/*
 * Shared stylesheet for bitcoindigital.de.
 * Vanilla CSS, no frameworks / external fonts / icon libraries (ADR-0001).
 * Dark is the default theme; light applies under prefers-color-scheme: light.
 * Comments/identifiers English; user-facing text lives in the HTML (German,
 * ADR-0002).
 */

/* ============================ Design tokens ============================ */
:root {
  color-scheme: dark;

  /* Accent — the single brand colour (Bitcoin orange). Used sparingly. */
  --accent: #f7931a;
  --accent-strong: #ffa838;   /* hover on dark surfaces */
  --on-accent: #1a1204;       /* text on an accent fill */
  --link: #ffb055;            /* body links on dark */

  /* Neutral surfaces / text (dark default) */
  --bg: #0e1013;
  --surface: #171b21;
  --surface-2: #1e242c;
  --surface-3: #262d37;
  --text: #eef1f5;
  --text-muted: #9aa4b2;
  --border: #2a313b;
  --border-strong: #3a434f;

  /* Status (green = tax-free, amber = countdown) */
  --ok-bg: #12281c;
  --ok-ink: #4fce85;
  --ok-border: #245239;
  --warn-bg: #2c2410;
  --warn-ink: #f0b44f;
  --warn-border: #574616;
  --neg-ink: #ff6f61;

  /* Spacing scale */
  --space-1: .25rem;
  --space-2: .5rem;
  --space-3: .75rem;
  --space-4: 1rem;
  --space-5: 1.5rem;
  --space-6: 2rem;
  --space-8: 3rem;

  /* Radii */
  --radius-sm: 8px;
  --radius: 12px;
  --radius-lg: 18px;
  --radius-pill: 999px;

  /* Shadows */
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, .35);
  --shadow: 0 2px 6px rgba(0, 0, 0, .3), 0 10px 30px rgba(0, 0, 0, .28);
  --shadow-lg: 0 8px 40px rgba(0, 0, 0, .45);

  /* Motion */
  --transition-fast: 120ms ease;
  --transition: 200ms ease;
  --transition-slow: 700ms cubic-bezier(.22, .61, .36, 1);

  /* Type */
  --font: system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial,
    "Noto Sans", sans-serif;
  --fs-lead: clamp(1.05rem, 0.98rem + 0.5vw, 1.2rem);
  --fs-h1: clamp(1.7rem, 1.3rem + 1.9vw, 2.4rem);
  --fs-h2: clamp(1.2rem, 1.08rem + 0.6vw, 1.4rem);
  --fs-result: clamp(1.4rem, 1.1rem + 1.6vw, 1.9rem);

  --maxw: 720px;
}

@media (prefers-color-scheme: light) {
  :root {
    color-scheme: light;
    --accent-strong: #d97e05;
    --link: #b5620a;

    --bg: #f5f6f8;
    --surface: #ffffff;
    --surface-2: #eef1f4;
    --surface-3: #e5e9ee;
    --text: #14181d;
    --text-muted: #5b636e;
    --border: #e0e4e9;
    --border-strong: #cbd2da;

    --ok-bg: #e7f6ec;
    --ok-ink: #1c7a3e;
    --ok-border: #b6e3c4;
    --warn-bg: #fdf2e2;
    --warn-ink: #8a5300;
    --warn-border: #f4d8ab;
    --neg-ink: #c0392b;

    --shadow-sm: 0 1px 2px rgba(20, 22, 28, .06);
    --shadow: 0 1px 2px rgba(20, 22, 28, .06), 0 8px 24px rgba(20, 22, 28, .08);
    --shadow-lg: 0 12px 40px rgba(20, 22, 28, .12);
  }
}

/* ============================ Base ============================ */
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  font-family: var(--font);
  font-size: 1.0625rem;
  line-height: 1.6;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
}

