*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
[hidden] { display: none !important; }

:root {
  --primary: #5B6BF8;
  --primary-dark: #4a59e8;
  --secondary: #2a2a3a;
  --gold: #F5C518;
  --bg: #0f0f13;
  --surface: #1a1a24;
  --surface2: #22222e;
  --surface3: #2a2a3a;
  --text: #ffffff;
  --text-muted: #888880;
  --border: rgba(255,255,255,0.08);
  --radius: 12px;
  --font: 'Segoe UI', system-ui, sans-serif;
}

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
}

[data-theme="gold"] {
  --primary: #F5C518;
  --primary-dark: #d4a800;
  --secondary: #2a2a22;
  --bg: #111110;
  --surface: #1c1c18;
  --surface2: #242420;
  --surface3: #2e2e28;
}
[data-theme="gold"] .btn-primary { color: #111; }
[data-theme="gold"] .nav-challenge-badge { color: #111; }
[data-theme="gold"] .nav-hamburger { color: #111; }

a { color: var(--primary); text-decoration: none; }
button {
  cursor: pointer;
  border: none;
  border-radius: var(--radius);
  padding: 10px 20px;
  font-size: 1rem;
  font-family: var(--font);
  transition: opacity 0.2s;
}
button:hover { opacity: 0.85; }
button:disabled { opacity: 0.4; cursor: not-allowed; }

.btn-primary { background: var(--primary); color: #fff; font-weight: 700; border-radius: 50px; }
.btn-secondary { background: var(--surface3); color: var(--text); font-weight: 600; border-radius: 50px; border: 1px solid var(--border); }
.btn-outline { background: transparent; border: 1px solid var(--border); color: var(--text); border-radius: 50px; }

input, select {
  width: 100%;
  padding: 10px 14px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface2);
  color: var(--text);
  font-size: 1rem;
  font-family: var(--font);
}
input:focus, select:focus { outline: 2px solid var(--primary); border-color: transparent; }

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
}
.label-tag {
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1.5px;
  color: var(--primary);
}

.error-msg { color: #e74c3c; font-size: 0.875rem; margin-top: 6px; }
.success-msg { color: #2ecc71; font-size: 0.875rem; margin-top: 6px; }

.page-container {
  max-width: 900px;
  margin: 0 auto;
  padding: 20px 16px 60px;
}

.ad-unit {
  margin: 12px 0;
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--surface);
  border: 1px solid var(--border);
}
.ad-unit .ad-label {
  display: block;
  font-size: 0.6rem;
  font-weight: 700;
  letter-spacing: 1px;
  color: var(--text-muted);
  text-align: center;
  padding: 4px 0 2px;
  text-transform: uppercase;
}
.ad-banner-footer {
  margin-top: 24px;
  border-top: 1px solid var(--border);
  padding-top: 16px;
}