:root {
  --font-sans: system-ui, -apple-system, Segoe UI, Roboto, Ubuntu, Cantarell, 'Helvetica Neue', sans-serif;

  /* MODERN BRIGHT THEME */
  --bg: #f3f4f6;               /* Light gray background */
  --bg-soft: #ffffff;          /* Pure white (headers/footers) */
  --card: #ffffff;             /* White cards */
  --text: #111827;             /* Very dark gray text */
  --muted: #6b7280;            /* Medium gray for help text */

  /* ACCENTS: Professional Blue */
  --accent: #2563eb;           /* Royal Blue (Links/Buttons) */
  --accent-2: #1d4ed8;         /* Darker Blue (Hover state) */
  --accent-3: #3b82f6;         /* Lighter Blue */
  --accent-4: #f59e0b;         /* Amber */

  /* STATUS COLORS */
  --danger: #ef4444;           /* Red */
  --warning: #f59e0b;          /* Orange */
  --ok: #10b981;               /* Emerald Green */

  /* BORDERS & SHAPES */
  --border: #e5e7eb;           /* Very light border */
  --radius: 12px;              /* Smooth rounded corners */
  --ring: 0 0 0 3px rgba(37, 99, 235, 0.2); /* Blue focus ring */
}

/* ==========================================================================
   Keep the structural CSS below unchanged
   ========================================================================== */

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; background: var(--bg); color: var(--text); font-family: var(--font-sans); }
a { color: var(--accent); text-decoration: none; transition: color .2s ease; }
a:hover { color: var(--accent-2); text-decoration: none; }

/* Updated Button for Light Mode */
button {
  border-radius: 12px;
  border: 1px solid transparent;
  background: var(--accent);
  color: #ffffff; padding: .65rem .95rem; cursor: pointer;
  transition: transform .05s ease, box-shadow .2s ease, background-color .2s ease;
  font-weight: 500;
}
button:hover { box-shadow: 0 4px 12px rgba(37, 99, 235, 0.25); background-color: var(--accent-2); }
button:active { transform: translateY(1px); }
button[disabled] { opacity: .6; cursor: not-allowed; background-color: var(--muted); }

/* Updated Inputs for Light Mode */
input, select {
  background: #ffffff; color: var(--text); border: 1px solid #d1d5db;
  border-radius: 12px; padding: .6rem .75rem; transition: border-color .2s ease, box-shadow .2s ease;
}
input:focus, select:focus { outline: none; border-color: var(--accent); box-shadow: var(--ring); }

/* Updated Card with subtle shadow */
.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius); padding: 1rem;
  box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -1px rgba(0, 0, 0, 0.03);
}

header, footer { background: var(--bg-soft); border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); }
.container { max-width: 1000px; margin: 0 auto; padding: 0 1rem; }
.flex { display: flex; gap: .75rem; }
.row { display: flex; flex-wrap: wrap; gap: 1rem; }
.col { flex: 1 1 300px; }
.hide { display: none !important; }

.tag {
  display: inline-block; padding: .25rem .6rem;
  background: #eef2ff;
  border: 1px solid #c7d2fe; border-radius: 999px; font-size: .78rem; color: var(--accent);
}
.badge { padding: .2rem .55rem; border-radius: 999px; font-size: .75rem; border: 1px solid transparent; font-weight: 500; }
.badge.ok { background: #dcfce7; color: #166534; }
.badge.warn { background: #fef3c7; color: #92400e; }
.badge.danger { background: #fee2e2; color: #991b1b; }
hr { border: none; border-top: 1px solid var(--border); margin: 1rem 0; }

@media (max-width: 640px) {
  nav .left, nav .right { gap: .5rem; }
}