/* Modern styles with system light/dark mode */
:root{
  --bg: #f6f7fb;
  --card: #ffffff;
  --muted: #556;
  --text: #0b1220;
  --accent: #6750a4;
  --accent-contrast: white;
  --shadow: 0 6px 18px rgba(11,18,32,0.06);
}

@media (prefers-color-scheme: dark){
  :root{
    --bg: #0b1220;
    --card: #0f1724;
    --muted: #9aa4b2;
    --text: #e6eef8;
    --accent: #8b5cf6;
    --accent-contrast: black;
    --shadow: 0 8px 22px rgba(2,6,23,0.6);
  }
}

/* Attribute overrides when user explicitly picks a theme */
:root[data-theme="light"]{
  --bg: #f6f7fb;
  --card: #ffffff;
  --muted: #556;
  --text: #0b1220;
  --accent: #6750a4;
  --accent-contrast: white;
  --shadow: 0 6px 18px rgba(11,18,32,0.06);
}

:root[data-theme="dark"]{
  --bg: #0b1220;
  --card: #0f1724;
  --muted: #9aa4b2;
  --text: #e6eef8;
  --accent: #8b5cf6;
  --accent-contrast: black;
  --shadow: 0 8px 22px rgba(2,6,23,0.6);
}

html,body{
  height:100%;
  background: linear-gradient(180deg, var(--bg), color-mix(in srgb, var(--bg) 92%, black 8%));
  color:var(--text);
}

.container{
  margin:4vh auto;
  padding:1rem;
}

.card{
  background:var(--card);
  border-radius:12px;
  padding:1.25rem 1.5rem;
  box-shadow:var(--shadow);
  border:1px solid color-mix(in srgb, var(--card) 92%, black 8%);
}

header h1{
  margin:0 0 .25rem 0;
  font-weight:600;
}

.header-with-controls{
  display:flex;
  gap:1rem;
  align-items:center;
  justify-content:space-between;
  padding-right:0.5rem; /* give some room on the right */
}

.theme-controls select{
  padding:0.35rem 0.5rem;
  border-radius:8px;
}

.theme-controls{
  position:fixed;
  top:12px;
  right:12px;
  display:flex;
  gap:0.35rem;
  align-items:center;
  justify-content:flex-end;
  z-index:9999;
}

.theme-btn{
  background:transparent;
  border:none;
  font-size:1.05rem;
  padding:0.45rem;
  border-radius:999px;
  cursor:pointer;
  transition:transform .12s ease, background .12s ease, box-shadow .12s ease;
}

.theme-btn:focus{
  outline:2px solid color-mix(in srgb, var(--accent) 30%, transparent 70%);
  outline-offset:3px;
}

.theme-btn:hover{ transform:translateY(-1px); }

.theme-btn.active{
  background: color-mix(in srgb, var(--accent) 12%, transparent 88%);
  box-shadow: 0 6px 14px color-mix(in srgb, var(--accent) 18%, transparent 82%);
}

.muted{ color:var(--muted); }

.results{
  margin-top:1rem;
  padding-top:0.5rem;
  border-top:1px dashed color-mix(in srgb, var(--muted) 30%, transparent 70%);
}

.estimate-value{
  font-weight:800;
  font-size:1.35rem;
}

/* Tweak buttons */
button.contrast{
  background: linear-gradient(90deg, var(--accent), color-mix(in srgb, var(--accent) 80%, black 20%));
  color:var(--accent-contrast);
  border:none;
  box-shadow: 0 6px 16px color-mix(in srgb, var(--accent) 20%, transparent 80%);
}

input[type="number"], input[type="datetime-local"]{
  background:transparent;
  border-radius:8px;
  padding:0.5rem;
}

@media (max-width:520px){
  .container{ padding:0.5rem; }
  .card{ padding:1rem; }
  .header-with-controls{
    flex-direction:column;
    align-items:flex-start;
    gap:0.5rem;
  }
  .theme-controls{ align-items:flex-start; width:100%; }
}