/* True-Cost Energy Bill Decoder — styles.
   Animated modern UI: stepped flow, building cost-stack, popping anomaly
   flags, animated gauge, drawing sparkline, staggered entrances.
   prefers-reduced-motion disables all of it. */

:root {
  --bg: #f4f5fb;
  --card: #ffffff;
  --ink: #161a2b;
  --muted: #5b6076;
  --line: #e4e6f0;
  --accent: #5b4def;
  --accent-deep: #4335c4;
  --accent-soft: #efedff;
  --teal: #0e9f8a;
  --warn: #b45309;
  --warn-soft: #fef3e2;
  --track: #e8eaf3;
  --gauge: #5b4def;
  --radius: 16px;
  --shadow: 0 10px 30px rgba(22, 26, 43, 0.08);
  --font: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: var(--font);
  background: var(--bg);
  color: var(--ink);
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}

.skip-link {
  position: absolute; left: -9999px; top: 0;
  background: var(--ink); color: #fff; padding: 0.6rem 1rem; z-index: 100;
  border-radius: 0 0 8px 0;
}
.skip-link:focus { left: 0; }

.wrap { max-width: 960px; margin: 0 auto; padding: 0 1.25rem; }

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

.site-header {
  background: linear-gradient(135deg, #1c1f38 0%, #3730a3 60%, #5b4def 100%);
  color: #fff;
  padding: 2.2rem 0 1.6rem;
  position: relative;
  overflow: hidden;
}
.site-header::after {
  content: ""; position: absolute; inset: 0;
  background: radial-gradient(600px 200px at 80% -40px, rgba(255,255,255,.14), transparent 70%);
  pointer-events: none;
}
.brand { display: flex; align-items: center; gap: 0.8rem; }
.brand-bolt {
  width: 44px; height: 44px; border-radius: 12px;
  background: linear-gradient(135deg, #ffd166, #f4a259);
  display: grid; place-items: center; font-size: 1.5rem;
  box-shadow: 0 6px 18px rgba(244, 162, 89, 0.45);
}
.site-header h1 { font-size: 1.5rem; margin: 0; letter-spacing: -0.01em; }
.tagline { margin: 0.35rem 0 0; color: #cfd2ff; font-size: 1rem; }

/* progress */
.progress {
  list-style: none; display: flex; gap: 0.5rem; margin: 1.4rem 0 0; padding: 0;
}
.progress-step {
  flex: 1; background: rgba(255,255,255,.12); color: #e7e8ff;
  border-radius: 10px; padding: 0.55rem 0.8rem; font-size: 0.85rem;
  display: flex; align-items: center; gap: 0.5rem;
  transition: background .3s, transform .3s;
}
.progress-step .n {
  width: 24px; height: 24px; border-radius: 50%; flex: none;
  background: rgba(255,255,255,.2); display: grid; place-items: center;
  font-size: 0.75rem; font-weight: 700;
}
.progress-step.current { background: rgba(255,255,255,.22); transform: translateY(-2px); }
.progress-step.current .n { background: #ffd166; color: #1c1f38; }
.progress-step.done .n { background: var(--teal); color: #fff; }

/* ---------- steps ---------- */

main { padding: 2rem 0 3rem; }

.step { display: none; }
.step.active { display: block; }
.step-enter { animation: stepIn 0.45s cubic-bezier(.22,.8,.3,1); }
@keyframes stepIn {
  from { opacity: 0; transform: translateX(28px); }
  to { opacity: 1; transform: none; }
}

.step h2 { font-size: 1.6rem; letter-spacing: -0.02em; margin: 0 0 0.4rem; outline: none; }
.step-lede { color: var(--muted); margin: 0 0 1.4rem; max-width: 60ch; }

/* staggered entrances */
.stagger > .stagger-item {
  opacity: 0;
  animation: riseIn 0.5s cubic-bezier(.22,.8,.3,1) forwards;
  animation-delay: calc(var(--i, 0) * 70ms);
}
@keyframes riseIn {
  from { opacity: 0; transform: translateY(14px); }
  to { opacity: 1; transform: none; }
}

