*,
*::before,
*::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

:root {
    --bg: #f5f7fa;
    --bg-card: #ffffff;
    --bg-card2: #f0f4f8;
    --bg-hover: #e8f0f7;
    --border: rgba(7, 48, 66, 0.1);
    --border-md: rgba(7, 48, 66, 0.18);
    --border-hi: rgba(7, 48, 66, 0.28);

    --text: #073042;
    --text-2: #3a5a6e;
    --text-3: #7a96a4;

    --accent: #3087b9;
    --accent-dim: rgba(48, 135, 185, 0.1);
    --accent-hi: #3d9fd4;

    --green: #26c165;
    --green-dim: rgba(38, 193, 101, 0.1);
    --red: #d93025;
    --red-dim: rgba(217, 48, 37, 0.08);
    --blue: #3087b9;
    --blue-dim: rgba(48, 135, 185, 0.1);

    --navy: #073042;
    --navy-dim: rgba(7, 48, 66, 0.07);

    --radius-sm: 6px;
    --radius: 10px;
    --radius-lg: 14px;

    --font: 'DM Sans', sans-serif;
    --mono: 'DM Mono', monospace;

    --shadow: 0 4px 24px rgba(7, 48, 66, 0.1);
    --shadow-sm:
        0 1px 4px rgba(7, 48, 66, 0.07), 0 2px 12px rgba(7, 48, 66, 0.06);
}

html {
    font-size: 15px;
}

body {
    font-family: var(--font);
    background: var(--bg);
    color: var(--text);
    min-height: 100vh;
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

.shell {
    max-width: 680px;
    margin: 0 auto;
    padding: 0 1rem 4rem;
}

.top-bar {
    position: sticky;
    top: 0;
    z-index: 100;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0.75rem 1.25rem;
    margin: 0 -1rem 1.5rem;
    background: rgba(255, 255, 255, 0.92);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border);
    box-shadow: 0 1px 8px rgba(7, 48, 66, 0.06);
}

.top-bar-left {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 13px;
    color: var(--text-2);
}

.brand-dot {
    width: 7px;
    height: 7px;
    border-radius: 50%;
    background: var(--green);
    box-shadow: 0 0 6px rgba(38, 193, 101, 0.5);
    flex-shrink: 0;
}

.brand-name {
    font-weight: 600;
    color: var(--navy);
}
.top-bar-sep {
    color: var(--text-3);
}
.top-bar-candidate {
    color: var(--text-2);
    max-width: 180px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.timer {
    display: flex;
    align-items: center;
    gap: 6px;
    font-family: var(--mono);
    font-size: 15px;
    font-weight: 500;
    color: var(--navy);
    background: var(--navy-dim);
    border: 1px solid var(--border);
    padding: 4px 12px;
    border-radius: 99px;
    transition:
        color 0.3s,
        border-color 0.3s,
        background 0.3s;
}

.timer.urgent {
    color: var(--red);
    border-color: rgba(217, 48, 37, 0.25);
    background: var(--red-dim);
    animation: pulse-timer 1s ease-in-out infinite;
}

@keyframes pulse-timer {
    0%,
    100% {
        opacity: 1;
    }
    50% {
        opacity: 0.7;
    }
}

.card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 1.5rem;
    margin-bottom: 1rem;
    box-shadow: var(--shadow-sm);
}

.start-hero {
    padding: 2rem 0 1.5rem;
    text-align: center;
}

.start-badge {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    font-size: 11px;
    font-weight: 600;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: #ffffff;
    background: var(--navy);
    border: 1px solid rgba(7, 48, 66, 0.2);
    padding: 4px 14px;
    border-radius: 99px;
    margin-bottom: 1.25rem;
}

.start-title {
    font-size: 26px;
    font-weight: 700;
    letter-spacing: -0.02em;
    color: var(--navy);
    margin-bottom: 0.5rem;
    line-height: 1.25;
}

.start-sub {
    font-size: 14px;
    color: var(--text-2);
    max-width: 440px;
    margin: 0 auto 2rem;
    line-height: 1.7;
}

