:root {
  color-scheme: dark;
  --bg: #080d1b;
  --bg-deep: #070b16;
  --panel: #10182a;
  --panel-soft: #121d32;
  --panel-glass: rgba(17, 26, 45, .85);
  --line: rgba(154, 176, 215, .13);
  --line-strong: rgba(154, 176, 215, .22);
  --text: #f3f6ff;
  --muted: #929db4;
  --faint: #66738d;
  --cyan: #65e2df;
  --blue: #7a9dff;
  --violet: #b18aff;
  --green: #69d6b0;
  --danger: #ff8a98;
  --shadow: 0 24px 80px rgba(0, 0, 0, .22);
  --font: "Manrope", "Segoe UI", sans-serif;
  --mono: "DM Mono", Consolas, monospace;
}

:root[data-theme="light"] {
  color-scheme: light;
  --bg: #f3f6fb;
  --bg-deep: #eaf0f8;
  --panel: #fff;
  --panel-soft: #f6f9ff;
  --panel-glass: rgba(255, 255, 255, .91);
  --line: rgba(50, 73, 114, .13);
  --line-strong: rgba(50, 73, 114, .24);
  --text: #18243a;
  --muted: #5f6d83;
  --faint: #748197;
  --cyan: #087f83;
  --blue: #405fc5;
  --violet: #7551b8;
  --green: #167c5c;
  --danger: #bd3547;
  --shadow: 0 20px 65px rgba(37, 57, 92, .1);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 96px; }
body {
  margin: 0;
  background:
    radial-gradient(ellipse at 11% 18%, rgba(35, 83, 130, .16), transparent 31rem),
    radial-gradient(ellipse at 84% 32%, rgba(91, 53, 142, .12), transparent 35rem),
    var(--bg);
  color: var(--text);
  font-family: var(--font);
  font-size: 14px;
  line-height: 1.6;
  min-width: 320px;
}
button, input, select { font: inherit; }
button, a, input, select { -webkit-tap-highlight-color: transparent; }
button { color: inherit; }
a { color: inherit; text-decoration: none; }
button:focus-visible, a:focus-visible, input:focus-visible, select:focus-visible, .table-scroll:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
}
.skip-link, .visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}
.skip-link:focus {
  z-index: 100;
  width: auto;
  height: auto;
  margin: 0;
  padding: 10px 16px;
  clip: auto;
  background: var(--panel);
}
.site-header {
  height: 78px;
  max-width: 1440px;
  margin: 0 auto;
  padding: 0 5.5%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid var(--line);
}
.brand { display: inline-flex; align-items: center; gap: 10px; font-size: 14px; font-weight: 800; letter-spacing: -.45px; white-space: nowrap; }
.brand b { font: 500 9px var(--mono); color: var(--cyan); letter-spacing: .12em; margin-left: 4px; }
.brand-mark { display: grid; place-items: center; width: 30px; height: 30px; border: 1px solid rgba(101, 226, 223, .38); border-radius: 10px; color: var(--cyan); font-size: 18px; box-shadow: inset 0 0 14px rgba(101, 226, 223, .09); }
.main-nav { display: flex; align-items: center; gap: 34px; margin-left: 40px; }
.main-nav a { color: var(--muted); font-size: 12px; font-weight: 700; transition: color .2s ease; }
.main-nav a:hover, .main-nav a:focus-visible { color: var(--text); }
.header-actions { display: flex; align-items: center; gap: 13px; }
.element-badge { display: flex; align-items: center; gap: 8px; color: var(--muted); border: 1px solid var(--line); border-radius: 99px; padding: 7px 11px; font: 10px var(--mono); text-transform: uppercase; letter-spacing: .06em; }
.status-dot { width: 6px; height: 6px; background: var(--green); border-radius: 50%; box-shadow: 0 0 9px rgba(105, 214, 176, .55); }
.icon-button, .menu-toggle { cursor: pointer; border: 1px solid var(--line); background: var(--panel); border-radius: 10px; width: 35px; height: 35px; display: grid; place-items: center; color: var(--muted); font-size: 17px; transition: color .2s, border-color .2s, transform .2s; }
.icon-button:hover { color: var(--cyan); border-color: var(--line-strong); transform: translateY(-1px); }
