:root {
    --ink: #0f172a;
    --muted: #64748b;
    --gold: #fbbf24;
    --gold-deep: #b45309;
    --paper: #f8fafc;
    --white: #ffffff;
    --line: #dbe3ec;
    --bg-soft: #eef6ff;
    --green-soft: #dcfce7;
    --green: #16a34a;
    --red-soft: #fee2e2;
    --red: #dc2626;
    --blue-soft: #dbeafe;
    --blue: #1d4ed8;
    --shadow: 0 24px 55px rgba(15, 23, 42, 0.08);
    --panel: #ffffff;
    --panel-alt: #f8fbff;
    --header-bg: rgba(15, 23, 42, 0.97);
}

body[data-theme='dark'] {
    --ink: #e2e8f0;
    --muted: #a5b4cf;
    --paper: #020817;
    --white: #0f172a;
    --line: #243045;
    --bg-soft: #0b1220;
    --green-soft: rgba(22, 163, 74, 0.18);
    --red-soft: rgba(220, 38, 38, 0.18);
    --blue-soft: rgba(59, 130, 246, 0.16);
    --panel: #111827;
    --panel-alt: #0b1220;
    --header-bg: rgba(2, 8, 23, 0.96);
    --shadow: 0 24px 55px rgba(2, 6, 23, 0.62);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
    margin: 0;
    min-height: 100vh;
    color: var(--ink);
    background: radial-gradient(circle at top right, rgba(251, 191, 36, 0.24), transparent 28%), linear-gradient(180deg, var(--paper) 0%, #eef2ff 100%);
    font-family: "Segoe UI", Arial, sans-serif;
    transition: background 0.25s ease, color 0.25s ease;
}

body[data-theme='dark'] {
    background: radial-gradient(circle at top right, rgba(249, 115, 22, 0.18), transparent 30%), linear-gradient(180deg, #020817 0%, #0f172a 100%);
}

.hidden { display: none !important; }

.portal-main {
    width: min(960px, 92%);
    margin: 0 auto;
    padding: 48px 0 80px;
}

.portal-card {
    background: var(--panel);
    border: 1px solid var(--line);
    border-radius: 22px;
    box-shadow: var(--shadow);
    padding: clamp(24px, 4vw, 38px);
}

.portal-header {
    text-align: center;
    margin-bottom: 26px;
}

.portal-header h1 {
    margin: 12px 0 8px;
    font-size: clamp(34px, 4vw, 46px);
}

.portal-header p {
    color: var(--muted);
    font: 16px/1.7 Arial, sans-serif;
}

.access-gate {
    display: flex;
    align-items: center;
    justify-content: center;
}

.gate-card {
    width: min(620px, 100%);
    padding: clamp(22px, 3vw, 34px);
    background: var(--panel-alt);
    border: 1px solid var(--line);
    border-radius: 18px;
}

.gate-card-head {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 14px;
    padding-bottom: 16px;
    border-bottom: 1px solid var(--line);
}

.gate-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    color: var(--gold-deep);
    font: 700 12px Arial, sans-serif;
    text-transform: uppercase;
    letter-spacing: 0.12em;
}

.gate-step {
    color: var(--muted);
    font: 700 12px Arial, sans-serif;
}

#pinStage,
#loginStage {
    margin-top: 20px;
}

.gate-label {
    display: block;
    margin: 16px 0 8px;
    color: var(--muted);
    font: 700 12px Arial, sans-serif;
    letter-spacing: 0.08em;
    text-transform: uppercase;
}

#pinStage input,
#loginStage input {
    width: 100%;
    min-height: 48px;
    padding: 12px 14px;
    border-radius: 12px;
    border: 1px solid var(--line);
    background: var(--white);
    color: var(--ink);
    font: 15px Arial, sans-serif;
}

.gate-input-row {
    display: flex;
    gap: 12px;
    margin-top: 12px;
}

.gate-input-row input {
    flex: 1;
}

.primary-btn {
    min-height: 44px;
    padding: 10px 16px;
    border-radius: 12px;
    border: 1px solid var(--gold);
    background: linear-gradient(135deg, var(--gold) 0%, var(--gold-deep) 100%);
    color: var(--white);
    font: 700 13px Arial, sans-serif;
    cursor: pointer;
}

#loginStage .primary-btn {
    margin-top: 16px;
    width: 100%;
}

.error-message {
    color: var(--red);
    min-height: 20px;
    font: 700 12px Arial, sans-serif;
    margin-top: 10px;
}

