:root {
  --bg: #f8fbff;
  --surface: #ffffff;
  --surface-soft: #f3f7ff;
  --surface-blue: #eef5ff;
  --text: #0c1830;
  --muted: #5c6980;
  --line: #dbe4f0;
  --line-strong: #c7d4e6;
  --primary: #1769ff;
  --primary-strong: #0754df;
  --primary-soft: #e9f1ff;
  --teal: #0ba881;
  --green: #16a36a;
  --warning: #d97706;
  --danger: #dc2626;
  --shadow-sm: 0 8px 24px rgba(27, 55, 94, .07);
  --shadow-lg: 0 24px 70px rgba(23, 51, 90, .11);
  --radius-sm: 10px;
  --radius-md: 16px;
  --radius-lg: 22px;
  --shell: 1390px;
  --font: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  color-scheme: light;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 90px; }
body {
  margin: 0;
  min-width: 320px;
  color: var(--text);
  background:
    radial-gradient(circle at 80% 10%, rgba(44, 129, 255, .10), transparent 28rem),
    linear-gradient(180deg, #fff 0, var(--bg) 44rem, #fff 100%);
  font-family: var(--font);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
body.dialog-open { overflow: hidden; }
button, input, select, textarea { font: inherit; }
button, a { -webkit-tap-highlight-color: transparent; }
button { color: inherit; }
a { color: inherit; }
img, svg { display: block; }

.skip-link {
  position: fixed;
  z-index: 1000;
  top: 10px;
  left: 10px;
  padding: 10px 14px;
  color: #fff;
  background: var(--text);
  border-radius: 8px;
  transform: translateY(-160%);
  transition: transform .2s ease;
}
.skip-link:focus { transform: translateY(0); }

.shell { width: min(calc(100% - 48px), var(--shell)); margin-inline: auto; }
.narrow-shell { width: min(calc(100% - 48px), 1160px); }

.site-header {
  position: sticky;
  z-index: 50;
  top: 0;
  border-bottom: 1px solid rgba(219, 228, 240, .85);
  background: rgba(255, 255, 255, .86);
  backdrop-filter: blur(16px);
}
.header-inner { min-height: 82px; display: flex; align-items: center; gap: 28px; }
.brand { display: inline-flex; align-items: center; gap: 12px; min-width: max-content; text-decoration: none; }
.brand img { width: 46px; height: 46px; }
.brand-text { display: flex; align-items: baseline; gap: 5px; font-size: 18px; letter-spacing: -.02em; }
.brand-text strong { font-size: 23px; }
.brand-text span { color: #344158; }
.main-nav { display: flex; align-items: center; justify-content: flex-end; gap: 34px; margin-left: auto; }
.main-nav a { color: #2e384b; font-size: 15px; font-weight: 650; text-decoration: none; }
.main-nav a:hover { color: var(--primary); }
.github-button, .install-button {
  min-height: 44px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 9px;
  border: 1px solid var(--line-strong);
  border-radius: 11px;
  background: #fff;
  padding: 9px 16px;
  font-weight: 700;
  text-decoration: none;
  box-shadow: 0 3px 10px rgba(28, 52, 83, .04);
  transition: border-color .2s, transform .2s, box-shadow .2s;
}
.github-button svg { width: 21px; height: 21px; }
.github-button:hover, .install-button:hover { border-color: #9db7df; transform: translateY(-1px); box-shadow: var(--shadow-sm); }

.hero { padding-top: 58px; padding-bottom: 52px; }
.hero-heading { display: flex; align-items: flex-end; justify-content: space-between; gap: 30px; margin-bottom: 28px; }
.eyebrow, .section-kicker {
  margin: 0 0 10px;
  color: var(--primary);
  font-size: 13px;
  font-weight: 800;
  letter-spacing: .09em;
  text-transform: uppercase;
}
.status-dot { display: inline-block; width: 8px; height: 8px; margin-right: 7px; border-radius: 50%; background: var(--green); box-shadow: 0 0 0 5px rgba(22, 163, 106, .12); }
h1 { max-width: 900px; margin: 0; font-size: clamp(38px, 4.3vw, 66px); line-height: 1.03; letter-spacing: -.052em; }
.hero-copy { max-width: 750px; margin: 17px 0 0; color: var(--muted); font-size: clamp(17px, 1.5vw, 21px); line-height: 1.55; }
.hero-copy strong { color: var(--primary); }
.install-button { flex: 0 0 auto; cursor: pointer; }
.install-button svg { width: 21px; height: 21px; fill: none; stroke: currentColor; stroke-linecap: round; stroke-linejoin: round; stroke-width: 1.8; }

