CSS: Searching a Dataset with Filters

css-searching-a-dataset-with-filters.markdown

CSS: Searching a Dataset with Filters

Searching and filtering a list with CSS. In order to have three characters of specificity, I parse the specific list of words to get all relevant permutations instead of any combination of the full alphabet. This limits the potential 1, 2, and 3 letter combinations to 1,245 permutations instead of 18,278 which allows its complexity to be digested by CodePen.

The filters map to attribute selector wildcards in CSS, so the "finding" of elements is actually fairly simple.

A Pen by HARUN PEHLİVAN on CodePen.

License.

index.html

<input type="radio" name="filters" id="contains" checked="checked"/>
<input type="radio" name="filters" id="starts-with"/>
<input type="radio" name="filters" id="ends-with"/>
<input type="radio" name="a1" id="a1nil" checked="checked"/>
<input type="radio" name="a1" id="a1q"/>
<input type="radio" name="a1" id="a1w"/>
<input type="radio" name="a1" id="a1e"/>
<input type="radio" name="a1" id="a1r"/>
<input type="radio" name="a1" id="a1t"/>
<input type="radio" name="a1" id="a1y"/>
<input type="radio" name="a1" id="a1u"/>
<input type="radio" name="a1" id="a1i"/>
<input type="radio" name="a1" id="a1o"/>
<input type="radio" name="a1" id="a1p"/>
<input type="radio" name="a1" id="a1a"/>
<input type="radio" name="a1" id="a1s"/>
<input type="radio" name="a1" id="a1d"/>
<input type="radio" name="a1" id="a1f"/>
<input type="radio" name="a1" id="a1g"/>
<input type="radio" name="a1" id="a1h"/>
<input type="radio" name="a1" id="a1j"/>
<input type="radio" name="a1" id="a1k"/>
<input type="radio" name="a1" id="a1l"/>
<input type="radio" name="a1" id="a1z"/>
<input type="radio" name="a1" id="a1x"/>
<input type="radio" name="a1" id="a1c"/>
<input type="radio" name="a1" id="a1v"/>
<input type="radio" name="a1" id="a1b"/>
<input type="radio" name="a1" id="a1n"/>
<input type="radio" name="a1" id="a1m"/>
<input type="radio" name="a2" id="a2nil" checked="checked"/>
<input type="radio" name="a2" id="a2q"/>
<input type="radio" name="a2" id="a2w"/>
<input type="radio" name="a2" id="a2e"/>
<input type="radio" name="a2" id="a2r"/>
<input type="radio" name="a2" id="a2t"/>
<input type="radio" name="a2" id="a2y"/>
<input type="radio" name="a2" id="a2u"/>
<input type="radio" name="a2" id="a2i"/>
<input type="radio" name="a2" id="a2o"/>
<input type="radio" name="a2" id="a2p"/>
<input type="radio" name="a2" id="a2a"/>
<input type="radio" name="a2" id="a2s"/>
<input type="radio" name="a2" id="a2d"/>
<input type="radio" name="a2" id="a2f"/>
<input type="radio" name="a2" id="a2g"/>
<input type="radio" name="a2" id="a2h"/>
<input type="radio" name="a2" id="a2j"/>
<input type="radio" name="a2" id="a2k"/>
<input type="radio" name="a2" id="a2l"/>
<input type="radio" name="a2" id="a2z"/>
<input type="radio" name="a2" id="a2x"/>
<input type="radio" name="a2" id="a2c"/>
<input type="radio" name="a2" id="a2v"/>
<input type="radio" name="a2" id="a2b"/>
<input type="radio" name="a2" id="a2n"/>
