-index: 0;
    overflow: hidden;
    pointer-events: none;
}

.gradient-orb {
    position: absolute;
    border-radius: 50%;
    filter: blur(80px);
    opacity: 0.6;
    animation: orb-float 20s ease-in-out infinite;
}

.orb-1 {
    width: 600px;
    height: 600px;
    background: var(--orb-1);
    top: -200px;
    left: -100px;
    animation-delay: 0s;
}

.orb-2 {
    width: 500px;
    height: 500px;
    background: var(--orb-2);
    bottom: -150px;
    right: -100px;
    animation-delay: -7s;
}

.orb-3 {
    width: 400px;
    height: 400px;
    background: var(--orb-3);
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    animation-delay: -14s;
}

.orb-4 {
    width: 700px;
    height: 700px;
    background: var(--orb-1);
    top: -300px;
    right: -200px;
    animation-delay: -3s;
}

.orb-5 {
    width: 500px;
    height: 500px;
    background: var(--orb-2);
    bottom: -200px;
    left: -150px;
    animation-delay: -10s;
}

.orb-6 {
    width: 600px;
    height: 600px;
    background: var(--orb-1);
    top: -200px;
    left: 30%;
    animation-delay: -5s;
}

.orb-7 {
    width: 400px;
    height: 400px;
    background: var(--orb-3);
    bottom: -100px;
    right: 20%;
    animation-delay: -12s;
}

@keyframes orb-float {
    0%, 100% {
        transform: translate(0, 0) scale(1);
    }
    25% {
        transform: translate(30px, -30px) scale(1.05);
    }
    50% {
        transform: translate(-20px, 20px) scale(0.95);
    }
    75% {
        transform: translate(20px, 30px) scale(1.02);
    }
}

.grid-pattern {
    position: absolute;
    inset: 0;
    background-image: 
        linear-gradient(var(--border-medium) 1px, transparent 1px),
        linear-gradient(90deg, var(--border-medium) 1px, transparent 1px);
    background-size: 60px 60px;
    opacity: 0.3;
    mask-image: radial-gradient(ellipse at center, black 0%, transparent 70%);
    -webkit-mask-image: radial-gradient(ellipse at center, black 0%, transparent 70%);
}

/* ============================================
   Mobile Navigation - 默认隐藏
   ============================================ */

.mobile-nav {
    display: none;
}

/* ============================================
   Section Header
   ============================================ */

.section-header {
    margin-bottom: var(--space-12);
}

.section-header.centered {
    text-align: center;
}

.section-tag {
    display: inline-flex;
    align-items: center;
    gap: var(--space-2);
    font-size: var(--text-sm);
    font-weight: 500;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.1em;
    margin-bottom: var(--space-4);
}

.section-tag::before {
    content: '';
    width: 24px;
    height: 2px;
    background: var(--accent-primary);
}

.section-header.centered .section-tag {
    justify-content: center;
}

.section-header.centered .section-tag::before {
    width: 32px;
}

.section-title {
    font-size: var(--text-4xl);
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: var(--space-4);
}

.section-desc {
    font-size: var(--text-lg);
    color: var(--text-secondary);
    max-width: 600px;
    line-height: 1.7;
}

.section-header.centered .section-desc {
    margin: 0 auto;
}