.hero-grid { display: grid; grid-template-columns: minmax(0, .96fr) minmax(0, 1.04fr); gap: 24px; align-items: stretch; }
.tool-card, .result-card {
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  background: rgba(255, 255, 255, .96);
  box-shadow: var(--shadow-lg);
}
.tool-card { padding: clamp(22px, 2.5vw, 34px); }
.card-heading, .preview-toolbar { display: flex; align-items: center; justify-content: space-between; gap: 16px; margin-bottom: 20px; }
.card-heading > div, .preview-toolbar > div { display: flex; align-items: center; gap: 11px; }
.card-heading h2, .preview-toolbar h2 { margin: 0; font-size: 20px; letter-spacing: -.025em; }
.step-badge { display: inline-grid; place-items: center; width: 32px; height: 28px; border-radius: 8px; color: var(--primary); background: var(--primary-soft); font-size: 11px; font-weight: 900; letter-spacing: .06em; }
.step-badge-alt { color: #087d68; background: #e8fbf6; }
.runtime-status { display: inline-flex; align-items: center; gap: 7px; color: #5b677a; font-size: 12px; font-weight: 700; white-space: nowrap; }
.runtime-status > span { width: 8px; height: 8px; border-radius: 50%; background: #94a3b8; }
.runtime-status[data-status="loading"] > span { background: var(--warning); animation: pulse 1s ease infinite; }
.runtime-status[data-status="ready"] { color: #087d56; }
.runtime-status[data-status="ready"] > span { background: var(--green); }
.runtime-status[data-status="error"] { color: var(--danger); }
.runtime-status[data-status="error"] > span { background: var(--danger); }
@keyframes pulse { 50% { opacity: .38; } }

.dropzone {
  min-height: 165px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  border: 2px dashed #79a8ff;
  border-radius: 16px;
  background: linear-gradient(145deg, #fafdff, #f1f6ff);
  padding: 22px;
  text-align: center;
  cursor: pointer;
  outline: none;
  transition: background .2s, border-color .2s, transform .2s, box-shadow .2s;
}
.dropzone:hover, .dropzone:focus-visible, .dropzone.is-dragging { border-color: var(--primary); background: #edf4ff; box-shadow: 0 0 0 5px rgba(23, 105, 255, .09); }
.dropzone.is-dragging { transform: scale(1.008); }
.upload-icon { width: 54px; height: 48px; color: var(--primary); margin-bottom: 10px; }
.upload-icon svg { width: 100%; height: 100%; fill: none; stroke: currentColor; stroke-width: 2.1; stroke-linecap: round; stroke-linejoin: round; }
.dropzone strong { font-size: 18px; }
.dropzone > span:not(.upload-icon) { margin-top: 5px; color: var(--muted); }
.dropzone .file-limit { font-size: 11px; }
.selected-files { margin: 12px 0 0; padding: 12px 14px; border: 1px solid #cfe0fb; border-radius: 12px; color: #344158; background: #f6f9ff; font-size: 13px; line-height: 1.4; }
.selected-files strong { color: var(--primary-strong); }