/* ---------- step 1: country cards ---------- */

.country-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(230px, 1fr)); gap: 1rem; }
.country-card {
  background: var(--card); border: 2px solid var(--line); border-radius: var(--radius);
  padding: 1.2rem; text-align: left; cursor: pointer; font: inherit; color: inherit;
  display: flex; flex-direction: column; gap: 0.3rem;
  transition: transform .25s, box-shadow .25s, border-color .25s;
  box-shadow: var(--shadow);
}
.country-card:hover { transform: translateY(-4px); border-color: var(--accent); }
.country-card:focus-visible { outline: 3px solid var(--accent); outline-offset: 2px; }
.country-card[aria-pressed="true"] { border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-soft), var(--shadow); }
.country-code {
  align-self: flex-start; font-size: 0.7rem; font-weight: 800; letter-spacing: 0.08em;
  background: var(--accent-soft); color: var(--accent-deep);
  padding: 0.2rem 0.55rem; border-radius: 999px;
}
.country-name { font-size: 1.2rem; font-weight: 700; }
.country-meta { font-size: 0.85rem; color: var(--muted); }
.country-intro { font-size: 0.9rem; color: var(--muted); margin-top: 0.3rem; }

/* ---------- step 2: bill entry ---------- */

.card {
  background: var(--card); border-radius: var(--radius); box-shadow: var(--shadow);
  padding: 1.4rem; margin-bottom: 1.2rem;
}
.card h3 { margin: 0 0 0.8rem; font-size: 1.1rem; }

.kwh-row { display: flex; flex-wrap: wrap; gap: 1rem; align-items: flex-end; }
.field { display: flex; flex-direction: column; gap: 0.3rem; flex: 1 1 220px; }
.field label { font-weight: 600; font-size: 0.95rem; }
.field .unit-hint { font-weight: 400; color: var(--muted); font-size: 0.85rem; }

input[type="text"], input[type="number"], input:not([type]), select {
  font: inherit; padding: 0.65rem 0.8rem; border: 2px solid var(--line);
  border-radius: 10px; background: #fbfbfe; color: var(--ink); width: 100%;
  transition: border-color .2s, box-shadow .2s;
}
input:focus, select:focus { outline: none; border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-soft); }
input[aria-invalid="true"] { border-color: #dc2626; animation: shake .4s; }
@keyframes shake { 25% { transform: translateX(-4px); } 50% { transform: translateX(4px); } 75% { transform: translateX(-2px); } }
input.flash { border-color: var(--teal); box-shadow: 0 0 0 3px rgba(14,159,138,.2); }

.check-row { display: flex; align-items: center; gap: 0.6rem; margin-top: 1rem; font-size: 0.95rem; }
.check-row input { width: 1.15rem; height: 1.15rem; accent-color: var(--accent); }

.line-row {
  border: 1px solid var(--line); border-radius: 12px; padding: 1rem;
  margin-bottom: 0.9rem; background: #fbfbfe;
}
.line-row.custom { border-style: dashed; border-color: var(--accent); background: var(--accent-soft); }
.line-top { display: flex; justify-content: space-between; align-items: center; gap: 0.6rem; margin-bottom: 0.5rem; }
.line-label { font-weight: 650; }
.line-cat {
  font-size: 0.75rem; font-weight: 700; color: var(--accent-deep);
  background: var(--accent-soft); padding: 0.2rem 0.6rem; border-radius: 999px; white-space: nowrap;
}
.line-amount-row { display: flex; align-items: center; gap: 0.6rem; }
.cur { font-weight: 700; color: var(--muted); font-size: 1.1rem; }
.line-amount-row .line-amount { max-width: 220px; }
.line-hint { font-size: 0.85rem; color: var(--muted); margin: 0.5rem 0 0; }

.helper-toggle {
  font: inherit; font-size: 0.8rem; font-weight: 600; cursor: pointer;
  background: #fff; border: 1px solid var(--line); border-radius: 999px;
  padding: 0.35rem 0.8rem; color: var(--accent-deep); white-space: nowrap;
  transition: background .2s;
}
.helper-toggle:hover { background: var(--accent-soft); }
.helper-panel {
  margin-top: 0.7rem; background: #fff; border: 1px dashed var(--accent);
  border-radius: 10px; padding: 0.8rem;
}
.helper-hint { font-size: 0.85rem; color: var(--muted); margin: 0 0 0.6rem; }
.helper-inputs { display: flex; flex-wrap: wrap; gap: 0.6rem; align-items: flex-end; }
.helper-inputs label { display: flex; flex-direction: column; gap: 0.25rem; font-size: 0.85rem; font-weight: 600; flex: 1 1 120px; }
.helper-inputs .unit { font-weight: 400; color: var(--muted); }

