/**
 * CAS Exam Experience — instructions, live assessment, modals.
 * Light, focused layout inspired by professional assessment platforms.
 *
 * @package College_Aptitude_Suite
 */

:root {
	--cex-bg: #f0f3f7;
	--cex-surface: #ffffff;
	--cex-surface-2: #f8fafc;
	--cex-border: #e2e8f0;
	--cex-border-strong: #cbd5e1;
	--cex-text: #1e293b;
	--cex-text-secondary: #64748b;
	--cex-muted: #94a3b8;
	--cex-primary: #2d7ff9;
	--cex-primary-dark: #1d6fe8;
	--cex-primary-bg: #eff6ff;
	--cex-primary-ring: rgba(45, 127, 249, 0.2);
	--cex-success: #16a34a;
	--cex-success-bg: #f0fdf4;
	--cex-warning: #d97706;
	--cex-warning-bg: #fffbeb;
	--cex-danger: #dc2626;
	--cex-danger-bg: #fef2f2;
	--cex-radius: 12px;
	--cex-radius-sm: 8px;
	--cex-radius-lg: 16px;
	--cex-shadow: 0 1px 3px rgba(15, 23, 42, 0.06), 0 8px 24px rgba(15, 23, 42, 0.06);
	--cex-shadow-lg: 0 12px 40px rgba(15, 23, 42, 0.12);
	--cex-font: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
	--cex-transition: 0.15s ease;
}

/* ── Page modes ── */
body.cas-exam-instructions .sp-main,
body.cas-exam-live .sp-main {
	padding-top: 0;
}

body.cas-exam-instructions .sp-container,
body.cas-exam-live .sp-container {
	max-width: 1200px;
	padding-top: 24px;
	padding-bottom: 48px;
}

body.cas-exam-live .sp-footer--hidden {
	display: none;
}

body.cas-exam-live .sp-header {
	border-bottom: 1px solid var(--cex-border);
	box-shadow: 0 1px 0 rgba(15, 23, 42, 0.04);
}

body.cas-exam-gate-open {
	overflow: hidden;
}

/* ── Buttons ── */
.cas-exam-btn {
	display: inline-flex;
	align-items: center;
	justify-content: center;
	gap: 8px;
	padding: 10px 18px;
	font-family: var(--cex-font);
	font-size: 14px;
	font-weight: 600;
	line-height: 1;
	border-radius: var(--cex-radius-sm);
	border: 1px solid transparent;
	cursor: pointer;
	text-decoration: none;
	transition: background var(--cex-transition), border-color var(--cex-transition), color var(--cex-transition), box-shadow var(--cex-transition);
}

.cas-exam-btn--primary {
	background: var(--cex-primary);
	color: #fff;
	border-color: var(--cex-primary);
}

.cas-exam-btn--primary:hover {
	background: var(--cex-primary-dark);
	color: #fff;
}

.cas-exam-btn--secondary {
	background: var(--cex-surface);
	color: var(--cex-text);
	border-color: var(--cex-border-strong);
}

.cas-exam-btn--secondary:hover {
	background: var(--cex-surface-2);
	border-color: var(--cex-muted);
}

.cas-exam-btn--ghost {
	background: transparent;
	color: var(--cex-text-secondary);
	border-color: var(--cex-border);
}

.cas-exam-btn--ghost:hover {
	background: var(--cex-surface-2);
	color: var(--cex-text);
}

.cas-exam-btn--danger {
	background: var(--cex-danger);
	color: #fff;
	border-color: var(--cex-danger);
}

.cas-exam-btn--danger:hover:not(:disabled) {
	background: #b91c1c;
}

.cas-exam-btn--warn {
	background: var(--cex-warning-bg);
	color: var(--cex-warning);
	border-color: #fcd34d;
}

.cas-exam-btn--lg {
	padding: 14px 24px;
	font-size: 15px;
	border-radius: var(--cex-radius);
}

.cas-exam-btn--sm {
	padding: 8px 14px;
	font-size: 13px;
}

.cas-exam-btn--block {
	width: 100%;
}

.cas-exam-btn:disabled,
.cas-exam-btn.is-disabled {
	opacity: 0.5;
	cursor: not-allowed;
}

