/* SimpleML design system — one accent gradient, neutral everything else */

:root {
    --brand-a: #667eea;
    --brand-b: #764ba2;
    --brand-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --ink: #1f2333;
    --ink-soft: #6b7085;
    --surface: #ffffff;
    --page-bg: #f6f7fb;
    --line: #e7e8f0;
    --radius: 14px;
}

body {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    background: var(--page-bg);
    color: var(--ink);
    font-family: "Segoe UI", system-ui, -apple-system, sans-serif;
}

footer {
    margin-top: auto;
}

/* Focused content width — simple apps read better narrow */
.app-container {
    flex: 1;
    width: 100%;
    max-width: 1000px;
    margin: 0 auto;
    padding: 2rem 1rem 4rem;
}

/* ---------- Navbar ---------- */
.navbar-simple {
    background: var(--surface);
    border-bottom: 1px solid var(--line);
}

.navbar-simple .navbar-brand {
    font-weight: 800;
    font-size: 1.25rem;
    background: var(--brand-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.navbar-simple .nav-link {
    color: var(--ink-soft);
    font-weight: 500;
}

.navbar-simple .nav-link:hover,
.navbar-simple .nav-link.active {
    color: var(--ink);
}

.navbar-simple .nav-link.active {
    font-weight: 700;
    color: var(--brand-a);
}

/* ---------- Cards ---------- */
.card {
    border: 1px solid var(--line);
    border-radius: var(--radius);
    box-shadow: 0 1px 3px rgba(31, 35, 51, 0.05);
}

.card-header {
    background: transparent;
    border-bottom: 1px solid var(--line);
    font-weight: 600;
}

/* ---------- Buttons ---------- */
.btn {
    border-radius: 10px;
    font-weight: 600;
}

.btn-primary {
    background: var(--brand-gradient);
    border: none;
    color: #fff;
}

.btn-primary:hover,
.btn-primary:focus {
    background: var(--brand-gradient);
    filter: brightness(1.08);
    color: #fff;
}

/* ---------- Hero blocks ---------- */
.hero {
    background: var(--brand-gradient);
    color: #fff;
    border-radius: var(--radius);
    padding: 2.5rem 2rem;
}

.hero p {
    color: rgba(255, 255, 255, 0.85);
}

.hero-score {
    font-size: clamp(3.5rem, 10vw, 6rem);
    font-weight: 800;
    line-height: 1;
}

/* ---------- Step indicator (Upload → Train → Predict) ---------- */
.steps {
    display: flex;
    gap: 0.5rem;
    margin: 1.5rem 0 2rem;
}

.steps .step {
    flex: 1;
    text-align: center;
    padding: 0.6rem 0.5rem;
    border-radius: 10px;
    background: var(--surface);
    border: 1px solid var(--line);
    color: var(--ink-soft);
    font-weight: 600;
    font-size: 0.9rem;
}

.steps .step.active {
    background: var(--brand-gradient);
    border-color: transparent;
    color: #fff;
}

.steps .step.done {
    border-color: var(--brand-a);
    color: var(--brand-a);
}

/* ---------- Misc ---------- */
.stat-inline {
    color: var(--ink-soft);
    font-weight: 500;
}

.stat-inline strong {
    color: var(--ink);
    font-weight: 800;
}

.list-row {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: space-between;
    gap: 0.75rem 1rem;
    padding: 1rem 1.25rem;
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: var(--radius);
}

.badge-soft {
    background: rgba(102, 126, 234, 0.12);
    color: var(--brand-a);
    font-weight: 600;
    border-radius: 999px;
    padding: 0.35em 0.8em;
}

.text-brand {
    color: var(--brand-a);
}

/* Loading state on submit buttons */
.btn-loading {
    pointer-events: none;
    opacity: 0.8;
}

/* Collapsed advanced sections */
details.advanced summary {
    cursor: pointer;
    font-weight: 600;
    color: var(--ink-soft);
    padding: 0.75rem 0;
    list-style: none;
}

details.advanced summary::-webkit-details-marker {
    display: none;
}

details.advanced summary::before {
    content: "▸ ";
}

details.advanced[open] summary::before {
    content: "▾ ";
}