/* ============================================================================
   Zero kW design system
   ----------------------------------------------------------------------------
   One stylesheet for every page. Pages should not carry their own palette —
   if something needs a color, it takes a token from here so the whole product
   moves together.

   The look is deliberately document-like rather than dashboard-like: this tool
   produces numbers people put in front of a CFO, and heavy chrome undermines
   that. Dark ink header, quiet page, high-contrast figures.
   ========================================================================= */

:root {
  /* Surfaces */
  --zk-bg:        #f6f8fa;
  --zk-card:      #ffffff;
  --zk-card-alt:  #fbfefd;
  --zk-line:      #e3e7ec;
  --zk-line-soft: #eef1f4;

  /* Ink */
  --zk-ink:       #0d1117;
  --zk-ink-2:     #3d4754;
  --zk-ink-3:     #6b7684;
  --zk-on-dark:   #ffffff;
  --zk-on-dark-2: #9fb0c3;

  /* Brand */
  --zk-accent:       #0b6b5b;
  --zk-accent-hover: #0e8f79;
  --zk-mint:         #4ade9f;

  /* Status */
  --zk-good:      #0b6b5b;
  --zk-good-bg:   #e6f4f0;
  --zk-good-line: #b7ded4;
  --zk-warn:      #a8620a;
  --zk-warn-bg:   #fff8e8;
  --zk-warn-line: #f0dfb8;
  --zk-bad:       #a32020;
  --zk-bad-bg:    #fdecec;
  --zk-bad-line:  #f2c2c2;

  /* Chart series — distinguishable in order, and in greyscale print */
  --zk-s1: #0b6b5b;
  --zk-s2: #2f6fb5;
  --zk-s3: #a8620a;
  --zk-s4: #7b4ea8;
  --zk-s5: #0e8f79;
  --zk-s6: #a32020;

  --zk-radius:   10px;
  --zk-radius-s: 7px;
  --zk-font: -apple-system, BlinkMacSystemFont, "Segoe UI", Inter, Roboto, Helvetica, Arial, sans-serif;
  --zk-mono: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--zk-bg);
  color: var(--zk-ink);
  font: 16px/1.55 var(--zk-font);
  -webkit-font-smoothing: antialiased;
  /* The full-bleed hero uses 100vw, which counts the vertical scrollbar and
     would otherwise push the page sideways by its width. */
  overflow-x: hidden;
}

/* ---------------------------------------------------------------- header */

.zk-header { background: var(--zk-ink); color: var(--zk-on-dark); padding: 24px 20px; }
.zk-wrap   { max-width: 1080px; margin: 0 auto; }
.zk-hdr    { display: flex; align-items: flex-end; justify-content: space-between; gap: 20px; flex-wrap: wrap; }
.zk-brand  { font-size: 23px; font-weight: 700; letter-spacing: -0.02em; color: var(--zk-on-dark); text-decoration: none; display: inline-block; }
.zk-brand span { color: var(--zk-mint); }
.zk-tag    { color: var(--zk-on-dark-2); font-size: 14px; margin-top: 4px; }

.zk-nav    { display: flex; gap: 6px; flex-wrap: wrap; }
.zk-nav a  {
  color: var(--zk-on-dark-2); text-decoration: none; font-size: 14px; font-weight: 600;
  padding: 7px 13px; border-radius: var(--zk-radius-s); border: 1px solid #2a323c; white-space: nowrap;
}
.zk-nav a:hover { color: var(--zk-on-dark); border-color: #4a5563; }
.zk-nav a.on    { background: #1d252e; color: var(--zk-on-dark); border-color: #39424e; }

/*
 * The second nav row.
 *
 * Sits inside the dark header but reads as subordinate: no pill borders, a
 * lighter weight, and an underline rather than a filled chip for the current
 * page. The point is that a glance separates "which section am I in" from
 * "which page am I on" without reading either.
 */
.zk-subnav {
  display: flex; gap: 20px; flex-wrap: wrap;
  padding: 12px 0 2px; margin-top: 14px;
  border-top: 1px solid #2a323c;
}
.zk-subnav a {
  color: var(--zk-on-dark-2); text-decoration: none; font-size: 14px; font-weight: 500;
  padding: 4px 1px; border-bottom: 2px solid transparent; white-space: nowrap;
}
.zk-subnav a:hover  { color: var(--zk-on-dark); border-bottom-color: #4a5563; }
.zk-subnav a.on     { color: var(--zk-on-dark); border-bottom-color: var(--zk-mint); font-weight: 600; }