.menu-toggle { display: none; width: auto; padding: 0 12px; font-size: 11px; font-weight: 700; }

.hero { max-width: 1240px; min-height: 526px; padding: 75px 4.5% 72px; margin: 0 auto; display: grid; grid-template-columns: 1fr .95fr; align-items: center; gap: 30px; }
.hero-copy { position: relative; z-index: 1; }
.eyebrow { margin: 0 0 13px; color: var(--cyan); font: 500 9px var(--mono); letter-spacing: .2em; }
.eyebrow-line { display: inline-block; width: 21px; height: 1px; margin: 0 9px 3px 0; background: var(--cyan); }
h1, h2, h3, h4, p { margin-top: 0; }
.hero h1 { margin: 0; font-size: clamp(48px, 6vw, 76px); line-height: 1.04; font-weight: 800; letter-spacing: -.075em; }
.hero h1 span { color: var(--cyan); }
.hero-description { max-width: 440px; margin: 22px 0 25px; color: var(--muted); font-size: 14px; line-height: 1.9; }
.primary-button, .secondary-button { display: inline-flex; min-height: 42px; align-items: center; justify-content: center; gap: 16px; padding: 0 17px; border-radius: 10px; border: 1px solid transparent; cursor: pointer; font-size: 11px; font-weight: 800; transition: transform .2s, box-shadow .2s, background .2s; }
.primary-button { color: #08161b; background: linear-gradient(115deg, #7ce5d2, #77b8ff); box-shadow: 0 8px 28px rgba(69, 197, 195, .15); }
.primary-button:hover { transform: translateY(-2px); box-shadow: 0 11px 30px rgba(69, 197, 195, .25); }
.primary-button:disabled, .icon-button:disabled { opacity: .4; cursor: not-allowed; transform: none; box-shadow: none; }
.hero-cta { min-width: 158px; }
.hero-note { margin-top: 28px; display: flex; align-items: center; gap: 9px; color: var(--faint); font-size: 9px; font-weight: 700; }
.hero-note > span { color: var(--cyan); font-size: 13px; }
.hero-note i { width: 3px; height: 3px; border-radius: 50%; background: var(--faint); }
.hero-art { height: 364px; position: relative; isolation: isolate; display: grid; place-items: center; }
.hero-art::before { content: ""; position: absolute; z-index: -1; width: 330px; height: 300px; border-radius: 50%; background: radial-gradient(ellipse, rgba(68, 99, 194, .2), transparent 68%); filter: blur(8px); }
.orbit { position: absolute; border: 1px solid rgba(130, 157, 222, .15); border-radius: 50%; transform: rotate(-25deg); }
.orbit-one { width: 330px; height: 158px; }
.orbit-two { width: 305px; height: 215px; transform: rotate(56deg); }
.orbit-three { width: 260px; height: 260px; border-style: dashed; border-color: rgba(130, 157, 222, .1); }
.atom { z-index: 2; position: absolute; width: 85px; height: 85px; display: grid; place-items: center; border-radius: 50%; border: 1px solid rgba(137, 169, 255, .48); background: radial-gradient(circle at 37% 30%, rgba(116, 146, 255, .46), rgba(29, 43, 85, .92) 72%); color: #fff; box-shadow: 0 0 34px rgba(109, 133, 255, .24), inset 0 0 28px rgba(157, 174, 255, .15); }
.atom span { font: 500 26px var(--mono); }
.atom-center { width: 108px; height: 108px; background: radial-gradient(circle at 35% 30%, rgba(100, 228, 224, .46), rgba(23, 72, 98, .95) 74%); border-color: rgba(101, 226, 223, .65); box-shadow: 0 0 46px rgba(101, 226, 223, .24), inset 0 0 27px rgba(101, 226, 223, .15); }
.atom-left { transform: translate(-130px, 59px) scale(.68); }
.atom-right { transform: translate(130px, 59px) scale(.68); }
.bond { z-index: 1; position: absolute; top: 53%; width: 83px; height: 2px; background: linear-gradient(90deg, transparent, rgba(104, 212, 226, .8), transparent); }
.bond-left { left: calc(50% - 106px); transform: rotate(-26deg); }
.bond-right { right: calc(50% - 106px); transform: rotate(26deg); }