.container {
  width: 100%;
  max-width: var(--maxw);
  margin-inline: auto;
  padding-inline: var(--space-5);
}

h1 { font-size: var(--fs-h1); line-height: 1.15; margin: 0 0 var(--space-2); letter-spacing: -.02em; }
h2 { font-size: var(--fs-h2); margin: var(--space-6) 0 var(--space-3); letter-spacing: -.01em; }
h3 { font-size: 1.08rem; margin: var(--space-5) 0 var(--space-2); }

.lead { font-size: var(--fs-lead); color: var(--text-muted); margin: 0 0 var(--space-5); }

a { color: var(--link); text-decoration-thickness: 1px; text-underline-offset: 2px; }
a:hover { color: var(--accent-strong); }

/* Visible focus everywhere. */
:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

/* ============================ Header ============================ */
.site-header { border-bottom: 1px solid var(--border); background: var(--surface); }
.site-header .container { display: flex; align-items: center; gap: var(--space-3); padding-block: var(--space-3); }

.brand {
  display: inline-flex; align-items: center; gap: var(--space-2);
  font-weight: 700; font-size: 1.05rem; text-decoration: none; color: var(--text);
}
.brand:hover { color: var(--text); }
.brand .mark {
  display: inline-grid; place-items: center; width: 1.7rem; height: 1.7rem;
  border-radius: var(--radius-sm); background: var(--accent); color: var(--on-accent);
  font-weight: 800;
}

main { padding-block: var(--space-6) var(--space-8); }

/* ============================ Breadcrumb ============================ */
.breadcrumb { margin: 0 0 var(--space-5); }
.breadcrumb ol {
  list-style: none; margin: 0; padding: 0;
  display: flex; flex-wrap: nowrap; align-items: center; min-width: 0;
  font-size: .85rem; color: var(--text-muted);
}
.breadcrumb li { display: flex; align-items: center; min-width: 0; }
.breadcrumb li:first-child { flex: none; }
.breadcrumb li + li::before { content: "\203A"; color: var(--text-muted); padding: 0 var(--space-2); flex: none; }
.breadcrumb a {
  display: inline-flex; align-items: center; min-height: 44px;
  color: var(--text-muted); text-decoration: none;
}
.breadcrumb a:hover { color: var(--text); text-decoration: underline; }
.breadcrumb [aria-current="page"] { min-width: 0; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }

/* ============================ Cards / forms ============================ */
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow);
  padding: var(--space-5);
}

.field { margin-bottom: var(--space-4); }
.field label { display: block; font-weight: 600; margin-bottom: var(--space-1); }
.field .hint { display: block; font-size: .9rem; color: var(--text-muted); margin-top: var(--space-1); }

input[type="date"], input[type="month"], input[type="number"], input[type="text"] {
  width: 100%;
  font: inherit;
  font-variant-numeric: tabular-nums;
  color: var(--text);
  background: var(--surface-2);
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-sm);
  padding: var(--space-3);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}
input:hover { border-color: var(--accent); }
input:focus { border-color: var(--accent); box-shadow: 0 0 0 3px rgba(247, 147, 26, .22); outline: none; }

button.primary {
  font: inherit; font-weight: 700; cursor: pointer;
  color: var(--on-accent); background: var(--accent);
  border: none; border-radius: var(--radius-sm);
  padding: var(--space-3) var(--space-5);
  transition: background var(--transition-fast), transform var(--transition-fast);
}
button.primary:hover { background: var(--accent-strong); }
button.primary:active { transform: translateY(1px); }
@media (max-width: 480px) { button.primary { width: 100%; } }

/* ============================ Result (Haltefrist) ============================ */
.result {
  margin-top: var(--space-5);
  border-radius: var(--radius);
  border: 1px solid var(--border);
  padding: var(--space-5);
  background: var(--surface-2);
}
.result[hidden] { display: none; }
.result.is-error { background: var(--warn-bg); border-color: var(--warn-border); color: var(--warn-ink); }

.result-main { display: flex; align-items: center; gap: var(--space-5); flex-wrap: wrap; }
.result-text { flex: 1 1 220px; min-width: 0; }

