/* ===================================================================
   BSIT Lab Notebook — worksheet compiler
   A page styled like a real spiral lab notebook: punch holes, a
   composition-book red margin rule, graph-paper fill, and manila
   folder tabs for navigation.
=================================================================== */

:root{
  --paper:        #eee9dd;
  --paper-edge:   #e2dcc9;
  --grid-line:    #c4d3ca;
  --ink:          #212a1f;
  --ink-soft:     #4c5646;
  --margin-red:   #a5333d;
  --folder:       #d9c9a0;
  --folder-active:#f0c64a;
  --folder-shadow:#b7a06c;
  --hole:         #d7d0bd;
  --hole-shadow:  #a89e83;
  --code-bg:      #f7f4e9;
  --line-blue:    #7e97ad;
}

*{ box-sizing:border-box; }

body{
  margin:0;
  min-height:100vh;
  background: var(--paper-edge);
  font-family:'Inter', system-ui, sans-serif;
  color: var(--ink);
  padding: 40px 16px 80px;
}

/* -------------------- notebook shell -------------------- */
.notebook{
  max-width: 880px;
  margin: 0 auto;
  position: relative;
}

.spiral{
  position:absolute;
  left: -6px;
  top: 70px;
  bottom: 30px;
  width: 34px;
  display:flex;
  flex-direction:column;
  justify-content:space-between;
  z-index: 5;
  pointer-events:none;
}
.spiral span{
  display:block;
  width: 22px;
  height: 22px;
  border-radius: 50%;
  background: radial-gradient(circle at 35% 35%, #fbf8ef, var(--hole) 55%, var(--hole-shadow) 100%);
  box-shadow: inset 0 0 0 3px var(--paper-edge);
}

/* -------------------- header -------------------- */
.masthead{
  padding: 28px 40px 24px 56px;
  background: var(--paper);
  border-radius: 4px 4px 0 0;
  position: relative;
}
.masthead::after{
  content:"";
  position:absolute;
  left:0; right:0; bottom:0;
  height:2px;
  background: repeating-linear-gradient(90deg, var(--margin-red) 0 10px, transparent 10px 18px);
  opacity:.6;
}
.kicker{
  font-family:'Space Mono', monospace;
  font-size:.72rem;
  letter-spacing:.18em;
  text-transform:uppercase;
  color: var(--margin-red);
  margin: 0 0 6px;
}
.masthead h1{
  font-family:'Space Mono', monospace;
  font-weight:700;
  font-size: clamp(1.5rem, 4vw, 2.15rem);
  margin: 0 0 8px;
  letter-spacing:-.01em;
}
.masthead p{
  margin:0;
  color: var(--ink-soft);
  font-size: .95rem;
  max-width: 46ch;
}

/* -------------------- folder tabs -------------------- */
.tabs{
  display:flex;
  gap: 6px;
  padding: 0 40px 0 56px;
  background: var(--paper-edge);
}
.tab{
  --lift: 0px;
  font-family:'Space Mono', monospace;
  font-size:.82rem;
  font-weight:700;
  letter-spacing:.02em;
  color: var(--ink-soft);
  background: var(--folder);
  border: none;
  cursor: pointer;
  padding: 12px 20px 14px;
  border-radius: 8px 8px 0 0;
  position: relative;
  top: 6px;
  transform: translateY(var(--lift));
  box-shadow: 0 -1px 0 var(--folder-shadow) inset;
  transition: transform .18s ease, background .18s ease, color .18s ease;
}
.tab .num{
  color: var(--margin-red);
  margin-right: 8px;
}
.tab:hover{ --lift: -3px; }
.tab[aria-selected="true"]{
  background: var(--paper);
  color: var(--ink);
  top: 0;
  --lift: -6px;
  box-shadow: 0 -2px 0 var(--folder-active) inset;
}

/* -------------------- content card -------------------- */
.page{
  background: var(--paper);
  border-radius: 0 4px 4px 4px;
  padding: 8px 40px 48px 12px;
  min-height: 420px;
  box-shadow: 0 24px 48px -28px rgba(20,25,15,.45);
  background-image:
    linear-gradient(var(--grid-line) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid-line) 1px, transparent 1px);
  background-size: 26px 26px;
  background-position: 12px 8px;
}
.page-inner{
  margin-left: 44px;
  border-left: 2px solid var(--margin-red);
  padding-left: 24px;
  padding-top: 24px;
}

/* -------------------- sheet content -------------------- */
.sheet-head{
  display:flex;
  align-items:flex-start;
  gap: 14px;
  margin-bottom: 22px;
  flex-wrap: wrap;
}
.tab-index{
  font-family:'Space Mono', monospace;
  font-size: 1.6rem;
  font-weight: 700;
  color: var(--folder-active);
  -webkit-text-stroke: 1.2px var(--ink);
  line-height: 1;
}
.sheet-head > div{ flex: 1 1 auto; min-width: 180px; }
.sheet-head h2{
  margin: 0 0 4px;
  font-family:'Space Mono', monospace;
  font-size: 1.3rem;
}
.sheet-sub{
  margin:0;
  color: var(--ink-soft);
  font-size: .92rem;
}