/* ── Badges ── */
.cas-exam-badge {
	display: inline-flex;
	align-items: center;
	padding: 4px 10px;
	font-size: 11px;
	font-weight: 700;
	letter-spacing: 0.04em;
	text-transform: uppercase;
	border-radius: 999px;
	background: var(--cex-surface-2);
	color: var(--cex-text-secondary);
	border: 1px solid var(--cex-border);
}

.cas-exam-badge--primary {
	background: var(--cex-primary-bg);
	color: var(--cex-primary);
	border-color: #bfdbfe;
}

.cas-exam-badge--easy { background: #ecfdf5; color: #047857; border-color: #a7f3d0; }
.cas-exam-badge--moderate { background: #fffbeb; color: #b45309; border-color: #fde68a; }
.cas-exam-badge--difficult { background: #fef2f2; color: #b91c1c; border-color: #fecaca; }
.cas-exam-badge--scheduled { background: #f5f3ff; color: #6d28d9; border-color: #ddd6fe; }

/* ══════════════════════════════════════
   INSTRUCTION PAGE
   ══════════════════════════════════════ */
.cas-exam-instr {
	font-family: var(--cex-font);
	color: var(--cex-text);
}

.cas-exam-instr__header {
	display: flex;
	align-items: flex-start;
	justify-content: space-between;
	gap: 24px;
	padding: 28px 32px;
	background: var(--cex-surface);
	border: 1px solid var(--cex-border);
	border-radius: var(--cex-radius-lg);
	box-shadow: var(--cex-shadow);
	margin-bottom: 24px;
}

.cas-exam-instr__eyebrow {
	display: block;
	font-size: 12px;
	font-weight: 600;
	text-transform: uppercase;
	letter-spacing: 0.06em;
	color: var(--cex-primary);
	margin-bottom: 8px;
}

.cas-exam-instr__title {
	margin: 0 0 10px;
	font-size: 28px;
	font-weight: 700;
	line-height: 1.2;
	letter-spacing: -0.02em;
	color: var(--cex-text);
}

.cas-exam-instr__lead {
	margin: 0;
	font-size: 15px;
	line-height: 1.6;
	color: var(--cex-text-secondary);
	max-width: 640px;
}

.cas-exam-instr__grid {
	display: grid;
	grid-template-columns: 1fr 340px;
	gap: 24px;
	align-items: start;
}

.cas-exam-panel {
	background: var(--cex-surface);
	border: 1px solid var(--cex-border);
	border-radius: var(--cex-radius-lg);
	padding: 24px 28px;
	margin-bottom: 16px;
	box-shadow: var(--cex-shadow);
}

.cas-exam-panel--warn {
	border-color: #fde68a;
	background: linear-gradient(180deg, #fffbeb 0%, #ffffff 100%);
}

.cas-exam-panel__title {
	margin: 0 0 16px;
	font-size: 16px;
	font-weight: 700;
	color: var(--cex-text);
}

.cas-exam-list {
	margin: 0;
	padding: 0 0 0 20px;
	color: var(--cex-text-secondary);
	font-size: 14px;
	line-height: 1.65;
}

.cas-exam-list li + li {
	margin-top: 10px;
}

.cas-exam-instr__sidebar {
	position: sticky;
	top: 100px;
	display: flex;
	flex-direction: column;
	gap: 16px;
}

.cas-exam-summary,
.cas-exam-checklist {
	background: var(--cex-surface);
	border: 1px solid var(--cex-border);
	border-radius: var(--cex-radius-lg);
	padding: 20px 22px;
	box-shadow: var(--cex-shadow);
}

.cas-exam-summary__title,
.cas-exam-checklist__title {
	margin: 0 0 14px;
	font-size: 14px;
	font-weight: 700;
	color: var(--cex-text);
	text-transform: uppercase;
	letter-spacing: 0.04em;
}

.cas-exam-summary__list {
	margin: 0;
}

.cas-exam-summary__row {
	display: flex;
	align-items: center;
	justify-content: space-between;
	gap: 12px;
	padding: 10px 0;
	border-bottom: 1px solid var(--cex-border);
}