/* The header owns its own bottom padding once a sub-row is present. */
.zk-header:has(.zk-subnav) { padding-bottom: 0; }

.zk-main   { padding: 26px 20px 60px; }
.zk-footer { color: var(--zk-ink-3); font-size: 13px; text-align: center; padding: 0 20px 40px; }

/* ----------------------------------------------------------------- cards */

.zk-card { background: var(--zk-card); border: 1px solid var(--zk-line); border-radius: var(--zk-radius); padding: 22px; margin-bottom: 20px; }
.zk-card--accent { background: var(--zk-card-alt); border-color: var(--zk-good-line); }

h2.zk-h, .zk-card > h2 {
  font-size: 15px; text-transform: uppercase; letter-spacing: 0.07em;
  color: var(--zk-ink-2); margin: 0 0 16px;
}
.zk-title { font-size: 19px; font-weight: 700; margin: 0 0 2px; }
.zk-meta  { font-size: 13px; color: var(--zk-ink-3); margin: -8px 0 16px; }

/* ----------------------------------------------------------------- forms */

.zk-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(210px, 1fr)); gap: 14px; }
.zk-row  { display: flex; gap: 14px; align-items: flex-end; flex-wrap: wrap; }

label, .zk-label { display: block; font-size: 13px; font-weight: 600; color: var(--zk-ink-2); margin-bottom: 5px; }

input[type=text], input[type=email], input[type=tel], input[type=date],
input[type=number], input:not([type]), select, textarea {
  width: 100%; padding: 9px 10px; border: 1px solid var(--zk-line);
  border-radius: var(--zk-radius-s); font: inherit; font-size: 15px;
  background: #fff; color: var(--zk-ink);
}
input:focus, select:focus, textarea:focus { outline: 2px solid var(--zk-accent); outline-offset: -1px; }
textarea { min-height: 92px; font-family: var(--zk-mono); font-size: 13px; }
input[type=file] {
  width: 100%; padding: 9px 10px; border: 1px dashed #b9c6cf;
  border-radius: var(--zk-radius-s); background: #fff; font: inherit; font-size: 14px;
}

.zk-btn {
  background: var(--zk-accent); color: #fff; border: 0; border-radius: var(--zk-radius-s);
  padding: 12px 22px; font: inherit; font-weight: 600; cursor: pointer; text-decoration: none;
  display: inline-block;
}
.zk-btn:hover { background: var(--zk-accent-hover); }
.zk-btn--ghost { background: transparent; color: var(--zk-accent); border: 1px solid var(--zk-line); }
.zk-btn--ghost:hover { background: var(--zk-good-bg); }

.zk-hint { font-size: 12px; color: var(--zk-ink-3); margin-top: 4px; font-weight: 400; }

/* ---------------------------------------------------------------- tables */

.zk-table { width: 100%; border-collapse: collapse; font-size: 15px; }
.zk-table th, .zk-table td { text-align: left; padding: 10px 8px; border-bottom: 1px solid var(--zk-line); vertical-align: top; }
.zk-table th { font-size: 12px; text-transform: uppercase; letter-spacing: 0.05em; color: var(--zk-ink-2); font-weight: 700; }
.zk-table .n, .zk-n { text-align: right; font-variant-numeric: tabular-nums; white-space: nowrap; }
.zk-table tr:last-child td { border-bottom: 0; }