.topbar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 18px;
    padding: 18px 6%;
    background: var(--header-bg);
    color: var(--white);
    box-shadow: 0 12px 28px rgba(15, 23, 42, 0.12);
}

.brand {
    font-size: 18px;
    font-weight: 700;
    letter-spacing: 0.03em;
}

.back-link {
    color: var(--white);
    text-decoration: none;
    font: 700 14px Arial, sans-serif;
}

.back-link i { color: var(--gold); margin-right: 8px; }

.exam-controls {
    display: flex;
    align-items: center;
    gap: 12px;
    flex-wrap: wrap;
}

.timer-pill,
.theme-switch {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    border-radius: 999px;
    border: 1px solid rgba(255,255,255,0.14);
    background: rgba(255,255,255,0.08);
    padding: 7px 10px;
}

.timer-pill {
    color: #fff;
    font: 700 13px Arial, sans-serif;
}

.timer-pill i { color: var(--gold); }

#timerDisplay.warning { color: #f9d44c; }

.theme-switch {
    padding: 4px;
    gap: 4px;
}

.theme-option {
    border: 0;
    border-radius: 999px;
    padding: 7px 10px;
    background: transparent;
    color: rgba(255,255,255,0.8);
    font: 700 12px Arial, sans-serif;
    cursor: pointer;
}

.theme-option.active {
    background: rgba(251, 191, 36, 0.22);
    color: var(--white);
}

main {
    width: min(1200px, 92%);
    margin: 0 auto;
    padding: 68px 0 90px;
}

.intro {
    max-width: 760px;
    margin-bottom: 30px;
}

.eyebrow {
    margin: 0 0 10px;
    color: var(--gold-deep);
    font: 700 11px Arial, sans-serif;
    letter-spacing: 0.18em;
    text-transform: uppercase;
}

h1 {
    margin: 0 0 12px;
    font-size: clamp(34px, 6vw, 58px);
    line-height: 1.02;
}

.intro p {
    color: var(--muted);
    font: 16px/1.7 Arial, sans-serif;
}

.test-box {
    padding: clamp(18px, 2vw, 28px);
    background: var(--panel);
    border: 1px solid var(--line);
    border-radius: 20px;
    box-shadow: var(--shadow);
}

.tab-bar {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin-bottom: 24px;
}

.tab {
    border: 0;
    border-radius: 999px;
    padding: 10px 14px;
    color: var(--ink);
    background: #edf2f7;
    font: 700 12px Arial, sans-serif;
    cursor: pointer;
    transition: all 0.2s ease;
}

body[data-theme='dark'] .tab {
    background: #0f172a;
    color: var(--ink);
    border: 1px solid var(--line);
}

.tab:hover { transform: translateY(-1px); }
.tab.active {
    background: linear-gradient(135deg, var(--gold) 0%, #f59e0b 100%);
    color: var(--ink);
    box-shadow: 0 12px 24px rgba(245, 158, 11, 0.25);
}

.exam-shell {
    display: grid;
    grid-template-columns: 240px minmax(0, 1fr);
    gap: 20px;
    align-items: start;
}

.exam-sidebar,
.exam-panel {
    background: linear-gradient(180deg, var(--panel) 0%, var(--panel-alt) 100%);
    border: 1px solid var(--line);
    border-radius: 18px;
    box-shadow: var(--shadow);
}

.exam-sidebar {
    padding: 16px 12px;
}

.nav-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    margin-bottom: 16px;
    padding: 0 6px 10px;
    border-bottom: 1px solid var(--line);
}

.nav-header p {
    margin: 0;
    color: var(--muted);
    font: 700 11px Arial, sans-serif;
    text-transform: uppercase;
    letter-spacing: 0.12em;
}

.nav-header strong {
    font: 700 11px Arial, sans-serif;
    color: var(--ink);
}

.palette-grid {
    display: grid;
    grid-template-columns: repeat(5, minmax(0, 1fr));
    gap: 7px;
}

.palette-button {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 100%;
    min-height: 34px;
    border: 1px solid #cbd5e1;
    border-radius: 9px;
    background: #f8fafc;
    color: var(--ink);
    font: 700 12px Arial, sans-serif;
    cursor: pointer;
    transition: all 0.2s ease;
}

body[data-theme='dark'] .palette-button {
    background: #0f172a;
    border-color: var(--line);
}

.palette-button:hover { transform: translateY(-1px); }
.palette-button.active {
    outline: 2px solid rgba(245, 158, 11, 0.75);
    outline-offset: 2px;
    border-color: rgba(245, 158, 11, 0.8);
}

