.arc-wrap { max-width: 980px; margin: 0 auto; padding: 20px 20px 70px; }
.arc-hero { text-align: center; padding: 14px 0 6px; }
.arc-hero .kicker { color: var(--g-2); text-transform: uppercase; letter-spacing: 1.2px; font-size: 12px; font-weight: 700; }
.arc-hero h1 { font-size: clamp(27px, 4.2vw, 44px); line-height: 1.07; letter-spacing: -1.2px; margin: 10px 0 10px; font-weight: 600; }
.arc-tagline { color: var(--muted); font-size: 15px; max-width: 620px; margin: 0 auto; line-height: 1.5; }

.arc-label { font-size: 12px; text-transform: uppercase; letter-spacing: .5px; color: var(--g-2); font-weight: 700; display: block; margin-bottom: 7px; }

/* quick presets */
.arc-quick-wrap { margin: 22px 0 8px; }
.arc-quick-row { display: flex; flex-wrap: wrap; gap: 8px; }
.arc-quick { padding: 8px 14px; border: 1px solid var(--line); border-radius: 99px; background: var(--surface); color: inherit; cursor: pointer; font: inherit; font-size: 13px; font-weight: 700; }
.arc-quick:hover { border-color: var(--accent); color: var(--ink); transform: translateY(-1px); }

/* layout */
.arc-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; margin-top: 14px; }
.arc-grid-out { grid-template-columns: 1.1fr .9fr; align-items: start; }
@media (max-width: 720px) { .arc-grid, .arc-grid-out { grid-template-columns: 1fr; } }

.arc-card { border: 1px solid var(--line); border-radius: 16px; background: var(--surface); padding: 16px 18px; }
.arc-card-h { font-size: 13px; text-transform: uppercase; letter-spacing: .6px; color: var(--g-2); font-weight: 800; margin: 0 0 14px; }

.arc-field { display: block; margin-bottom: 12px; }
.arc-field select, .arc-wh input { font: inherit; font-size: 14px; padding: 9px 11px; border-radius: 10px; border: 1px solid var(--line); background: var(--surface-2); color: inherit; width: 100%; }
.arc-wh { display: flex; align-items: flex-end; gap: 10px; margin-bottom: 12px; }
.arc-wh label { flex: 1; }
.arc-wh input { text-align: center; font-family: "DM Mono", monospace; }
.arc-x { font-size: 18px; color: var(--g-2); padding-bottom: 8px; font-weight: 700; }

.arc-derived { font-size: 13.5px; color: var(--muted); margin: 4px 0 0; }
.arc-derived b { color: var(--ink); font-family: "DM Mono", monospace; }
.arc-square-note { font-size: 12px; color: var(--g-2); margin: 8px 0 0; line-height: 1.4; }
.arc-disp { font-size: 12.5px; color: var(--muted); margin: 8px 0 0; line-height: 1.45; }
.arc-disp b { color: var(--ink); font-family: "DM Mono", monospace; }
.arc-dim-note { color: var(--g-2); }

.arc-adv-toggle { margin-top: 12px; background: none; border: 0; color: var(--accent); cursor: pointer; font: inherit; font-size: 13px; font-weight: 700; padding: 0; }
.arc-adv-toggle::before { content: "▸ "; }
.arc-adv-toggle[aria-expanded="true"]::before { content: "▾ "; }
.arc-adv { margin-top: 12px; padding-top: 12px; border-top: 1px solid var(--line); }

/* segmented controls */
.arc-seg { display: inline-flex; gap: 3px; padding: 3px; border: 1px solid var(--line); border-radius: 11px; background: var(--surface-2); margin-bottom: 14px; }
.arc-seg.arc-fit { margin-top: 4px; }
.arc-seg-opt { position: relative; }
.arc-seg-opt input { position: absolute; opacity: 0; pointer-events: none; }
.arc-seg-opt span { display: block; padding: 7px 16px; border-radius: 8px; font-size: 13px; font-weight: 700; color: var(--g-2); cursor: pointer; }
.arc-seg-opt input:checked + span { background: var(--solid); color: #fff; }

