:root {
  color-scheme: light;
  --bg: #eef4f8;
  --bg-alt: #f7fafc;
  --panel: rgba(255, 255, 255, 0.84);
  --text: #142026;
  --muted: #5f717a;
  --line: rgba(120, 150, 160, 0.32);
  --primary: #0f766e;
  --primary-dark: #115e59;
  --shadow: 0 16px 40px rgba(18, 27, 38, 0.12);
  --radius: 16px;
  --touch: 44px;
  --danger: #b42318;
  --primary-soft: rgba(15, 118, 110, 0.14);
}

:root[data-theme="dark"] {
  color-scheme: dark;
  --bg: #081216;
  --bg-alt: #0f1a1f;
  --panel: rgba(18, 32, 38, 0.88);
  --text: #e8f4f8;
  --muted: #a8c0c8;
  --line: rgba(160, 200, 210, 0.18);
  --primary: #2dd4bf;
  --primary-dark: #5eead4;
  --shadow: 0 20px 50px rgba(0, 0, 0, 0.4);
  --danger: #ff8a80;
  --primary-soft: rgba(45, 212, 191, 0.16);
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme]) {
    color-scheme: dark;
    --bg: #081216;
    --bg-alt: #0f1a1f;
    --panel: rgba(18, 32, 38, 0.88);
    --text: #e8f4f8;
    --muted: #a8c0c8;
    --line: rgba(160, 200, 210, 0.18);
    --primary: #2dd4bf;
    --primary-dark: #5eead4;
    --shadow: 0 20px 50px rgba(0, 0, 0, 0.4);
    --danger: #ff8a80;
    --primary-soft: rgba(45, 212, 191, 0.16);
  }
}

* { box-sizing: border-box; }

html, body { margin: 0; min-height: 100%; }

body {
  background: linear-gradient(160deg, rgba(15, 118, 110, 0.16), transparent 42%),
    linear-gradient(180deg, var(--bg), var(--bg-alt));
  color: var(--text);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, "Segoe UI", sans-serif;
  font-size: 16px;
  line-height: 1.45;
}

.hidden { display: none !important; }

.centered { min-height: 100vh; display: grid; place-items: center; padding: 24px; }

.card {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 18px;
}

.login { text-align: center; max-width: 420px; }
.eyebrow { letter-spacing: 0.08em; text-transform: uppercase; font-size: 12px; color: var(--primary-dark); margin-bottom: 0; }
.err { color: var(--danger); font-size: 14px; min-height: 1.2em; }

button {
  font: inherit;
  min-height: var(--touch);
  padding: 10px 16px;
  border-radius: 12px;
  border: 1px solid var(--line);
  background: var(--panel);
  color: var(--text);
  cursor: pointer;
}
button.primary { background: var(--primary); border-color: var(--primary); color: #042f2e; }
:root[data-theme="light"] button.primary,
:root:not([data-theme="dark"]) button.primary { color: #fff; }
button.primary:hover { background: var(--primary-dark); }
button.lg { width: 100%; font-weight: 600; }

.dc-theme-toggle {
  display: inline-flex;
  align-items: stretch;
  border: 1px solid var(--line);
  background: var(--panel);
  border-radius: 999px;
  overflow: hidden;
  padding: 2px;
  gap: 2px;
}
.dc-theme-toggle--login { margin: 16px auto 0; }
.dc-theme-btn {
  appearance: none;
  border: 0;
  background: transparent;
  color: var(--muted);
  font: inherit;
  font-size: 13px;
  font-weight: 600;
  padding: 6px 12px;
  border-radius: 999px;
  cursor: pointer;
  line-height: 1.2;
  min-height: 0;
}
.dc-theme-btn.is-active,
.dc-theme-btn[aria-pressed="true"] {
  background: var(--primary-soft, rgba(15, 118, 110, 0.14));
  color: var(--primary-dark);
}
.dc-theme-btn:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 1px;
}