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

:root {
    --primary: #2563eb;
    --primary-hover: #1d4ed8;
    --success: #10b981;
    --error: #ef4444;
    --background: #f8fafc;
    --card-bg: #ffffff;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --border: #e2e8f0;
}

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

.container {
    max-width: 900px;
    margin: 0 auto;
    padding: 2rem 1rem;
}

header {
    text-align: center;
    margin-bottom: 2rem;
}

header h1 {
    font-size: 2rem;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.subtitle {
    color: var(--text-secondary);
    font-size: 1rem;
}

.card {
    background: var(--card-bg);
    border-radius: 8px;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1), 0 1px 2px rgba(0, 0, 0, 0.06);
    padding: 1.5rem;
    margin-bottom: 1.5rem;
}

.input-card form {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.input-card label {
    font-weight: 600;
    color: var(--text-primary);
}

.input-card textarea {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid var(--border);
    border-radius: 8px;
    font-family: 'Monaco', 'Menlo', 'Ubuntu Mono', monospace;
    font-size: 1rem;
    resize: vertical;
    transition: border-color 0.2s, box-shadow 0.2s;
}

.input-card textarea:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.char-count {
    font-size: 0.875rem;
    color: var(--text-secondary);
    text-align: right;
}

.char-count.warning {
    color: var(--error);
}

button[type="submit"] {
    background-color: var(--primary);
    color: white;
    border: none;
    padding: 0.75rem 1.5rem;
    font-size: 1rem;
    font-weight: 600;
    border-radius: 8px;
    cursor: pointer;
    transition: background-color 0.2s, transform 0.1s;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
}

button[type="submit"]:hover {
    background-color: var(--primary-hover);
}

button[type="submit"]:active {
    transform: scale(0.98);
}

.checkbox-option {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 0.5rem;
    margin-top: 0.75rem;
    font-size: 0.875rem;
    color: var(--text-primary);
    cursor: pointer;
}

.checkbox-option input[type="checkbox"] {
    width: 16px;
    height: 16px;
    cursor: pointer;
}

.checkbox-hint {
    color: var(--text-secondary);
    font-size: 0.8rem;
    width: 100%;
    margin-left: 1.5rem;
}

button[type="submit"]:disabled {
    opacity: 0.7;
    cursor: not-allowed;
}

.spinner {
    width: 18px;
    height: 18px;
    border: 2px solid rgba(255, 255, 255, 0.3);
    border-top-color: white;
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

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

.examples {
    margin-top: 1.5rem;
    padding-top: 1.5rem;
    border-top: 1px solid var(--border);
}

.examples p {
    color: var(--text-secondary);
    font-size: 0.875rem;
    margin-bottom: 0.75rem;
}

.example-buttons {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.example-btn {
    background-color: var(--background);
    color: var(--text-primary);
    border: 1px solid var(--border);
    padding: 0.5rem 1rem;
    font-size: 0.875rem;
    border-radius: 6px;
    cursor: pointer;
    transition: background-color 0.2s, border-color 0.2s;
}

.example-btn:hover {
    background-color: var(--border);
    border-color: var(--text-secondary);
}

.error-card {
    background-color: #fef2f2;
    border: 1px solid #fecaca;
    color: var(--error);
    padding: 1rem 1.5rem;
    border-radius: 8px;
    margin-bottom: 1.5rem;
}

.results-card {
    animation: fadeIn 0.3s ease-out;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.structure-container {
    display: flex;
    justify-content: center;
    margin-bottom: 1.5rem;
    padding: 1rem;
    background: var(--background);
    border-radius: 8px;
}

#svg-container svg {
    max-width: 100%;
    height: auto;
}

.name-section {
    margin-bottom: 1.5rem;
    padding: 1rem;
    background: #f1f5f9;
    border-radius: 8px;
}

.name-label {
    font-size: 0.75rem;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 0.5rem;
}

.name-value {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
}

.name-value.unknown,
.name-value.not-requested {
    font-style: italic;
    color: var(--text-secondary);
    font-weight: 400;
}

.name-iupac {
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-top: 0.25rem;
}

.properties-section {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
    margin-bottom: 1.5rem;
}

.property-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.5rem 0;
    border-bottom: 1px solid var(--border);
}

.property-row:last-child {
    border-bottom: none;
}

.property-label {
    font-weight: 500;
    color: var(--text-secondary);
}

.property-value {
    font-weight: 600;
    color: var(--text-primary);
}

.property-value.formula {
    font-size: 1.125rem;
}

.smiles-row {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.5rem;
}

.smiles-container {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    width: 100%;
    background: var(--background);
    padding: 0.75rem;
    border-radius: 6px;
}

.property-value.smiles {
    font-family: 'Monaco', 'Menlo', 'Ubuntu Mono', monospace;
    font-size: 0.875rem;
    word-break: break-all;
    flex: 1;
}

.copy-btn {
    background: none;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 0.25rem;
    border-radius: 4px;
    transition: color 0.2s, background-color 0.2s;
    flex-shrink: 0;
}

.copy-btn:hover {
    color: var(--primary);
    background-color: rgba(37, 99, 235, 0.1);
}

.properties-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.property-box {
    background: var(--background);
    padding: 1rem;
    border-radius: 8px;
    text-align: center;
}

.property-box-label {
    display: block;
    font-size: 0.75rem;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 0.25rem;
}

.property-box-value {
    display: block;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
}

.lipinski-section {
    border-top: 1px solid var(--border);
    padding-top: 1.5rem;
}

.lipinski-section h3 {
    font-size: 1rem;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.lipinski-explanation {
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-bottom: 0.75rem;
    line-height: 1.5;
}

.lipinski-result {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1rem;
    border-radius: 8px;
}

.lipinski-result.pass {
    background-color: #ecfdf5;
    color: var(--success);
}

.lipinski-result.fail {
    background-color: #fef2f2;
    color: var(--error);
}

.lipinski-result .icon {
    font-size: 1.25rem;
}

.lipinski-result .violations {
    font-size: 0.875rem;
    margin-top: 0.25rem;
}

.toast {
    position: fixed;
    bottom: 2rem;
    left: 50%;
    transform: translateX(-50%);
    background-color: var(--text-primary);
    color: white;
    padding: 0.75rem 1.5rem;
    border-radius: 8px;
    font-size: 0.875rem;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    transition: opacity 0.3s, transform 0.3s;
}

.toast.hidden {
    opacity: 0;
    transform: translateX(-50%) translateY(10px);
    pointer-events: none;
}

.hidden {
    display: none !important;
}

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

    header h1 {
        font-size: 1.5rem;
    }

    .properties-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .example-buttons {
        flex-direction: column;
    }

    .example-btn {
        width: 100%;
    }
}