.custom-inputs { display: grid; gap: 0.6rem; }
.custom-cat-label { display: flex; flex-direction: column; gap: 0.3rem; font-size: 0.9rem; font-weight: 600; max-width: 280px; }
.remove-line, .remove-history {
  border: none; background: var(--line); color: var(--muted); border-radius: 50%;
  width: 28px; height: 28px; cursor: pointer; font-size: 0.8rem; flex: none;
  transition: background .2s, color .2s;
}
.remove-line:hover, .remove-history:hover { background: #fca5a5; color: #7f1d1d; }

.btn {
  font: inherit; font-weight: 700; cursor: pointer; border: none; border-radius: 12px;
  padding: 0.8rem 1.6rem; transition: transform .2s, box-shadow .2s, background .2s;
}
.btn-primary {
  background: linear-gradient(135deg, var(--accent), var(--accent-deep)); color: #fff;
  box-shadow: 0 8px 20px rgba(91, 77, 239, 0.35); font-size: 1.05rem;
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 12px 26px rgba(91, 77, 239, 0.45); }
.btn-primary:active { transform: translateY(0); }
.btn-ghost { background: #fff; border: 2px solid var(--line); color: var(--ink); }
.btn-ghost:hover { border-color: var(--accent); }
.btn-small { padding: 0.5rem 1rem; font-size: 0.9rem; border-radius: 10px; }
.step-nav { display: flex; gap: 0.8rem; margin-top: 1.2rem; flex-wrap: wrap; }
.add-line-wrap { margin: 0.4rem 0 1rem; }

/* ---------- step 3: results ---------- */

.results-hero {
  background: linear-gradient(135deg, #1c1f38, #3730a3);
  color: #fff; border-radius: 20px; padding: 1.8rem; margin-bottom: 1.2rem;
  box-shadow: var(--shadow); text-align: center; position: relative; overflow: hidden;
}
.results-hero::before {
  content: ""; position: absolute; inset: 0;
  background: radial-gradient(500px 220px at 50% -60px, rgba(255,209,102,.18), transparent 70%);
  pointer-events: none;
}
.eyebrow { text-transform: uppercase; letter-spacing: 0.12em; font-size: 0.75rem; color: #cfd2ff; margin: 0 0 0.4rem; }
.true-rate { font-size: clamp(2.6rem, 8vw, 4rem); font-weight: 800; letter-spacing: -0.03em; margin: 0; font-variant-numeric: tabular-nums; }
.true-rate-sub { color: #cfd2ff; margin: 0.3rem 0 1rem; }
#rate-gauge { max-width: 420px; margin: 0 auto; }
#rate-gauge svg { width: 100%; height: auto; display: block; }
.gauge-center { fill: #fff; font-size: 15px; font-weight: 800; }
.gauge-avg-label { fill: #cfd2ff; font-size: 10px; font-weight: 700; }
.gauge-caption { color: #e7e8ff; font-size: 0.95rem; margin: 0.4rem 0 0; }
.gauge-note { color: #cfd2ff; }

/* cost stack */
.stack-bar {
  display: flex; height: 64px; border-radius: 14px; overflow: hidden;
  background: var(--track); box-shadow: inset 0 2px 6px rgba(0,0,0,.06);
}
.stack-seg {
  background: var(--seg-color); min-width: 0; position: relative;
  display: flex; flex-direction: column; justify-content: center;
  padding: 0 0.6rem; overflow: hidden; white-space: nowrap;
}
.stack-seg + .stack-seg { border-left: 2px solid #fff; }
.seg-label { color: #fff; font-size: 0.72rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.04em; opacity: 0.95; }
.seg-value { color: #fff; font-weight: 800; font-variant-numeric: tabular-nums; }
.stack-legend { list-style: none; margin: 0.9rem 0 0; padding: 0; display: grid; gap: 0.4rem; }
.stack-legend li { font-size: 0.92rem; display: flex; align-items: center; gap: 0.5rem; flex-wrap: wrap; }
.dot { width: 12px; height: 12px; border-radius: 4px; flex: none; }
.credit-note { color: var(--teal); font-weight: 600; }
.stack-empty, .muted { color: var(--muted); }

