/* 테마 스타일 - 색상, 그라데이션, 폰트, 그림자 등 테마 요소 */

/* 기본 색상 */
:root {
    --primary-gradient: linear-gradient(to right, rgba(255, 78, 255, 1), rgba(153, 179, 255, 1));
    --primary-light: rgba(153, 179, 255, 1);
    --primary-dark: rgba(255, 78, 255, 1);
    --secondary: #f64f59;
    --text-primary: #333333;
    --text-secondary: #666666;
    --text-light: #888888;
    --bg-light: #f8f8f8;
    --bg-white: #ffffff;
    --border-light: #e0e0e0;
    --shadow-light: 0 2px 10px rgba(0, 0, 0, 0.1);
    --shadow-medium: 0 4px 15px rgba(0, 0, 0, 0.15);
    --shadow-hover: 0 6px 20px rgba(0, 0, 0, 0.2);
    --favorite-color: #ffcc00;
}

/* 기본 타이포그래피 및 배경 */
body {
    font-family: 'Noto Sans KR', 'Nunito', sans-serif;
    color: var(--text-primary);
    background-color: var(--bg-light);
    line-height: 1.6;
    margin-bottom: 70px;
    padding-bottom: 10px;
}

h1, h2, h3, h4, h5, h6 {
    font-family: 'Nunito', 'Noto Sans KR', sans-serif;
    line-height: 1.3;
}
.container {
    background-color: var(--bg-white);
}

/* 헤더 스타일 */
.header {
    background-image: var(--primary-gradient);
    color: white;
    padding-bottom: 20px;
    border-radius: 0 0 15px 15px;
    box-shadow: var(--shadow-light);
}

.header .back-btn {
    color: white;
}

.header h1 {
    color: white;
    font-weight: 700;
}

/* 프로그레스 바 */
.progress-bar {
    background-color: rgba(255, 255, 255, 0.3);
    border-radius: 10px;
    height: 8px;
    overflow: hidden;
}

.progress-fill {
    background-color: white;
    height: 100%;
    transition: width 0.5s ease;
}

.progress-text {
    color: white;
    font-size: 0.85rem;
    margin-top: 5px;
    text-align: right;
}

/* 카테고리 섹션 */
.category-section {
    background-color: var(--bg-white);
    border-radius: 10px;
    box-shadow: var(--shadow-light);
    padding: 15px;
}

.category-header h2 {
    color: var(--primary-dark);
    font-size: 1.2rem;
    font-weight: 700;
    margin: 0;
}

.category-title {
    color: var(--text-secondary);
    font-weight: 700;
    font-size: 0.9rem;
    padding-bottom: 5px;
    border-bottom: 2px solid var(--primary-light);
    margin-bottom: 8px;
    display: inline-block;
}

/* 단어 카드 */
.card-container {
    margin-top: 20px;
}

.card {
    box-shadow: var(--shadow-medium);
}

.card-front, .card-back {
    background-color: var(--bg-white);
    border-radius: 15px;
}

/* 단어 아이콘 */
.word-icon {
    font-size: 2.5rem;
    color: var(--primary-light);
    margin-bottom: 15px;
}

/* 단어 텍스트 */
.english-word {
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    text-fill-color: transparent;
}

/* 스펠링 테이블 */
.spelling-table .letter td {
    background-color: rgba(33, 212, 253, 0.1);
    color: var(--primary-dark);
}

/* 단어 뜻 */
.word-meaning {
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    text-fill-color: transparent;
}

/* 버튼 테마 */
.flip-btn {
    background-image: var(--primary-gradient);
}

.nav-btn {
    border: 1px solid var(--border-light);
}

/* 학습 옵션 영역 */
.learning-options {
    background-color: var(--bg-white);
    box-shadow: 0 -3px 10px rgba(0, 0, 0, 0.1);
}

.option-btn i {
    color: var(--primary-dark);
}

/* 로딩 화면 */
.loader {
    color: var(--text-secondary);
}

.spinner {
    border-color: rgba(183, 33, 255, 0.3);
    border-top-color: var(--primary-dark);
}

/* 완료 화면 */
.completion-screen {
    background-color: rgba(0, 0, 0, 0.7);
}

.completion-content {
    background-color: var(--bg-white);
    box-shadow: var(--shadow-medium);
}

.completion-icon {
    font-size: 3rem;
    color: var(--primary-light);
    margin-bottom: 15px;
}

.points-earned {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--favorite-color);
    margin: 20px 0;
}

/* 오류 화면 */
.error-message {
    color: var(--text-secondary);
}

.error-message i {
    color: var(--secondary);
    font-size: 3rem;
    margin-bottom: 15px;
}

.retry-btn {
    background-image: var(--primary-gradient);
    color: white;
    padding: 10px 25px;
    border-radius: 25px;
    margin-top: 15px;
}

/* 학년별 배경 테마 */
.theme-elementary {
    --primary-gradient: linear-gradient(to right, rgba(255, 78, 255, 1), rgba(153, 179, 255, 1));
    --primary-light: rgba(153, 179, 255, 1);
    --primary-dark: rgba(255, 78, 255, 1);
}

.theme-middle {
    --primary-gradient: linear-gradient(to right, rgba(255, 78, 255, 0.9), rgba(153, 179, 255, 0.9));
    --primary-light: rgba(153, 179, 255, 0.9);
    --primary-dark: rgba(255, 78, 255, 0.9);
}

.theme-high {
    --primary-gradient: linear-gradient(to right, rgba(255, 78, 255, 0.8), rgba(153, 179, 255, 0.8));
    --primary-light: rgba(153, 179, 255, 0.8);
    --primary-dark: rgba(255, 78, 255, 0.8);
}

.theme-university {
    --primary-gradient: linear-gradient(to right, rgba(255, 78, 255, 0.7), rgba(153, 179, 255, 0.7));
    --primary-light: rgba(153, 179, 255, 0.7);
    --primary-dark: rgba(255, 78, 255, 0.7);
}