.stats-row {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 10px;
    margin-bottom: 1.5rem;
}

.stat-box {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1rem 0.75rem;
    text-align: center;
    transition:
        border-color 0.2s,
        box-shadow 0.2s;
    box-shadow: var(--shadow-sm);
}

.stat-box:hover {
    border-color: var(--accent);
    box-shadow: 0 2px 12px rgba(48, 135, 185, 0.1);
}

.stat-val {
    font-size: 20px;
    font-weight: 700;
    color: var(--navy);
    font-family: var(--mono);
    letter-spacing: -0.02em;
}

.stat-lbl {
    font-size: 11px;
    color: var(--text-3);
    margin-top: 3px;
    text-transform: uppercase;
    letter-spacing: 0.06em;
}

.alert {
    display: flex;
    gap: 10px;
    padding: 12px 16px;
    border-radius: var(--radius);
    font-size: 13px;
    line-height: 1.65;
    margin-bottom: 1.25rem;
}

.alert-warn {
    background: rgba(48, 135, 185, 0.07);
    border: 1px solid rgba(48, 135, 185, 0.22);
    color: #1a5f85;
}

.alert-danger {
    background: var(--red-dim);
    border: 1px solid rgba(217, 48, 37, 0.2);
    color: var(--red);
}

.alert i {
    font-size: 15px;
    flex-shrink: 0;
    margin-top: 1px;
}
.alert strong {
    display: block;
    margin-bottom: 3px;
    color: inherit;
}

.field-group {
    margin-bottom: 1.1rem;
}

.field-label {
    display: block;
    font-size: 12px;
    font-weight: 600;
    color: var(--text-2);
    margin-bottom: 6px;
    letter-spacing: 0.04em;
    text-transform: uppercase;
}

.field-req {
    color: var(--green);
    margin-left: 2px;
}

.field-input {
    width: 100%;
    padding: 10px 14px;
    border: 1.5px solid var(--border-md);
    border-radius: var(--radius);
    font-size: 14px;
    font-family: var(--font);
    background: #ffffff;
    color: var(--navy);
    transition:
        border-color 0.2s,
        box-shadow 0.2s;
    outline: none;
}

.field-input::placeholder {
    color: var(--text-3);
}

.field-input:focus {
    border-color: var(--accent);
    box-shadow: 0 0 0 3px rgba(48, 135, 185, 0.12);
}

.tc-box {
    background: var(--bg-card2);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 14px 16px;
    font-size: 12.5px;
    color: var(--text-2);
    line-height: 1.75;
    max-height: 140px;
    overflow-y: auto;
    margin-bottom: 12px;
}

.tc-box::-webkit-scrollbar {
    width: 4px;
}
.tc-box::-webkit-scrollbar-track {
    background: transparent;
}
.tc-box::-webkit-scrollbar-thumb {
    background: var(--border-md);
    border-radius: 4px;
}

.tc-title {
    font-weight: 600;
    color: var(--navy);
    margin-bottom: 6px;
    display: block;
}

.check-row {
    display: flex;
    align-items: flex-start;
    gap: 10px;
    font-size: 13px;
    color: var(--text-2);
    line-height: 1.5;
    cursor: pointer;
    user-select: none;
}

.check-row input[type='checkbox'] {
    appearance: none;
    width: 16px;
    height: 16px;
    min-width: 16px;
    border: 1.5px solid var(--border-hi);
    border-radius: 4px;
    background: #ffffff;
    cursor: pointer;
    position: relative;
    margin-top: 1px;
    transition:
        background 0.15s,
        border-color 0.15s;
}

.check-row input[type='checkbox']:checked {
    background: var(--green);
    border-color: var(--green);
}

.check-row input[type='checkbox']:checked::after {
    content: '';
    position: absolute;
    left: 3px;
    top: 1px;
    width: 8px;
    height: 5px;
    border-left: 2px solid #fff;
    border-bottom: 2px solid #fff;
    transform: rotate(-45deg);
}

