:root {
    --white: #ffffff;
    --black: #222222;
    --meisei: #7f3033;
    --meisei2: #f9f3f3;
    --meisei3: #faf5f5;
    --gray: #666666;
    --gray2: #aaaaaa;
    --gray3: #e2e2e2;
    --gray4: #fafafa;

    --card-bg: var(--white);
    --text-dark: var(--black);
    --text-gray: var(--gray);
    --primary: var(--meisei);
    --border: var(--gray3);

    --correct-bg: #e6f7ef;
    --correct-border: #4ade80;
    --error-bg: #ffe4e6;
    --error-border: #f43f5e;

    --shadow: 0 4px 35px rgba(69, 27, 27, 0.08);
}

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

body {
    font-family: 'Inter', 'Noto Sans JP', sans-serif;
    background-color: var(--meisei2);
    color: var(--text-dark);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    line-height: 1.3;
}

.app-container {
    width: 100%;
    max-width: 800px;
    padding: 20px;
}

header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 24px;
}

.back-link {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    color: var(--text-gray);
    text-decoration: none;
    font-weight: 600;
    background: transparent;
    padding: 8px 16px;
    border-radius: 9999px;
    border: 1px solid var(--border);
    transition: all 0.25s ease;
    font-size: 0.9rem;
}

.back-link:hover {
    color: var(--primary);
    border-color: var(--primary);
}

h1 {
    font-family: 'Outfit', sans-serif;
    font-weight: 700;
    font-size: 1.8rem;
    color: var(--primary);
    letter-spacing: 0.03em;
}

/* ── Settings Panel ──────────────────── */
.settings-panel {
    background: var(--card-bg);
    border-radius: 32px;
    padding: 18px 28px;
    margin: 0 auto 28px;
    width: fit-content;
    display: flex;
    align-items: center;
    gap: 16px;
    box-shadow: var(--shadow);
    border: 1px solid var(--border);
}

#csv-file-input {
    display: none;
}

.file-label {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    background: var(--meisei3);
    color: var(--text-dark);
    padding: 10px 20px;
    border-radius: 9999px;
    cursor: pointer;
    font-size: 0.9rem;
    font-weight: 600;
    border: 1px solid var(--border);
    transition: all 0.25s ease;
}

.file-label:hover {
    border-color: var(--primary);
    color: var(--primary);
    scale: 0.985;
}

#file-name-display {
    font-size: 0.9rem;
    color: var(--text-gray);
    font-weight: 500;
}

/* ── Drill Card ──────────────────────── */
.drill-card {
    position: relative;
    background: var(--card-bg);
    border-radius: 32px;
    padding: 48px;
    text-align: center;
    box-shadow: var(--shadow);
    border: 1px solid var(--border);
}

.japanese-word {
    font-family: 'Outfit', sans-serif;
    font-weight: 700;
    font-size: clamp(1.4rem, 4vw, 2rem);
    margin-top: 16px;
    margin-bottom: 36px;
    color: var(--text-dark);
    word-break: keep-all;
    letter-spacing: 0.03em;
}

/* ── Input Grid ──────────────────────── */
.inputs-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
}

.input-group {
    text-align: left;
    position: relative;
}

.input-group label {
    display: block;
    margin-bottom: 8px;
    font-size: 0.8rem;
    color: var(--text-gray);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.04em;
}

.input-group input {
    width: 100%;
    padding: 14px 18px;
    font-size: 1.2rem;
    text-align: left;
    font-family: 'Outfit', sans-serif;
    font-weight: 600;
    background: var(--gray4);
    border: 1px solid var(--border);
    border-radius: 16px;
    color: var(--text-dark);
    transition: all 0.25s ease;
    outline: none;
}

.input-group input:focus {
    background: var(--white);
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(127, 48, 51, 0.1);
}

.input-group input.correct {
    background: var(--correct-bg);
    border-color: var(--correct-border);
    color: #166534;
}

.input-group input.error {
    background: var(--error-bg);
    border-color: var(--error-border);
    color: #9f1239;
}

.feedback {
    min-height: 22px;
    margin-top: 6px;
    font-size: 0.88rem;
    font-weight: 600;
    color: var(--text-gray);
}