.art-label { position: absolute; display: flex; flex-direction: column; color: var(--cyan); font: 10px var(--mono); letter-spacing: .12em; }
.art-label small { margin-top: 4px; color: var(--faint); font: 8px var(--mono); letter-spacing: .15em; }
.label-a { top: 49px; right: 48px; }
.label-b { bottom: 47px; left: 34px; color: var(--violet); }
.art-spark { position: absolute; color: var(--cyan); font-size: 18px; }
.spark-a { right: 20%; bottom: 23%; }
.spark-b { top: 17%; left: 20%; font-size: 32px; }

.section-wrap { width: min(1120px, 91%); margin-left: auto; margin-right: auto; }
.workspace-section { padding: 30px 0 70px; }
.periodic-section, .examples-section { padding: 26px 0 76px; }
.section-heading { display: flex; align-items: end; justify-content: space-between; gap: 20px; margin-bottom: 20px; }
.section-heading .eyebrow { margin-bottom: 7px; }
.section-heading h2, .about-card h2 { margin: 0; font-size: clamp(25px, 3vw, 33px); line-height: 1.2; letter-spacing: -.055em; }
.section-intro { max-width: 330px; margin: 0 0 3px; color: var(--muted); font-size: 11px; line-height: 1.7; }
.workspace-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.panel { border: 1px solid var(--line); border-radius: 16px; background: var(--panel-glass); box-shadow: var(--shadow); backdrop-filter: blur(12px); }
.builder-panel, .result-panel { min-height: 416px; padding: 22px; }
.panel-heading { display: flex; justify-content: space-between; align-items: flex-start; gap: 12px; }
.panel-heading > div { display: flex; align-items: flex-start; gap: 11px; }
.step-marker { display: grid; place-items: center; flex: 0 0 auto; width: 30px; height: 30px; border-radius: 9px; color: var(--cyan); background: rgba(101, 226, 223, .1); font: 10px var(--mono); }
.step-violet { color: var(--violet); background: rgba(177, 138, 255, .12); }
.panel-heading h3 { margin: 0; font-size: 13px; letter-spacing: -.02em; }
.panel-heading p { margin: 3px 0 0; color: var(--muted); font-size: 10px; }
.text-button { padding: 4px 0; color: var(--muted); background: none; border: 0; cursor: pointer; font-size: 10px; font-weight: 700; transition: color .2s; }
.text-button:hover:not(:disabled) { color: var(--cyan); }
.text-button:disabled { opacity: .4; cursor: not-allowed; }
.builder-labels { display: grid; grid-template-columns: 1fr 116px 32px; gap: 8px; margin: 24px 0 7px; color: var(--faint); font: 8px var(--mono); text-transform: uppercase; letter-spacing: .08em; }
.builder-labels span:nth-child(2) { grid-column: 2; }
.builder-row { position: relative; display: grid; grid-template-columns: 1fr 116px 32px; gap: 8px; margin-bottom: 11px; }
.builder-row input, .search-field, .filter-field select { width: 100%; min-width: 0; border: 1px solid var(--line); border-radius: 8px; background: var(--bg-deep); color: var(--text); }
.builder-row input { height: 39px; padding: 0 11px; font-size: 11px; outline: none; }
.builder-row input::placeholder { color: var(--faint); }
.builder-row input:focus { border-color: rgba(101, 226, 223, .55); }
.builder-row.row-invalid .element-input, .builder-row.row-invalid .quantity-input { border-color: var(--danger); }
.remove-row { display: grid; place-items: center; width: 32px; border: 1px solid var(--line); border-radius: 8px; color: var(--muted); background: transparent; cursor: pointer; font-size: 19px; }
.remove-row:hover { color: var(--danger); border-color: rgba(255, 138, 152, .45); }
.row-error { display: none; grid-column: 1 / -1; color: var(--danger); font-size: 9px; margin-top: -6px; }
.row-invalid .row-error:not(:empty) { display: block; }
.builder-actions { display: flex; justify-content: space-between; align-items: center; gap: 10px; margin-top: 14px; }