.records{
  display:grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 18px;
  margin-bottom: 20px;
}
.record{
  background: var(--code-bg);
  border: 1px solid var(--grid-line);
  border-radius: 6px;
  padding: 16px 18px;
}
.record-label{
  margin: 0 0 10px;
  font-family:'Space Mono', monospace;
  font-weight:700;
  font-size:.82rem;
  text-transform: uppercase;
  letter-spacing:.06em;
  color: var(--margin-red);
}
.record-grid{
  margin:0;
  display:grid;
  grid-template-columns: max-content 1fr;
  gap: 4px 12px;
  font-size: .88rem;
}
.record-grid dt{
  font-family:'Space Mono', monospace;
  color: var(--line-blue);
}
.record-grid dd{ margin:0; }

.dump{
  border-top: 1px dashed var(--grid-line);
  padding-top: 12px;
}
.dump summary{
  cursor:pointer;
  font-family:'Space Mono', monospace;
  font-size:.8rem;
  color: var(--ink-soft);
}
.dump pre{
  background: var(--code-bg);
  border: 1px solid var(--grid-line);
  border-radius: 6px;
  padding: 14px;
  overflow-x:auto;
  font-family:'IBM Plex Mono', 'Space Mono', monospace;
  font-size: .78rem;
  line-height: 1.5;
  margin-top: 10px;
}

.table-wrap{
  overflow-x:auto;
  border: 1px solid var(--grid-line);
  border-radius: 6px;
  background: var(--code-bg);
}
.ledger{
  width:100%;
  border-collapse: collapse;
  font-size: .84rem;
  min-width: 640px;
}
.ledger th{
  font-family:'Space Mono', monospace;
  text-align:left;
  font-size:.72rem;
  text-transform:uppercase;
  letter-spacing:.05em;
  color: var(--ink-soft);
  padding: 10px 12px;
  border-bottom: 2px solid var(--margin-red);
}
.ledger td{
  padding: 9px 12px;
  border-bottom: 1px solid var(--grid-line);
}
.ledger tbody tr:hover{ background: rgba(240,198,74,.18); }
.table-note{
  margin: 10px 0 0;
  font-size: .78rem;
  color: var(--ink-soft);
  font-style: italic;
}

/* -------------------- loading state -------------------- */
.loading{
  font-family:'Space Mono', monospace;
  font-size:.9rem;
  color: var(--ink-soft);
  padding: 30px 0;
  display:flex;
  align-items:center;
  gap:10px;
}
.loading::before{
  content:"";
  width:10px; height:10px;
  border-radius:50%;
  background: var(--margin-red);
  animation: pulse 1s ease-in-out infinite;
}
@keyframes pulse{
  0%,100%{ opacity:.3; transform:scale(.8); }
  50%{ opacity:1; transform:scale(1.1); }
}

.footer-note{
  text-align:center;
  font-size:.78rem;
  color: var(--ink-soft);
  margin-top: 18px;
  font-family:'Space Mono', monospace;
}

/* -------------------- table picker -------------------- */
.table-picker-btn{
  font-family:'Space Mono', monospace;
  font-size: .8rem;
  font-weight: 700;
  color: var(--ink);
  background: var(--folder-active);
  border: none;
  border-radius: 999px;
  padding: 9px 16px;
  cursor: pointer;
  white-space: nowrap;
  box-shadow: 0 2px 0 var(--folder-shadow);
  transition: transform .12s ease;
}
.table-picker-btn:hover{ transform: translateY(-1px); }
.table-picker-btn:active{ transform: translateY(1px); box-shadow: none; }
.table-picker-btn .current-table{
  font-weight: 400;
  opacity: .75;
}

dialog.table-modal{
  border: none;
  border-radius: 10px;
  padding: 0;
  max-width: 480px;
  width: calc(100% - 40px);
  background: transparent;
}
dialog.table-modal::backdrop{
  background: rgba(20, 25, 15, .55);
}
.modal-card{
  background: var(--paper);
  border-radius: 10px;
  overflow: hidden;
  box-shadow: 0 24px 48px -20px rgba(0,0,0,.5);
}
.modal-head{
  display:flex;
  align-items:center;
  justify-content: space-between;
  padding: 16px 20px;
  border-bottom: 1px dashed var(--grid-line);
}
.modal-head h3{
  margin:0;
  font-family:'Space Mono', monospace;
  font-size: 1rem;
}
.modal-close{
  background: none;
  border: none;
  font-size: 1.4rem;
  line-height: 1;
  cursor: pointer;
  color: var(--ink-soft);
  padding: 2px 6px;
}
.modal-close:hover{ color: var(--margin-red); }
.modal-options{
  display:grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 10px;
  padding: 18px 20px 22px;
}
.table-option{
  font-family:'Space Mono', monospace;
  font-size: .82rem;
  text-align:left;
  background: var(--folder);
  border: none;
  border-radius: 6px;
  padding: 12px 14px;
  cursor: pointer;
  color: var(--ink);
  box-shadow: 0 -2px 0 var(--folder-shadow) inset;
  transition: background .15s ease, transform .12s ease;
}
.table-option:hover{ transform: translateY(-1px); }
.table-option.active{
  background: var(--folder-active);
  box-shadow: 0 -2px 0 var(--margin-red) inset;
}

@media (max-width: 640px){
  .masthead, .tabs{ padding-left: 36px; }
  .spiral{ display:none; }
  .page{ padding-right: 20px; }
  .page-inner{ margin-left: 0; padding-left: 16px; }
  .modal-options{ grid-template-columns: 1fr; }
}