.diff-correct { color: #10b981; }
.diff-incorrect { color: #f43f5e; text-decoration: underline; }

/* ── Controls ────────────────────────── */
.controls {
    margin-top: 32px;
}

#btn-skip {
    background: var(--white);
    border: 1px solid var(--border);
    color: var(--text-gray);
    padding: 10px 28px;
    border-radius: 9999px;
    cursor: pointer;
    font-weight: 600;
    font-size: 0.9rem;
    transition: all 0.25s ease;
}

#btn-skip:hover {
    border-color: var(--primary);
    color: var(--primary);
    scale: 0.985;
}

@keyframes shake {
    0%, 100% { transform: translateX(0); }
    25% { transform: translateX(-5px); }
    75% { transform: translateX(5px); }
}

.shake {
    animation: shake 0.3s ease-in-out;
}

/* ── Setup Card ──────────────────────── */
.setup-card {
    padding: 40px;
    margin-top: 0;
}

.setup-title, .result-title {
    font-family: 'Outfit', sans-serif;
    color: var(--primary);
    font-size: 1.8rem;
    margin-bottom: 24px;
    font-weight: 700;
}

.total-info {
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-gray);
    margin-bottom: 28px;
}

#total-questions {
    color: var(--primary);
    font-size: 1.3rem;
    font-weight: 700;
}

.input-row {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 16px;
    margin-bottom: 28px;
}

.input-row label {
    font-weight: 600;
    color: var(--text-dark);
}

.input-row input {
    width: 80px;
    padding: 10px;
    border: 1px solid var(--border);
    border-radius: 12px;
    font-size: 1.1rem;
    font-family: 'Outfit', sans-serif;
    font-weight: 700;
    text-align: center;
    outline: none;
    background: var(--gray4);
    transition: all 0.2s;
}

.input-row input:focus {
    border-color: var(--primary);
    background: var(--white);
}

/* ── Buttons ──────────────────────────── */
.btn-primary, .btn-secondary {
    border: none;
    padding: 14px 36px;
    border-radius: 9999px;
    cursor: pointer;
    font-weight: 700;
    font-size: 1rem;
    transition: all 0.25s ease;
    font-family: inherit;
}

.btn-primary {
    background: var(--primary);
    color: var(--white);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(127, 48, 51, 0.25);
}

.btn-secondary {
    background: var(--white);
    color: var(--text-gray);
    border: 1px solid var(--border);
    margin-top: 16px;
}

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

/* ── Progress ────────────────────────── */
.progress-info {
    position: absolute;
    top: 20px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--gray4);
    border: 1px solid var(--border);
    padding: 5px 16px;
    border-radius: 9999px;
    font-weight: 600;
    font-size: 0.85rem;
    color: var(--text-gray);
    white-space: nowrap;
}

/* ── Result ──────────────────────────── */
.score-display {
    font-family: 'Outfit', sans-serif;
    font-size: 2rem;
    font-weight: 800;
    color: var(--primary);
    margin-bottom: 32px;
}

#mistakes-container {
    background: var(--gray4);
    border: 1px solid var(--border);
    border-radius: 20px;
    padding: 24px;
    margin-bottom: 28px;
    text-align: left;
}

.mistakes-title {
    font-size: 1.1rem;
    color: #9f1239;
    margin-bottom: 14px;
    text-align: center;
    font-weight: 700;
}

.mistakes-list {
    list-style: none;
    max-height: 220px;
    overflow-y: auto;
    margin-bottom: 20px;
}

.mistakes-list li {
    background: var(--white);
    border: 1px solid var(--border);
    padding: 10px 14px;
    border-radius: 12px;
    margin-bottom: 8px;
    font-size: 0.92rem;
    font-weight: 600;
}

.mistakes-list li .jp {
    color: var(--primary);
    margin-bottom: 4px;
    display: block;
}

/* ── Mobile ───────────────────────────── */
@media (max-width: 600px) {
    .drill-card { padding: 48px 20px 24px; }

    .inputs-grid {
        grid-template-columns: 1fr;
    }

    .japanese-word {
        margin-top: 16px;
        white-space: normal;
        word-break: keep-all;
    }

    .input-group input {
        font-size: 1.1rem;
        padding: 12px 14px;
    }
}