dialog.reference-modal{width:min(1240px,calc(100% - 32px));max-width:none;max-height:calc(100dvh - 32px);border-radius:20px;overflow:auto}
.reference-dialog{min-width:0}.reference-header{display:flex;align-items:flex-start;justify-content:space-between;gap:20px;padding:25px 28px 17px;background:var(--surface);position:sticky;top:0;z-index:6;border-bottom:1px solid var(--line)}.reference-header h2{font-size:25px;line-height:1.25;letter-spacing:-.65px;margin:0 0 7px;font-weight:600}.reference-header p{margin:0;color:var(--muted);font-size:12px}.reference-header>.icon-btn{flex:none}.reference-tabs{display:flex;gap:5px;flex-wrap:wrap;padding:15px 28px 0}.reference-tabs button{border:1px solid transparent;padding:10px 15px;border-radius:9px;background:transparent;color:var(--muted);font-size:12px;line-height:1.4}.reference-tabs button[aria-pressed=true]{background:var(--blue-soft);color:var(--blue);border-color:var(--line)}.reference-body{padding:18px 28px 25px}.reference-intro{font-size:13px;line-height:1.8;color:var(--muted);max-width:760px;margin:0 0 19px}.reference-tools{display:grid;grid-template-columns:minmax(0,1fr) minmax(190px,.6fr);gap:14px;margin-bottom:12px}.reference-tools label{display:grid;gap:7px;font-size:11px;color:var(--muted)}.reference-tools input,.reference-tools select{width:100%;min-width:0;background:var(--surface);border:1px solid var(--line);border-radius:9px;color:var(--ink);min-height:42px;padding:10px 12px;font:inherit;font-size:13px}.reference-search-status{min-height:18px;font-size:11px;color:var(--muted);margin:0 0 12px}.reference-scroll{max-width:100%;min-width:0;overflow:auto;overscroll-behavior:contain;border-radius:9px;scrollbar-gutter:stable}.reference-scroll:focus-visible{outline:2px solid var(--blue);outline-offset:3px}.reference-note{font-size:11px;line-height:1.8;color:var(--muted);margin:16px 0 0}.reference-legend{display:flex;gap:11px 18px;flex-wrap:wrap;margin-top:20px;font-size:10px;color:var(--muted)}.reference-legend>span{display:flex;align-items:center;gap:6px;line-height:1.6}.reference-sources{margin-top:18px;padding-top:15px;border-top:1px solid var(--line);font-size:11px;color:var(--muted)}.reference-sources summary{cursor:pointer}.reference-sources a{display:flex;align-items:center;gap:6px;width:fit-content;color:var(--blue);margin-top:12px;font-size:11px}.reference-trigger{display:inline-flex;align-items:center;gap:5px;white-space:nowrap}.materials-nav .subnav button{text-align:left;width:100%;font-size:11px;color:var(--muted);background:none;border:0;padding:9px 8px;line-height:1.55;border-radius:7px}.materials-nav .subnav button:hover{background:var(--blue-soft);color:var(--blue)}
[data-category]{--category-color:#3277b9}[data-category=alkali]{--category-color:#cc673e}[data-category=alkaline]{--category-color:#a27627}[data-category=transition]{--category-color:#5275bc}[data-category=post]{--category-color:#298781}[data-category=metalloid]{--category-color:#69882c}[data-category=nonmetal]{--category-color:#378257}[data-category=halogen]{--category-color:#9a5f9e}[data-category=noble]{--category-color:#6557b1}[data-category=lanthanide]{--category-color:#b96285}[data-category=actinide]{--category-color:#897044}[data-category=unknown]{--category-color:#76808e}
.periodic-grid{display:grid;grid-template-columns:23px repeat(18,minmax(43px,1fr));grid-template-rows:20px repeat(7,62px) 10px repeat(2,62px);gap:4px;min-width:900px;padding:2px}.periodic-axis{display:flex;align-items:center;justify-content:center;font-size:10px;color:var(--muted);font-variant-numeric:tabular-nums}.periodic-cell{position:relative;min-width:0;border:1px solid color-mix(in srgb,var(--category-color) 24%,var(--line));border-radius:6px;background:color-mix(in srgb,var(--category-color) 9%,var(--surface));color:var(--ink);display:flex;flex-direction:column;align-items:center;justify-content:center;padding:11px 1px 3px;transition:background .12s,opacity .12s;line-height:1.2}.periodic-cell small{position:absolute;left:5px;top:4px;font-size:8px;color:var(--muted)}.periodic-cell strong{font-size:20px;font-weight:600;letter-spacing:-.4px}.periodic-cell>span{font-size:8px;color:var(--muted);margin-top:4px;font-variant-numeric:tabular-nums;white-space:nowrap}.periodic-cell:hover,.periodic-cell[aria-pressed=true]{background:color-mix(in srgb,var(--category-color) 22%,var(--surface));border-color:var(--category-color)}.periodic-cell[aria-pressed=true]{box-shadow:inset 