/* ===== Design Tokens ===== */
:root {
    --color-bg: #ffffff;
    --color-text: #1a1a1a;
    --color-accent: #0066cc;
    --color-border: #e0e0e0;
    --color-muted: #666666;

    --font-family: 'Noto Sans JP', -apple-system, BlinkMacSystemFont, sans-serif;
    --max-width: 640px;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-family);
    font-size: 16px;
    line-height: 1.7;
    color: var(--color-text);
    background: var(--color-bg);
}

/* ===== Layout ===== */
.app-container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 2rem 1rem;
}

/* ===== Typography ===== */
h1,
h2,
h3,
h4 {
    font-weight: 600;
    line-height: 1.4;
}

h1 {
    font-size: 1.25rem;
}

h2 {
    font-size: 1.125rem;
}

h3 {
    font-size: 1rem;
}

h4 {
    font-size: 0.9375rem;
}

a {
    color: var(--color-accent);
    text-decoration: underline;
}

a:hover {
    text-decoration: none;
}

/* ===== Utility ===== */
.hidden {
    display: none !important;
}

/* ===== Header ===== */
.header {
    margin-bottom: 2rem;
    padding-bottom: 1rem;
    border-bottom: 1px solid var(--color-border);
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.logo-icon {
    display: none;
}

.logo h1 {
    color: var(--color-text);
}

.header-badge {
    font-size: 0.75rem;
    color: var(--color-muted);
}

/* ===== Introduction ===== */
.intro-card {
    margin-bottom: 2rem;
}

.intro-icon {
    display: none;
}

.intro-card h2 {
    margin-bottom: 1rem;
}

.intro-description {
    color: var(--color-muted);
    margin-bottom: 1.5rem;
}

.disclaimer-box {
    padding: 1rem;
    border: 1px solid var(--color-border);
    margin-bottom: 1.5rem;
}

.disclaimer-icon {
    display: none;
}

.disclaimer-text {
    font-size: 0.875rem;
    color: var(--color-muted);
}

.disclaimer-text strong {
    color: var(--color-text);
}

/* ===== Buttons ===== */
.primary-btn,
.secondary-btn,
.nav-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    font-size: 0.9375rem;
    font-weight: 500;
    font-family: inherit;
    cursor: pointer;
    border: 1px solid;
    background: none;
    transition: opacity 0.15s;
}

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

.primary-btn:hover:not(:disabled) {
    opacity: 0.85;
}

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

.primary-btn svg,
.secondary-btn svg {
    width: 18px;
    height: 18px;
}

.secondary-btn {
    border-color: var(--color-border);
    color: var(--color-text);
}

.secondary-btn:hover:not(:disabled) {
    border-color: var(--color-text);
}

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

/* ===== Progress ===== */
.progress-container {
    margin-bottom: 2rem;
}

.progress-info {
    display: flex;
    justify-content: space-between;
    font-size: 0.875rem;
    color: var(--color-muted);
    margin-bottom: 0.5rem;
}

.progress-bar {
    height: 4px;
    background: var(--color-border);
}

.progress-fill {
    height: 100%;
    background: var(--color-accent);
    transition: width 0.3s;
    width: 0%;
}

/* ===== Section Header ===== */
.section-header {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1.5rem;
    padding-bottom: 1rem;
    border-bottom: 1px solid var(--color-border);
}

.section-number {
    width: 28px;
    height: 28px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.875rem;
    font-weight: 600;
    border: 1px solid var(--color-text);
}

.section-info h3 {
    margin-bottom: 0.25rem;
}

.section-info p {
    font-size: 0.875rem;
    color: var(--color-muted);
}

/* ===== Question Card ===== */
.question-card {
    margin-bottom: 2rem;
}

.question-header {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-bottom: 1rem;
}

.question-number {
    font-weight: 600;
    color: var(--color-accent);
}

.question-category {
    font-size: 0.75rem;
    color: var(--color-muted);
}

.question-text {
    font-weight: 500;
    margin-bottom: 1.5rem;
}

/* ===== Options ===== */
.options-container {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.option-item {
    position: relative;
}

.option-input {
    position: absolute;
    opacity: 0;
    pointer-events: none;
}

.option-label {
    display: block;
    padding: 1rem;
    border: 1px solid var(--color-border);
    cursor: pointer;
    transition: border-color 0.15s;
}

.option-label:hover {
    border-color: var(--color-muted);
}

.option-input:checked+.option-label {
    border-color: var(--color-accent);
}

.option-content {
    display: flex;
    align-items: flex-start;
    gap: 0.75rem;
}

.option-radio {
    width: 18px;
    height: 18px;
    border: 1px solid var(--color-muted);
    flex-shrink: 0;
    margin-top: 2px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.option-input:checked+.option-label .option-radio {
    border-color: var(--color-accent);
}