.cas-exam-summary__row:last-child {
	border-bottom: none;
	padding-bottom: 0;
}

.cas-exam-summary__row dt {
	margin: 0;
	font-size: 13px;
	color: var(--cex-text-secondary);
	font-weight: 500;
}

.cas-exam-summary__row dd {
	margin: 0;
	font-size: 14px;
	font-weight: 700;
	color: var(--cex-text);
}

.cas-exam-checklist__items {
	margin: 0;
	padding: 0;
	list-style: none;
}

.cas-exam-checklist__items li {
	position: relative;
	padding-left: 22px;
	font-size: 13px;
	color: var(--cex-text-secondary);
	line-height: 1.5;
}

.cas-exam-checklist__items li + li {
	margin-top: 10px;
}

.cas-exam-checklist__items li::before {
	content: '';
	position: absolute;
	left: 0;
	top: 7px;
	width: 8px;
	height: 8px;
	border-radius: 50%;
	background: var(--cex-success);
}

.cas-exam-instr__actions {
	display: flex;
	flex-direction: column;
	gap: 10px;
}

/* ══════════════════════════════════════
   LIVE EXAM SHELL
   ══════════════════════════════════════ */
.cas-exam-shell {
	font-family: var(--cex-font);
	color: var(--cex-text);
	margin: 0 -8px;
}

.cas-exam-topbar {
	display: grid;
	grid-template-columns: minmax(180px, 1fr) minmax(200px, 1.2fr) auto;
	align-items: center;
	gap: 20px;
	padding: 14px 20px;
	background: var(--cex-surface);
	border: 1px solid var(--cex-border);
	border-radius: var(--cex-radius-lg);
	box-shadow: var(--cex-shadow);
	margin-bottom: 16px;
}

.cas-exam-topbar__label {
	display: block;
	font-size: 11px;
	font-weight: 600;
	text-transform: uppercase;
	letter-spacing: 0.06em;
	color: var(--cex-muted);
}

.cas-exam-topbar__title {
	margin: 4px 0 0;
	font-size: 16px;
	font-weight: 700;
	line-height: 1.3;
	color: var(--cex-text);
}

.cas-exam-topbar__right {
	display: flex;
	align-items: center;
	gap: 12px;
	justify-content: flex-end;
}

.cas-exam-progress {
	display: flex;
	align-items: center;
	gap: 12px;
	width: 100%;
}

.cas-exam-progress__label {
	font-size: 12px;
	font-weight: 600;
	color: var(--cex-text-secondary);
	white-space: nowrap;
}

.cas-exam-progress__track {
	flex: 1;
	height: 8px;
	background: var(--cex-border);
	border-radius: 999px;
	overflow: hidden;
}

.cas-exam-progress__fill {
	height: 100%;
	background: linear-gradient(90deg, var(--cex-primary), #60a5fa);
	border-radius: 999px;
	transition: width 0.3s ease;
}

.cas-exam-progress__pct {
	font-size: 12px;
	font-weight: 700;
	color: var(--cex-text);
	min-width: 36px;
	text-align: right;
	font-variant-numeric: tabular-nums;
}

.cas-exam-timer {
	display: flex;
	align-items: center;
	gap: 8px;
	padding: 8px 14px;
	background: var(--cex-danger-bg);
	border: 1px solid #fecaca;
	border-radius: 999px;
}

.cas-exam-timer.is-warning {
	background: var(--cex-warning-bg);
	border-color: #fde68a;
}

.cas-exam-timer.is-critical {
	animation: cex-timer-pulse 1s ease infinite;
}

@keyframes cex-timer-pulse {
	0%, 100% { box-shadow: 0 0 0 0 rgba(220, 38, 38, 0.3); }
	50% { box-shadow: 0 0 0 6px rgba(220, 38, 38, 0); }
}

.cas-exam-timer__icon {
	font-size: 16px;
	color: var(--cex-danger);
}

.cas-exam-timer__label {
	font-size: 11px;
	font-weight: 600;
	color: var(--cex-danger);
	text-transform: uppercase;
	letter-spacing: 0.04em;
}