/* --------------------------------------------------------------- signals */

.zk-banner { padding: 15px 18px; border-radius: 9px; margin-bottom: 20px; font-weight: 600; }
.zk-ok   { background: var(--zk-good-bg); color: var(--zk-good); border: 1px solid var(--zk-good-line); }
.zk-warn { background: var(--zk-warn-bg); color: var(--zk-warn); border: 1px solid var(--zk-warn-line); }
.zk-bad  { background: var(--zk-bad-bg);  color: var(--zk-bad);  border: 1px solid var(--zk-bad-line); }
.zk-note { background: var(--zk-warn-bg); border: 1px solid var(--zk-warn-line); color: #6b5320; padding: 12px 15px; border-radius: 9px; margin-top: 14px; font-size: 14px; }

.zk-pill {
  display: inline-block; font-size: 11px; text-transform: uppercase; letter-spacing: 0.05em;
  padding: 2px 8px; border-radius: 20px; background: var(--zk-line-soft);
  color: var(--zk-ink-2); font-weight: 700; margin-left: 6px;
}
.zk-pill--good { background: var(--zk-good-bg); color: var(--zk-good); }
.zk-pill--warn { background: var(--zk-warn-bg); color: var(--zk-warn); }

.zk-basis { font-size: 13px; color: var(--zk-ink-3); margin-top: 3px; font-weight: 400; }
.zk-amount { font-weight: 700; font-variant-numeric: tabular-nums; color: var(--zk-accent); white-space: nowrap; }

.zk-items { margin: 10px 0 0; padding: 0; list-style: none; font-size: 14px; }
.zk-items li { display: flex; justify-content: space-between; gap: 14px; padding: 5px 0; border-bottom: 1px dashed var(--zk-line); }
.zk-items li:last-child { border-bottom: 0; }

/* Findings / callouts with a severity spine */
.zk-finding { border-left: 3px solid var(--zk-line); padding: 2px 0 2px 14px; margin-bottom: 18px; }
.zk-finding.opportunity { border-color: var(--zk-good); }
.zk-finding.warning     { border-color: var(--zk-warn); }
.zk-finding h3 { margin: 0 0 4px; font-size: 16px; }
.zk-finding p  { margin: 0; color: var(--zk-ink-2); font-size: 14px; }

/* ------------------------------------------------------- stats & charts */

/* Stat tiles. Proportional figures deliberately — tabular-nums makes a large
   standalone number look loose. Tabular figures belong in tables and axes. */
.zk-stats { display: grid; grid-template-columns: repeat(auto-fit, minmax(180px, 1fr)); gap: 14px; margin-bottom: 20px; }
.zk-stat  { background: var(--zk-card); border: 1px solid var(--zk-line); border-radius: var(--zk-radius); padding: 18px 20px; }
.zk-stat-v { font-size: 30px; font-weight: 700; letter-spacing: -0.02em; line-height: 1.1; }
.zk-stat-l { font-size: 12px; text-transform: uppercase; letter-spacing: 0.06em; color: var(--zk-ink-2); margin-top: 6px; font-weight: 600; }
.zk-stat-s { font-size: 12px; color: var(--zk-ink-3); margin-top: 3px; }

.zk-chart-head { display: flex; align-items: baseline; justify-content: space-between; gap: 16px; margin-bottom: 6px; }
.zk-chart-head h2 { margin: 0; }
.zk-toggle {
  background: none; border: 1px solid var(--zk-line); border-radius: var(--zk-radius-s);
  color: var(--zk-ink-2); font: inherit; font-size: 12px; font-weight: 600;
  padding: 4px 10px; cursor: pointer; white-space: nowrap;
}
.zk-toggle:hover { border-color: var(--zk-ink-3); color: var(--zk-ink); }

/* Sized to include the x-axis band, so the card never grows an inner scrollbar. */
.zk-plot { position: relative; height: 300px; margin: 10px 0 6px; }
.zk-grid2 { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
.zk-grid2 .zk-plot { height: 260px; }
.zk-tablewrap { margin-top: 14px; max-height: 340px; overflow: auto; border-top: 1px solid var(--zk-line); }
.zk-tablewrap .zk-table { font-size: 13px; }
.zk-tablewrap th { position: sticky; top: 0; background: var(--zk-card); }