<input type="radio" name="a2" id="a2m"/>
<input type="radio" name="a3" id="a3nil" checked="checked"/>
<input type="radio" name="a3" id="a3q"/>
<input type="radio" name="a3" id="a3w"/>
<input type="radio" name="a3" id="a3e"/>
<input type="radio" name="a3" id="a3r"/>
<input type="radio" name="a3" id="a3t"/>
<input type="radio" name="a3" id="a3y"/>
<input type="radio" name="a3" id="a3u"/>
<input type="radio" name="a3" id="a3i"/>
<input type="radio" name="a3" id="a3o"/>
<input type="radio" name="a3" id="a3p"/>
<input type="radio" name="a3" id="a3a"/>
<input type="radio" name="a3" id="a3s"/>
<input type="radio" name="a3" id="a3d"/>
<input type="radio" name="a3" id="a3f"/>
<input type="radio" name="a3" id="a3g"/>
<input type="radio" name="a3" id="a3h"/>
<input type="radio" name="a3" id="a3j"/>
<input type="radio" name="a3" id="a3k"/>
<input type="radio" name="a3" id="a3l"/>
<input type="radio" name="a3" id="a3z"/>
<input type="radio" name="a3" id="a3x"/>
<input type="radio" name="a3" id="a3c"/>
<input type="radio" name="a3" id="a3v"/>
<input type="radio" name="a3" id="a3b"/>
<input type="radio" name="a3" id="a3n"/>
<input type="radio" name="a3" id="a3m"/>
<nav>
  <h2>CSS Searching a Dataset with Filters</h2>
  <section class="alpha-1">
    <h1>Char 1</h1>
    <label for="a1nil">clear</label>
    <label for="a1q">q</label>
    <label for="a1w">w</label>
    <label for="a1e">e</label>
    <label for="a1r">r</label>
    <label for="a1t">t</label>
    <label for="a1y">y</label>
    <label for="a1u">u</label>
    <label for="a1i">i</label>
    <label for="a1o">o</label>
    <label for="a1p">p</label>
    <label for="a1a">a</label>
    <label for="a1s">s</label>
    <label for="a1d">d</label>
    <label for="a1f">f</label>
    <label for="a1g">g</label>
    <label for="a1h">h</label>
    <label for="a1j">j</label>
    <label for="a1k">k</label>
    <label for="a1l">l</label>
    <label for="a1z">z</label>
    <label for="a1x">x</label>
    <label for="a1c">c</label>
    <label for="a1v">v</label>
    <label for="a1b">b</label>
    <label for="a1n">n</label>
    <label for="a1m">m</label>
  </section>
  <section class="alpha-2">
    <h1>Char 2</h1>
    <label for="a2nil">clear</label>
    <label for="a2q">q</label>
    <label for="a2w">w</label>
    <label for="a2e">e</label>
    <label for="a2r">r</label>
    <label for="a2t">t</label>
    <label for="a2y">y</label>
    <label for="a2u">u</label>
    <label for="a2i">i</label>
    <label for="a2o">o</label>
    <label for="a2p">p</label>
    <label for="a2a">a</label>
    <label for="a2s">s</label>
    <label for="a2d">d</label>
    <label for="a2f">f</label>
    <label for="a2g">g</label>
    <label for="a2h">h</label>
    <label for="a2j">j</label>
    <label for="a2k">k</label>
    <label for="a2l">l</label>
    <label for="a2z">z</label>
    <label for="a2x">x</label>
    <label for="a2c">c</label>
    <label for="a2v">v</label>
    <label for="a2b">b</label>
    <label for="a2n">n</label>
    <label for="a2m">m</label>
  </section>
  <section class="alpha-3">
