:root {
    --bg-main: #f8fafc;
    --bg-card: #ffffff;
    --text-main: #0f172a;
    --text-muted: #64748b;
    --border-light: #e2e8f0;
    --accent-blue: #2563eb;
    --accent-hover: #1d4ed8;
    --danger: #e11d48;
    --shadow-soft: 0 14px 32px rgba(15, 23, 42, 0.08);
    --shadow-card: 0 1px 3px rgba(0, 0, 0, 0.05);
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    padding: 0;
    font-family: 'Inter', system-ui, -apple-system, sans-serif;
    background-color: var(--bg-main);
    color: var(--text-main);
}

.app-header {
    background-color: var(--text-main);
    color: #ffffff;
    padding: 1rem 2rem;
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    margin-bottom: 2rem;
}

.app-header h1 {
    margin: 0;
    font-size: 1.5rem;
    font-weight: 700;
    letter-spacing: -0.025em;
}

.app-header p {
    margin: 0.25rem 0 0 0;
    color: #94a3b8;
    font-size: 0.875rem;
}

.main-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 2rem 3rem;
}

.panel-shell {
    display: grid;
    grid-template-columns: minmax(0, 1fr) 320px;
    gap: 1.5rem;
    align-items: start;
    margin-bottom: 2rem;
}

.panel-main,
.panel-sidebar,
.dashboard-panel {
    background: var(--bg-card);
    border: 1px solid var(--border-light);
    border-radius: 12px;
    box-shadow: var(--shadow-soft);
}

.panel-main,
.panel-sidebar,
.dashboard-panel {
    padding: 1.5rem;
}

.section-heading h2 {
    margin: 0 0 0.35rem;
    font-size: 1.25rem;
    letter-spacing: -0.02em;
}

.section-heading p {
    margin: 0 0 1.25rem;
    color: var(--text-muted);
    line-height: 1.5;
}

#dataset-cards-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
    margin-bottom: 1.5rem;
}

.dataset-card {
    background: var(--bg-card);
    border: 1px solid var(--border-light);
    border-radius: 8px;
    padding: 1.25rem;
    box-shadow: var(--shadow-card);
    display: flex;
    flex-direction: column;
    min-height: 100%;
}

.card-title-input {
    border: none;
    border-bottom: 2px solid var(--border-light);
    padding: 0.5rem 0;
    margin-bottom: 1rem;
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--text-main);
    outline: none;
    transition: border-color 0.2s;
    background: transparent;
}

.card-title-input:focus {
    border-bottom-color: var(--accent-blue);
}

.card-genes-input,
.config-field input,
.config-field textarea {
    width: 100%;
    border: 1px solid var(--border-light);
    border-radius: 6px;
    padding: 0.75rem;
    font-size: 0.875rem;
    box-sizing: border-box;
    background: #fff;
    color: var(--text-main);
}

.card-genes-input {
    font-family: 'Fira Code', monospace;
    resize: vertical;
    min-height: 320px;
}

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

.config-panel {
    border: 1px solid var(--border-light);
    border-radius: 10px;
    background: linear-gradient(180deg, #ffffff 0%, #f8fafc 100%);
    padding: 1.25rem;
}

.config-panel h3 {
    margin: 0 0 1rem;
    font-size: 1rem;
}

.config-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 1rem;
}

.config-field {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.config-field label {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-main);
}

.config-field-wide {
    grid-column: 1 / -1;
}

.range-inputs {
    display: grid;
    grid-template-columns: 1fr auto 1fr;
    gap: 0.75rem;
    align-items: center;
}

.range-inputs span {
    color: var(--text-muted);
    font-size: 0.875rem;
}

.panel-sidebar {
    position: sticky;
    top: 1.5rem;
}

.btn-primary {
    background-color: var(--accent-blue);
    color: white;
    border: none;
    padding: 0.75rem 2rem;
    border-radius: 6px;
    font-weight: 600;
    cursor: pointer;
    transition: background-color 0.2s;
    font-size: 1rem;
    display: block;
    width: 100%;
    max-width: 300px;
    margin: 0 auto;
}

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

.status-message {
    margin-top: 1rem;
    border-radius: 8px;
    padding: 0.85rem 1rem;
    font-size: 0.925rem;
}

.loading-message {
    background: rgba(37, 99, 235, 0.08);
    color: var(--accent-blue);
}

.error-message {
    background: rgba(225, 29, 72, 0.08);
    color: var(--danger);
    font-weight: 600;
}

#dashboard-container {
    margin-top: 2rem;
}

.tab-nav {
    display: flex;
    gap: 0.5rem;
    border-bottom: 2px solid var(--border-light);
    margin-bottom: 2rem;
    padding-bottom: 0;
    flex-wrap: wrap;
}

.tab-button {
    background: transparent;
    border: none;
    padding: 0.75rem 1.5rem;
    font-weight: 600;
    color: var(--text-muted);
    cursor: pointer;
    border-bottom: 3px solid transparent;
    margin-bottom: -2px;
    transition: all 0.2s;
}

.tab-button:hover {
    color: var(--text-main);
}

.tab-button.active {
    color: var(--accent-blue);
    border-bottom-color: var(--accent-blue);
}

.tab-content h3 {
    margin-top: 0;
}

.viz-container {
    width: 100%;
    min-height: 500px;
    border: 1px solid var(--border-light);
    border-radius: 10px;
    background: linear-gradient(180deg, #ffffff 0%, #f8fafc 100%);
    padding: 0.5rem;
}

.viz-container-tall {
    min-height: 600px;
}

.insight-panel {
    margin-top: 1rem;
    border: 1px solid var(--border-light);
    border-radius: 10px;
    padding: 1rem;
    background: #f8fafc;
}

@media (max-width: 1100px) {
    .panel-shell {
        grid-template-columns: 1fr;
    }

    .panel-sidebar {
        position: static;
    }
}

@media (max-width: 800px) {
    .main-container {
        padding: 0 1rem 2rem;
    }

    #dataset-cards-container,
    .config-grid {
        grid-template-columns: 1fr;
    }

    .app-header {
        padding: 1rem;
    }
}