/* results */
.arc-results .arc-row { display: flex; align-items: flex-start; gap: 10px; padding: 10px 0; border-bottom: 1px solid var(--line); }
.arc-results .arc-row:last-of-type { border-bottom: 0; }
.arc-row-l { flex: none; width: 36%; font-size: 12px; text-transform: uppercase; letter-spacing: .4px; color: var(--g-2); font-weight: 700; padding-top: 2px; }
.arc-row-v { flex: 1; font-size: 13.5px; line-height: 1.5; }
.arc-row-v b { font-family: "DM Mono", monospace; font-weight: 600; }
.arc-sub { color: var(--g-2); font-size: 12.5px; }
.arc-ok { color: #2faa6f; font-weight: 700; }
.arc-warn { color: #d8902a; font-weight: 600; font-family: "DM Mono", monospace; font-size: 12.5px; }
.arc-copy { flex: none; background: var(--surface-2); border: 1px solid var(--line); border-radius: 7px; width: 28px; height: 28px; cursor: pointer; color: var(--g-2); font-size: 13px; }
.arc-copy:hover { border-color: var(--accent); color: var(--ink); }

.arc-btn { display: inline-flex; align-items: center; gap: 7px; padding: 10px 18px; border-radius: 11px; border: 1px solid var(--line); background: var(--surface-2); cursor: pointer; font: inherit; font-size: 14px; font-weight: 700; color: inherit; }
.arc-btn:hover { border-color: var(--line-2); transform: translateY(-1px); }
.arc-btn.primary { background: var(--solid); color: #fff; border-color: var(--solid); margin-top: 14px; }
.arc-btn.ghost { background: transparent; }

/* preview */
.arc-svg { display: grid; place-items: center; min-height: 200px; padding: 6px; }
.arc-legend { display: flex; flex-wrap: wrap; gap: 14px; justify-content: center; margin-top: 12px; font-size: 12px; color: var(--g-2); }
.arc-legend span { display: inline-flex; align-items: center; gap: 6px; }
.arc-legend i { width: 14px; height: 14px; border-radius: 3px; display: inline-block; }
.lg-source { background: var(--surface-2); border: 1.5px solid #8B95A3; }
.lg-kept { border: 2px solid #FF4A3F; }
.lg-crop { background: repeating-linear-gradient(45deg, transparent, transparent 2px, rgba(255,74,63,.6) 2px, rgba(255,74,63,.6) 4px); }
.lg-bars { background: #14171C; opacity: .55; border: 1px solid var(--line); }

/* image preview */
.arc-img { margin-top: 14px; }
.arc-img-actions { display: flex; gap: 10px; flex-wrap: wrap; }
.arc-img-note { font-size: 12.5px; color: var(--g-2); margin: 10px 0 0; }
.arc-canvas { display: block; margin: 14px auto 0; border-radius: 10px; cursor: grab; touch-action: none; max-width: 100%; }
.arc-canvas:active { cursor: grabbing; }

/* content */
.arc-content { margin-top: 40px; border-top: 1px solid var(--line); padding-top: 24px; }
.arc-content h2 { font-size: 20px; font-weight: 700; letter-spacing: -.4px; margin: 26px 0 10px; }
.arc-content h2:first-child { margin-top: 0; }
.arc-content p { color: var(--muted); line-height: 1.6; font-size: 14.5px; margin: 0 0 12px; }
.arc-faq details { border: 1px solid var(--line); border-radius: 12px; background: var(--surface); padding: 4px 14px; margin-bottom: 10px; }
.arc-faq summary { cursor: pointer; font-weight: 700; padding: 11px 0; font-size: 14.5px; }
.arc-faq p { padding: 0 0 12px; margin: 0; }
.arc-related { margin-top: 18px; font-size: 14px; }
.arc-related a { color: var(--accent); font-weight: 600; }

.toast { position: fixed; left: 50%; bottom: 26px; transform: translateX(-50%) translateY(20px); opacity: 0; pointer-events: none; background: var(--ink); color: var(--bg, #14171c); padding: 10px 18px; border-radius: 99px; font-size: 13px; font-weight: 700; display: flex; gap: 8px; align-items: center; transition: opacity .2s, transform .2s; z-index: 50; }
.toast.show { opacity: 1; transform: translateX(-50%) translateY(0); }