:root {
    --ink: #1f2328;
    --muted: #57606a;
    --line: #d0d7de;
    --line-soft: #eaeef2;
    --bg: #ffffff;
    --bg-soft: #f6f8fa;
    --accent: #0b5394;
    --accent-soft: #e7f0fa;
    --radius: 6px;
    --maxw: 880px;
}

* { box-sizing: border-box; }

html, body { margin: 0; padding: 0; }

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    line-height: 1.55;
    color: var(--ink);
    background: var(--bg);
    -webkit-font-smoothing: antialiased;
}

header {
    max-width: var(--maxw);
    margin: 0 auto;
    padding: 3rem 1.25rem 1.5rem;
    border-bottom: 1px solid var(--line-soft);
}

header h1 {
    margin: 0 0 0.25rem;
    font-size: 1.75rem;
    letter-spacing: -0.01em;
}

.subtitle {
    margin: 0 0 0.5rem;
    font-size: 1rem;
    color: var(--muted);
}

.hint {
    margin: 0;
    font-size: 0.9rem;
    color: var(--muted);
}

main {
    max-width: var(--maxw);
    margin: 0 auto;
    padding: 2rem 1.25rem 3rem;
}

/* Flow diagram */
.flow {
    display: flex;
    align-items: stretch;
    gap: 0.5rem;
    margin-bottom: 2.5rem;
}

.flow-step {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    gap: 0.5rem;
    padding: 1rem 0.5rem;
    border: 1px solid var(--line-soft);
    border-radius: var(--radius);
    background: var(--bg-soft);
}

.flow-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 38px;
    height: 38px;
    border-radius: 50%;
    background: var(--bg);
    border: 1px solid var(--line);
    color: var(--accent);
}

.flow-icon svg { width: 20px; height: 20px; }

.flow-step p {
    margin: 0;
    font-size: 0.82rem;
    color: var(--ink);
}

.flow-num {
    display: inline-block;
    font-weight: 700;
    color: var(--accent);
    margin-right: 0.15rem;
}

.flow-arrow {
    display: flex;
    align-items: center;
    color: var(--line);
}

.flow-arrow svg { width: 22px; height: 22px; }

/* Steps */
.step-section {
    margin-bottom: 2.5rem;
}

.step-section h2,
.faq h2 {
    font-size: 1.05rem;
    font-weight: 600;
    margin: 0 0 1rem;
    color: var(--ink);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.step-tag {
    display: inline-block;
    font-size: 0.7rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--accent);
    background: var(--accent-soft);
    padding: 0.15rem 0.5rem;
    border-radius: 999px;
}

.cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 0.75rem;
}

.card {
    display: block;
    width: 100%;
    text-align: left;
    background: var(--bg);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: 1rem 1.1rem;
    font: inherit;
    color: inherit;
    cursor: pointer;
    transition: border-color 0.15s ease, background-color 0.15s ease;
}

.card:hover {
    border-color: var(--accent);
    background: var(--bg-soft);
}

.card:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 2px;
}

.card.selected {
    border-color: var(--accent);
    background: var(--accent-soft);
    box-shadow: inset 0 0 0 1px var(--accent);
}

.card-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 32px;
    height: 32px;
    border-radius: var(--radius);
    background: var(--accent-soft);
    color: var(--accent);
    margin-bottom: 0.5rem;
}

.card-icon svg { width: 18px; height: 18px; }

.card h3 {
    margin: 0 0 0.25rem;
    font-size: 1rem;
    font-weight: 600;
}

.card p {
    margin: 0;
    font-size: 0.85rem;
    color: var(--muted);
}

.card .tag {
    display: inline-block;
    margin-top: 0.5rem;
    font-size: 0.7rem;
    color: var(--muted);
    border: 1px solid var(--line);
    border-radius: 999px;
    padding: 0.1rem 0.45rem;
    background: var(--bg-soft);
}

.card-note {
    margin-top: 0.6rem !important;
    font-size: 0.78rem;
    line-height: 1.45;
    color: #7a4f01;
    background: #fff8e1;
    border: 1px solid #f0e0b6;
    border-radius: 4px;
    padding: 0.5rem 0.6rem;
}

.hidden {
    display: none !important;
}

/* Download panel */
.download-panel {
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: 1.5rem;
    background: var(--bg-soft);
}