.secondary-button { min-height: 37px; padding: 0 12px; color: var(--text); background: transparent; border-color: var(--line-strong); gap: 7px; font-size: 10px; }
.secondary-button:hover { background: var(--panel-soft); border-color: var(--cyan); }
.secondary-button span { color: var(--cyan); font-size: 15px; }
.builder-actions .primary-button { min-height: 37px; gap: 10px; font-size: 10px; }
.inline-error { min-height: 13px; margin: 8px 0 0; color: var(--danger); font-size: 9px; }
.formula-preview { display: flex; align-items: center; justify-content: space-between; min-height: 66px; border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.formula-preview > div { display: flex; flex-direction: column; gap: 1px; }
.micro-label { color: var(--faint); font: 8px var(--mono); letter-spacing: .11em; }
.formula-large { color: var(--cyan); font: 22px var(--mono); }
.count-pill { padding: 5px 9px; border: 1px solid var(--line); border-radius: 99px; color: var(--muted); font: 9px var(--mono); }
.fine-print { margin: 11px 0 0; color: var(--faint); font-size: 9px; line-height: 1.6; }
.small-icon { width: 31px; height: 31px; border-radius: 9px; font-size: 17px; }
.small-icon.is-favorite { color: #ff87a5; border-color: rgba(255, 135, 165, .35); }
.result-content { min-height: 285px; padding: 17px 0 12px; text-align: center; }
.result-content > h4 { margin: 10px 0 7px; font-size: 13px; }
.result-content > p { max-width: 370px; margin: 0 auto; color: var(--muted); font-size: 10px; line-height: 1.7; }
.empty-visual { position: relative; width: 100px; height: 100px; margin: 5px auto 9px; display: grid; place-items: center; }
.empty-orbit { position: absolute; width: 83px; height: 83px; border: 1px dashed rgba(177, 138, 255, .4); border-radius: 50%; }
.empty-core { display: grid; place-items: center; width: 48px; height: 48px; border: 1px solid rgba(177, 138, 255, .45); border-radius: 50%; color: var(--violet); background: rgba(177, 138, 255, .08); font: 20px var(--mono); }
.result-footer { display: flex; justify-content: space-between; border-top: 1px solid var(--line); padding-top: 12px; gap: 9px; }
.result-footer .text-button { font-size: 9px; }
.match-badge, .proposed-badge { display: inline-block; padding: 4px 8px; border-radius: 5px; background: rgba(105, 214, 176, .1); color: var(--green); font: 8px var(--mono); letter-spacing: .08em; }
.proposed-badge { background: rgba(177, 138, 255, .1); color: var(--violet); }
.result-name { margin: 8px 0 0; font-size: 14px; }
.result-formula { margin: 0 auto; color: var(--cyan); font: 28px var(--mono); line-height: 1.3; }
.molecule-graphic { width: min(100%, 300px); margin: 3px auto 7px; }
.molecule-graphic svg { display: block; width: 100%; height: 98px; overflow: visible; animation: molecule-appear .35s ease-out both; }
@keyframes molecule-appear { from { opacity: 0; transform: translateY(4px) scale(.97); } to { opacity: 1; transform: translateY(0) scale(1); } }
.molecule-bond { stroke: rgba(139, 164, 207, .65); stroke-width: 3; stroke-linecap: round; }
.molecule-atom { stroke-width: 1.5; }
.atom-h { fill: #dcecff; stroke: #96b8e8; }
.atom-c { fill: #39465d; stroke: #8999b3; }
.atom-n { fill: #657cf6; stroke: #9caaff; }
.atom-o { fill: #ef7188; stroke: #ffacb8; }
.atom-generic { fill: rgba(177, 138, 255, .22); stroke: rgba(177, 138, 255, .7); }
.molecule-label { fill: #0d1423; font: 11px var(--mono); font-weight: 600; }
.molecule-graphic > span { display: block; color: var(--faint); font-size: 8px; text-align: center; }
.atom-legend { display: flex; justify-content: center; gap: 10px; margin-top: 4px; }