.paste-divider { display: flex; align-items: center; gap: 13px; margin: 19px 0 12px; color: #6d7890; font-size: 12px; }
.paste-divider::before, .paste-divider::after { content: ""; flex: 1; height: 1px; background: var(--line); }
.textarea-label { display: flex; align-items: center; justify-content: space-between; gap: 10px; margin-bottom: 7px; font-size: 13px; font-weight: 750; }
.text-button { border: 0; color: var(--primary); background: transparent; padding: 4px 0; cursor: pointer; font-size: 12px; font-weight: 750; }
textarea {
  width: 100%;
  min-height: 128px;
  resize: vertical;
  border: 1px solid var(--line-strong);
  border-radius: 12px;
  color: #24314a;
  background: #fbfdff;
  padding: 13px 14px;
  font: 13px/1.55 ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
  outline: none;
  transition: border-color .2s, box-shadow .2s;
}
textarea:focus, select:focus-visible { border-color: var(--primary); box-shadow: 0 0 0 4px rgba(23, 105, 255, .10); }

.format-grid { display: grid; grid-template-columns: minmax(0, 1fr) 46px minmax(0, 1fr); gap: 12px; align-items: end; margin-top: 17px; }
.format-grid label { display: grid; gap: 7px; color: #29354a; font-size: 13px; font-weight: 750; }
select { width: 100%; min-height: 48px; border: 1px solid var(--line-strong); border-radius: 11px; color: var(--text); background: #fff; padding: 0 39px 0 13px; outline: none; cursor: pointer; }
.swap-button, .icon-button {
  min-width: 44px;
  min-height: 44px;
  display: inline-grid;
  place-items: center;
  border: 1px solid var(--line);
  border-radius: 11px;
  color: #41506b;
  background: #f8faff;
  cursor: pointer;
}
.swap-button { height: 48px; }
.swap-button svg, .icon-button svg { width: 22px; height: 22px; fill: none; stroke: currentColor; stroke-width: 1.8; stroke-linecap: round; stroke-linejoin: round; }
.swap-button:hover, .icon-button:hover { color: var(--primary); border-color: #9ebfff; background: var(--primary-soft); }

.primary-button, .download-button {
  width: 100%;
  min-height: 56px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  border: 0;
  border-radius: 12px;
  color: #fff;
  background: linear-gradient(120deg, #0c5eea, #2c7cff);
  padding: 13px 20px;
  font-size: 16px;
  font-weight: 800;
  cursor: pointer;
  box-shadow: 0 12px 23px rgba(23, 105, 255, .24);
  transition: transform .2s, box-shadow .2s, filter .2s;
}
.tool-card > .primary-button { margin-top: 16px; }
.primary-button svg, .download-button svg { width: 23px; height: 23px; fill: none; stroke: currentColor; stroke-linecap: round; stroke-linejoin: round; stroke-width: 1.8; }
.primary-button:hover:not(:disabled), .download-button:hover:not(:disabled) { transform: translateY(-1px); box-shadow: 0 16px 28px rgba(23, 105, 255, .30); filter: saturate(1.08); }
.primary-button:disabled, .download-button:disabled { cursor: not-allowed; color: #8b97ab; background: #e7ecf4; box-shadow: none; }
.primary-button.is-loading svg { animation: spin 1s linear infinite; }
@keyframes spin { to { transform: rotate(360deg); } }

.options-panel { margin: 20px 0 0; border: 0; border-top: 1px solid var(--line); padding: 17px 0 0; }
.options-panel legend { display: flex; align-items: center; gap: 7px; margin: 0 0 12px; padding: 0; color: #303d55; font-size: 13px; font-weight: 800; }
.options-panel legend svg { width: 18px; height: 18px; fill: none; stroke: currentColor; stroke-width: 1.6; stroke-linecap: round; stroke-linejoin: round; }
.option-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 9px; }
.toggle-row { position: relative; min-height: 68px; display: flex; align-items: center; justify-content: space-between; gap: 12px; border: 1px solid #e2e9f3; border-radius: 12px; padding: 11px 12px; cursor: pointer; background: #fbfcfe; }
.toggle-row > span:first-child { display: grid; gap: 3px; }
.toggle-row strong { font-size: 12px; }
.toggle-row small { color: #718097; font-size: 10px; line-height: 1.35; }
.toggle-row input { position: absolute; opacity: 0; pointer-events: none; }
.toggle { position: relative; flex: 0 0 39px; width: 39px; height: 23px; border-radius: 999px; background: #cbd5e1; transition: background .2s; }
.toggle::after { content: ""; position: absolute; top: 3px; left: 3px; width: 17px; height: 17px; border-radius: 50%; background: #fff; box-shadow: 0 1px 4px rgba(15, 23, 42, .22); transition: transform .2s; }
.toggle-row input:checked + .toggle { background: var(--primary); }
.toggle-row input:checked + .toggle::after { transform: translateX(16px); }
.toggle-row:has(input:focus-visible) { box-shadow: 0 0 0 4px rgba(23, 105, 255, .10); border-color: var(--primary); }