0 0 0 1px var(--category-color)}.periodic-cell.is-dim:not([aria-pressed=true]){opacity:.23}.periodic-family-slot{border:1px dashed var(--line);border-radius:6px;display:flex;align-items:center;justify-content:center;flex-direction:column;text-align:center;font-size:9px;line-height:1.6;color:var(--muted)}.periodic-detail{grid-column:4/span 9;grid-row:2/span 3;display:flex;gap:20px;align-items:center;align-self:center;padding:18px 28px;min-width:0}.reference-element-mark{display:flex;flex-direction:column;flex:none;justify-content:center;align-items:center;border-radius:15px;width:90px;height:102px;background:color-mix(in srgb,var(--category-color) 13%,var(--surface));color:var(--category-color);position:relative}.reference-element-mark small{position:absolute;top:10px;left:12px;font-size:12px}.reference-element-mark strong{font-size:42px;letter-spacing:-1px;font-weight:600}.periodic-detail h3,.periodic-mobile-detail h3{font-size:23px;font-weight:600;letter-spacing:-.5px;margin:0 0 7px}.periodic-detail p,.periodic-mobile-detail p{font-size:12px;color:var(--muted);margin:0 0 17px}.periodic-detail dl,.periodic-mobile-detail dl{display:flex;gap:14px 30px;flex-wrap:wrap;margin:0}.periodic-detail dt,.periodic-mobile-detail dt{font-size:10px;color:var(--muted);margin-bottom:5px}.periodic-detail dd,.periodic-mobile-detail dd{margin:0;font-size:13px}.periodic-mobile-detail{display:none}.periodic-legend i{width:9px;height:9px;border-radius:3px;background:var(--category-color)}
.solubility-scroll{max-height:48dvh;border:1px solid var(--line)}.solubility-table{border-collapse:separate;border-spacing:0;width:100%;font-size:12px;text-align:center;min-width:1040px;font-variant-numeric:tabular-nums}.solubility-table th{background:var(--surface-alt);font-size:12px;font-weight:550;padding:10px 7px;white-space:nowrap;border-bottom:1px solid var(--line);border-right:1px solid var(--line)}.solubility-table thead th{position:sticky;top:0;z-index:3}.solubility-table thead th:first-child{left:0;z-index:4;font-size:9px;min-width:100px}.solubility-table tbody th{position:sticky;left:0;z-index:2}.solubility-table td{border-bottom:1px solid var(--line);border-right:1px solid var(--line);padding:0}.solubility-table sup{font-size:9px;margin-left:1px}.solubility-table sub{font-size:9px}.solubility-cell{width:100%;height:33px;min-width:40px;background:var(--surface);border:0;font-size:12px;font-weight:500;position:relative}.soluble{color:var(--blue)}.slight{color:#a96f16}.insoluble{color:var(--ink)}.decomposes{color:#c26449}.unknown,.water{color:var(--muted)}.solubility-cell.soluble{background:color-mix(in srgb,var(--blue) 6%,var(--surface))}.solubility-cell.slight{background:color-mix(in srgb,#be8c32 10%,var(--surface))}.solubility-cell.decomposes{background:color-mix(in srgb,#c26449 7%,var(--surface))}.solubility-cell[aria-pressed=true]{box-shadow:inset 0 0 0 2px var(--blue);z-index:1}.solubility-cell:focus-visible{outline:2px solid var(--blue);outline-offset:-3px}.solubility-table .selected-axis{background:var(--blue-soft);color:var(--blue)}.solubility-result{display:flex;justify-content:space-between;align-items:center;gap:15px;min-height:55px;background:var(--surface-alt);border-radius:9px;padding:13px 16px;margin:17px 0;font-size:17px}.solubility-result strong{font-size:13px;font-weight:550}.reference-result-plus{font-size:13px;color:var(--muted);padding:0 8px}.solubility-legend b{min-width:22px;text-align:center;font-size:12px;font-weight:550}
.activity-direction{display:flex;justify-content:space-between;font-size:11px;color:var(--muted);padding:10px 0 13px;position:relative;margin-bottom:20px}.activity-direction:after{content:'';position:absolute;bottom:0;left:0;right:0;height:3px;border-radius:5px;background:linear-gradient(90deg,var(--blue),color-mix(in srgb,var(--blue) 10%,var(--surface)))}.activity-series{list-style:none;display:flex;flex-wrap:wrap;gap:8px;padding:0;margin:20px 0 25px}.activity-metal{width:59px;height:64px;border:1px solid var(--line);border-radius:9px;font-size:22px;font-weight:550;letter-spacing:-.4px;background:var(--surface-alt);color:var(--ink)}.activity-metal.before-hydrogen{background:var(--blue-soft);color:var(--blue)}.activity-metal.after-hydrogen{background:color-mix(in srgb,#368a6b 9%,var(--surface));color:#368a6b}.activity-metal.hydrogen{border-style:dashed}.activity-metal[aria-pressed=true]{border:2px