*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
body { font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif; background: #0f0f1a; color: #e0e0e0; line-height: 1.6; min-height: 100vh; }

header { background: #16162a; border-bottom: 2px solid rgba(200, 255, 0, 0.2); padding: 1.5rem 1.25rem; }
.header-inner { max-width: 780px; margin: 0 auto; display: flex; align-items: center; gap: 1rem; }
.header-icon { flex-shrink: 0; }
.header-text h1 { font-size: 1.6rem; font-weight: 700; color: #fff; letter-spacing: -0.02em; }
.header-text p { font-size: 0.85rem; color: #888; margin-top: 0.15rem; }

main { max-width: 780px; margin: 0 auto; padding: 2rem 1.25rem 3rem; }

.intro { margin-bottom: 2rem; }
.intro h2 { color: #fff; font-size: 1.15rem; margin-bottom: 0.5rem; }
.intro p { color: #aaa; font-size: 0.95rem; }

.section-label { color: #c8ff00; font-size: 0.75rem; font-weight: 600; text-transform: uppercase; letter-spacing: 0.1em; margin-bottom: 0.75rem; }
.section-label--ssl { color: #a855f7; }

.cards { display: grid; grid-template-columns: repeat(auto-fill, minmax(220px, 1fr)); gap: 1rem; margin-bottom: 2rem; }
.cards--flush { margin-bottom: 0; }

.card { background: #1a1a2e; border: 1px solid rgba(200, 255, 0, 0.12); border-radius: 12px; padding: 1.5rem; display: flex; flex-direction: column; gap: 0.75rem; }
.card-icon { width: 40px; height: 40px; background: rgba(200, 255, 0, 0.1); border-radius: 10px; display: flex; align-items: center; justify-content: center; }
.card h3 { color: #fff; font-size: 1.05rem; font-weight: 600; }
.card .subtitle { color: #c8ff00; font-size: 0.7rem; font-weight: 600; text-transform: uppercase; letter-spacing: 0.08em; }
.card p { color: #999; font-size: 0.85rem; flex-grow: 1; }

.card--ssl { border-color: rgba(168, 85, 247, 0.25); }
.card--ssl .card-icon { background: rgba(168, 85, 247, 0.1); }
.subtitle--ssl { color: #a855f7; }

.btn-download { display: inline-flex; align-items: center; gap: 0.5rem; background: #c8ff00; color: #0f0f1a; text-decoration: none; font-weight: 600; font-size: 0.875rem; padding: 0.65rem 1.1rem; border-radius: 8px; transition: background 0.2s, transform 0.1s; align-self: flex-start; }
.btn-download:hover { opacity: 0.9; }
.btn-download:active { transform: scale(0.97); }
.btn-download--ssl { background: #a855f7; color: #fff; }

.top-grid { display: flex; gap: 1rem; flex-wrap: wrap; align-items: stretch; margin-bottom: 1.5rem; }
.top-grid__col { flex: 1; min-width: 220px; }

.guide { margin-bottom: 2rem; }
.guide h2 { color: #fff; font-size: 1.15rem; margin-bottom: 1rem; }
.guide input[type="radio"] { position: absolute; opacity: 0; pointer-events: none; }
.guide > label { display: inline-block; padding: 0.5rem 1rem; border-radius: 8px; background: #1a1a2e; border: 1px solid rgba(200, 255, 0, 0.12); color: #888; font-size: 0.85rem; font-weight: 600; cursor: pointer; transition: all 0.2s; margin: 0 0.25rem 0.75rem 0; }
.guide input[type="radio"]:checked + label { background: rgba(200, 255, 0, 0.12); color: #c8ff00; border-color: rgba(200, 255, 0, 0.3); }

.tab-content { display: none; }
.guide > #tab-ios:checked ~ .tab-content-ios,
.guide > #tab-android:checked ~ .tab-content-android,
.guide > #tab-macos:checked ~ .tab-content-macos,
.guide > #tab-win:checked ~ .tab-content-win,
.guide > #tab-deb:checked ~ .tab-content-deb,
.guide > #tab-rhel:checked ~ .tab-content-rhel { display: block; }

.code-wrap { position: relative; margin: 0.75rem 0; }
.code-wrap pre { background: #12121f; border: 1px solid rgba(200, 255, 0, 0.08); border-radius: 8px; padding: 1rem; padding-right: 3rem; font-family: 'SF Mono', 'Fira Code', 'Cascadia Code', monospace; font-size: 0.8rem; color: #c8ff00; overflow-x: auto; line-height: 1.7; margin: 0; white-space: pre-wrap; word-break: break-all; }
.code-wrap .copy-btn { position: absolute; top: 0.5rem; right: 0.5rem; background: rgba(200, 255, 0, 0.1); border: 1px solid rgba(200, 255, 0, 0.2); border-radius: 6px; color: #c8ff00; cursor: pointer; padding: 0.35rem; display: flex; align-items: center; justify-content: center; transition: background 0.2s; }
.code-wrap .copy-btn:hover { background: rgba(200, 255, 0, 0.2); }

.steps { list-style: none; counter-reset: steps; display: flex; flex-direction: column; gap: 1rem; }
.step { counter-increment: steps; background: #1a1a2e; border: 1px solid rgba(200, 255, 0, 0.08); border-radius: 12px; padding: 1.25rem; padding-left: 4rem; position: relative; }
.step::before { content: counter(steps); position: absolute; left: 1.25rem; top: 1.25rem; width: 2rem; height: 2rem; background: rgba(200, 255, 0, 0.12); color: #c8ff00; border-radius: 50%; display: flex; align-items: center; justify-content: center; font-weight: 700; font-size: 0.9rem; }
.step h3 { color: #fff; font-size: 0.95rem; font-weight: 600; margin-bottom: 0.4rem; }
.step p { color: #aaa; font-size: 0.875rem; }
.step p strong, .hint p strong { color: #fff; }

.path { display: inline; background: rgba(200, 255, 0, 0.08); color: #c8ff00; padding: 0.15rem 0.5rem; border-radius: 4px; font-size: 0.75rem; font-weight: 500; word-break: break-word; }

.hint { background: rgba(200, 255, 0, 0.06); border-left: 3px solid #c8ff00; border-radius: 0 8px 8px 0; padding: 1rem 1.25rem; margin-top: 1.25rem; }
.hint > strong { color: #c8ff00; display: block; margin-bottom: 0.25rem; font-size: 0.85rem; }
.hint p { color: #aaa; font-size: 0.85rem; }
.hint__intro { color: #aaa; font-size: 0.85rem; margin-bottom: 0.75rem; }

.p-mt-sm { margin-top: 0.5rem; }

footer { max-width: 780px; margin: 0 auto; padding: 1.5rem 1.25rem; border-top: 1px solid rgba(255, 255, 255, 0.06); text-align: center; color: #555; font-size: 0.8rem; }
footer a { color: #888; text-decoration: none; }
footer a:hover { color: #c8ff00; }

@media (max-width: 480px) {
    .step { padding-left: 3.5rem; }
    .step::before { left: 1rem; top: 1.25rem; }
    .step h3 { font-size: 0.9rem; }
    .step p { font-size: 0.8rem; }
    .cards { grid-template-columns: 1fr; }
}

/* Empty-Placeholder */
body.placeholder { display: flex; flex-direction: column; align-items: center; justify-content: center; text-align: center; padding: 2rem; }
.placeholder__icon { margin-bottom: 1.5rem; }
body.placeholder h1 { color: #fff; font-size: 1.4rem; margin-bottom: 0.5rem; }
body.placeholder p { color: #888; font-size: 0.95rem; max-width: 400px; }