.result-card { display: grid; grid-template-columns: minmax(260px, .82fr) minmax(340px, 1.18fr); overflow: hidden; }
.preview-column, .output-column { min-width: 0; padding: clamp(21px, 2vw, 28px); }
.preview-column { display: flex; flex-direction: column; border-right: 1px solid var(--line); background: linear-gradient(160deg, #f8fbff, #eef5ff); }
.privacy-pill { display: inline-flex; align-items: center; gap: 5px; color: #087d68; font-size: 11px; font-weight: 800; white-space: nowrap; }
.privacy-pill svg { width: 18px; height: 18px; fill: none; stroke: currentColor; stroke-width: 1.7; stroke-linecap: round; stroke-linejoin: round; }
.molecule-viewer { position: relative; min-height: 370px; flex: 1; display: grid; place-items: center; overflow: hidden; border: 1px solid #d2dff0; border-radius: 16px; background:
  radial-gradient(circle at 32% 18%, rgba(255, 255, 255, .95), transparent 13rem),
  linear-gradient(145deg, #f9fcff, #e6f0ff);
}
.molecule-viewer::before { content: ""; position: absolute; inset: 0; opacity: .28; background-image: linear-gradient(#cbdcf1 1px, transparent 1px), linear-gradient(90deg, #cbdcf1 1px, transparent 1px); background-size: 28px 28px; mask-image: radial-gradient(circle, #000 0, transparent 75%); }
.molecule-svg { position: relative; z-index: 1; width: 100%; height: 100%; max-height: 390px; filter: drop-shadow(0 12px 12px rgba(24, 52, 86, .13)); }
.molecule-bond { stroke: #49566b; stroke-width: 5; stroke-linecap: round; }
.molecule-atom circle { stroke: rgba(11, 23, 45, .33); stroke-width: 1.7; }
.atom-label { fill: #fff; font: 700 10px var(--font); pointer-events: none; }
.preview-empty { position: relative; z-index: 1; display: grid; justify-items: center; gap: 7px; color: #60708b; text-align: center; padding: 30px; }
.preview-empty strong { color: #26344c; font-size: 16px; }
.preview-empty span:last-child { font-size: 12px; }
.preview-empty-icon { color: var(--primary); font-size: 64px; line-height: 1; filter: drop-shadow(0 8px 13px rgba(23,105,255,.22)); }
.viewer-actions { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; margin-top: 12px; }
.secondary-button { min-height: 43px; display: inline-flex; align-items: center; justify-content: center; gap: 7px; border: 1px solid var(--line-strong); border-radius: 10px; color: #334158; background: rgba(255,255,255,.78); font-size: 12px; font-weight: 750; cursor: pointer; }
.secondary-button svg { width: 18px; height: 18px; fill: none; stroke: currentColor; stroke-width: 1.7; stroke-linecap: round; stroke-linejoin: round; }
.secondary-button:hover { color: var(--primary); border-color: #9bbcff; background: #fff; }