    <h1>Char 3</h1>
    <label for="a3nil">clear</label>
    <label for="a3q">q</label>
    <label for="a3w">w</label>
    <label for="a3e">e</label>
    <label for="a3r">r</label>
    <label for="a3t">t</label>
    <label for="a3y">y</label>
    <label for="a3u">u</label>
    <label for="a3i">i</label>
    <label for="a3o">o</label>
    <label for="a3p">p</label>
    <label for="a3a">a</label>
    <label for="a3s">s</label>
    <label for="a3d">d</label>
    <label for="a3f">f</label>
    <label for="a3g">g</label>
    <label for="a3h">h</label>
    <label for="a3j">j</label>
    <label for="a3k">k</label>
    <label for="a3l">l</label>
    <label for="a3z">z</label>
    <label for="a3x">x</label>
    <label for="a3c">c</label>
    <label for="a3v">v</label>
    <label for="a3b">b</label>
    <label for="a3n">n</label>
    <label for="a3m">m</label>
  </section>
  <section class="filters">
    <h1>Filters</h1>
    <label for="contains">contains</label>
    <label for="starts-with">starts with</label>
    <label for="ends-with">ends with</label>
  </section>
</nav>
<main>
  <h2><span id="f"></span><span class="quote"><span id="o1"></span><span id="o2"></span><span id="o3"></span></span></h2>
  <ul>
    <li dv="speech">speech</li>
    <li dv="buy">buy</li>
    <li dv="brand">brand</li>
    <li dv="empirical">empirical</li>
    <li dv="offspring">offspring</li>
    <li dv="like">like</li>
    <li dv="neutral">neutral</li>
    <li dv="crime">crime</li>
    <li dv="pneumonia">pneumonia</li>
    <li dv="aid">aid</li>
    <li dv="mold">mold</li>
    <li dv="accompany">accompany</li>
    <li dv="bin">bin</li>
    <li dv="pastel">pastel</li>
    <li dv="laundry">laundry</li>
    <li dv="producer">producer</li>
    <li dv="posture">posture</li>
    <li dv="throne">throne</li>
    <li dv="beef">beef</li>
    <li dv="colon">colon</li>
    <li dv="secretary">secretary</li>
    <li dv="reason">reason</li>
    <li dv="portrait">portrait</li>
    <li dv="sniff">sniff</li>
    <li dv="print">print</li>
    <li dv="quiet">quiet</li>
    <li dv="minister">minister</li>
    <li dv="break">break</li>
    <li dv="crown">crown</li>
    <li dv="edge">edge</li>
    <li dv="rebel">rebel</li>
    <li dv="case">case</li>
    <li dv="dance">dance</li>
    <li dv="disgrace">disgrace</li>
    <li dv="bottom">bottom</li>
    <li dv="merit">merit</li>
    <li dv="blade">blade</li>
    <li dv="frog">frog</li>
    <li dv="mourning">mourning</li>
    <li dv="member">member</li>
    <li dv="feel">feel</li>
    <li dv="bed">bed</li>
    <li dv="behead">behead</li>
    <li dv="organize">organize</li>
    <li dv="request">request</li>
    <li dv="service">service</li>
    <li dv="despise">despise</li>
    <li dv="glue">glue</li>
    <li dv="tribute">tribute</li>
    <li dv="east">east</li>
    <li dv="hotdog">hotdog</li>
    <li dv="rate">rate</li>
    <li dv="seat">seat</li>
    <li dv="soul">soul</li>
    <li dv="cook">cook</li>
    <li dv="inch">inch</li>
    <li dv="lily">lily</li>
    <li dv="week">week</li>
    <li dv="porter">porter</li>