.atom-legend span { display: inline-flex; align-items: center; gap: 4px; color: var(--faint); font-size: 8px; }
.atom-legend span::before { content: ""; width: 6px; height: 6px; border-radius: 50%; background: currentColor; }
.legend-h { color: #a6c8f8 !important; }.legend-c { color: #aab6c9 !important; }.legend-n { color: #8295ff !important; }.legend-o { color: #ff93a4 !important; }
.result-metadata { display: grid; grid-template-columns: 1fr 1fr; gap: 6px 14px; text-align: left; margin: 9px 0; }
.result-metadata > div { display: flex; flex-direction: column; }
.result-metadata span { color: var(--faint); font-size: 8px; }
.result-metadata strong { color: var(--text); font-size: 9px; font-weight: 700; overflow-wrap: anywhere; }
.equation-box { display: flex; justify-content: space-between; gap: 8px; align-items: center; border: 1px solid var(--line); border-radius: 7px; padding: 8px 9px; margin: 8px 0; text-align: left; }
.equation-box strong { color: var(--text); font: 10px var(--mono); }
.result-description { margin-top: 7px !important; text-align: left; font-size: 9px !important; }
.result-content:has(.result-formula) { text-align: left; }
.result-content:has(.result-formula) > .match-badge, .result-content:has(.result-formula) > .proposed-badge { margin-top: 1px; }
.result-content:has(.result-formula) > .result-formula { text-align: center; }
.result-content:has(.result-formula) > .result-name { text-align: center; }
.utility-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; margin-top: 16px; }
.compact-panel { min-height: 132px; padding: 17px 20px; }
.mini-icon { display: grid; place-items: center; width: 27px; height: 27px; border-radius: 8px; color: #f090b0; background: rgba(240, 144, 176, .1); font-size: 17px; }
.history-icon { color: var(--blue); background: rgba(122, 157, 255, .11); }
.saved-list { display: flex; gap: 7px; flex-wrap: wrap; list-style: none; margin: 15px 0 0; padding: 0; }
.saved-list > li { position: relative; display: flex; align-items: center; border: 1px solid var(--line); border-radius: 7px; overflow: hidden; }
.saved-list .list-empty { border: 0; color: var(--faint); font-size: 9px; padding: 4px 0; }
.saved-item { display: flex; align-items: center; gap: 9px; padding: 6px 9px; color: var(--muted); background: transparent; border: 0; cursor: pointer; text-align: left; font-size: 9px; }
.saved-item strong { color: var(--text); font-size: 9px; }
.saved-item span { color: var(--cyan); font: 10px var(--mono); }
.saved-item:hover { background: var(--panel-soft); }
.saved-remove { align-self: stretch; border: 0; border-left: 1px solid var(--line); padding: 0 7px; color: var(--faint); background: transparent; cursor: pointer; font-size: 14px; }
.saved-remove:hover { color: var(--danger); }

.periodic-panel { padding: 18px; }
.table-toolbar { display: flex; align-items: center; gap: 10px; margin-bottom: 17px; }
.search-field { display: flex; align-items: center; gap: 9px; max-width: 330px; height: 37px; padding: 0 11px; color: var(--faint); }
.search-field > span:first-child { font-size: 21px; line-height: 1; }
.search-field input { width: 100%; color: var(--text); background: transparent; border: 0; outline: 0; font-size: 10px; }
.search-field input::placeholder { color: var(--faint); }
.filter-field select { height: 37px; min-width: 150px; padding: 0 10px; font-size: 10px; }
.table-status { margin-left: auto; color: var(--faint); font: 9px var(--mono); white-space: nowrap; }
.table-scroll { width: 100%; overflow-x: auto; padding: 1px 1px 10px; scrollbar-color: var(--line-strong) transparent; scrollbar-width: thin; }
.periodic-grid { display: grid; grid-template-columns: repeat(18, 47px); grid-template-rows: repeat(9, 59px); gap: 3px; width: max-content; margin: 0 auto; }