.gs-section {
    border-top: 1px solid var(--border);
    padding-top: 1.25rem;
    margin-top: 1.25rem;
}

.gs-label {
    font-size: 11px;
    font-weight: 600;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--text-3);
    margin-bottom: 6px;
}

.gs-hint {
    font-size: 11.5px;
    color: var(--text-3);
    margin-top: 6px;
    line-height: 1.6;
}

.gs-hint code {
    font-family: var(--mono);
    font-size: 11px;
    background: var(--bg-card2);
    padding: 1px 5px;
    border-radius: 4px;
    border: 1px solid var(--border);
    color: var(--accent);
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 9px 20px;
    border: 1.5px solid var(--border-md);
    border-radius: var(--radius);
    font-size: 14px;
    font-family: var(--font);
    font-weight: 500;
    cursor: pointer;
    background: #ffffff;
    color: var(--text-2);
    transition:
        background 0.15s,
        border-color 0.15s,
        color 0.15s,
        box-shadow 0.15s;
    user-select: none;
}

.btn:hover:not(:disabled) {
    background: var(--bg-card2);
    border-color: var(--accent);
    color: var(--navy);
    box-shadow: 0 1px 6px rgba(48, 135, 185, 0.12);
}

.btn:disabled {
    opacity: 0.4;
    cursor: not-allowed;
}

.btn-primary {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 10px 26px;
    border: none;
    border-radius: var(--radius);
    font-size: 14px;
    font-family: var(--font);
    font-weight: 600;
    cursor: pointer;
    background: var(--green);
    color: #ffffff;
    transition:
        background 0.15s,
        transform 0.1s,
        box-shadow 0.15s;
    box-shadow: 0 2px 12px rgba(38, 193, 101, 0.35);
    user-select: none;
}

.btn-primary:hover:not(:disabled) {
    background: #1faa57;
    box-shadow: 0 4px 20px rgba(38, 193, 101, 0.4);
    transform: translateY(-1px);
}

.btn-primary:active:not(:disabled) {
    transform: translateY(0);
}
.btn-primary:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    box-shadow: none;
}

.btn-danger {
    background: var(--red-dim);
    border: 1.5px solid rgba(217, 48, 37, 0.22);
    color: var(--red);
}

.btn-danger:hover:not(:disabled) {
    background: rgba(217, 48, 37, 0.13);
    border-color: var(--red);
    box-shadow: 0 1px 6px rgba(217, 48, 37, 0.12);
}

.progress-track {
    height: 4px;
    background: var(--bg-card2);
    border-radius: 99px;
    margin-bottom: 1.5rem;
    overflow: hidden;
    border: 1px solid var(--border);
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--navy), var(--accent));
    border-radius: 99px;
    transition: width 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

.dots-wrap {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    margin-bottom: 1.25rem;
}

.dot {
    width: 28px;
    height: 28px;
    border-radius: 6px;
    border: 1.5px solid var(--border);
    font-size: 10px;
    font-weight: 600;
    font-family: var(--mono);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    color: var(--text-3);
    background: #ffffff;
    transition: all 0.15s;
    box-shadow: 0 1px 3px rgba(7, 48, 66, 0.05);
}

.dot:hover {
    border-color: var(--accent);
    color: var(--accent);
    background: var(--accent-dim);
}
.dot.answered {
    background: var(--blue-dim);
    border-color: rgba(48, 135, 185, 0.4);
    color: var(--accent);
}
.dot.current {
    background: var(--navy-dim);
    border-color: var(--navy);
    color: var(--navy);
}
.dot.current.answered {
    background: var(--navy);
    border-color: var(--navy);
    color: #ffffff;
}

.quiz-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 12px;
    color: var(--text-3);
    margin-bottom: 1.25rem;
    font-family: var(--mono);
}

.q-tag {
    display: inline-flex;
    align-items: center;
    gap: 5px;
    font-size: 10px;
    font-weight: 600;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--accent);
    background: var(--accent-dim);
    border: 1px solid rgba(48, 135, 185, 0.2);
    padding: 3px 10px;
    border-radius: 99px;
    margin-bottom: 10px;
}

