/* PSAT 계산 트레이너 - 나이트 스터디 테마 */

/* CSS 변수 정의 */
:root {
    --primary-bg: #0F0F23;
    --secondary-bg: #1A1A2E;
    --accent-bg: #2D2D44;
    --card-bg: #3A3A5C;
    --primary-text: #F0F0F0;
    --secondary-text: #B8B8CC;
    --accent-color: #D4AF37;
    --success-color: #4CAF50;
    --error-color: #F44336;
    --warning-color: #FF9800;
    --border-color: #3A3A5C;
    --shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
    --border-radius: 16px;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* 기본 스타일 리셋 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    background: linear-gradient(135deg, var(--primary-bg) 0%, var(--secondary-bg) 100%);
    color: var(--primary-text);
    font-family: 'Noto Sans KR', sans-serif;
    min-height: 100vh;
    line-height: 1.6;
    overflow-x: hidden;
}

/* 메인 앱 컨테이너 */
#app {
    width: 100%;
    min-height: 100vh;
    position: relative;
}

/* 화면 전환 */
.screen {
    width: 100%;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    animation: fadeIn 0.3s ease-in-out;
}

.screen.hidden {
    display: none;
}

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

/* 앱 헤더 */
.app-header {
    text-align: center;
    padding: 40px 20px 30px;
    background: linear-gradient(135deg, var(--secondary-bg), var(--accent-bg));
    border-bottom: 1px solid var(--border-color);
}

.app-header h1 {
    font-family: 'Montserrat', sans-serif;
    font-size: 2.5rem;
    color: var(--accent-color);
    margin-bottom: 10px;
    font-weight: 700;
}

.app-subtitle {
    color: var(--secondary-text);
    font-size: 1.1rem;
}

/* 화면 헤더 */
.screen-header {
    display: flex;
    align-items: center;
    padding: 20px;
    background: var(--accent-bg);
    border-bottom: 1px solid var(--border-color);
}

.back-btn {
    background: var(--primary-bg);
    color: var(--primary-text);
    border: 1px solid var(--border-color);
    padding: 8px 16px;
    border-radius: 8px;
    cursor: pointer;
    transition: var(--transition);
    margin-right: 15px;
    display: flex;
    align-items: center;
    gap: 8px;
}

.back-btn:hover {
    background: var(--accent-color);
    color: var(--primary-bg);
}

.screen-header h2 {
    font-size: 1.5rem;
    color: var(--primary-text);
}

/* 메인 콘텐츠 */
.main-content {
    flex: 1;
    padding: 40px 20px;
    display: flex;
    flex-direction: column;
    align-items: center;
}

/* 메뉴 카드들 */
.menu-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 20px;
    width: 100%;
    max-width: 900px;
}

.menu-card {
    background: var(--card-bg);
    border-radius: var(--border-radius);
    padding: 30px;
    text-align: center;
    cursor: pointer;
    transition: var(--transition);
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow);
}

.menu-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 12px 40px rgba(0, 0, 0, 0.4);
    border-color: var(--accent-color);
}

.menu-card .card-icon {
    font-size: 3rem;
    margin-bottom: 20px;
    display: block;
}

.menu-card h3 {
    font-size: 1.5rem;
    margin-bottom: 10px;
    color: var(--primary-text);
}

.menu-card p {
    color: var(--secondary-text);
    font-size: 1rem;
}

/* 선택 화면 */
.selection-content {
    flex: 1;
    padding: 30px 20px;
}

.selection-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
    max-width: 1000px;
    margin: 0 auto;
}

.selection-card {
    background: var(--card-bg);
    border-radius: var(--border-radius);
    padding: 25px;
    text-align: center;
    cursor: pointer;
    transition: var(--transition);
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow);
}

.selection-card:hover {
    transform: translateY(-3px);
    border-color: var(--accent-color);
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.3);
}

.selection-card .card-icon {
    font-size: 2.5rem;
    margin-bottom: 15px;
    display: block;
}

.selection-card h3 {
    font-size: 1.3rem;
    margin-bottom: 8px;
    color: var(--primary-text);
}

.selection-card p {
    color: var(--secondary-text);
    font-size: 0.9rem;
}

/* 타임어택 정보 */
.time-attack-info {
    margin-bottom: 30px;
}

.info-card {
    background: var(--card-bg);
    border-radius: var(--border-radius);
    padding: 20px;
    border: 1px solid var(--border-color);
    max-width: 500px;
    margin: 0 auto;
}