.cas-exam-timer__value {
	font-size: 16px;
	font-weight: 800;
	color: var(--cex-danger);
	font-variant-numeric: tabular-nums;
	min-width: 52px;
}

/* Violation banner */
.cas-violation-banner {
	display: flex;
	align-items: center;
	flex-wrap: wrap;
	gap: 10px 14px;
	padding: 12px 16px;
	margin-bottom: 16px;
	background: var(--cex-warning-bg);
	border: 1px solid #fcd34d;
	border-radius: var(--cex-radius);
	color: #92400e;
	font-size: 13px;
	font-weight: 500;
}

.cas-violation-banner[hidden] {
	display: none !important;
}

.cas-violation-banner__icon {
	display: flex;
	align-items: center;
	justify-content: center;
	width: 22px;
	height: 22px;
	border-radius: 50%;
	background: var(--cex-warning);
	color: #fff;
	font-size: 13px;
	font-weight: 800;
	flex-shrink: 0;
}

.cas-violation-banner__count {
	margin-left: auto;
	font-size: 12px;
	font-weight: 700;
	color: #b45309;
}

/* Layout grid */
.cas-exam-layout {
	display: grid;
	grid-template-columns: minmax(0, 1fr) 300px;
	gap: 16px;
	align-items: start;
}

/* Question panel */
.cas-question-panel {
	background: var(--cex-surface);
	border: 1px solid var(--cex-border);
	border-radius: var(--cex-radius-lg);
	box-shadow: var(--cex-shadow);
	overflow: hidden;
	min-height: 480px;
	display: flex;
	flex-direction: column;
}

.cas-question-panel__header {
	padding: 18px 24px;
	border-bottom: 1px solid var(--cex-border);
	background: var(--cex-surface-2);
}

.cas-question-panel__heading {
	display: flex;
	align-items: center;
	flex-wrap: wrap;
	gap: 10px;
}

.cas-question-panel__number {
	font-size: 13px;
	font-weight: 700;
	color: var(--cex-primary);
	text-transform: uppercase;
	letter-spacing: 0.04em;
}

.cas-question-panel__body {
	flex: 1;
	padding: 28px 24px;
}

.cas-question-panel__text {
	font-size: 17px;
	font-weight: 500;
	line-height: 1.7;
	color: var(--cex-text);
	margin: 0 0 24px;
}

.cas-question-panel__footer {
	display: flex;
	align-items: center;
	justify-content: space-between;
	gap: 12px;
	flex-wrap: wrap;
	padding: 16px 24px;
	border-top: 1px solid var(--cex-border);
	background: var(--cex-surface-2);
}

.cas-question-panel__footer-left,
.cas-question-panel__footer-right {
	display: flex;
	gap: 10px;
	flex-wrap: wrap;
}

/* MCQ options */
.cas-options {
	display: flex;
	flex-direction: column;
	gap: 10px;
}

.cas-option {
	display: flex;
	align-items: flex-start;
	gap: 14px;
	padding: 16px 18px;
	border: 2px solid var(--cex-border);
	border-radius: var(--cex-radius);
	cursor: pointer;
	transition: border-color var(--cex-transition), background var(--cex-transition), box-shadow var(--cex-transition);
	background: var(--cex-surface);
}

.cas-option:hover {
	border-color: #93c5fd;
	background: var(--cex-primary-bg);
}

.cas-option.is-selected {
	border-color: var(--cex-primary);
	background: var(--cex-primary-bg);
	box-shadow: 0 0 0 3px var(--cex-primary-ring);
}

.cas-option__radio {
	width: 20px;
	height: 20px;
	border: 2px solid var(--cex-border-strong);
	border-radius: 50%;
	flex-shrink: 0;
	margin-top: 2px;
	display: flex;
	align-items: center;
	justify-content: center;
	transition: all var(--cex-transition);
}

.cas-option.is-selected .cas-option__radio {
	border-color: var(--cex-primary);
	background: var(--cex-primary);
}