.element-tile { position: relative; min-width: 0; padding: 4px 2px; display: flex; flex-direction: column; align-items: center; justify-content: center; overflow: hidden; border: 1px solid var(--tile-border, var(--line)); border-radius: 6px; color: var(--text); background: var(--tile-bg, rgba(255, 255, 255, .025)); cursor: pointer; transition: transform .15s, border-color .15s, background .15s; }
.element-tile:hover, .element-tile:focus-visible { z-index: 1; transform: translateY(-2px); border-color: var(--tile-color, var(--cyan)); background: var(--tile-bg-hover, rgba(255, 255, 255, .08)); }
.element-tile.is-selected { box-shadow: inset 0 0 0 1px var(--tile-color, var(--cyan)); background: var(--tile-bg-hover, rgba(255, 255, 255, .1)); }
.element-tile.is-filtered { visibility: hidden; pointer-events: none; }
.tile-number { position: absolute; top: 3px; left: 4px; color: var(--muted); font: 7px var(--mono); }
.tile-symbol { margin-top: 5px; color: var(--tile-color, var(--cyan)); font: 700 14px var(--mono); line-height: 1.2; }
.tile-name { width: 100%; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; color: var(--muted); font-size: 6px; line-height: 1.35; text-align: center; }
.category-alkali-metal { --tile-color: #ffad8c; --tile-border: rgba(255, 173, 140, .18); --tile-bg: rgba(255, 173, 140, .045); --tile-bg-hover: rgba(255, 173, 140, .12); }
.category-alkaline-earth-metal { --tile-color: #f5d179; --tile-border: rgba(245, 209, 121, .18); --tile-bg: rgba(245, 209, 121, .045); --tile-bg-hover: rgba(245, 209, 121, .12); }
.category-transition-metal { --tile-color: #8fb8ff; --tile-border: rgba(143, 184, 255, .18); --tile-bg: rgba(143, 184, 255, .045); --tile-bg-hover: rgba(143, 184, 255, .12); }
.category-post-transition-metal { --tile-color: #79d8cc; --tile-border: rgba(121, 216, 204, .18); --tile-bg: rgba(121, 216, 204, .045); --tile-bg-hover: rgba(121, 216, 204, .12); }
.category-metalloid { --tile-color: #b5a0ff; --tile-border: rgba(181, 160, 255, .2); --tile-bg: rgba(181, 160, 255, .05); --tile-bg-hover: rgba(181, 160, 255, .13); }
.category-nonmetal { --tile-color: #80dca8; --tile-border: rgba(128, 220, 168, .18); --tile-bg: rgba(128, 220, 168, .045); --tile-bg-hover: rgba(128, 220, 168, .12); }
.category-halogen { --tile-color: #ff9cb5; --tile-border: rgba(255, 156, 181, .18); --tile-bg: rgba(255, 156, 181, .045); --tile-bg-hover: rgba(255, 156, 181, .12); }
.category-noble-gas { --tile-color: #9aaeff; --tile-border: rgba(154, 174, 255, .18); --tile-bg: rgba(154, 174, 255, .045); --tile-bg-hover: rgba(154, 174, 255, .12); }
.category-lanthanide { --tile-color: #df9aff; --tile-border: rgba(223, 154, 255, .18); --tile-bg: rgba(223, 154, 255, .045); --tile-bg-hover: rgba(223, 154, 255, .12); }
.category-actinide { --tile-color: #ff8fbb; --tile-border: rgba(255, 143, 187, .18); --tile-bg: rgba(255, 143, 187, .045); --tile-bg-hover: rgba(255, 143, 187, .12); }
:root[data-theme="light"] .tile-number { color: #586780; }
.f-block-labels { display: flex; gap: 32px; justify-content: center; margin: -2px 0 5px; color: var(--faint); font: 8px var(--mono); text-transform: uppercase; letter-spacing: .1em; }
.category-legend { display: flex; flex-wrap: wrap; justify-content: center; gap: 7px 13px; padding: 14px 2px 12px; border-bottom: 1px solid var(--line); }
.legend-item { display: flex; align-items: center; gap: 5px; color: var(--muted); font-size: 8px; }
.legend-item::before { content: ""; width: 7px; height: 7px; border: 1px solid var(--tile-color); border-radius: 2px; background: var(--tile-bg-hover); }