/* anomalies — attention-drawing, not alarming */
.anomaly-list { list-style: none; margin: 0; padding: 0; display: grid; gap: 0.8rem; }
.anomaly {
  display: flex; gap: 0.9rem; align-items: flex-start;
  background: #f0fdfa; border: 1px solid #99e6d6; border-radius: 12px; padding: 1rem 1.1rem;
}
.anomaly.attention {
  background: var(--warn-soft); border-color: #f5c97b;
  animation: flagPop 0.55s cubic-bezier(.2,1.4,.4,1) backwards;
  animation-delay: calc(var(--i, 0) * 120ms);
}
.anomaly.info { animation: riseIn 0.5s ease backwards; animation-delay: calc(var(--i, 0) * 120ms); }
@keyframes flagPop {
  0% { opacity: 0; transform: scale(0.85); }
  60% { opacity: 1; transform: scale(1.03); }
  100% { opacity: 1; transform: scale(1); }
}
.anomaly.attention .anomaly-icon { animation: softPulse 2.4s ease-in-out 1s infinite; }
@keyframes softPulse {
  0%, 100% { box-shadow: 0 0 0 0 rgba(180, 83, 9, 0.35); }
  50% { box-shadow: 0 0 0 8px rgba(180, 83, 9, 0); }
}
.anomaly-icon {
  flex: none; width: 34px; height: 34px; border-radius: 50%;
  display: grid; place-items: center; font-weight: 800;
}
.anomaly.attention .anomaly-icon { background: #f59e0b; color: #fff; }
.anomaly.info .anomaly-icon { background: var(--teal); color: #fff; font-style: normal; }
.anomaly.none .anomaly-icon { background: #d1fae5; color: #065f46; }
.anomaly strong { display: block; margin-bottom: 0.2rem; }
.anomaly p { margin: 0; font-size: 0.92rem; color: var(--muted); }

/* line decode */
.decode-row {
  border: 1px solid var(--line); border-radius: 12px; margin-bottom: 0.6rem;
  background: #fbfbfe; overflow: hidden;
}
.decode-row summary {
  display: flex; align-items: center; gap: 0.8rem; padding: 0.85rem 1rem;
  cursor: pointer; list-style: none; font-weight: 600;
}
.decode-row summary::-webkit-details-marker { display: none; }
.decode-row summary::before {
  content: "›"; color: var(--accent); font-weight: 800; font-size: 1.2rem;
  transition: transform .25s; flex: none;
}
.decode-row[open] summary::before { transform: rotate(90deg); }
.decode-label { flex: 1; }
.decode-amount { font-variant-numeric: tabular-nums; }
.decode-share {
  font-size: 0.8rem; font-weight: 700; color: var(--accent-deep);
  background: var(--accent-soft); padding: 0.2rem 0.6rem; border-radius: 999px;
}
.invalid-note { color: var(--warn); font-size: 0.85em; }
.decode-body { padding: 0 1rem 1rem; }
.decode-bar { height: 8px; background: var(--track); border-radius: 999px; overflow: hidden; margin-bottom: 0.6rem; }
.decode-fill { height: 100%; border-radius: 999px; transition: width .8s cubic-bezier(.22,.8,.3,1); }
.decode-body p { margin: 0; font-size: 0.92rem; color: var(--muted); }
.decode-body p strong { color: var(--ink); }

/* tips */
.tips-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 0.9rem; }
.tip-card {
  background: linear-gradient(180deg, #fff, #f8f9ff);
  border: 1px solid var(--line); border-radius: 12px; padding: 1.1rem;
  transition: transform .25s, box-shadow .25s;
}
.tip-card:hover { transform: translateY(-3px); box-shadow: var(--shadow); }
.tip-card h4 { margin: 0 0 0.4rem; font-size: 1rem; color: var(--accent-deep); }
.tip-card p { margin: 0; font-size: 0.9rem; color: var(--muted); }