.q-num {
    font-size: 11px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--text-3);
    font-family: var(--mono);
    margin-bottom: 8px;
}

.q-text {
    font-size: 15px;
    line-height: 1.7;
    color: var(--navy);
    margin-bottom: 1rem;
    user-select: none;
    -webkit-user-select: none;
    font-weight: 400;
}

.code-block {
    font-family: var(--mono);
    font-size: 12.5px;
    background: var(--navy);
    border: 1px solid rgba(7, 48, 66, 0.15);
    border-radius: var(--radius);
    padding: 14px 16px;
    margin: 6px 0 14px;
    line-height: 1.7;
    white-space: pre;
    overflow-x: auto;
    color: #a8c8d8;
    user-select: none;
    -webkit-user-select: none;
    position: relative;
}

.code-block::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 2px;
    background: linear-gradient(
        90deg,
        var(--green),
        var(--accent),
        transparent
    );
    border-radius: var(--radius) var(--radius) 0 0;
}

.opts {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.opt {
    display: flex;
    align-items: flex-start;
    gap: 12px;
    padding: 12px 16px;
    border: 1.5px solid var(--border);
    border-radius: var(--radius);
    cursor: pointer;
    font-size: 13.5px;
    line-height: 1.55;
    color: var(--text-2);
    background: #ffffff;
    text-align: left;
    width: 100%;
    transition:
        background 0.15s,
        border-color 0.15s,
        color 0.15s,
        transform 0.1s,
        box-shadow 0.15s;
    font-family: var(--font);
    box-shadow: 0 1px 3px rgba(7, 48, 66, 0.04);
}

.opt:hover:not(.locked) {
    background: var(--bg-hover);
    border-color: var(--accent);
    color: var(--navy);
    transform: translateX(2px);
    box-shadow: 0 2px 8px rgba(48, 135, 185, 0.1);
}

.opt-letter {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 22px;
    height: 22px;
    min-width: 22px;
    border-radius: 5px;
    background: var(--bg-card2);
    border: 1px solid var(--border-md);
    font-family: var(--mono);
    font-size: 11px;
    font-weight: 600;
    color: var(--text-3);
    margin-top: 1px;
    transition:
        background 0.15s,
        border-color 0.15s,
        color 0.15s;
}

.opt:hover:not(.locked) .opt-letter {
    background: var(--accent-dim);
    border-color: var(--accent);
    color: var(--accent);
}

.opt.correct {
    background: var(--green-dim);
    border-color: rgba(38, 193, 101, 0.4);
    color: #167a3e;
    transform: none;
    box-shadow: 0 1px 6px rgba(38, 193, 101, 0.12);
}

.opt.correct .opt-letter {
    background: rgba(38, 193, 101, 0.15);
    border-color: rgba(38, 193, 101, 0.45);
    color: #1faa57;
}

.opt.wrong {
    background: var(--red-dim);
    border-color: rgba(217, 48, 37, 0.3);
    color: var(--red);
    transform: none;
}

.opt.wrong .opt-letter {
    background: rgba(217, 48, 37, 0.1);
    border-color: rgba(217, 48, 37, 0.35);
    color: var(--red);
}

.opt.show-correct {
    background: var(--green-dim);
    border-color: rgba(38, 193, 101, 0.4);
    color: #167a3e;
    box-shadow: 0 1px 6px rgba(38, 193, 101, 0.12);
}

.opt.show-correct .opt-letter {
    background: rgba(38, 193, 101, 0.15);
    border-color: rgba(38, 193, 101, 0.45);
    color: #1faa57;
}

.opt.locked {
    cursor: default;
    transform: none !important;
}

.explanation {
    margin-top: 14px;
    padding: 12px 16px;
    background: rgba(48, 135, 185, 0.06);
    border: 1px solid rgba(48, 135, 185, 0.18);
    border-radius: var(--radius);
    font-size: 13px;
    color: #1a5f85;
    line-height: 1.7;
    animation: slide-in 0.2s ease;
}