.badge {
  display: inline-block; font-size: .8rem; font-weight: 700; letter-spacing: .03em;
  text-transform: uppercase; padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-pill); border: 1px solid transparent;
}
.badge.ok { background: var(--ok-bg); color: var(--ok-ink); border-color: var(--ok-border); }
.badge.warn { background: var(--warn-bg); color: var(--warn-ink); border-color: var(--warn-border); }

.result .headline {
  font-size: var(--fs-result); font-weight: 700; letter-spacing: -.01em;
  font-variant-numeric: tabular-nums; margin: var(--space-3) 0 var(--space-1);
}
.result .detail { color: var(--text-muted); margin: 0; font-variant-numeric: tabular-nums; }

/* Progress ring */
.ring { width: clamp(88px, 24vw, 112px); height: auto; flex: none; }
.ring-track { fill: none; stroke: var(--surface-3); stroke-width: 10; }
.ring-value {
  fill: none; stroke-width: 10; stroke-linecap: round;
  transform: rotate(-90deg); transform-origin: center; transform-box: fill-box;
  transition: stroke-dashoffset var(--transition-slow);
}
.ring.ring-ok .ring-value { stroke: var(--ok-ink); }
.ring.ring-warn .ring-value { stroke: var(--warn-ink); }
.ring-label { fill: var(--text); font-size: 26px; font-weight: 700; font-variant-numeric: tabular-nums; }

@keyframes rise { from { opacity: 0; transform: translateY(6px); } to { opacity: 1; transform: none; } }
.result:not(.is-error) .result-main { animation: rise var(--transition) ease both; }

/* ============================ Price box (Satoshi / Sparplan) ============================ */
.price-box {
  margin: 0 0 var(--space-4);
  min-height: 4rem;                    /* reserve space → no shift on price load */
  display: flex; flex-direction: column; justify-content: center;
  padding: var(--space-3) var(--space-4);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-size: .95rem;
  font-variant-numeric: tabular-nums;
}
.price-box p { margin: var(--space-1) 0; }
.price-box .price-meta { color: var(--text-muted); }
.price-box .field { margin: var(--space-2) 0 var(--space-1); }

.link-btn {
  font: inherit; color: var(--link); background: none; border: none;
  padding: 2px 3px; cursor: pointer; text-decoration: underline; border-radius: 4px;
}
.link-btn:hover { color: var(--accent-strong); }

/* ============================ Result stats (Sparplan) ============================ */
.stats { display: grid; grid-template-columns: 1fr; gap: 0 var(--space-5); margin: var(--space-5) 0 0; }
@media (min-width: 520px) { .stats { grid-template-columns: 1fr 1fr; } }
.stats > div { padding: var(--space-3) 0; border-bottom: 1px solid var(--border); }
.stats dt { margin: 0; font-size: .85rem; color: var(--text-muted); }
.stats dd { margin: var(--space-1) 0 0; font-size: 1.2rem; font-weight: 700; letter-spacing: -.01em; font-variant-numeric: tabular-nums; }
.value-pos { color: var(--ok-ink); }
.value-neg { color: var(--neg-ink); }

/* ============================ Inline SVG chart ============================ */
.chart-figure { margin: var(--space-5) 0 0; }
.chart {
  width: 100%; height: auto; display: block;
  background: var(--surface-2); border: 1px solid var(--border); border-radius: var(--radius);
}
.chart-line { fill: none; stroke-width: 2; }
.chart-invested { stroke: var(--text-muted); }
.chart-value { stroke: var(--accent); }
.chart-axis { fill: var(--text-muted); font-size: 11px; font-variant-numeric: tabular-nums; }
.chart-baseline { stroke: var(--border-strong); stroke-width: 1; }
.chart-legend { display: flex; flex-wrap: wrap; gap: var(--space-4); margin: var(--space-2) 0 0; font-size: .9rem; color: var(--text-muted); }
.chart-legend .k { display: inline-block; width: .8rem; height: .8rem; border-radius: 3px; vertical-align: middle; margin-right: var(--space-1); }
.chart-legend .k-invested { background: var(--text-muted); }
.chart-legend .k-value { background: var(--accent); }
.chart-figure figcaption { margin-top: var(--space-2); font-size: .9rem; color: var(--text-muted); }

