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

:root {
    --bg-dark: #111111;
    --bg-darker: #0a0a0a;
    --card-light: #fafafa;
    --text-dark: #1a1a1a;
    --text-light: #666666;
    --accent-blue: #3b82f6;
    --accent-purple: #8b5cf6;
    --shadow-card: 0 10px 30px rgba(0, 0, 0, 0.3);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Noto Sans KR', sans-serif;
    background: var(--bg-dark);
    color: var(--text-dark);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
}

/* SEO 콘텐츠 (검색엔진용, 시각적으로 숨김) */
.seo-content {
    position: absolute;
    left: -9999px;
    width: 1px;
    height: 1px;
    overflow: hidden;
    opacity: 0;
    pointer-events: none;
}

.app-container {
    width: 100%;
    max-width: 600px;
    position: relative;
}

.screen {
    display: none;
    width: 100%;
}

.screen.active {
    display: block;
    animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* 시작 화면 */
.start-content {
    text-align: center;
    padding: 40px 20px;
}

.app-title {
    font-size: 3rem;
    font-weight: 700;
    color: var(--card-light);
    margin-bottom: 20px;
    letter-spacing: -1px;
}

.app-subtitle {
    font-size: 1.2rem;
    color: var(--text-light);
    margin-bottom: 40px;
    line-height: 1.6;
}

.start-button {
    padding: 18px 50px;
    font-size: 1.2rem;
    font-weight: 600;
    background: var(--card-light);
    color: var(--text-dark);
    border: none;
    border-radius: 50px;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: var(--shadow-card);
}

.start-button:hover {
    transform: translateY(-2px);
    box-shadow: 0 15px 40px rgba(0, 0, 0, 0.4);
}

.start-button:active {
    transform: translateY(0);
}

/* 진행 바 */
.progress-bar {
    width: 100%;
    height: 4px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 2px;
    margin-bottom: 40px;
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--accent-blue), var(--accent-purple));
    border-radius: 2px;
    transition: width 0.3s ease;
    width: 0%;
}

/* 질문 카드 */
.question-card {
    background: var(--card-light);
    border-radius: 24px;
    padding: 50px 40px;
    margin-bottom: 40px;
    box-shadow: var(--shadow-card);
    text-align: center;
    min-height: 300px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
}

.question-number {
    font-size: 0.9rem;
    color: var(--text-light);
    margin-bottom: 20px;
    font-weight: 500;
    letter-spacing: 1px;
}

.question-text {
    font-size: 1.5rem;
    line-height: 1.8;
    color: var(--text-dark);
    font-weight: 500;
}

/* 답변 버튼 */
.answer-buttons {
    display: flex;
    gap: 20px;
    justify-content: center;
}

.answer-btn {
    width: 120px;
    height: 120px;
    border-radius: 50%;
    border: none;
    font-size: 2.5rem;
    font-weight: 700;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.2);
    color: white;
}

.answer-o {
    background: linear-gradient(135deg, #10b981, #059669);
}

.answer-x {
    background: linear-gradient(135deg, #ef4444, #dc2626);
}

.answer-btn:hover {
    transform: scale(1.1);
    box-shadow: 0 12px 30px rgba(0, 0, 0, 0.3);
}

.answer-btn:active {
    transform: scale(0.95);
}

/* 추가 검사 제안 화면 */
.offer-card {
    background: var(--card-light);
    border-radius: 24px;
    padding: 50px 40px;
    box-shadow: var(--shadow-card);
    text-align: center;
}

.offer-card h2 {
    font-size: 1.8rem;
    color: var(--text-dark);
    margin-bottom: 20px;
    font-weight: 600;
}

.offer-card p {
    font-size: 1.1rem;
    color: var(--text-light);
    line-height: 1.8;
    margin-bottom: 40px;
}

.offer-buttons {
    display: flex;
    gap: 15px;
    justify-content: center;
    flex-wrap: wrap;
}

.offer-btn {
    padding: 16px 40px;
    font-size: 1.1rem;
    font-weight: 600;
    border: none;
    border-radius: 50px;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.15);
}

.offer-btn.accept {
    background: linear-gradient(135deg, var(--accent-blue), var(--accent-purple));
    color: white;
}

.offer-btn.skip {
    background: rgba(255, 255, 255, 0.1);
    color: var(--text-dark);
    border: 2px solid rgba(0, 0, 0, 0.1);
}

.offer-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
}

.offer-btn:active {
    transform: translateY(0);
}

/* 결과 화면 */
.result-content {
    text-align: center;
    padding: 40px 20px;
}

.result-label {
    font-size: 1.2rem;
    color: var(--text-light);
    margin-bottom: 20px;
}

.result-mbti {
    font-size: 4rem;
    font-weight: 700;
    color: var(--card-light);
    margin-bottom: 30px;
    letter-spacing: 4px;
    text-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
}

.result-description {
    font-size: 1.4rem;
    color: var(--card-light);
    line-height: 1.8;
    margin-bottom: 50px;
    font-weight: 500;
}

.result-buttons {
    display: flex;
    gap: 15px;
    justify-content: center;
    flex-wrap: wrap;
}

.result-btn {
    padding: 16px 35px;
    font-size: 1.1rem;
    font-weight: 600;
    border: none;
    border-radius: 50px;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.2);
}

.result-btn.save {
    background: var(--card-light);
    color: var(--text-dark);
}

.result-btn.restart {
    background: rgba(255, 255, 255, 0.1);
    color: var(--card-light);
    border: 2px solid rgba(255, 255, 255, 0.2);
}

.result-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
}

.result-btn:active {
    transform: translateY(0);
}

/* 반응형 */
@media (max-width: 480px) {
    .app-title {
        font-size: 2.2rem;
    }

    .question-card {
        padding: 40px 30px;
        min-height: 250px;
    }

    .question-text {
        font-size: 1.3rem;
    }

    .answer-btn {
        width: 100px;
        height: 100px;
        font-size: 2rem;
    }

    .result-mbti {
        font-size: 3rem;
    }

    .result-description {
        font-size: 1.2rem;
    }

    .offer-buttons,
    .result-buttons {
        flex-direction: column;
    }

    .offer-btn,
    .result-btn {
        width: 100%;
    }
}