.explanation i {
    margin-right: 5px;
    color: var(--accent);
}

@keyframes slide-in {
    from {
        opacity: 0;
        transform: translateY(-4px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 1rem;
    gap: 8px;
}

.nav-right {
    display: flex;
    gap: 8px;
}

.results-hero {
    text-align: center;
    padding: 2rem 0 1.5rem;
}

.results-avatar {
    width: 64px;
    height: 64px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1rem;
    font-size: 22px;
    font-weight: 700;
    font-family: var(--mono);
    background: linear-gradient(135deg, var(--navy), #0d4d6b);
    border: 3px solid rgba(7, 48, 66, 0.15);
    color: #ffffff;
    letter-spacing: -0.02em;
    box-shadow: 0 4px 16px rgba(7, 48, 66, 0.2);
}

.results-name {
    font-size: 13px;
    color: var(--text-3);
    margin-bottom: 0.25rem;
    font-family: var(--mono);
}

.results-score {
    font-size: 52px;
    font-weight: 700;
    font-family: var(--mono);
    letter-spacing: -0.03em;
    line-height: 1;
    margin: 0.5rem 0 0.35rem;
}

.results-grade {
    font-size: 13px;
    font-weight: 600;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    padding: 4px 14px;
    border-radius: 99px;
    display: inline-block;
    margin-bottom: 0.35rem;
}

.grade-pass {
    background: var(--green-dim);
    color: #167a3e;
    border: 1px solid rgba(38, 193, 101, 0.3);
}
.grade-mid {
    background: var(--accent-dim);
    color: #1a5f85;
    border: 1px solid rgba(48, 135, 185, 0.3);
}
.grade-fail {
    background: var(--red-dim);
    color: var(--red);
    border: 1px solid rgba(217, 48, 37, 0.25);
}

.results-pct {
    font-size: 14px;
    color: var(--text-3);
    font-family: var(--mono);
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 10px;
    margin-bottom: 1rem;
}

.r-stat {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1rem 0.75rem;
    text-align: center;
    box-shadow: var(--shadow-sm);
}

.r-val {
    font-size: 22px;
    font-weight: 600;
    font-family: var(--mono);
    letter-spacing: -0.02em;
}

.r-lbl {
    font-size: 11px;
    color: var(--text-3);
    margin-top: 3px;
    text-transform: uppercase;
    letter-spacing: 0.06em;
}

.sheet-confirm {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    font-size: 12px;
    color: #167a3e;
    opacity: 0.85;
    margin-bottom: 1.25rem;
    font-family: var(--mono);
}

.blocked-wrap {
    text-align: center;
    padding: 4rem 1rem;
}

.blocked-icon {
    font-size: 48px;
    color: var(--red);
    margin-bottom: 1.25rem;
    opacity: 0.8;
}

.blocked-title {
    font-size: 20px;
    font-weight: 600;
    margin-bottom: 0.75rem;
    color: var(--navy);
}

.blocked-body {
    font-size: 14px;
    color: var(--text-2);
    line-height: 1.7;
    max-width: 360px;
    margin: 0 auto;
}

.divider {
    height: 1px;
    background: var(--border);
    margin: 1.25rem 0;
}

.text-right {
    text-align: right;
}
.flex-end {
    display: flex;
    justify-content: flex-end;
}
.mt-1 {
    margin-top: 1rem;
}
.mb-1 {
    margin-bottom: 1rem;
}

@keyframes fade-up {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.fade-up {
    animation: fade-up 0.3s ease both;
}

::-webkit-scrollbar {
    width: 6px;
    height: 6px;
}
::-webkit-scrollbar-track {
    background: transparent;
}
::-webkit-scrollbar-thumb {
    background: rgba(7, 48, 66, 0.15);
    border-radius: 6px;
}
::-webkit-scrollbar-thumb:hover {
    background: rgba(7, 48, 66, 0.25);
}