/* Intro/Landing Page Styles - TETR.IO inspired */

#intro-screen {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 2000;
    background: #000;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    overflow: hidden;
    transition: opacity 0.5s ease, transform 0.5s ease;
}

#intro-screen.hidden {
    opacity: 0;
    pointer-events: none;
    transform: scale(1.02);
}

/* Subtle animated background */
.intro-background {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: 
        radial-gradient(ellipse at 50% 50%, rgba(30, 40, 50, 0.4) 0%, transparent 70%),
        linear-gradient(180deg, #000 0%, #0a0a0f 50%, #000 100%);
    animation: introBackgroundPulse 8s ease-in-out infinite;
}

.intro-background::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: 
        linear-gradient(rgba(100, 200, 255, 0.01) 1px, transparent 1px),
        linear-gradient(90deg, rgba(100, 200, 255, 0.01) 1px, transparent 1px);
    background-size: 80px 80px;
    opacity: 0.5;
}

@keyframes introBackgroundPulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.8; }
}

/* Content container */
.intro-content {
    position: relative;
    z-index: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 30px;
    animation: introFadeIn 1s ease-out;
}

@keyframes introFadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Logo */
.intro-logo {
    font-size: 72px;
    font-weight: 800;
    letter-spacing: 8px;
    text-transform: uppercase;
    animation: introLogoGlow 3s ease-in-out infinite;
}

.intro-logo-dust {
    color: #fff;
    text-shadow: 0 0 30px rgba(255, 255, 255, 0.3);
}

.intro-logo-grounds {
    color: #64c8ff;
    text-shadow: 0 0 30px rgba(100, 200, 255, 0.5);
}

@keyframes introLogoGlow {
    0%, 100% {
        filter: brightness(1);
    }
    50% {
        filter: brightness(1.1);
    }
}

/* Tagline */
.intro-tagline {
    color: #666;
    font-size: 16px;
    letter-spacing: 4px;
    text-transform: uppercase;
    margin-top: -10px;
}

/* Enter button */
.intro-enter-btn {
    position: relative;
    margin-top: 40px;
    padding: 18px 60px;
    font-size: 18px;
    font-weight: 700;
    letter-spacing: 6px;
    text-transform: uppercase;
    color: #fff;
    background: transparent;
    border: 2px solid rgba(100, 200, 255, 0.5);
    cursor: pointer;
    overflow: hidden;
    transition: all 0.3s ease;
}

.intro-enter-btn span {
    position: relative;
    z-index: 1;
}

.intro-enter-btn .btn-glow {
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    background: radial-gradient(circle, rgba(100, 200, 255, 0.3) 0%, transparent 70%);
    transform: translate(-50%, -50%);
    transition: all 0.4s ease;
    border-radius: 50%;
}

.intro-enter-btn:hover {
    border-color: rgba(100, 200, 255, 0.8);
    color: #64c8ff;
    text-shadow: 0 0 20px rgba(100, 200, 255, 0.5);
}

.intro-enter-btn:hover .btn-glow {
    width: 300px;
    height: 300px;
}

.intro-enter-btn:active {
    transform: scale(0.98);
}

/* Hint text */
.intro-hint {
    color: #333;
    font-size: 12px;
    letter-spacing: 2px;
    animation: introPulse 2s ease-in-out infinite;
}

@keyframes introPulse {
    0%, 100% { opacity: 0.3; }
    50% { opacity: 0.6; }
}

/* Footer */
.intro-footer {
    position: absolute;
    bottom: 30px;
    left: 0;
    right: 0;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 40px;
    z-index: 1;
}

.intro-footer-left,
.intro-footer-right {
    flex: 1;
}

.intro-footer-right {
    text-align: right;
}

.intro-footer-links {
    display: flex;
    align-items: center;
    gap: 12px;
}

.intro-link {
    color: #444;
    font-size: 11px;
    letter-spacing: 1px;
    text-decoration: none;
    transition: color 0.3s ease;
}

.intro-link:hover {
    color: #64c8ff;
}

.intro-link-divider {
    color: #333;
    font-size: 10px;
}

.intro-copyright,
.intro-version {
    color: #333;
    font-size: 11px;
    letter-spacing: 1px;
}

.intro-copyright {
    font-weight: 600;
}

/* Responsive */
@media (max-width: 768px) {
    .intro-logo {
        font-size: 36px;
        letter-spacing: 4px;
    }
    
    .intro-tagline {
        font-size: 12px;
        letter-spacing: 2px;
    }
    
    .intro-enter-btn {
        padding: 14px 40px;
        font-size: 14px;
        letter-spacing: 4px;
    }
    
    .intro-footer {
        flex-direction: column;
        align-items: center;
        gap: 10px;
        padding: 0 20px;
    }
    
    .intro-footer-left,
    .intro-footer-right {
        text-align: center;
    }
    
    .intro-footer-links {
        order: -1;
    }
}