    <li dv="silence">silence</li>
    <li dv="eject">eject</li>
    <li dv="contact">contact</li>
    <li dv="injury">injury</li>
    <li dv="stick">stick</li>
    <li dv="button">button</li>
    <li dv="resist">resist</li>
    <li dv="retailer">retailer</li>
    <li dv="dressing">dressing</li>
    <li dv="flight">flight</li>
    <li dv="volcano">volcano</li>
    <li dv="dream">dream</li>
    <li dv="money">money</li>
    <li dv="tourist">tourist</li>
    <li dv="leash">leash</li>
    <li dv="dare">dare</li>
    <li dv="candidate">candidate</li>
    <li dv="fish">fish</li>
    <li dv="analysis">analysis</li>
    <li dv="official">official</li>
    <li dv="reaction">reaction</li>
    <li dv="hostile">hostile</li>
    <li dv="just">just</li>
    <li dv="graze">graze</li>
    <li dv="bathtub">bathtub</li>
    <li dv="clear">clear</li>
    <li dv="captivate">captivate</li>
    <li dv="risk">risk</li>
    <li dv="dairy">dairy</li>
    <li dv="apathy">apathy</li>
    <li dv="say">say</li>
    <li dv="scratch">scratch</li>
    <li dv="passage">passage</li>
    <li dv="stress">stress</li>
    <li dv="village">village</li>
    <li dv="invite">invite</li>
    <li dv="route">route</li>
    <li dv="fool">fool</li>
    <li dv="accurate">accurate</li>
    <li dv="window">window</li>
    <li dv="betray">betray</li>
    <li dv="blue">blue</li>
    <li dv="abandon">abandon</li>
    <li dv="quest">quest</li>
    <li dv="beginning">beginning</li>
    <li dv="voucher">voucher</li>
    <li dv="cow">cow</li>
    <li dv="extract">extract</li>
    <li dv="trail">trail</li>
    <li dv="smile">smile</li>
    <li dv="useful">useful</li>
    <li dv="smash">smash</li>
    <li dv="red">red</li>
    <li dv="credit">credit</li>
    <li dv="instinct">instinct</li>
    <li dv="storage">storage</li>
    <li dv="brush">brush</li>
    <li dv="coverage">coverage</li>
    <li dv="oral">oral</li>
    <li dv="effort">effort</li>
    <li dv="compete">compete</li>
    <li dv="timber">timber</li>
    <li dv="flesh">flesh</li>
    <li dv="afford">afford</li>
    <li dv="filter">filter</li>
    <li dv="meadow">meadow</li>
    <li dv="nickel">nickel</li>
    <li dv="valid">valid</li>
    <li dv="coma">coma</li>
    <li dv="baseball">baseball</li>
    <li dv="encourage">encourage</li>
    <li dv="penetrate">penetrate</li>
    <li dv="bare">bare</li>
    <li dv="shine">shine</li>
    <li dv="finance">finance</li>
    <li dv="episode">episode</li>
    <li dv="honest">honest</li>
    <li dv="miner">miner</li>
    <li dv="vote">vote</li>
    <li dv="harass">harass</li>
    <li dv="crosswalk">crosswalk</li>
    <li dv="copper">copper</li>
    <li dv="magazine">magazine</li>
    <li dv="suffering">suffering</li>
    <li dv="moment">moment</li>
    <li dv="greet">greet</li>
    <li dv="practical">practical</li>
    <li dv="monarch">monarch</li>
    <li dv="bounce">bounce</li>
    <li dv="fun">fun</li>
    <li dv="workshop">workshop</li>
    <li dv="harvest">harvest</li>
    <li dv="plaster">plaster</li>
    <li dv="mars">mars</li>
  </ul>
</main>