solid var(--blue)}.activity-selected{padding:23px 25px;border:1px solid var(--line);border-radius:12px;background:var(--surface-alt);margin:20px 0 27px}.activity-selected strong{font-size:19px;font-weight:550}.activity-selected p{font-size:13px;line-height:1.9;margin:11px 0 0;color:var(--muted);max-width:800px}.activity-explanations{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:28px}.activity-explanations h3{font-size:15px;margin:0 0 10px;font-weight:550}.activity-explanations p{font-size:12px;line-height:1.9;color:var(--muted);margin:0}.instruction-overview{margin:0 0 30px;padding:27px;border:1px solid var(--line);border-radius:16px;background:var(--surface)}.instruction-overview>h2{font-size:21px;margin:0 0 12px;font-weight:600;letter-spacing:-.4px}.instruction-overview>p{font-size:13px;color:var(--muted);line-height:1.9;margin:0 0 22px;max-width:760px}.instruction-modes{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:22px}.instruction-mode h3{display:flex;align-items:center;gap:8px;font-size:15px;margin:0 0 10px;font-weight:550}.instruction-mode svg{color:var(--blue);flex:none}.instruction-mode p{font-size:12px;line-height:1.9;color:var(--muted);margin:0}.instruction-note{font-size:12px;line-height:1.9;color:var(--muted);margin:22px 0 0;padding-top:18px;border-top:1px solid var(--line)}.exam-useful{margin:24px 0 28px}.exam-useful h2{font-size:19px;font-weight:580;margin:0 0 15px;letter-spacing:-.3px}.exam-useful-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:10px}.exam-useful a{border:1px solid var(--line);border-radius:11px;padding:16px 18px;display:flex;align-items:center;justify-content:space-between;gap:15px;background:var(--surface)}.exam-useful a:hover{border-color:var(--blue)}.exam-useful strong{display:block;font-size:13px;font-weight:550}.exam-useful small{display:block;margin-top:6px;color:var(--muted);font-size:11px;line-height:1.7}.exam-useful svg{flex:none;color:var(--blue)}
@media(max-width:760px){.reference-header{padding:20px 18px 14px}.reference-header h2{font-size:21px}.reference-body{padding:17px 18px 22px}.reference-tabs{padding:12px 18px 0;gap:4px}.reference-tabs button{padding:8px 10px;font-size:10px}.reference-tools{grid-template-columns:1fr;gap:11px}.reference-intro{font-size:12px}.periodic-detail{visibility:hidden}.periodic-mobile-detail{display:flex;align-items:center;gap:18px;padding:20px 0 0}.periodic-mobile-detail .reference-element-mark{width:65px;height:77px;border-radius:10px}.periodic-mobile-detail .reference-element-mark strong{font-size:32px}.periodic-mobile-detail h3{font-size:19px}.periodic-mobile-detail p{font-size:10px;margin-bottom:12px}.periodic-mobile-detail dl{gap:10px 18px}.periodic-mobile-detail dt{font-size:9px}.periodic-mobile-detail dd{font-size:11px}.reference-legend{font-size:9px;gap:9px 13px}.solubility-result{align-items:flex-start;flex-direction:column;gap:8px;padding:13px}.solubility-result strong{font-size:12px}.activity-metal{width:47px;height:53px;font-size:19px}.activity-series{gap:6px}.activity-selected{padding:19px}.activity-explanations{grid-template-columns:1fr;gap:22px}.instruction-overview{padding:23px}.instruction-modes{grid-template-columns:1fr;gap:22px}.exam-useful-grid{grid-template-columns:1fr}.instruction-overview>h2{font-size:19px}.instruction-note{margin-top:19px}.practice-header-actions{gap:12px}.practice-title h1{max-width:125px}}
@media(max-width:480px){dialog.reference-modal{width:calc(100% - 16px);max-height:calc(100dvh - 16px);border-radius:15px}.reference-tabs button{font-size:10px;flex:1 1 auto;text-align:center}.reference-trigger-label{position:absolute;width:1px;height:1px;overflow:hidden;clip-path:inset(50%)}.reference-trigger{min-width:25px;justify-content:center}.periodic-mobile-detail dl{flex-direction:column;gap:8px}.periodic-mobile-detail .reference-element-mark{align-self:flex-start}.reference-header h2{font-size:20px}}
@media(prefers-reduced-motion:reduce){.periodic-cell{transition:none}}

.exam-useful-grid>a:last-child:nth-child(odd){grid-column:1/-1}.utility-nav>.materials-nav{grid-column:1/-1}
@media(max-width:760px){.periodic-mobile-detail{padding:0 0 22px}}
.reference-heading{position:sticky;top:0;z-index:6;background:var(--surface)}.reference-heading .reference-header{position:static}.reference-heading .reference-tabs{padding-bottom:12px;background:var(--surface)}