.output-column { display: flex; flex-direction: column; }
.tabs { min-height: 45px; display: flex; align-items: stretch; border-bottom: 1px solid var(--line); }
.tab-button { position: relative; border: 0; color: #6a758a; background: transparent; padding: 0 13px; font-size: 12px; font-weight: 800; cursor: pointer; }
.tab-button.active { color: var(--primary); }
.tab-button.active::after { content: ""; position: absolute; left: 8px; right: 8px; bottom: -1px; height: 3px; border-radius: 3px 3px 0 0; background: var(--primary); }
.copy-button { min-width: 39px; min-height: 36px; margin: 4px 0 4px auto; border: 0; background: transparent; }
.code-preview { height: 270px; min-height: 220px; overflow: auto; margin: 0; border-bottom: 1px solid var(--line); color: #27334a; background: #fbfcff; padding: 17px; font: 11.5px/1.65 ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace; white-space: pre; scrollbar-color: #becbe0 transparent; }
.code-preview code { font: inherit; }
.summary-and-formats { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, .93fr); gap: 15px; padding-top: 15px; }
.summary-card, .format-list { border: 1px solid var(--line); border-radius: 13px; padding: 14px; background: #fff; }
.summary-card h3, .format-list h3 { margin: 0 0 10px; font-size: 13px; }
.summary-card h3 { display: flex; align-items: center; gap: 7px; }
.summary-card h3 svg { width: 18px; height: 18px; fill: none; stroke: #0aa9c4; stroke-width: 1.7; stroke-linecap: round; stroke-linejoin: round; }
.summary-card dl { margin: 0; }
.summary-card dl div { display: flex; align-items: center; justify-content: space-between; gap: 10px; min-height: 29px; border-top: 1px solid #edf1f6; font-size: 11px; }
.summary-card dl div:first-child { border-top: 0; }
.summary-card dt { color: #69778e; }
.summary-card dd { margin: 0; color: var(--primary); font-weight: 850; }
.format-pills { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 7px; }
.format-pills button { min-height: 32px; border: 1px solid #d8e5f8; border-radius: 8px; color: #1f5ec8; background: #f4f8ff; font-size: 10px; font-weight: 850; cursor: pointer; }
.format-pills button:hover { border-color: var(--primary); background: var(--primary-soft); }
.download-button { margin-top: auto; min-height: 50px; font-size: 14px; box-shadow: none; }

.value-strip { display: grid; grid-template-columns: repeat(3, 1fr); margin-top: 27px; border: 1px solid var(--line); border-radius: 18px; background: rgba(255,255,255,.82); box-shadow: var(--shadow-sm); }
.value-strip article { min-height: 122px; display: flex; align-items: center; gap: 19px; padding: 25px 31px; }
.value-strip article + article { border-left: 1px solid var(--line); }
.value-icon { flex: 0 0 58px; width: 58px; height: 58px; }
.value-icon svg { width: 100%; height: 100%; fill: none; stroke: currentColor; stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; }
.shield-icon, .download-icon { color: var(--primary); }
.batch-icon { color: var(--teal); }
.value-strip strong { display: block; margin-bottom: 5px; font-size: 15px; }
.value-strip p { margin: 0; color: var(--muted); font-size: 12px; line-height: 1.55; }

