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

:root {
    --color-bg: #f5f5f7;
    --color-surface: #ffffff;
    --color-text: #1d1d1f;
    --color-text-secondary: #86868b;
    --color-primary: #0071e3;
    --color-primary-hover: #0077ed;
    --color-border: rgba(0, 0, 0, 0.08);
    --color-shadow: rgba(0, 0, 0, 0.1);
    --radius: 20px;
    --radius-sm: 12px;
    --transition: cubic-bezier(0.4, 0, 0.2, 1);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", "Helvetica Neue", sans-serif;
    background: var(--color-bg);
    color: var(--color-text);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 24px;
    animation: fadeIn 0.6s var(--transition);
}

@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

.container {
    width: 100%;
    max-width: 1200px;
    animation: slideUp 0.8s var(--transition);
}

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

.header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 32px;
    gap: 24px;
    flex-wrap: wrap;
}

.title-section {
    animation: slideUp 0.8s var(--transition) 0.1s both;
}

h1 {
    font-size: 56px;
    font-weight: 600;
    letter-spacing: -0.02em;
    line-height: 1.1;
    margin-bottom: 8px;
}

.tagline {
    font-size: 21px;
    color: var(--color-text-secondary);
    font-weight: 400;
    letter-spacing: -0.01em;
}

.controls {
    display: flex;
    gap: 12px;
    animation: slideUp 0.8s var(--transition) 0.2s both;
}

.btn-primary,
.btn-secondary {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 12px 24px;
    border-radius: var(--radius-sm);
    border: none;
    font-size: 15px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s var(--transition);
    font-family: inherit;
    letter-spacing: -0.01em;
}

.btn-primary {
    background: var(--color-primary);
    color: white;
}

.btn-primary:hover:not(:disabled) {
    background: var(--color-primary-hover);
    transform: translateY(-1px);
    box-shadow: 0 8px 16px rgba(0, 113, 227, 0.2);
}

.btn-primary:active:not(:disabled) {
    transform: translateY(0);
}

.btn-secondary {
    background: var(--color-surface);
    color: var(--color-text);
    border: 1px solid var(--color-border);
}

.btn-secondary:hover:not(:disabled) {
    background: var(--color-bg);
    transform: translateY(-1px);
    box-shadow: 0 4px 12px var(--color-shadow);
}

.btn-secondary:active:not(:disabled) {
    transform: translateY(0);
}

button:disabled {
    opacity: 0.4;
    cursor: not-allowed;
}

.viewport-container {
    animation: slideUp 0.8s var(--transition) 0.3s both;
}

.viewport {
    background: var(--color-surface);
    border-radius: var(--radius);
    overflow: hidden;
    aspect-ratio: 16 / 10;
    position: relative;
    border: 1px solid var(--color-border);
    box-shadow: 0 2px 16px var(--color-shadow);
    transition: box-shadow 0.3s var(--transition);
}

.viewport:hover {
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.12);
}

.empty-state {
    position: absolute;
    inset: 0;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    color: var(--color-text-secondary);
    gap: 16px;
    pointer-events: none;
    animation: pulse 2s ease-in-out infinite;
}

@keyframes pulse {
    0%, 100% {
        opacity: 1;
    }
    50% {
        opacity: 0.6;
    }
}

.empty-state svg {
    opacity: 0.3;
}

.empty-state p {
    font-size: 17px;
    font-weight: 500;
}

.empty-state .hint {
    font-size: 13px;
    opacity: 0.7;
}

canvas {
    width: 100% !important;
    height: 100% !important;
    display: block;
    border-radius: var(--radius);
}

/* Loading animation */
@keyframes spin {
    from {
        transform: rotate(0deg);
    }
    to {
        transform: rotate(360deg);
    }
}

.loading {
    position: absolute;
    inset: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--color-surface);
    border-radius: var(--radius);
}

.loading::after {
    content: '';
    width: 40px;
    height: 40px;
    border: 3px solid var(--color-border);
    border-top-color: var(--color-primary);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

/* Responsive */
@media (max-width: 768px) {
    body {
        padding: 16px;
    }
    
    h1 {
        font-size: 40px;
    }
    
    .tagline {
        font-size: 17px;
    }
    
    .header {
        flex-direction: column;
        margin-bottom: 24px;
    }
    
    .controls {
        width: 100%;
    }
    
    .btn-primary,
    .btn-secondary {
        flex: 1;
        justify-content: center;
    }
    
    .viewport {
        aspect-ratio: 4 / 3;
    }
}