.option-radio::after {
    content: '';
    width: 10px;
    height: 10px;
    background: var(--color-accent);
    opacity: 0;
}

.option-input:checked+.option-label .option-radio::after {
    opacity: 1;
}

.option-text {
    font-size: 0.9375rem;
}

.option-description {
    font-size: 0.8125rem;
    color: var(--color-muted);
    margin-top: 0.25rem;
}

/* ===== Navigation ===== */
.navigation-buttons {
    display: flex;
    justify-content: space-between;
    gap: 1rem;
}

.nav-btn {
    flex: 1;
    max-width: 160px;
}

/* ===== Result ===== */
.result-card {
    margin-bottom: 2rem;
}

.result-header {
    margin-bottom: 1.5rem;
}

.result-icon {
    display: none;
}

.result-header h2 {
    text-align: center;
}

.result-grade {
    text-align: center;
    margin-bottom: 2rem;
    padding: 2rem 0;
    border-top: 1px solid var(--color-border);
    border-bottom: 1px solid var(--color-border);
}

.grade-badge {
    display: inline-flex;
    align-items: baseline;
    gap: 0.25rem;
}

.grade-number {
    font-size: 3rem;
    font-weight: 700;
    line-height: 1;
    color: var(--color-accent);
}

.grade-text {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--color-text);
}

.grade-subtitle {
    margin-top: 0.5rem;
    color: var(--color-muted);
}

/* ===== Result Explanation ===== */
.result-explanation {
    padding: 1rem;
    border: 1px solid var(--color-border);
    margin-bottom: 1.5rem;
}

.result-explanation h4 {
    margin-bottom: 0.75rem;
}

.explanation-content {
    font-size: 0.9375rem;
    color: var(--color-muted);
}

.explanation-content p {
    margin-bottom: 0.75rem;
}

.explanation-content ul {
    margin-left: 1.25rem;
    margin-top: 0.5rem;
}

.explanation-content li {
    margin-bottom: 0.25rem;
}

/* ===== Scores ===== */
.result-scores {
    margin-bottom: 1.5rem;
}

.result-scores h4 {
    margin-bottom: 1rem;
}

.scores-container {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 0.75rem;
}

.score-item {
    padding: 0.75rem;
    border: 1px solid var(--color-border);
}

.score-label {
    font-size: 0.8125rem;
    margin-bottom: 0.5rem;
}

.score-bar {
    height: 4px;
    background: var(--color-border);
    margin-bottom: 0.25rem;
}

.score-fill {
    height: 100%;
    background: var(--color-accent);
}

.score-value {
    font-size: 0.75rem;
    color: var(--color-muted);
    text-align: right;
}

/* ===== Result Notice ===== */
.result-notice {
    padding: 1rem;
    border: 1px solid var(--color-border);
    margin-bottom: 1.5rem;
}

.notice-icon {
    display: none;
}

.result-notice p {
    font-size: 0.875rem;
    color: var(--color-muted);
}

/* ===== Result Actions ===== */
.result-actions {
    display: flex;
    justify-content: center;
    gap: 1rem;
}

/* ===== Grade Comparison ===== */
.grade-comparison {
    margin-top: 2rem;
    padding-top: 2rem;
    border-top: 1px solid var(--color-border);
}

.grade-comparison h3 {
    margin-bottom: 1rem;
}

.comparison-table {
    width: 100%;
    overflow-x: auto;
}

.comparison-row {
    display: grid;
    grid-template-columns: 1.5fr repeat(3, 1fr);
}

.comparison-row.header {
    border-bottom: 1px solid var(--color-text);
}

.comparison-row.header .comparison-cell {
    font-weight: 600;
}

.comparison-cell {
    padding: 0.75rem 0.5rem;
    font-size: 0.8125rem;
    border-bottom: 1px solid var(--color-border);
}

/* ===== Footer ===== */
.footer {
    margin-top: 3rem;
    padding-top: 1.5rem;
    border-top: 1px solid var(--color-border);
    font-size: 0.8125rem;
    color: var(--color-muted);
}

.footer-note {
    margin-top: 0.5rem;
}

/* ===== Responsive ===== */
@media (max-width: 480px) {
    .app-container {
        padding: 1.5rem 1rem;
    }

    .header-content {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.5rem;
    }

    .navigation-buttons {
        flex-direction: column;
    }

    .nav-btn {
        max-width: none;
    }

    .scores-container {
        grid-template-columns: 1fr;
    }

    .result-actions {
        flex-direction: column;
    }

    .result-actions button {
        width: 100%;
    }

    .comparison-table {
        font-size: 0.75rem;
    }
}