.element-detail { min-height: 58px; padding: 11px 3px 0; display: flex; align-items: baseline; gap: 9px; flex-wrap: wrap; color: var(--muted); font-size: 9px; }
.element-detail .detail-title { color: var(--cyan); font-size: 10px; }
.detail-placeholder { color: var(--faint); }

.example-grid { display: grid; grid-template-columns: repeat(5, 1fr); gap: 12px; }
.example-card { min-height: 194px; padding: 15px; display: flex; flex-direction: column; border: 1px solid var(--line); border-radius: 13px; background: var(--panel-glass); transition: transform .2s, border-color .2s; }
.example-card:hover { transform: translateY(-3px); border-color: var(--line-strong); }
.example-card-top { display: flex; justify-content: space-between; align-items: center; min-height: 31px; }
.example-symbol { color: var(--cyan); font: 17px var(--mono); }
.example-category { color: var(--faint); font-size: 7px; text-align: right; }
.example-card h3 { margin: 11px 0 6px; font-size: 11px; }
.example-card p { margin: 0 0 9px; color: var(--muted); font-size: 9px; line-height: 1.6; }
.example-link { width: fit-content; margin-top: auto; padding: 0; border: 0; color: var(--cyan); background: transparent; cursor: pointer; font-size: 9px; font-weight: 800; }
.example-link:hover { text-decoration: underline; text-underline-offset: 3px; }
.about-section { padding: 0 0 70px; }
.about-card { display: grid; grid-template-columns: 45px 1fr auto; align-items: start; gap: 18px; padding: 27px 30px; border: 1px solid var(--line); border-radius: 15px; background: linear-gradient(120deg, rgba(101, 226, 223, .045), rgba(177, 138, 255, .04)), var(--panel); }
.about-symbol { width: 36px; height: 36px; display: grid; place-items: center; border: 1px solid rgba(101, 226, 223, .35); border-radius: 50%; color: var(--cyan); font: italic 17px Georgia, serif; }
.about-card .eyebrow { margin-bottom: 7px; }
.about-card h2 { margin-bottom: 10px; font-size: 20px; }
.about-card p:last-child { max-width: 760px; margin: 0; color: var(--muted); font-size: 10px; line-height: 1.8; }
.text-link { margin-top: 31px; color: var(--cyan); white-space: nowrap; font-size: 9px; font-weight: 800; }
.text-link span { margin-left: 6px; }
.site-footer { max-width: 1120px; min-height: 72px; margin: 0 auto; padding: 15px 0; display: flex; justify-content: space-between; align-items: center; border-top: 1px solid var(--line); color: var(--faint); font-size: 9px; }
.footer-brand { color: var(--muted); font-size: 11px; }
.footer-brand .brand-mark { width: 25px; height: 25px; border-radius: 8px; font-size: 15px; }
.site-footer > span span { color: var(--cyan); }
.toast { position: fixed; z-index: 20; right: 20px; bottom: 20px; max-width: min(380px, calc(100vw - 40px)); padding: 12px 16px; border: 1px solid var(--line-strong); border-radius: 10px; color: var(--text); background: var(--panel); box-shadow: var(--shadow); font-size: 11px; opacity: 0; pointer-events: none; transform: translateY(8px); transition: opacity .2s, transform .2s; }
.toast.is-visible { opacity: 1; transform: translateY(0); }

@media (max-width: 900px) {
  .site-header { padding: 0 4%; }
  .main-nav { gap: 17px; margin-left: 16px; }
  .main-nav a { font-size: 10px; }
  .hero { min-height: 470px; padding-top: 55px; }
  .hero-art { transform: scale(.86); }
  .workspace-grid { grid-template-columns: 1fr; }
  .builder-panel, .result-panel { min-height: 0; }
  .result-content { min-height: 230px; }
  .example-grid { grid-template-columns: repeat(3, 1fr); }
}
@media (max-width: 640px) {
  html { scroll-padding-top: 75px; }
  .site-header { height: 65px; padding: 0 5%; }
  .brand { gap: 7px; font-size: 11px; }