.download-summary {
    display: flex;
    flex-wrap: wrap;
    gap: 1.5rem;
    margin-bottom: 1.25rem;
    font-size: 0.95rem;
}

.download-summary > div {
    display: flex;
    flex-direction: column;
}

.download-summary .label {
    font-size: 0.7rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--muted);
    margin-bottom: 0.1rem;
}

.button {
    display: inline-block;
    background: var(--accent);
    color: #fff;
    padding: 0.65rem 1.25rem;
    border-radius: var(--radius);
    text-decoration: none;
    font-weight: 600;
    font-size: 0.95rem;
}

.button:hover {
    background: #094075;
}

.prompt-block {
    margin-top: 1.5rem;
    padding-top: 1.25rem;
    border-top: 1px solid var(--line-soft);
}

.prompt-block h4 {
    margin: 0 0 0.5rem;
    font-size: 0.85rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--muted);
}

.prompt-block blockquote {
    margin: 0 0 0.6rem;
    padding: 0.75rem 0.9rem;
    background: var(--bg);
    border: 1px solid var(--line-soft);
    border-left: 3px solid var(--accent);
    border-radius: 4px;
    font-size: 0.9rem;
    color: var(--ink);
}

.copy-btn {
    font: inherit;
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--accent);
    background: var(--bg);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: 0.35rem 0.75rem;
    cursor: pointer;
}

.copy-btn:hover {
    border-color: var(--accent);
}

.copy-btn:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 2px;
}

.download-details {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
    margin-top: 1.5rem;
    padding-top: 1.25rem;
    border-top: 1px solid var(--line-soft);
}

.detail-block h4 {
    margin: 0 0 0.5rem;
    font-size: 0.85rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--muted);
}

.detail-block ul,
.detail-block ol {
    margin: 0;
    padding-left: 1.2rem;
    font-size: 0.9rem;
}

.detail-block li {
    margin-bottom: 0.3rem;
}

code {
    background: var(--bg);
    border: 1px solid var(--line-soft);
    padding: 0.05rem 0.3rem;
    border-radius: 3px;
    font-size: 0.85em;
}

.reset-line {
    margin: 1.5rem 0 0;
    text-align: right;
    font-size: 0.85rem;
}

.reset-line a {
    color: var(--muted);
}

#error-banner {
    border: 1px solid #f0c674;
    background: #fff8e1;
    color: #7a4f01;
    border-radius: var(--radius);
    padding: 1rem;
    font-size: 0.9rem;
}

/* FAQ */
.faq {
    margin-top: 3rem;
    padding-top: 2rem;
    border-top: 1px solid var(--line-soft);
}

.faq details {
    border: 1px solid var(--line-soft);
    border-radius: var(--radius);
    margin-bottom: 0.5rem;
    background: var(--bg-soft);
}

.faq summary {
    cursor: pointer;
    padding: 0.75rem 1rem;
    font-size: 0.92rem;
    font-weight: 600;
    list-style: none;
}

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

.faq summary::before {
    content: "+";
    display: inline-block;
    width: 1rem;
    color: var(--accent);
    font-weight: 700;
}

.faq details[open] summary::before { content: "\2212"; }

.faq summary:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 2px;
}

.faq details p {
    margin: 0;
    padding: 0 1rem 0.9rem 2rem;
    font-size: 0.9rem;
    color: var(--muted);
}

footer {
    border-top: 1px solid var(--line-soft);
    max-width: var(--maxw);
    margin: 0 auto;
    padding: 1.5rem 1.25rem 2.5rem;
    color: var(--muted);
    font-size: 0.8rem;
}

footer p {
    margin: 0 0 0.35rem;
}

footer .footer-links {
    margin-top: 0.5rem;
}

footer a {
    color: var(--accent);
    text-decoration: none;
}

footer a:hover {
    text-decoration: underline;
}

@media (max-width: 680px) {
    header { padding: 2rem 1rem 1rem; }
    main { padding: 1.5rem 1rem 2rem; }
    .flow { flex-direction: column; }
    .flow-step { flex-direction: row; justify-content: flex-start; text-align: left; }
    .flow-arrow { justify-content: center; transform: rotate(90deg); }
    .download-details { grid-template-columns: 1fr; }
    .download-summary { gap: 1rem; }
}