.content-section { padding: 92px 0; }
.muted-section { border-block: 1px solid #e6edf6; background: #f7faff; }
.content-section h2 { max-width: 820px; margin: 0; font-size: clamp(29px, 3vw, 46px); line-height: 1.1; letter-spacing: -.043em; }
.section-lead { max-width: 830px; margin: 18px 0 0; color: var(--muted); font-size: 17px; line-height: 1.75; }
.format-cards { display: grid; grid-template-columns: repeat(3, 1fr); gap: 17px; margin-top: 42px; }
.format-cards article { min-height: 220px; border: 1px solid var(--line); border-radius: 17px; background: #fff; padding: 25px; box-shadow: 0 10px 30px rgba(24, 50, 83, .05); }
.format-cards article > span { display: inline-flex; align-items: center; min-height: 30px; border-radius: 8px; color: var(--primary); background: var(--primary-soft); padding: 5px 10px; font-size: 11px; font-weight: 900; }
.format-cards h3 { margin: 20px 0 9px; font-size: 19px; }
.format-cards p { margin: 0; color: var(--muted); font-size: 14px; line-height: 1.7; }
.steps-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; margin-top: 43px; }
.steps-grid article { position: relative; border-top: 2px solid #cddcf2; padding: 28px 10px 0 0; }
.steps-grid article > span { position: absolute; top: -20px; left: 0; display: grid; place-items: center; width: 39px; height: 39px; border: 5px solid #f7faff; border-radius: 50%; color: #fff; background: var(--primary); font-size: 13px; font-weight: 900; }
.steps-grid h3 { margin: 0 0 10px; font-size: 19px; }
.steps-grid p { margin: 0; color: var(--muted); font-size: 14px; line-height: 1.7; }
.example-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 15px; margin-top: 33px; }
.example-card { min-height: 102px; display: grid; grid-template-columns: 52px 1fr auto; align-items: center; gap: 14px; border: 1px solid var(--line); border-radius: 15px; color: var(--text); background: #fff; padding: 17px; text-align: left; cursor: pointer; box-shadow: 0 7px 20px rgba(24, 50, 83, .04); transition: border-color .2s, transform .2s, box-shadow .2s; }
.example-card:hover { border-color: #9cbcff; transform: translateY(-2px); box-shadow: var(--shadow-sm); }
.example-symbol { display: grid; place-items: center; width: 52px; height: 52px; border-radius: 13px; color: var(--primary); background: var(--primary-soft); font-size: 22px; font-weight: 900; }
.example-card > span:nth-child(2) { display: grid; gap: 5px; }
.example-card strong { font-size: 15px; }
.example-card small { color: var(--muted); font-size: 11px; }
.example-card > span:last-child { color: var(--primary); font-size: 21px; }
.faq-list { display: grid; gap: 11px; margin-top: 35px; }
.faq-list details { border: 1px solid var(--line); border-radius: 13px; background: #fff; padding: 0 19px; }
.faq-list summary { min-height: 61px; display: flex; align-items: center; justify-content: space-between; gap: 20px; cursor: pointer; font-size: 15px; font-weight: 800; list-style: none; }
.faq-list summary::-webkit-details-marker { display: none; }
.faq-list summary::after { content: "+"; color: var(--primary); font-size: 23px; font-weight: 400; }
.faq-list details[open] summary::after { content: "−"; }
.faq-list p { margin: -2px 0 19px; color: var(--muted); font-size: 14px; line-height: 1.7; }

.site-footer { display: grid; place-items: center; min-height: 90px; border-top: 1px solid var(--line); color: #657186; background: #fff; text-align: center; }
.site-footer p { margin: 0; font-size: 13px; }

.message-dialog { width: min(calc(100% - 32px), 500px); border: 0; border-radius: 18px; color: var(--text); background: #fff; padding: 0; box-shadow: 0 32px 90px rgba(10, 25, 50, .28); }
.message-dialog::backdrop { background: rgba(9, 20, 38, .57); backdrop-filter: blur(4px); }
.message-dialog form { position: relative; display: grid; grid-template-columns: 52px 1fr; gap: 16px; padding: 28px; }
.dialog-icon { display: grid; place-items: center; width: 52px; height: 52px; border-radius: 14px; color: #c56a08; background: #fff3df; }
.dialog-icon svg { width: 27px; height: 27px; fill: none; stroke: currentColor; stroke-width: 1.8; stroke-linecap: round; stroke-linejoin: round; }
.message-dialog h2 { margin: 2px 0 8px; font-size: 19px; }
.message-dialog p { margin: 0; color: var(--muted); font-size: 14px; line-height: 1.6; }
.dialog-close { position: absolute; top: 14px; right: 14px; width: 40px; height: 40px; display: grid; place-items: center; border: 0; border-radius: 10px; color: #64748b; background: transparent; cursor: pointer; }
.dialog-close:hover { background: #f1f5f9; }
.dialog-close svg { width: 20px; height: 20px; fill: none; stroke: currentColor; stroke-width: 2; stroke-linecap: round; }
.dialog-action { grid-column: 1 / -1; min-height: 46px; margin-top: 7px; font-size: 14px; box-shadow: none; }