.palette-button.unanswered {
    background: #f8fafc;
    border-color: #cbd5e1;
    color: var(--ink);
}

body[data-theme='dark'] .palette-button.unanswered {
    background: #0f172a;
    border-color: var(--line);
    color: var(--ink);
}

.palette-button.correct {
    background: var(--green-soft);
    border-color: #22c55e;
    color: #166534;
}

.palette-button.incorrect {
    background: var(--red-soft);
    border-color: #ef4444;
    color: #991b1b;
}

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

.question-header,
.summary-topbar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 14px;
    margin-bottom: 18px;
}

.question-header h2,
.summary-topbar h2 {
    margin: 0;
    font-size: clamp(1.4rem, 2vw, 2rem);
}

.status-strip {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin-bottom: 16px;
}

.status-pill {
    display: inline-flex;
    align-items: center;
    padding: 7px 10px;
    border-radius: 999px;
    background: var(--blue-soft);
    border: 1px solid rgba(59, 130, 246, 0.25);
    color: var(--blue);
    font: 700 12px Arial, sans-serif;
}

.status-pill.muted {
    background: #f1f5f9;
    border-color: var(--line);
    color: var(--muted);
}

body[data-theme='dark'] .status-pill.muted {
    background: rgba(148, 163, 184, 0.08);
    border-color: var(--line);
}

.question-card {
    padding: 22px 18px 16px;
    border: 1px solid var(--line);
    border-radius: 16px;
    background: linear-gradient(180deg, var(--panel) 0%, var(--panel-alt) 100%);
}

.question-text {
    margin: 0 0 18px;
    font-size: clamp(1.1rem, 2vw, 1.5rem);
    line-height: 1.5;
    font-weight: 700;
}

.option-list {
    display: grid;
    gap: 12px;
}

.option-btn {
    display: flex;
    align-items: center;
    gap: 12px;
    width: 100%;
    padding: 14px 16px;
    border: 1px solid #cbd5e1;
    border-radius: 12px;
    background: var(--panel);
    color: var(--ink);
    text-align: left;
    font: 15px/1.5 Arial, sans-serif;
    cursor: pointer;
    transition: all 0.2s ease;
}

.option-btn:hover:not(:disabled) {
    border-color: rgba(245, 158, 11, 0.8);
    background: #fffbea;
    transform: translateY(-1px);
}

body[data-theme='dark'] .option-btn:hover:not(:disabled) {
    background: rgba(251, 191, 36, 0.08);
}

.option-btn.selected {
    border-color: rgba(59, 130, 246, 0.8);
    background: #eff6ff;
}

.option-btn.correct {
    border-color: #22c55e;
    background: var(--green-soft);
    color: #166534;
}

.option-btn.incorrect {
    border-color: #ef4444;
    background: var(--red-soft);
    color: #991b1b;
}

.option-btn:disabled { cursor: default; }

.option-label {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 28px;
    height: 28px;
    border-radius: 50%;
    background: #e2e8f0;
    color: var(--ink);
    font: 700 12px Arial, sans-serif;
    flex-shrink: 0;
}

.answer-panel {
    display: none;
    margin-top: 18px;
    padding: 16px 18px;
    border: 1px solid #bfdbfe;
    border-radius: 12px;
    background: linear-gradient(180deg, #eff6ff 0%, #f8fbff 100%);
}

.answer-panel.visible {
    display: block;
}

.answer-header {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 10px;
    margin-bottom: 8px;
}

.answer-header strong {
    font-size: 15px;
}

.status-badge {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 6px 10px;
    border-radius: 999px;
    font: 700 11px Arial, sans-serif;
    letter-spacing: 0.04em;
    text-transform: uppercase;
}

.status-badge.correct {
    background: var(--green-soft);
    color: #166534;
}

.status-badge.review {
    background: #fef3c7;
    color: #92400e;
}

.answer-body {
    color: var(--ink);
    font: 15px/1.7 Arial, sans-serif;
}

.answer-body p { margin: 10px 0 0; }

.question-nav {
    display: flex;
    justify-content: space-between;
    margin-top: 18px;
    gap: 12px;
}

.primary-btn,
.secondary-btn,
.submit-button {
    border: 0;
    border-radius: 12px;
    padding: 12px 16px;
    font: 700 14px Arial, sans-serif;
    cursor: pointer;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.primary-btn,
.submit-button {
    background: linear-gradient(135deg, var(--gold), #f59e0b);
    color: var(--ink);
    box-shadow: 0 10px 22px rgba(245, 158, 11, 0.2);
}