style.scss

$filters: contains, starts-with, ends-with;
$alpha: nil,a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z;
$words: 'speech','buy','brand','empirical','offspring','like','neutral','crime','pneumonia','aid','mold','accompany','bin','pastel','laundry','producer','posture','throne','beef','colon','secretary','reason','portrait','sniff','print','quiet','minister','break','crown','edge','rebel','case','dance','disgrace','bottom','merit','blade','frog','mourning','member','feel','bed','behead','organize','request','service','despise','glue','tribute','east','hotdog','rate','seat','soul','cook','inch','lily','week','porter','silence','eject','contact','injury','stick','button','resist','retailer','dressing','flight','volcano','dream','money','tourist','leash','dare','candidate','fish','analysis','official','reaction','hostile','just','graze','bathtub','clear','captivate','risk','dairy','apathy','say','scratch','passage','stress','village','invite','route','fool','accurate','window','betray','blue','abandon','quest','beginning','voucher','cow','extract','trail','smile','useful','smash','red','credit','instinct','storage','brush','coverage','oral','effort','compete','timber','flesh','afford','filter','meadow','nickel','valid','coma','baseball','encourage','penetrate','bare','shine','finance','episode','honest','miner','vote','harass','crosswalk','copper','magazine','suffering','moment','greet','practical','monarch','bounce','fun','workshop','harvest','plaster','mars';//,'protest','minute','makeup','diagram','cheek','flourish','revenge','wreck','clearance','entertain','lock','green','cluster','flower','private','proper','hole','agreement','see','dry','eternal','chain','cafe','ignorant','forge','mystery','spy','death','security','burial','collar','mess','cabin','plead','evening','bank','sculpture','vehicle','polish','rack','mechanism','content','lump','pride','deadly','widen','marriage','cigarette','stadium','stock','character','salon','industry','lose','ordinary','hunting','berry','stroll','price','pound','elegant','sit','keep','elapse','element','cherry','shoulder','pay','dominate','depend','workout','reduction','garage','sphere','ratio','ditch','value','ambition','pumpkin','miracle','estimate','agree','pier','pity','stand','abstract','gallery','context','stun','river','suspicion','energy','player','god','grateful','inflation','volunteer','limited','europe','scandal','vague','employee','theorist','intensify','lecture','tongue','mass','utter','pigeon','bridge','prize','meat','steel','similar','modest','clerk','pleasant','wild','mutter','economy','spin','motif','tool','delivery','parachute','session','swing','primary','orchestra','raid','variable','drug','score','reception','father','jam','movie','bulletin','salmon','cutting','goat','drawer','tease','export','pole','memory','bottle','large','tumble','reality','grant','nerve','detective','promote','fog','fireplace','reptile','tissue','will','enhance','harbor','influence','looting','scenario','cream','quantity','sting','fibre','birthday','pudding','advocate','domestic','central','rubbish','talk','dark','text','sofa','due','top','offensive','favorable','meet','fuss','quality','image','urine','deny','plaintiff','sickness','toll','round','lion','debt','spray','divide','native','snack','take','feminine','raw','squash','dollar','junior','tape','journal','express','poetry','donor','expect','spend','think','applaud','relate','edition','clue','academy','cage','president','cool','retreat','leader','whole','steak','proof','eyebrow','pour','champion','belly','way','sense','lean','justice','fare','monk','person','sail','priority','umbrella','project','winter','omission','sunrise','advice','platform','exemption';

$ones: null;
$twos: null;
$threes: null;

// we want to take a list, a string, a starting index and amount of chars to check
// if it is unique in the list, we add the sequence to the list
@function check-char($list, $string, $index, $amount) {
  // if we have enough chars for the desired amount left in the string
  @if str-length($string) >= ($index + $amount - 1) {
    // get the sequence of letters
    $seq: str-slice($string, $index, $index + $amount - 1);
    // if list isnt a list yet
    @if $list == null {
      // return a new list with the value
      @return ($seq);
    // else if it isnt in the list
    } @elseif index($list, $seq) == null { 
      // add it to the list
      @return append($list, $seq); 
    // else, ignore this sequence
    } @else {
      // return the original list
      @return $list;
    }
  // return null so we can ignore
  } @else {
    @return null;
  }
}

// thanks, hugo!
// https://css-tricks.com/snippets/sass/str-replace-function/
@function str-replace($string, $search, $replace: '') {
  $index: str-index($string, $search);
  @if $index {
    @return str-slice($string, 1, $index - 1) + $replace + str-replace(str-slice($string, $index + str-length($search)), $search, $replace);
  }
  @return $string;
}

// for each word
@each $word in $words {
  // for each char
  @for $i from 1 through str-length($word) {
    // check the ones for that char
    $one: check-char($ones, $word, $i, 1);
    // check the twos for the two chars from this position
    $two: check-char($twos, $word, $i, 2);
    // check the threes for the three chars from this position
    $three: check-char($threes, $word, $i, 3);
    // if we got a new list from the function, set it
    @if $one != null { $ones: $one; }
    @if $two != null { $twos: $two; }
    @if $three != null { $threes: $three; }
  }
}

// deactivating second char menu
#a1nil:checked ~ nav section.alpha-2,
#a1nil:checked ~ nav section.alpha-3,
#a2nil:checked ~ nav section.alpha-3 { opacity: 0.2; pointer-events: none; }