.cas-option.is-selected .cas-option__radio::after {
	content: '';
	width: 8px;
	height: 8px;
	background: #fff;
	border-radius: 50%;
}

.cas-option__key {
	font-weight: 700;
	color: var(--cex-primary);
	min-width: 22px;
	font-size: 14px;
}

.cas-option__text {
	font-size: 15px;
	color: var(--cex-text);
	line-height: 1.55;
	flex: 1;
}

.cas-text-answer {
	display: block;
	width: 100%;
	padding: 14px 16px;
	font-family: var(--cex-font);
	font-size: 14px;
	line-height: 1.55;
	color: var(--cex-text);
	background: var(--cex-surface);
	border: 2px solid var(--cex-border);
	border-radius: var(--cex-radius);
	resize: vertical;
	min-height: 120px;
}

.cas-text-answer:focus {
	outline: none;
	border-color: var(--cex-primary);
	box-shadow: 0 0 0 3px var(--cex-primary-ring);
}

/* Navigator */
.cas-navigator-panel {
	background: var(--cex-surface);
	border: 1px solid var(--cex-border);
	border-radius: var(--cex-radius-lg);
	box-shadow: var(--cex-shadow);
	position: sticky;
	top: 88px;
	overflow: hidden;
}

.cas-navigator-panel__header {
	padding: 18px 18px 14px;
	border-bottom: 1px solid var(--cex-border);
}

.cas-navigator-panel__title {
	margin: 0 0 14px;
	font-size: 14px;
	font-weight: 700;
	color: var(--cex-text);
}

.cas-navigator-stats {
	display: grid;
	grid-template-columns: 1fr 1fr;
	gap: 8px;
}

.cas-navigator-stat {
	text-align: center;
	padding: 10px 8px;
	background: var(--cex-surface-2);
	border-radius: var(--cex-radius-sm);
	border: 1px solid var(--cex-border);
}

.cas-navigator-stat__val {
	font-size: 18px;
	font-weight: 800;
	color: var(--cex-text);
	font-variant-numeric: tabular-nums;
}

.cas-navigator-stat__lbl {
	font-size: 10px;
	color: var(--cex-muted);
	text-transform: uppercase;
	letter-spacing: 0.04em;
	margin-top: 2px;
}

.cas-navigator-panel__body {
	padding: 14px 18px;
}

.cas-navigator {
	display: grid;
	grid-template-columns: repeat(5, 1fr);
	gap: 8px;
}

.cas-nav-btn {
	aspect-ratio: 1;
	border: 2px solid var(--cex-border);
	background: var(--cex-surface-2);
	border-radius: var(--cex-radius-sm);
	cursor: pointer;
	font-size: 13px;
	font-weight: 600;
	color: var(--cex-text-secondary);
	transition: all var(--cex-transition);
	display: flex;
	align-items: center;
	justify-content: center;
	font-family: var(--cex-font);
	padding: 0;
}

.cas-nav-btn:hover {
	border-color: var(--cex-primary);
	color: var(--cex-primary);
}

.cas-nav-btn.is-unanswered {
	background: var(--cex-surface-2);
	border-color: var(--cex-border);
	color: var(--cex-muted);
}

.cas-nav-btn.is-answered {
	background: var(--cex-success-bg);
	border-color: var(--cex-success);
	color: var(--cex-success);
}

.cas-nav-btn.is-review {
	background: var(--cex-warning-bg);
	border-color: var(--cex-warning);
	color: var(--cex-warning);
}

.cas-nav-btn.is-current {
	border-color: var(--cex-primary);
	background: var(--cex-primary-bg);
	color: var(--cex-primary);
	box-shadow: 0 0 0 3px var(--cex-primary-ring);
	font-weight: 800;
}

.cas-navigator-legend {
	display: flex;
	flex-wrap: wrap;
	gap: 8px 12px;
	margin-top: 14px;
	padding-top: 14px;
	border-top: 1px solid var(--cex-border);
}

.cas-legend-item {
	display: flex;
	align-items: center;
	gap: 6px;
	font-size: 11px;
	color: var(--cex-muted);
}