@media (max-width: 860px) { .zk-grid2 { grid-template-columns: 1fr; } }

/* Rebate / program listings */
.zk-prog { border-top: 1px solid var(--zk-line); padding: 16px 0 4px; }
.zk-prog:first-of-type { border-top: 0; padding-top: 0; }
.zk-progtop { display: flex; justify-content: space-between; gap: 16px; align-items: baseline; flex-wrap: wrap; }
.zk-progname { font-weight: 700; font-size: 16px; }
.zk-apply { display: inline-block; margin-top: 9px; font-size: 14px; font-weight: 600; color: var(--zk-accent); text-decoration: none; }
.zk-apply:hover { text-decoration: underline; }
.zk-impact { margin-top: 6px; font-weight: 700; font-variant-numeric: tabular-nums; }

@media (max-width: 640px) {
  .zk-grid { grid-template-columns: 1fr; }
  .zk-hdr  { align-items: flex-start; }
}

/* Residential / commercial fork. One control, always visible, above the search. */
.zk-seg { display: inline-flex; background: var(--zk-line-soft); border-radius: 9px; padding: 3px; margin-bottom: 18px; }
.zk-seg a {
  padding: 8px 20px; border-radius: 7px; text-decoration: none; font-weight: 600;
  font-size: 14px; color: var(--zk-ink-2);
}
.zk-seg a.on { background: var(--zk-card); color: var(--zk-ink); box-shadow: 0 1px 2px rgba(13,17,23,.08); }
.zk-seg a:hover:not(.on) { color: var(--zk-ink); }

/* ------------------------------------------------------------------ home */

/* The hero continues the header's dark band rather than sitting on the page,
   so the fold reads as one surface instead of two stacked bars. */
.zk-hero {
  background: var(--zk-ink); color: var(--zk-on-dark);
  /* Full-bleed out of the 1080px column, while keeping the text on that column. */
  margin: -26px calc(50% - 50vw) 34px;
  padding: 44px max(20px, calc(50vw - 540px)) 52px;
}
.zk-hero h1 {
  font-size: clamp(28px, 4.4vw, 44px); line-height: 1.15; letter-spacing: -0.025em;
  font-weight: 700; margin: 0 0 16px; max-width: 26ch;
}
.zk-hero-sub { color: var(--zk-on-dark-2); font-size: 17px; line-height: 1.6; max-width: 62ch; margin: 0 0 30px; }
.zk-hero-label { color: var(--zk-on-dark-2); font-size: 13px; font-weight: 600; margin-bottom: 8px; display: block; }
.zk-hero-row { display: flex; gap: 10px; flex-wrap: wrap; }
.zk-hero-row input { width: 170px; font-size: 17px; letter-spacing: 0.06em; font-variant-numeric: tabular-nums; }

.zk-proof {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(170px, 1fr));
  gap: 1px; background: var(--zk-line); border: 1px solid var(--zk-line);
  border-radius: var(--zk-radius); overflow: hidden; margin: 0 0 34px;
}
.zk-proof div { background: var(--zk-card); padding: 18px 20px; }
.zk-proof strong { display: block; font-size: 24px; font-weight: 700; letter-spacing: -0.02em; }
.zk-proof span { display: block; font-size: 12px; color: var(--zk-ink-3); margin-top: 4px; }

.zk-center { text-align: center; margin-bottom: 18px; }

.zk-fork { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
.zk-forkcard { display: flex; flex-direction: column; }
.zk-forkcard .zk-btn { margin-top: 6px; margin-right: 8px; align-self: flex-start; }
.zk-forkkicker {
  font-size: 11px; text-transform: uppercase; letter-spacing: 0.08em;
  font-weight: 700; color: var(--zk-accent); margin-bottom: 6px;
}

.zk-check { list-style: none; padding: 0; margin: 14px 0 20px; font-size: 14px; color: var(--zk-ink-2); }
.zk-check li { position: relative; padding-left: 22px; margin-bottom: 9px; line-height: 1.5; }
.zk-check li::before {
  content: ''; position: absolute; left: 2px; top: 7px; width: 9px; height: 5px;
  border-left: 2px solid var(--zk-accent); border-bottom: 2px solid var(--zk-accent);
  transform: rotate(-45deg);
}
.zk-check--tight li { margin-bottom: 6px; }
.zk-check--muted li::before { border-color: var(--zk-ink-3); }