// selected label states
%active-label { 
  background: #1A659E;
  color: white;
}

@mixin active-word {
  color: #1A659E; 
  background: white; 
  opacity: 1; 
  order: 1;
  box-shadow: 0px 1px 2px rgba(0,0,0,0.1);
}

// deactivating all li
li { 
  opacity: 0.2;
  order: 2; 
}

// showing all when no filter
#a1nil:checked ~ main li { @include active-word; }

// each filter
@each $filter in $filters {
  ##{$filter}:checked ~ nav [for="#{$filter}"] { @extend %active-label; }
  ##{$filter}:checked ~ main #f::before { content: "#{str-replace($filter, '-', ' ')} "; }
}

// each alpha
@each $char in $alpha {
  #a1#{$char}:checked ~ nav [for="a1#{$char}"],
  #a2#{$char}:checked ~ nav [for="a2#{$char}"],
  #a3#{$char}:checked ~ nav [for="a3#{$char}"] { @extend %active-label; }
  @if $char != 'nil' {
    #a1#{$char}:checked ~ main #o1::after,
    #a2#{$char}:checked ~ main #o2::after,
    #a3#{$char}:checked ~ main #o3::after {
      content: "#{$char}";
    }
  }
}

// extending ends up killing us, so the selectors are split up.
$sel: '';
@each $one in $ones {
  // first letter nil second
  $sel: $sel + '#contains:checked ~ #a1#{$one}:checked ~ #a2nil:checked ~ main [dv*="#{$one}"],';
  $sel: $sel + '#starts-with:checked ~ #a1#{$one}:checked ~ #a2nil:checked ~ main [dv^="#{$one}"],';
  $sel: $sel + '#ends-with:checked ~ #a1#{$one}:checked ~ #a2nil:checked ~ main [dv$="#{$one}"],';
}
@each $two in $twos {
  $char-1: str-slice($two, 1, 1);
  $char-2: str-slice($two, 2, 2);
  // active combinations
  $sel: $sel + '#contains:checked ~ #a1#{$char-1}:checked ~ #a2#{$char-2}:checked ~ #a3nil:checked ~ main [dv*="#{$two}"],';
  $sel: $sel + '#starts-with:checked ~ #a1#{$char-1}:checked ~ #a2#{$char-2}:checked ~ #a3nil:checked ~ main [dv^="#{$two}"],';
  $sel: $sel + '#ends-with:checked ~ #a1#{$char-1}:checked ~ #a2#{$char-2}:checked ~ #a3nil:checked ~ main [dv$="#{$two}"],';
}

// this is one large comma-separated selector, done for each first letter and its permutations.
// if we built one massive selector for everything, stuff stops working.
#{$sel} { @include active-word; }

// reset the selector
$sel: '';
@each $three in $threes {
  $char-1: str-slice($three, 1, 1);
  $char-2: str-slice($three, 2, 2);
  $char-3: str-slice($three, 3, 3);
  // active combinations
  $sel: $sel + '#contains:checked ~ #a1#{$char-1}:checked ~ #a2#{$char-2}:checked ~ #a3#{$char-3}:checked ~ main [dv*="#{$three}"],';
  $sel: $sel + '#starts-with:checked ~ #a1#{$char-1}:checked ~ #a2#{$char-2}:checked ~ #a3#{$char-3}:checked ~ main [dv^="#{$three}"],';
  $sel: $sel + '#ends-with:checked ~ #a1#{$char-1}:checked ~ #a2#{$char-2}:checked ~ #a3#{$char-3}:checked ~ main [dv$="#{$three}"],';
  // reset selector every 50 to split up the big one
  $index: index($threes, $three);
  @if $index % 50 == 0 {
    #{$sel} { @include active-word; }
    $sel: '';
  }
}

// clearing content on nil cases
@for $i from 1 through 3 {
  #a1nil:checked ~ main #o#{$i}::after { content: ""; }
}
// when 2 is nil and 3 is set
#a2nil:checked ~ main #o3::after { content: ""; }