/* history */
.history-controls { display: flex; flex-wrap: wrap; gap: 0.8rem; align-items: flex-end; margin-bottom: 1rem; }
.history-controls .field { flex: 1 1 140px; }
#history-list { list-style: none; margin: 0 0 1rem; padding: 0; display: grid; gap: 0.5rem; }
.history-row {
  display: flex; align-items: center; gap: 0.8rem; flex-wrap: wrap;
  border: 1px solid var(--line); border-radius: 10px; padding: 0.6rem 0.9rem; background: #fbfbfe;
}
.h-date { font-weight: 700; }
.h-rate { font-weight: 800; color: var(--accent-deep); font-variant-numeric: tabular-nums; }
.h-meta { color: var(--muted); font-size: 0.88rem; }
.h-delta { font-size: 0.85rem; font-weight: 700; margin-left: auto; }
.h-delta.up { color: #b45309; }
.h-delta.down { color: var(--teal); }
#sparkline { margin-top: 0.6rem; }
#sparkline svg { width: 100%; height: auto; display: block; background: #fbfbfe; border: 1px solid var(--line); border-radius: 12px; }
.spark-label { fill: var(--muted); font-size: 10px; }
.spark-value { fill: var(--accent-deep); font-size: 12px; font-weight: 800; }
.manual-add { display: flex; flex-wrap: wrap; gap: 0.6rem; align-items: flex-end; margin-top: 1rem; padding-top: 1rem; border-top: 1px dashed var(--line); }
.manual-add .field { flex: 1 1 130px; }
#manual-msg { font-size: 0.88rem; color: var(--teal); font-weight: 600; width: 100%; }

/* share */
.share-row { display: flex; gap: 0.7rem; flex-wrap: wrap; }
#share-fallback { margin-top: 0.8rem; min-height: 120px; }

/* faq */
.faq { margin-top: 2.5rem; }
.faq details { background: var(--card); border: 1px solid var(--line); border-radius: 12px; margin-bottom: 0.6rem; padding: 0.9rem 1.1rem; }
.faq summary { font-weight: 650; cursor: pointer; }
.faq p { color: var(--muted); font-size: 0.93rem; margin: 0.5rem 0 0; }

/* footer */
.site-footer { background: #1c1f38; color: #aeb3d6; padding: 2rem 0; font-size: 0.88rem; }
.site-footer h2 { color: #fff; font-size: 1rem; margin: 0 0 0.5rem; }
.site-footer ul { margin: 0 0 1rem; padding-left: 1.1rem; }
.site-footer li { margin-bottom: 0.3rem; }
.disclaimer { border-top: 1px solid rgba(255,255,255,.12); padding-top: 1rem; color: #8b90b8; }

#error-banner, #data-error {
  background: #fef2f2; border: 1px solid #fca5a5; color: #991b1b;
  border-radius: 12px; padding: 1rem 1.2rem; margin-bottom: 1.2rem;
}

/* ---------- print ---------- */
#print-summary { display: none; }
@media print {
  .site-header, .site-footer, .no-print, .faq, .step-nav, .share-row, #history-section { display: none !important; }
  .step { display: none !important; }
  .step.active { display: block !important; }
  #print-summary { display: block !important; }
  body { background: #fff; }
  .card { box-shadow: none; border: 1px solid #ddd; }
  #print-summary table { width: 100%; border-collapse: collapse; margin: 1rem 0; }
  #print-summary th, #print-summary td { border: 1px solid #ccc; padding: 0.4rem 0.6rem; text-align: left; }
  #print-summary .total-row { font-weight: 800; }
  .print-foot { font-size: 0.8rem; color: #555; }
}

/* ---------- responsive ---------- */
@media (max-width: 640px) {
  .progress-step span:last-child { display: none; }
  .progress-step { justify-content: center; }
  .decode-row summary { flex-wrap: wrap; }
  .card { padding: 1rem; }
  .stack-bar { height: 56px; }
  .seg-label { display: none; }
}

/* ---------- reduced motion ---------- */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation: none !important;
    transition: none !important;
    scroll-behavior: auto !important;
  }
  .stagger > .stagger-item { opacity: 1; }
}