.secondary-btn {
    background: #edf2f7;
    color: var(--ink);
}

body[data-theme='dark'] .secondary-btn {
    background: rgba(148, 163, 184, 0.12);
    border: 1px solid var(--line);
}

.primary-btn:hover,
.secondary-btn:hover,
.submit-button:hover { transform: translateY(-1px); }

.primary-btn:disabled,
.secondary-btn:disabled { opacity: 0.5; cursor: default; }

.summary-grid {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 12px;
    margin-bottom: 20px;
}

.summary-box {
    padding: 16px 18px;
    border: 1px solid var(--line);
    border-radius: 14px;
    background: linear-gradient(180deg, var(--panel) 0%, var(--panel-alt) 100%);
}

.summary-box span {
    display: block;
    margin-bottom: 8px;
    color: var(--muted);
    font: 700 12px Arial, sans-serif;
    text-transform: uppercase;
    letter-spacing: 0.08em;
}

.summary-box strong {
    display: block;
    font-size: clamp(1.3rem, 2vw, 1.8rem);
}

.summary-box small {
    color: var(--muted);
    font: 700 12px Arial, sans-serif;
}

.score-box {
    background: linear-gradient(135deg, #fff7d6 0%, #fffdf6 100%);
    border-color: rgba(245, 158, 11, 0.4);
}

.score-flash {
    animation: scorePulse 0.8s ease;
}

@keyframes scorePulse {
    0% { transform: scale(0.9); box-shadow: 0 0 0 rgba(245, 158, 11, 0); }
    35% { transform: scale(1.06); box-shadow: 0 18px 28px rgba(245, 158, 11, 0.24); }
    100% { transform: scale(1); box-shadow: 0 0 0 rgba(245, 158, 11, 0); }
}

.review-list {
    display: grid;
    gap: 16px;
}

.review-card {
    padding: 16px 18px;
    border: 1px solid var(--line);
    border-radius: 14px;
    background: var(--panel);
}

.review-card.correct { border-left: 5px solid #16a34a; }
.review-card.wrong { border-left: 5px solid #dc2626; }
.review-card.unanswered { border-left: 5px solid #94a3b8; }

.review-head {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    margin-bottom: 10px;
    font: 700 12px Arial, sans-serif;
    color: var(--muted);
}

.review-status {
    display: inline-flex;
    align-items: center;
    padding: 6px 8px;
    border-radius: 999px;
    font: 700 11px Arial, sans-serif;
    text-transform: uppercase;
}

.review-status.correct { background: var(--green-soft); color: #166534; }
.review-status.wrong { background: var(--red-soft); color: #991b1b; }
.review-status.unanswered { background: #e2e8f0; color: #475569; }

.review-question {
    margin: 0 0 12px;
    font-size: 1.08rem;
    line-height: 1.55;
    font-weight: 700;
}

.review-options {
    display: grid;
    gap: 8px;
    margin-bottom: 12px;
}

.review-option {
    display: block;
    border-radius: 10px;
    padding: 8px 10px;
    background: #f8fafc;
    border: 1px solid var(--line);
    color: var(--ink);
    font: 14px/1.5 Arial, sans-serif;
}

.review-option.correct {
    background: var(--green-soft);
    border-color: #22c55e;
    color: #166534;
}

.review-option.incorrect {
    background: var(--red-soft);
    border-color: #ef4444;
    color: #991b1b;
}

.review-option.selected {
    box-shadow: inset 0 0 0 2px rgba(59, 130, 246, 0.25);
}

.review-answer-line {
    font: 15px/1.6 Arial, sans-serif;
    margin: 6px 0;
}

.review-explanation {
    margin-top: 12px;
    padding-top: 12px;
    border-top: 1px solid var(--line);
    font: 14px/1.7 Arial, sans-serif;
    color: var(--muted);
}

.review-explanation strong { color: var(--ink); }
.review-explanation p { margin: 8px 0 0; }

.error-box {
    padding: 18px;
    border-radius: 14px;
    border: 1px solid #fecaca;
    background: #fef2f2;
    color: #991b1b;
    font: 15px/1.6 Arial, sans-serif;
}

@media (max-width: 900px) {
    .exam-shell {
        grid-template-columns: 1fr;
    }
    .summary-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }
}

@media (max-width: 640px) {
    .question-header,
    .summary-topbar,
    .question-nav {
        flex-direction: column;
        align-items: stretch;
    }
    .palette-grid {
        grid-template-columns: repeat(4, minmax(0, 1fr));
    }
    .summary-grid {
        grid-template-columns: 1fr;
    }
}