  .brand-mark { width: 27px; height: 27px; border-radius: 8px; }
  .brand b { font-size: 8px; }
  .main-nav { position: absolute; z-index: 10; top: 57px; left: 4%; right: 4%; margin: 0; padding: 8px; display: none; flex-direction: column; align-items: stretch; gap: 0; border: 1px solid var(--line-strong); border-radius: 12px; background: var(--panel); box-shadow: var(--shadow); }
  .main-nav.is-open { display: flex; }
  .main-nav a { padding: 11px 12px; font-size: 12px; }
  .main-nav a + a { border-top: 1px solid var(--line); }
  .header-actions { gap: 7px; }
  .element-badge { padding: 6px 8px; font-size: 8px; }
  .icon-button { width: 32px; height: 32px; }
  .menu-toggle { display: grid; height: 32px; }
  .hero { min-height: 0; padding: 53px 6% 35px; grid-template-columns: 1fr; gap: 0; }
  .hero h1 { font-size: clamp(48px, 14vw, 68px); }
  .hero-description { margin: 17px 0 20px; font-size: 12px; }
  .hero-note { flex-wrap: wrap; font-size: 8px; gap: 7px; }
  .hero-art { height: 250px; margin-top: -4px; transform: scale(.76); transform-origin: center top; }
  .section-wrap { width: 90%; }
  .workspace-section { padding: 22px 0 49px; }
  .periodic-section, .examples-section { padding: 20px 0 50px; }
  .section-heading { align-items: flex-start; flex-direction: column; gap: 8px; margin-bottom: 15px; }
  .section-heading h2 { font-size: 27px; }
  .section-intro { max-width: 100%; font-size: 10px; }
  .builder-panel, .result-panel { padding: 16px; }
  .builder-labels, .builder-row { grid-template-columns: 1fr 92px 31px; gap: 6px; }
  .builder-labels { margin-top: 20px; font-size: 7px; }
  .builder-row input { padding: 0 8px; font-size: 10px; }
  .builder-actions { gap: 7px; }
  .builder-actions .primary-button { padding: 0 10px; gap: 6px; font-size: 9px; }
  .builder-actions .secondary-button { padding: 0 9px; font-size: 9px; }
  .utility-grid { grid-template-columns: 1fr; gap: 10px; margin-top: 10px; }
  .compact-panel { min-height: 110px; padding: 14px; }
  .periodic-panel { padding: 12px; }
  .table-toolbar { align-items: stretch; flex-wrap: wrap; }
  .search-field { max-width: none; flex: 1 1 100%; }
  .filter-field { flex: 1; }
  .filter-field select { width: 100%; min-width: 0; }
  .table-status { align-self: center; }
  .periodic-grid { margin-left: 0; }
  .f-block-labels { justify-content: flex-start; padding-left: max(0px, calc((100% - 880px) / 2)); }
  .category-legend { justify-content: flex-start; gap: 8px 10px; }
  .element-detail { gap: 5px 9px; }
  .example-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 8px; }
  .example-card { min-height: 181px; padding: 12px; }
  .example-category { max-width: 74px; }
  .about-card { grid-template-columns: 34px 1fr; gap: 12px; padding: 19px; }
  .about-symbol { width: 30px; height: 30px; }
  .about-card h2 { font-size: 17px; }
  .about-card p:last-child { font-size: 9px; }
  .text-link { grid-column: 2; margin-top: 0; }
  .site-footer { width: 90%; min-height: 66px; }
  .footer-brand { font-size: 9px; }
  .site-footer > span { font-size: 8px; }
}
@media (max-width: 380px) {
  .brand { font-size: 10px; }
  .brand b { display: none; }
  .element-badge { font-size: 7px; }
  .header-actions { gap: 5px; }
  .hero-note { max-width: 280px; }
  .builder-labels, .builder-row { grid-template-columns: minmax(0, 1fr) 78px 29px; }
  .result-footer { gap: 5px; }
  .result-footer .text-button { font-size: 8px; }
  .example-card h3 { font-size: 10px; }
}
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { scroll-behavior: auto !important; transition-duration: .01ms !important; animation-duration: .01ms !important; animation-iteration-count: 1 !important; }
}