/* ============================================
   动画样式
   ============================================ */

/* Scroll-driven Fade In */
.fade-in {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s cubic-bezier(0.4, 0, 0.2, 1),
                transform 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
    transition-delay: 0ms !important;
}

/* Staggered children */
.stagger-children > .fade-in:nth-child(1) { transition-delay: 0ms; }
.stagger-children > .fade-in:nth-child(2) { transition-delay: 80ms; }
.stagger-children > .fade-in:nth-child(3) { transition-delay: 160ms; }
.stagger-children > .fade-in:nth-child(4) { transition-delay: 240ms; }
.stagger-children > .fade-in:nth-child(5) { transition-delay: 320ms; }
.stagger-children > .fade-in:nth-child(6) { transition-delay: 480ms; }
.stagger-children > .fade-in:nth-child(7) { transition-delay: 560ms; }
.stagger-children > .fade-in:nth-child(8) { transition-delay: 640ms; }

/* Fade In from left */
.fade-in-left {
    opacity: 0;
    transform: translateX(-30px);
    transition: opacity 0.6s cubic-bezier(0.4, 0, 0.2, 1),
                transform 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

.fade-in-left.visible {
    opacity: 1;
    transform: translateX(0);
    transition-delay: 0ms !important;
}

/* Fade In from right */
.fade-in-right {
    opacity: 0;
    transform: translateX(30px);
    transition: opacity 0.6s cubic-bezier(0.4, 0, 0.2, 1),
                transform 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

.fade-in-right.visible {
    opacity: 1;
    transform: translateX(0);
    transition-delay: 0ms !important;
}

/* Scale In */
.scale-in {
    opacity: 0;
    transform: scale(0.9);
    transition: opacity 0.5s cubic-bezier(0.4, 0, 0.2, 1),
                transform 0.5s cubic-bezier(0.4, 0, 0.2, 1);
}

.scale-in.visible {
    opacity: 1;
    transform: scale(1);
    transition-delay: 0ms !important;
}

/* Number Count Up */
.count-up {
    display: inline-block;
}

/* Button Glow */
.btn-glow {
    position: relative;
    overflow: hidden;
}

.btn-glow::after {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(255,255,255,0.1) 0%, transparent 60%);
    opacity: 0;
    transition: opacity 0.3s;
}

.btn-glow:hover::after {
    opacity: 1;
}

/* Card Hover - global */
.card-hover {
    transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1),
                box-shadow 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.card-hover:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 40px rgba(0, 0, 0, 0.25);
}

/* Smooth section transitions */
.section-transition {
    position: relative;
}

/* Gradient border animation for cards */
@keyframes borderGlow {
    0%, 100% { border-color: rgba(22, 93, 255, 0.2); }
    50% { border-color: rgba(22, 93, 255, 0.4); }
}

.glow-border {
    animation: borderGlow 3s ease-in-out infinite;
}

/* Loading spinner */
@keyframes spin {
    to { transform: rotate(360deg); }
}

.spinner {
    width: 20px;
    height: 20px;
    border: 2px solid rgba(255, 255, 255, 0.2);
    border-top-color: var(--text-white);
    border-radius: 50%;
    animation: spin 0.6s linear infinite;
    display: inline-block;
}

/* Mobile nav slide-in */
@keyframes slideDown {
    from {
        transform: translateY(-10px);
    }
    to {
        transform: translateY(0);
    }
}

.nav-menu.active {
    animation: slideDown 0.3s ease-out;
}

/* Reduced motion */
@media (prefers-reduced-motion: reduce) {
    .fade-in,
    .fade-in-left,
    .fade-in-right,
    .scale-in {
        opacity: 1;
        transform: none;
        transition: none;
    }

    .stagger-children > .fade-in {
        transition-delay: 0ms !important;
    }

    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}