:root {
  --color-primary: #1450A3;
  --color-primary-dark: #0d3a7a;
  --color-secondary: #1E8E6F;
  --color-accent: #F5A623;
  --color-accent-dark: #d98c0c;
  --color-bg: #F6F8FB;
  --color-surface: #FFFFFF;
  --color-text: #1B2430;
  --color-muted: #6B7684;
  --color-border: #E1E7EF;
  --color-success: #1E8E6F;
  --color-error: #D64545;
  --radius: 10px;
  --shadow: 0 2px 10px rgba(20, 80, 163, 0.08);
}

* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.55;
}
a { color: var(--color-primary); text-decoration: none; }
.container { max-width: 1140px; margin: 0 auto; padding: 0 16px; }

/* Header */
.site-header { background: var(--color-surface); box-shadow: var(--shadow); position: sticky; top: 0; z-index: 50; }
.header-inner { display: flex; align-items: center; justify-content: space-between; padding: 14px 16px; }
.logo { font-size: 22px; font-weight: 800; color: var(--color-primary-dark); }
.logo span { color: var(--color-accent); }
.main-nav { display: none; gap: 18px; align-items: center; }
.main-nav a { font-weight: 600; color: var(--color-text); }
.main-nav a:hover { color: var(--color-primary); }
.btn-cta {
  background: var(--color-accent); color: #fff !important; padding: 9px 18px;
  border-radius: 6px; font-weight: 700 !important;
}
.btn-cta:hover { background: var(--color-accent-dark); }
.btn-ghost { border: 1px solid var(--color-border); padding: 8px 16px; border-radius: 6px; }
.nav-toggle { display: block; background: none; border: none; font-size: 26px; cursor: pointer; }

@media (min-width: 860px) {
  .main-nav { display: flex; }
  .nav-toggle { display: none; }
}
.main-nav.open { display: flex; flex-direction: column; position: absolute; top: 64px; right: 0; left: 0; background: #fff; padding: 16px; box-shadow: var(--shadow); }

/* Alerts */
.alert { padding: 12px 16px; border-radius: var(--radius); margin: 14px auto; }
.alert-success { background: #E4F6EF; color: var(--color-success); border: 1px solid #b9e6d4; }
.alert-error { background: #FCEAEA; color: var(--color-error); border: 1px solid #f3c1c1; }

/* Hero */
.hero { padding: 56px 0 40px; text-align: center; background: linear-gradient(180deg, #eef4ff 0%, var(--color-bg) 100%); }
.hero h1 { font-size: 30px; color: var(--color-primary-dark); margin-bottom: 12px; }
.hero p { color: var(--color-muted); max-width: 640px; margin: 0 auto 24px; font-size: 17px; }
.hero-actions { display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; }

/* Cards / grid */
.grid { display: grid; gap: 20px; grid-template-columns: 1fr; padding: 30px 0; }
@media (min-width: 700px) { .grid.cols-3 { grid-template-columns: repeat(3, 1fr); } .grid.cols-2 { grid-template-columns: repeat(2,1fr);} }
.card {
  background: var(--color-surface); border-radius: var(--radius); box-shadow: var(--shadow);
  padding: 22px; border: 1px solid var(--color-border);
}
.card h3 { margin-top: 0; color: var(--color-primary-dark); }

/* Buttons */
.btn { display: inline-block; padding: 11px 22px; border-radius: 8px; font-weight: 700; border: none; cursor: pointer; font-size: 15px; }
.btn-primary { background: var(--color-primary); color: #fff; }
.btn-primary:hover { background: var(--color-primary-dark); }
.btn-accent { background: var(--color-accent); color: #fff; }
.btn-accent:hover { background: var(--color-accent-dark); }
.btn-block { width: 100%; text-align: center; }
.btn-outline { background: transparent; border: 2px solid var(--color-primary); color: var(--color-primary); }