@media (max-width: 780px) { .zk-fork { grid-template-columns: 1fr; } }

.zk-hero-note { color: var(--zk-on-dark-2); font-size: 12px; margin: 10px 0 0; opacity: .8; }

/* Numbered how-it-works strip */
.zk-steps { display: grid; grid-template-columns: repeat(auto-fit, minmax(210px, 1fr)); gap: 16px; margin-bottom: 34px; }
.zk-step {
  background: var(--zk-card); border: 1px solid var(--zk-line);
  border-radius: var(--zk-radius); padding: 20px;
}
.zk-step span {
  display: inline-flex; align-items: center; justify-content: center;
  width: 26px; height: 26px; border-radius: 50%; background: var(--zk-good-bg);
  color: var(--zk-accent); font-size: 13px; font-weight: 700; margin-bottom: 10px;
}
.zk-step strong { display: block; font-size: 16px; margin-bottom: 5px; }
.zk-step p { margin: 0; font-size: 13.5px; color: var(--zk-ink-2); line-height: 1.5; }

/* ---------------------------------------------------------------- plans */
.zk-plans { display: grid; grid-template-columns: repeat(auto-fit, minmax(250px, 1fr)); gap: 20px; margin-bottom: 24px; align-items: start; }
.zk-plan { display: flex; flex-direction: column; position: relative; }
.zk-plan--feature { border-color: var(--zk-accent); box-shadow: 0 0 0 1px var(--zk-accent); }
.zk-plan-tag {
  position: absolute; top: -10px; right: 18px; background: var(--zk-accent); color: #fff;
  font-size: 11px; font-weight: 700; letter-spacing: .05em; text-transform: uppercase;
  padding: 3px 10px; border-radius: 20px;
}
.zk-plan-name { font-size: 13px; text-transform: uppercase; letter-spacing: .07em; font-weight: 700; color: var(--zk-ink-2); }
.zk-plan-price { font-size: 32px; font-weight: 700; letter-spacing: -.02em; margin: 6px 0 4px; }
.zk-plan-price span { font-size: 14px; font-weight: 500; color: var(--zk-ink-3); letter-spacing: 0; }
.zk-plan .zk-btn { margin-top: auto; align-self: flex-start; }

.zk-signup { display: grid; grid-template-columns: 1.35fr 1fr; gap: 20px; align-items: start; }
@media (max-width: 780px) { .zk-signup { grid-template-columns: 1fr; } }

/* --------------------------------------------------------------- reports */
.zk-rep-head { display: flex; justify-content: space-between; align-items: flex-start; gap: 20px; flex-wrap: wrap; margin-bottom: 20px; }
.zk-rep-kicker { font-size: 11px; text-transform: uppercase; letter-spacing: .08em; font-weight: 700; color: var(--zk-accent); }
.zk-rep-title { font-size: 26px; font-weight: 700; letter-spacing: -.02em; margin: 4px 0 4px; }
.zk-rep-actions { display: flex; gap: 8px; flex-wrap: wrap; }
.zk-subject th { text-transform: none; letter-spacing: 0; font-size: 13px; color: var(--zk-ink-3); font-weight: 600; }
.zk-rep-foot { border-top: 1px solid var(--zk-line); padding-top: 14px; margin-top: 4px; }

/* Print: drop the app chrome, keep the document. A report is a thing people
   hand to a finance team, so it has to survive Ctrl-P without a PDF library. */
@media print {
  .zk-header, .zk-footer, .zk-rep-actions, .zk-toggle, .zk-seg { display: none !important; }
  body { background: #fff; }
  .zk-main { padding: 0; }
  .zk-card { border: 1px solid #d5dae0; break-inside: avoid; box-shadow: none; margin-bottom: 12px; }
  .zk-stats { break-inside: avoid; }
  .zk-finding, .zk-step { break-inside: avoid; }
  a { color: inherit; text-decoration: none; }
  .zk-rep-title { font-size: 22px; }
  @page { margin: 14mm; }
}