.info-card h3 {
    color: var(--accent-color);
    margin-bottom: 15px;
    font-size: 1.2rem;
}

.info-card ul {
    list-style: none;
    padding: 0;
}

.info-card li {
    color: var(--secondary-text);
    margin: 8px 0;
    padding-left: 20px;
    position: relative;
}

.info-card li::before {
    content: "•";
    color: var(--accent-color);
    position: absolute;
    left: 0;
}

/* 문제 풀이 화면 */
.practice-header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px;
    background: var(--accent-bg);
    border-bottom: 1px solid var(--border-color);
    z-index: 1000;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.home-btn {
    background: var(--primary-bg);
    color: var(--primary-text);
    border: 1px solid var(--border-color);
    padding: 8px 12px;
    border-radius: 8px;
    cursor: pointer;
    transition: var(--transition);
    font-size: 1.2rem;
    display: flex;
    align-items: center;
    justify-content: center;
    min-width: 40px;
    height: 40px;
}

.home-btn:hover {
    background: var(--accent-color);
    color: var(--primary-bg);
    transform: scale(1.05);
}

.navigation-buttons {
    display: flex;
    gap: 8px;
}

.practice-info {
    display: flex;
    align-items: center;
    gap: 15px;
    color: var(--primary-text);
    font-size: 1.1rem;
}

.mode-indicator {
    background: var(--accent-color);
    color: var(--primary-bg);
    padding: 4px 12px;
    border-radius: 12px;
    font-size: 0.8rem;
    font-weight: 600;
}

.timer-container {
    background: var(--primary-bg);
    padding: 8px 16px;
    border-radius: 20px;
    border: 1px solid var(--border-color);
    width: 120px;
    text-align: center;
    flex-shrink: 0;
}

#timer {
    font-family: 'Montserrat', sans-serif;
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--accent-color);
}

.question-area {
    flex: 1;
    display: flex;
    flex-direction: column;
    padding: 20px;
    padding-top: 100px;
    min-height: 0;
}

.image-container {
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 20px;
    background: var(--primary-bg);
    border-radius: 12px;
    padding: 20px;
    border: 1px solid var(--border-color);
    min-height: 200px;
}

#problem-image {
    max-width: 100%;
    max-height: 300px;
    object-fit: contain;
    border-radius: 8px;
}

.text-container {
    background: var(--primary-bg);
    padding: 20px;
    border-radius: 12px;
    border: 1px solid var(--border-color);
}

#problem-text {
    font-size: 1.2rem;
    line-height: 1.7;
    color: var(--primary-text);
    text-align: left;
}

.answer-area {
    padding: 20px;
    background: var(--accent-bg);
    border-top: 1px solid var(--border-color);
    margin-top: 20px;
}

.answer-input-container {
    display: flex;
    gap: 10px;
    margin-bottom: 20px;
    max-width: 400px;
    margin-left: auto;
    margin-right: auto;
    align-items: center;
}

#answer-input {
    flex: 1;
    background: var(--primary-bg);
    border: 1px solid var(--border-color);
    color: var(--primary-text);
    padding: 12px 16px;
    border-radius: 8px;
    font-size: 1rem;
}

#answer-input:focus {
    outline: none;
    border-color: var(--accent-color);
}

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

.answer-buttons button {
    width: 80px;
    height: 80px;
    background: var(--primary-bg);
    border: 2px solid var(--border-color);
    border-radius: 50%;
    color: var(--primary-text);
    font-size: 2rem;
    font-weight: 700;
    cursor: pointer;
    transition: var(--transition);
}

.answer-buttons button:hover {
    transform: scale(1.1);
    border-color: var(--accent-color);
}

/* 객관식 옵션 */
.multiple-choice-options {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 15px;
    max-width: 600px;
    margin: 0 auto;
}

.option-button {
    background: var(--card-bg);
    border: 2px solid var(--border-color);
    border-radius: 12px;
    padding: 20px;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
}

.option-button:hover {
    border-color: var(--accent-color);
    transform: translateY(-2px);
}

.option-label {
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--accent-color);
    margin-bottom: 8px;
}

.option-value {
    font-size: 1rem;
    color: var(--primary-text);
}

.fraction {
    display: inline-block;
    text-align: center;
    vertical-align: middle;
}

.fraction-numerator {
    display: block;
    border-bottom: 1px solid var(--primary-text);
    padding-bottom: 2px;
}

/* 결과 화면 */
.result-content {
    flex: 1;
    padding: 40px 20px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
}