/* Forms */
.form-box { max-width: 440px; margin: 40px auto; background: var(--color-surface); padding: 30px; border-radius: var(--radius); box-shadow: var(--shadow); }
.form-group { margin-bottom: 16px; }
label { display: block; font-weight: 600; margin-bottom: 6px; font-size: 14px; }
input, select, textarea {
  width: 100%; padding: 11px 12px; border-radius: 8px; border: 1px solid var(--color-border);
  font-size: 15px; background: #fff;
}
input:focus, select:focus, textarea:focus { outline: 2px solid var(--color-primary); border-color: var(--color-primary); }

/* Filters (services page) */
.filter-bar { display: flex; flex-wrap: wrap; gap: 12px; margin-bottom: 24px; }
.filter-bar select { max-width: 220px; }

/* Dashboard */
.streak-card {
  background: linear-gradient(135deg, var(--color-accent), #ff7a45); color: #fff; padding: 24px;
  border-radius: var(--radius); display: flex; align-items: center; gap: 18px; margin-bottom: 24px;
}
.streak-flame { font-size: 44px; }
.streak-numbers { display: flex; gap: 26px; }
.streak-numbers div { text-align: center; }
.streak-numbers .num { font-size: 26px; font-weight: 800; display: block; }

table { width: 100%; border-collapse: collapse; background: #fff; border-radius: var(--radius); overflow: hidden; }
th, td { padding: 12px 14px; border-bottom: 1px solid var(--color-border); text-align: left; font-size: 14px; }
th { background: #F0F4FA; }
.table-wrap { overflow-x: auto; }

.tag { display: inline-block; padding: 3px 10px; border-radius: 20px; font-size: 12px; font-weight: 700; }
.tag-strong { background: #E4F6EF; color: var(--color-success); }
.tag-weak { background: #FCEAEA; color: var(--color-error); }

/* Exam interface */
.exam-shell { display: flex; flex-direction: column; gap: 16px; }
@media (min-width: 900px) { .exam-shell { flex-direction: row; } }
.exam-main { flex: 3; background: #fff; border-radius: var(--radius); padding: 22px; box-shadow: var(--shadow); }
.exam-sidebar { flex: 1; background: #fff; border-radius: var(--radius); padding: 16px; box-shadow: var(--shadow); position: sticky; top: 76px; align-self: flex-start; }
.timer-box { background: var(--color-primary-dark); color: #fff; text-align: center; padding: 12px; border-radius: 8px; font-size: 22px; font-weight: 800; margin-bottom: 14px; letter-spacing: 1px; }
.question-palette { display: grid; grid-template-columns: repeat(6, 1fr); gap: 6px; }
@media (min-width: 900px) { .question-palette { grid-template-columns: repeat(5, 1fr); } }
.palette-btn { width: 100%; aspect-ratio: 1; border-radius: 6px; border: 1px solid var(--color-border); background: #fff; font-size: 13px; cursor: pointer; }
.palette-answered { background: var(--color-success); color: #fff; border-color: var(--color-success); }
.palette-not-answered { background: var(--color-error); color: #fff; border-color: var(--color-error); }
.palette-marked { background: #9B51E0; color: #fff; border-color: #9B51E0; }
.palette-not-visited { background: #fff; }
.palette-legend { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 12px; font-size: 12px; }
.legend-dot { width: 10px; height: 10px; border-radius: 3px; display: inline-block; margin-right: 4px; }

.option-row { display: flex; align-items: flex-start; gap: 10px; padding: 12px; border: 1px solid var(--color-border); border-radius: 8px; margin-bottom: 10px; cursor: pointer; }
.option-row:hover { border-color: var(--color-primary); }
.option-row.selected { border-color: var(--color-primary); background: #eef4ff; }
.exam-nav-buttons { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 20px; }

/* Post-exam review */
.review-item { border-radius: var(--radius); padding: 16px; margin-bottom: 14px; border-left: 6px solid var(--color-border); background: #fff; }
.review-correct { border-left-color: var(--color-success); }
.review-incorrect { border-left-color: var(--color-error); }
.review-unattempted { border-left-color: #B0B8C2; }

.page-header { padding: 30px 0 10px; }
.page-header h1 { color: var(--color-primary-dark); }
.section { padding: 30px 0; }
.muted { color: var(--color-muted); }
.text-center { text-align: center; }