.cas-legend-dot {
	width: 12px;
	height: 12px;
	border-radius: 4px;
	border: 2px solid var(--cex-border);
	flex-shrink: 0;
}

.cas-legend-dot--answered { background: var(--cex-success-bg); border-color: var(--cex-success); }
.cas-legend-dot--review { background: var(--cex-warning-bg); border-color: var(--cex-warning); }
.cas-legend-dot--current { background: var(--cex-primary-bg); border-color: var(--cex-primary); }

.cas-navigator-panel__submit {
	padding: 14px 18px 18px;
	border-top: 1px solid var(--cex-border);
}

.cas-navigator-panel__hint {
	margin: 10px 0 0;
	font-size: 11px;
	color: var(--cex-muted);
	text-align: center;
	line-height: 1.45;
}

/* Webcam */
.cas-webcam-preview {
	position: fixed;
	bottom: 20px;
	right: 20px;
	width: 128px;
	height: 96px;
	border-radius: var(--cex-radius);
	border: 2px solid var(--cex-border-strong);
	object-fit: cover;
	box-shadow: var(--cex-shadow-lg);
	z-index: 500;
	background: #000;
}

/* Entry gate & modals */
.cas-exam-gate,
.cas-modal-overlay {
	position: fixed;
	inset: 0;
	z-index: 10000;
	background: rgba(15, 23, 42, 0.72);
	display: flex;
	align-items: center;
	justify-content: center;
	padding: 24px;
	backdrop-filter: blur(4px);
}

.cas-exam-gate__card,
.cas-modal {
	width: 100%;
	max-width: 480px;
	background: var(--cex-surface);
	border-radius: var(--cex-radius-lg);
	box-shadow: var(--cex-shadow-lg);
	padding: 32px 28px;
	text-align: center;
}

.cas-exam-gate__icon {
	width: 56px;
	height: 56px;
	margin: 0 auto 20px;
	border-radius: 50%;
	background: var(--cex-primary-bg);
	color: var(--cex-primary);
	font-size: 28px;
	line-height: 56px;
}

.cas-exam-gate__title,
.cas-modal h3 {
	margin: 0 0 12px;
	font-size: 22px;
	font-weight: 700;
	color: var(--cex-text);
}

.cas-exam-gate__text,
.cas-modal p {
	margin: 0 0 24px;
	font-size: 14px;
	line-height: 1.6;
	color: var(--cex-text-secondary);
}

.cas-exam-gate__actions,
.cas-modal__actions {
	display: flex;
	gap: 12px;
	justify-content: center;
	flex-wrap: wrap;
}

.cas-modal__actions .cas-exam-btn {
	min-width: 120px;
}

/* ── Responsive ── */
@media (max-width: 1024px) {
	.cas-exam-instr__grid {
		grid-template-columns: 1fr;
	}

	.cas-exam-instr__sidebar {
		position: static;
	}

	.cas-exam-topbar {
		grid-template-columns: 1fr;
		gap: 14px;
	}

	.cas-exam-topbar__right {
		justify-content: space-between;
	}
}

@media (max-width: 900px) {
	.cas-exam-layout {
		grid-template-columns: 1fr;
	}

	.cas-navigator-panel {
		position: static;
		order: -1;
	}

	.cas-question-panel {
		min-height: auto;
	}
}

@media (max-width: 640px) {
	.cas-exam-instr__header {
		flex-direction: column;
		padding: 22px 20px;
	}

	.cas-exam-instr__title {
		font-size: 22px;
	}

	.cas-exam-panel {
		padding: 20px 18px;
	}

	.cas-navigator {
		grid-template-columns: repeat(4, 1fr);
	}

	.cas-question-panel__body {
		padding: 20px 16px;
	}

	.cas-question-panel__footer {
		flex-direction: column;
		align-items: stretch;
	}

	.cas-question-panel__footer-left,
	.cas-question-panel__footer-right {
		width: 100%;
		justify-content: stretch;
	}

	.cas-question-panel__footer-right .cas-exam-btn {
		flex: 1;
	}

	.cas-webcam-preview {
		width: 96px;
		height: 72px;
		bottom: 12px;
		right: 12px;
	}
}