/* Light is the default palette; dark applies via system preference or the
   explicit toggle (data-theme attribute, set by /js/theme-toggle.js before
   paint to avoid a flash of the wrong theme). */
:root {
  --bg: #f5f6f8;
  --bg2: #ffffff;
  --bg3: #eef0f4;
  --border: #dde1e8;
  --text: #1a1d24;
  --text-muted: #5b6273;
  --text-dim: #8890a0;
  --accent: #3d63dd;
  --accent-hover: #2e4fc4;
  --success: #1f8a4c;
  --danger: #c92a2a;
  --warning: #a6690a;
  --code-bg: #f1f2f5;
  --success-soft-bg: rgba(31,138,76,0.12);
  --danger-soft-bg: rgba(201,42,42,0.10);
  --danger-soft-text: #c92a2a;
  --warning-soft-bg: rgba(166,105,10,0.12);
  --shadow: rgba(20,22,30,0.08);
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #0f1115;
    --bg2: #161922;
    --bg3: #1e2230;
    --border: #2a2f3f;
    --text: #e8eaf0;
    --text-muted: #9aa1b2;
    --text-dim: #6b7385;
    --accent: #4f7cff;
    --accent-hover: #6f93ff;
    --success: #2e9e5b;
    --danger: #e5484d;
    --warning: #d9a441;
    --code-bg: #0b0d12;
    --success-soft-bg: rgba(46,158,91,0.15);
    --danger-soft-bg: rgba(229,72,77,0.12);
    --danger-soft-text: #ff9b9e;
    --warning-soft-bg: rgba(217,164,65,0.15);
    --shadow: rgba(0,0,0,0.4);
  }
}

:root[data-theme="dark"] {
  --bg: #0f1115;
  --bg2: #161922;
  --bg3: #1e2230;
  --border: #2a2f3f;
  --text: #e8eaf0;
  --text-muted: #9aa1b2;
  --text-dim: #6b7385;
  --accent: #4f7cff;
  --accent-hover: #6f93ff;
  --success: #2e9e5b;
  --danger: #e5484d;
  --warning: #d9a441;
  --code-bg: #0b0d12;
  --success-soft-bg: rgba(46,158,91,0.15);
  --danger-soft-bg: rgba(229,72,77,0.12);
  --danger-soft-text: #ff9b9e;
  --warning-soft-bg: rgba(217,164,65,0.15);
  --shadow: rgba(0,0,0,0.4);
}

* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.5;
}
a { color: var(--accent); }

header.app-header {
  display: flex; align-items: center; gap: 1rem;
  padding: 0.75rem 1.5rem; background: var(--bg2); border-bottom: 1px solid var(--border);
}
header.app-header img.logo { height: 28px; }
header.app-header .app-name { font-weight: 700; font-size: 1.05rem; }
header.app-header nav { display: flex; gap: 0.25rem; margin-left: 1.5rem; flex: 1; }
header.app-header nav a {
  color: var(--text-muted); text-decoration: none; font-size: 0.875rem;
  padding: 0.4rem 0.7rem; border-radius: 6px;
}
header.app-header nav a:hover, header.app-header nav a.active { color: var(--text); background: var(--bg3); }
header.app-header .spacer { flex: 1; }
header.app-header form { margin: 0; }

main { max-width: 1100px; margin: 0 auto; padding: 1.5rem; }

.card { background: var(--bg2); border: 1px solid var(--border); border-radius: 10px; padding: 1.25rem; }
.card + .card { margin-top: 1rem; }

h1 { font-size: 1.4rem; }
h2 { font-size: 1.05rem; }

table { width: 100%; border-collapse: collapse; font-size: 0.875rem; }
th, td { text-align: left; padding: 0.55rem 0.6rem; border-bottom: 1px solid var(--border); }
th { color: var(--text-muted); font-weight: 600; font-size: 0.75rem; text-transform: uppercase; letter-spacing: 0.03em; }
tr:hover td { background: var(--bg3); }