// flexbox item gap
$gap: 4px;
$corner: 2px;

ul {
  display: flex;
  list-style: none;
  flex-wrap: wrap;
  padding: 1rem 0 0;
  margin: 1rem 0 0;
  border-top: 1px solid #E0E0E0;
  transition: all 2s linear;
  height: 250px;
  overflow-y: auto;
  li {
    padding: 0.5rem;
    box-sizing: border-box;
    text-align: center;
    font-size: 0.8em;
    width: 100%;
    width: calc(50% - #{$gap});
    @media (min-width: 600px) {
      width: calc(20% - #{$gap});
    }
    @media (min-width: 900px) {
      width: calc(10% - #{$gap});
    }
    margin-left: $gap / 2;
    margin-right: $gap / 2;
    margin-bottom: $gap;
    border-radius: $corner;
    // since we adjust flex ordering, we cant cancel any margins based on nth
    // eg. margin-right: $gap; &:nth-child(10n + 10) { margin-right: 0; }
  }
}

h1 {
  margin: 0.5rem 0 0.25rem;
  font-size: 1.2rem;
  text-align: center;
}

h2 {
  text-align: center;
  margin: 0;
  margin-top: 1rem;
  .quote::before { content: "“"; }
  .quote::after { content: "”"; }
  .quote { display: inline-block; }
}

body {
  padding: 1rem;
  box-sizing: border-box;
  text-align: center;
  background: #444;
  color: #444;
}

input {
  display: inline-block;
  opacity: 0.5;
}

nav, main {
  padding: 1rem;
  max-width: 1200px;
  margin-left: auto;
  margin-right: auto;
}

main {
  background: #F9F9F9;
  border-top: 1px solid #E0E0E0;
  border-radius: 0px 0px $corner * 2 $corner * 2;
  // height: 400px;
  // overflow-y: auto;
}

nav {
  display: flex;
  flex-wrap: wrap;
  background: #FFF;
  margin: 2rem auto 0;
  border-radius: $corner * 2 $corner * 2 0px 0px;
  h2 {
    flex-basis: 100%;
    text-align: center;
    font-size: 2rem;
  }
  section {
    display: flex;
    width: 100%;
    @media (min-width: 740px) {
      width: 33.33%;
    }
    justify-content: space-between;
    flex-wrap: wrap;
    box-sizing: border-box;
    padding: 1rem;
    h1 { 
      width: 100%; 
    }
    label {
      padding: 0.5rem 0.125rem;
      text-align: center;
      box-sizing: border-box;
      cursor: pointer;
      background: #F0F0F0;
      border-radius: $corner;
      box-shadow: inset 0px 0px 0px 1px rgba(0,0,0,0.025);
      &:hover {
        background: #E9E9E9;
      }
      &[for$="nil"] { text-transform: uppercase; font-size: 0.7rem; }
    }
    &.filters { 
      width: 100%; 
      label {
        width: calc(33.33% - #{$gap});
        margin-right: $gap * 0.5;
        margin-left: $gap * 0.5;
        text-transform: uppercase; 
        font-size: 0.7rem;
      }
    }
    
    &[class^="alpha-"] {
      label {
        // first line, 10%
        flex-basis: calc(10% - #{$gap});
        margin-bottom: $gap;
        margin-right: $gap;
        box-sizing: border-box;
        // reset, full width
        &:first-of-type { flex-basis: 100%; margin-right: 0; }
        // keyboard layout
        &:nth-of-type(11) { margin-right: 0; }
        &:nth-of-type(12) { margin-left: calc(5% + #{$gap * 0.5}); }
        &:nth-of-type(20) { margin-right: calc(5% + #{$gap * 0.5}); }
        &:nth-of-type(21) { margin-left: calc(15% + #{$gap * 0.5}); }
        &:nth-of-type(27) { margin-right: calc(15% + #{$gap * 0.5}); }
      }
    }
  }
}