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

body {
    font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
    line-height: 1.6;
    color: var(--text-light);
    background-color: var(--dark-bg);
    display: flex;
    flex-direction: column;
    height: 100vh;
}

header {
    background-color: var(--dark-surface);
    color: white;
    padding: 1rem;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.3);
    width: 100%;
    border-bottom: 1px solid var(--border-dark);
    position: relative;
}

h1 {
    font-size: 1.5rem;
    font-weight: 600;
    text-align: center;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 1rem;
    width: 100%;
    flex: 1;
    display: flex;
    flex-direction: column;
}

.app {
    display: flex;
    flex-direction: column;
    gap: 1rem;
    flex: 1;
}

/* Scrollbar Styling */
::-webkit-scrollbar {
    width: 10px;
    height: 10px;
}

::-webkit-scrollbar-track {
    background: var(--dark-surface);
}

::-webkit-scrollbar-thumb {
    background: var(--border-darker);
    border-radius: 5px;
}

::-webkit-scrollbar-thumb:hover {
    background: #666;
}

/* Loading animation */
.loading {
    display: flex;
    align-items: center;
    justify-content: center;
    height: 200px;
}

.spinner {
    width: 40px;
    height: 40px;
    border: 4px solid rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    border-top-color: var(--primary);
    animation: spin 1s ease-in-out infinite;
}

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

/* Responsiveness */
@media (max-width: 768px) {
    .submission-area {
        flex-direction: column;
    }

    .submission-column,
    .reference-column {
        width: 100%;
        border-right: none;
    }

    .submission-column {
        border-bottom: 1px solid var(--border-dark);
    }

    .feedback-area {
        flex-direction: column;
    }

    .grading-section {
        width: 100%;
    }
}