.btn {
  display: inline-block; background: var(--bg3); color: var(--text); border: 1px solid var(--border);
  padding: 0.45rem 0.85rem; border-radius: 6px; font-size: 0.875rem; cursor: pointer; text-decoration: none;
}
.btn:hover { border-color: var(--accent); }
.btn-primary { background: var(--accent); border-color: var(--accent); color: white; }
.btn-primary:hover { background: var(--accent-hover); }
.btn-danger { color: var(--danger); }
.btn-sm { padding: 0.25rem 0.55rem; font-size: 0.78rem; }
.btn-icon { padding: 0.45rem 0.6rem; font-size: 0.9rem; line-height: 1; flex-shrink: 0; }

input[type=text], input[type=email], input[type=password], input[type=number], textarea, select {
  width: 100%; background: var(--bg3); border: 1px solid var(--border); border-radius: 6px;
  color: var(--text); padding: 0.5rem 0.7rem; font-size: 0.9rem; font-family: inherit;
}
label { display: block; font-size: 0.8rem; color: var(--text-muted); margin-bottom: 1rem; }
label > span { display: block; margin-bottom: 0.3rem; }

.badge { display: inline-block; padding: 2px 8px; border-radius: 4px; font-size: 0.72rem; font-weight: 600; }
.badge-success { background: var(--success-soft-bg); color: var(--success); }
.badge-danger { background: var(--danger-soft-bg); color: var(--danger); }
.badge-warning { background: var(--warning-soft-bg); color: var(--warning); }
.badge-muted { background: var(--bg3); color: var(--text-muted); }

.error-banner {
  background: var(--danger-soft-bg); border: 1px solid var(--danger); color: var(--danger-soft-text);
  border-radius: 6px; padding: 0.6rem 0.9rem; margin-bottom: 1rem; font-size: 0.875rem;
}

.stat-row { display: flex; gap: 1rem; flex-wrap: wrap; margin-bottom: 1.5rem; }
.stat-tile { flex: 1 1 140px; background: var(--bg2); border: 1px solid var(--border); border-radius: 10px; padding: 1rem; text-align: center; }
.stat-tile .value { font-size: 1.6rem; font-weight: 700; }
.stat-tile .label { font-size: 0.78rem; color: var(--text-muted); margin-top: 0.2rem; }

.score-ring { font-size: 2rem; font-weight: 700; }
.score-breakdown { display: flex; gap: 1rem; flex-wrap: wrap; }
.score-breakdown .item { flex: 1 1 120px; background: var(--bg3); border-radius: 8px; padding: 0.75rem; text-align: center; }
.score-breakdown .item .n { font-size: 1.3rem; font-weight: 700; }
.score-breakdown .item .l { font-size: 0.72rem; color: var(--text-muted); }

pre.code-block {
  background: var(--code-bg); border: 1px solid var(--border); border-radius: 8px; padding: 1rem;
  overflow-x: auto; font-size: 0.82rem; line-height: 1.5; white-space: pre-wrap; word-break: break-word;
  color: var(--text);
}

.tc-row { display: flex; gap: 0.5rem; margin-bottom: 0.5rem; align-items: flex-start; }
.tc-row textarea { min-height: 2.4rem; }
.tc-row select { width: auto; }

/* Candidate exam page */
.exam-shell { display: grid; grid-template-columns: 1fr 1fr; gap: 0; height: 100vh; }
.exam-panel { padding: 1.25rem; overflow-y: auto; }
.exam-panel.left { border-right: 1px solid var(--border); }
.exam-timer {
  position: sticky; top: 0; background: var(--bg2); border: 1px solid var(--border); border-radius: 8px;
  padding: 0.6rem 1rem; text-align: center; font-weight: 700; font-size: 1.1rem; margin-bottom: 1rem;
}
.exam-timer.low { color: var(--danger); border-color: var(--danger); }
#editor-container { height: 55vh; border: 1px solid var(--border); border-radius: 8px; overflow: hidden; }
.exam-actions { display: flex; gap: 0.6rem; margin-top: 0.75rem; }
.sample-results { margin-top: 1rem; }
.sample-results .tc { background: var(--bg3); border-radius: 6px; padding: 0.6rem 0.8rem; margin-bottom: 0.5rem; font-size: 0.82rem; }

.thank-you { display: flex; align-items: center; justify-content: center; height: 100vh; text-align: center; }