.result-card {
    background: var(--card-bg);
    border-radius: var(--border-radius);
    padding: 40px;
    text-align: center;
    border: 1px solid var(--border-color);
    max-width: 500px;
    width: 100%;
}

.result-icon { font-size: 4rem; margin-bottom: 20px; }
.result-card h3 { font-size: 2rem; color: var(--accent-color); margin-bottom: 30px; }
.result-stats { display: grid; grid-template-columns: 1fr 1fr 1fr; gap: 20px; margin-bottom: 30px; }
.stat-label { display: block; color: var(--secondary-text); font-size: 0.9rem; margin-bottom: 5px; }
.stat-value { display: block; font-size: 1.5rem; font-weight: 700; }
.result-actions { display: flex; gap: 15px; margin-top: 30px; }

/* 리더보드 */
.leaderboard-content { flex: 1; padding: 20px; }
.leaderboard-tabs { display: flex; justify-content: center; margin-bottom: 30px; gap: 5px; }
.tab-btn { background: var(--primary-bg); color: var(--secondary-text); border: 1px solid var(--border-color); padding: 10px 20px; border-radius: 8px; cursor: pointer; transition: var(--transition); }
.tab-btn.active, .tab-btn:hover:not(.active) { background: var(--accent-color); color: var(--primary-bg); }
.leaderboard-list { max-width: 600px; margin: 0 auto; }
.leaderboard-item { background: var(--card-bg); border-radius: 12px; padding: 15px 20px; margin-bottom: 10px; display: flex; justify-content: space-between; align-items: center; }
.rank-info { display: flex; align-items: center; gap: 15px; }
.rank-number { font-size: 1.2rem; font-weight: 700; color: var(--accent-color); min-width: 30px; }
.rank-score { font-size: 1.1rem; font-weight: 600; }
.rank-time { font-size: 0.9rem; color: var(--secondary-text); }
.no-records { text-align: center; color: var(--secondary-text); padding: 20px; }

/* 로딩 및 에러 */
.loading-container, .error-content { display: flex; flex-direction: column; align-items: center; justify-content: center; height: 100%; padding: 40px 20px; text-align: center; }
.loading-spinner { width: 60px; height: 60px; border: 4px solid var(--border-color); border-top: 4px solid var(--accent-color); border-radius: 50%; animation: spin 1s linear infinite; margin-bottom: 30px; }
@keyframes spin { from { transform: rotate(0deg); } to { transform: rotate(360deg); } }
h2 { font-size: 1.5rem; margin-bottom: 10px; }
.retry-button { background: var(--accent-color); color: var(--primary-bg); border: none; padding: 12px 24px; border-radius: 8px; font-size: 1rem; font-weight: 600; cursor: pointer; margin-top: 20px; }

/* 버튼 공통 스타일 */
.action-btn { padding: 12px 24px; border-radius: 8px; font-size: 1rem; font-weight: 600; cursor: pointer; transition: var(--transition); border: none; }
.action-btn.primary { background: var(--accent-color); color: var(--primary-bg); }
.action-btn.primary:hover { background: #B8941F; }
.action-btn.secondary { background: var(--card-bg); color: var(--primary-text); border: 1px solid var(--border-color); }
.action-btn.secondary:hover { background: var(--accent-bg); }

/* --- ▼▼▼ 새로 추가된 스타일 ▼▼▼ --- */

/* 사용자 상태 표시 */
.user-status-container {
    padding: 0 20px 20px;
    display: flex;
    justify-content: flex-end;
    align-items: center;
    gap: 15px;
    max-width: 940px;
    margin: 0 auto;
}
.user-info {
    font-size: 1rem;
    color: var(--secondary-text);
}

/* 인증 화면 */
.auth-content {
    flex: 1;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 20px;
}
.auth-form {
    width: 100%;
    max-width: 400px;
    display: flex;
    flex-direction: column;
    gap: 15px;
    background: var(--card-bg);
    padding: 30px;
    border-radius: var(--border-radius);
    border: 1px solid var(--border-color);
}
.auth-form input {
    background: var(--primary-bg);
    border: 1px solid var(--border-color);
    color: var(--primary-text);
    padding: 12px 16px;
    border-radius: 8px;
    font-size: 1rem;
}
.auth-form input:focus {
    outline: none;
    border-color: var(--accent-color);
}
.auth-form p {
    text-align: center;
    color: var(--secondary-text);
    font-size: 0.9rem;
}
.auth-form a {
    color: var(--accent-color);
    text-decoration: none;
    font-weight: 600;
}
.auth-form a:hover {
    text-decoration: underline;
}