.toast { position: fixed; z-index: 80; left: 50%; bottom: max(24px, env(safe-area-inset-bottom)); max-width: min(440px, calc(100% - 32px)); border: 1px solid #cfe0fb; border-radius: 12px; color: #173354; background: rgba(255,255,255,.96); padding: 12px 17px; box-shadow: 0 18px 50px rgba(19,43,75,.20); font-size: 13px; font-weight: 700; opacity: 0; pointer-events: none; transform: translate(-50%, 16px); transition: opacity .2s, transform .2s; }
.toast.show { opacity: 1; transform: translate(-50%, 0); }

:focus-visible { outline: 3px solid rgba(23, 105, 255, .35); outline-offset: 2px; }
[hidden] { display: none !important; }

@media (max-width: 1180px) {
  .hero-grid { grid-template-columns: 1fr; }
  .result-card { min-height: 650px; }
  .molecule-viewer { min-height: 330px; }
  .value-strip article { padding-inline: 22px; }
}

@media (max-width: 900px) {
  .shell, .narrow-shell { width: min(calc(100% - 32px), var(--shell)); }
  .header-inner { min-height: 72px; gap: 14px; }
  .brand img { width: 41px; height: 41px; }
  .brand-text span { display: none; }
  .brand-text strong { font-size: 20px; }
  .main-nav { gap: 18px; }
  .main-nav a:nth-child(2) { display: none; }
  .hero { padding-top: 40px; }
  .hero-heading { align-items: flex-start; }
  .result-card { grid-template-columns: 1fr; }
  .preview-column { border-right: 0; border-bottom: 1px solid var(--line); }
  .molecule-viewer { min-height: 315px; }
  .value-strip { grid-template-columns: 1fr; }
  .value-strip article + article { border-left: 0; border-top: 1px solid var(--line); }
  .format-cards { grid-template-columns: repeat(2, 1fr); }
  .steps-grid, .example-grid { grid-template-columns: 1fr; }
  .steps-grid { gap: 40px; }
}

@media (max-width: 650px) {
  .shell, .narrow-shell { width: min(calc(100% - 24px), var(--shell)); }
  .site-header { position: relative; }
  .header-inner { min-height: 67px; }
  .brand { gap: 8px; }
  .brand img { width: 36px; height: 36px; }
  .brand-text strong { font-size: 17px; }
  .main-nav { display: none; }
  .github-button { margin-left: auto; min-height: 42px; padding: 8px 12px; }
  .github-button span { font-size: 12px; }
  .hero { padding-top: 30px; padding-bottom: 36px; }
  .hero-heading { display: block; margin-bottom: 20px; }
  h1 { font-size: clamp(35px, 11vw, 48px); }
  .hero-copy { margin-top: 13px; font-size: 16px; }
  .install-button { width: 100%; margin-top: 16px; }
  .tool-card, .result-card { border-radius: 17px; }
  .tool-card, .preview-column, .output-column { padding: 18px; }
  .card-heading { align-items: flex-start; }
  .runtime-status { max-width: 120px; white-space: normal; text-align: right; }
  .dropzone { min-height: 155px; padding: 18px 12px; }
  .dropzone strong { font-size: 16px; }
  .format-grid { grid-template-columns: 1fr 44px; }
  .format-grid label:last-child { grid-column: 1 / -1; }
  .swap-button { grid-row: 1; grid-column: 2; }
  .option-grid { grid-template-columns: 1fr; }
  .toggle-row { min-height: 64px; }
  .preview-toolbar { align-items: flex-start; }
  .privacy-pill { white-space: normal; text-align: right; }
  .molecule-viewer { min-height: 270px; }
  .viewer-actions { grid-template-columns: 1fr; }
  .summary-and-formats { grid-template-columns: 1fr; }
  .code-preview { height: 240px; }
  .value-strip article { min-height: 110px; padding: 20px; }
  .value-icon { flex-basis: 50px; width: 50px; height: 50px; }
  .content-section { padding: 68px 0; }
  .format-cards { grid-template-columns: 1fr; }
  .format-cards article { min-height: 190px; }
  .message-dialog form { grid-template-columns: 44px 1fr; padding: 23px; }
  .dialog-icon { width: 44px; height: 44px; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { scroll-behavior: auto !important; animation-duration: .01ms !important; animation-iteration-count: 1 !important; transition-duration: .01ms !important; }
}