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

:root {
    --primary-color: #2563eb;
    --primary-hover: #1d4ed8;
    --secondary-color: #64748b;
    --secondary-hover: #475569;
    --success-color: #10b981;
    --error-color: #ef4444;
    --bg-color: #f8fafc;
    --card-bg: #ffffff;
    --text-color: #1e293b;
    --border-color: #e2e8f0;
    --shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px 0 rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.6;
    min-height: 100vh;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
}

header {
    text-align: center;
    margin-bottom: 3rem;
    padding: 2rem;
    background: var(--card-bg);
    border-radius: 12px;
    box-shadow: var(--shadow);
}

header h1 {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
    color: var(--primary-color);
}

header p {
    color: var(--secondary-color);
    font-size: 1.1rem;
}

main {
    background: var(--card-bg);
    border-radius: 12px;
    padding: 2rem;
    box-shadow: var(--shadow-lg);
    margin-bottom: 2rem;
}

.form-section {
    margin-bottom: 2rem;
    padding-bottom: 2rem;
    border-bottom: 1px solid var(--border-color);
}

.form-section:last-of-type {
    border-bottom: none;
}

.form-section h2 {
    font-size: 1.5rem;
    margin-bottom: 1.5rem;
    color: var(--text-color);
}

.form-section h3 {
    font-size: 1.2rem;
    margin-bottom: 1rem;
    color: var(--primary-color);
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    color: var(--text-color);
}

.form-group input[type="text"],
.form-group input[type="email"],
.form-group textarea,
.form-group select {
    width: 100%;
    padding: 0.75rem;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    font-size: 1rem;
    font-family: inherit;
    transition: border-color 0.2s, box-shadow 0.2s;
}

.form-group input[type="text"]:focus,
.form-group input[type="email"]:focus,
.form-group textarea:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.form-group textarea {
    resize: vertical;
    min-height: 100px;
}

.form-group small {
    display: block;
    margin-top: 0.25rem;
    color: var(--secondary-color);
    font-size: 0.875rem;
}

.checkbox-group label {
    display: flex;
    align-items: center;
    cursor: pointer;
}

.checkbox-group input[type="checkbox"] {
    width: auto;
    margin-right: 0.5rem;
    cursor: pointer;
}

.form-row {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-bottom: 1.5rem;
}

.form-column {
    padding: 1.5rem;
    background: var(--bg-color);
    border-radius: 8px;
}

.actions {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
    justify-content: center;
    padding-top: 1rem;
}

.btn {
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
    text-decoration: none;
    display: inline-block;
}

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

.btn-primary:hover {
    background-color: var(--primary-hover);
    transform: translateY(-1px);
    box-shadow: var(--shadow-lg);
}

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

.btn-secondary:hover {
    background-color: var(--secondary-hover);
    transform: translateY(-1px);
    box-shadow: var(--shadow-lg);
}

.btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none;
}

/* Modal */
.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    overflow: auto;
    background-color: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(4px);
}

.modal-content {
    background-color: var(--card-bg);
    margin: 5% auto;
    padding: 2rem;
    border-radius: 12px;
    width: 90%;
    max-width: 800px;
    max-height: 80vh;
    overflow-y: auto;
    box-shadow: var(--shadow-lg);
    position: relative;
}

.close {
    color: var(--secondary-color);
    float: right;
    font-size: 2rem;
    font-weight: bold;
    cursor: pointer;
    position: absolute;
    right: 1rem;
    top: 1rem;
}

.close:hover {
    color: var(--text-color);
}

#latexPreview {
    background: #1e293b;
    color: #e2e8f0;
    padding: 1.5rem;
    border-radius: 8px;
    overflow-x: auto;
    font-family: 'Courier New', monospace;
    font-size: 0.9rem;
    line-height: 1.6;
    margin: 1rem 0;
    white-space: pre-wrap;
    word-wrap: break-word;
}

/* Status Message */
.status-message {
    position: fixed;
    top: 2rem;
    right: 2rem;
    padding: 1rem 1.5rem;
    border-radius: 8px;
    box-shadow: var(--shadow-lg);
    z-index: 2000;
    display: none;
    animation: slideIn 0.3s ease-out;
}

.status-message.show {
    display: block;
}

.status-message.success {
    background-color: var(--success-color);
    color: white;
}

.status-message.error {
    background-color: var(--error-color);
    color: white;
}

@keyframes slideIn {
    from {
        transform: translateX(100%);
        opacity: 0;
    }
    to {
        transform: translateX(0);
        opacity: 1;
    }
}

footer {
    text-align: center;
    padding: 2rem;
    color: var(--secondary-color);
}

/* Responsive */
@media (max-width: 768px) {
    .container {
        padding: 1rem;
    }

    header h1 {
        font-size: 2rem;
    }

    main {
        padding: 1.5rem;
    }

    .form-row {
        grid-template-columns: 1fr;
    }

    .actions {
        flex-direction: column;
    }

    .btn {
        width: 100%;
    }

    .modal-content {
        width: 95%;
        margin: 10% auto;
        padding: 1.5rem;
    }

    .status-message {
        right: 1rem;
        left: 1rem;
    }
}