/* ============================ Info notes ============================ */
.note {
  border-left: 3px solid var(--accent);
  background: var(--surface);
  border-radius: var(--radius-sm);
  padding: var(--space-3) var(--space-4);
  margin: var(--space-4) 0;
  font-size: .96rem;
}
.note strong { color: var(--text); }

/* ============================ Hub tool grid ============================ */
.tools {
  list-style: none; padding: 0; margin: var(--space-5) 0 0;
  display: grid; gap: var(--space-4);
  grid-template-columns: repeat(auto-fit, minmax(min(100%, 12.5rem), 1fr));
}
.tools li { display: flex; }               /* stretch children to equal height */
.tool {
  display: flex; flex-direction: column; width: 100%;
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius-lg); box-shadow: var(--shadow-sm);
  padding: var(--space-5); text-decoration: none; color: inherit;
  transition: transform var(--transition), border-color var(--transition), box-shadow var(--transition);
}
a.tool:hover { transform: translateY(-3px); border-color: var(--accent); box-shadow: var(--shadow); }
.tool h2 { margin: 0 0 var(--space-2); font-size: 1.15rem; }
.tool p { margin: 0; color: var(--text-muted); font-size: .96rem; }
.tool.soon { opacity: .65; }
.tool .tag {
  display: inline-block; margin-top: auto; align-self: flex-start;
  font-size: .72rem; font-weight: 700; text-transform: uppercase; letter-spacing: .04em;
  color: var(--text-muted); border: 1px solid var(--border-strong); border-radius: var(--radius-pill);
  padding: 2px var(--space-2);
}
.tool p + .tag { margin-top: var(--space-4); }

/* ============================ FAQ / prose ============================ */
details {
  border: 1px solid var(--border); border-radius: var(--radius-sm);
  padding: var(--space-1) var(--space-4); margin: var(--space-2) 0; background: var(--surface);
}
details summary { font-weight: 600; cursor: pointer; padding: var(--space-2) 0; }
details[open] summary { margin-bottom: var(--space-1); }

.prose { line-height: 1.75; }
.prose p, .prose li { color: var(--text); }
.prose li { margin: var(--space-1) 0; }
.prose address { font-style: normal; }

/* Tables (e.g. the past-halvings table) — scroll inside their own box. */
.table-wrap { overflow-x: auto; margin: var(--space-4) 0; }
.table-wrap table { width: 100%; border-collapse: collapse; font-size: .95rem; font-variant-numeric: tabular-nums; }
.table-wrap th, .table-wrap td { text-align: left; padding: var(--space-2) var(--space-3); border-bottom: 1px solid var(--border); white-space: nowrap; }
.table-wrap thead th { color: var(--text-muted); font-weight: 600; }
.table-wrap tr.is-next { color: var(--accent); font-weight: 600; }

/* ============================ Footer ============================ */
.site-footer {
  border-top: 1px solid var(--border); background: var(--surface);
  color: var(--text-muted); font-size: .9rem; padding-block: var(--space-5) var(--space-6);
}
.site-footer .disclaimer { margin: 0 0 var(--space-3); }
.site-footer nav { display: flex; flex-wrap: wrap; gap: var(--space-2) var(--space-5); }
.site-footer a { color: var(--text-muted); }
.site-footer a:hover { color: var(--text); }
.site-footer .copyright { margin: var(--space-4) 0 0; }

.skip-link { position: absolute; left: -9999px; }
.skip-link:focus {
  left: var(--space-4); top: var(--space-4); z-index: 10;
  background: var(--surface); padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-sm); border: 1px solid var(--border);
}

/* ============================ Reduced motion ============================ */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
    scroll-behavior: auto !important;
  }
}