/* codex: 2026-11-13 模态弹窗系统样式，含原题图解、奥数证明数学公式排版与答题互动卡片 */

.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background: rgba(30, 20, 15, 0.65);
    backdrop-filter: blur(4px);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 1000;
    padding: 20px;
    transition: opacity 0.25s ease;
}

.modal-overlay.hidden {
    display: none;
}

.modal-card {
    background: #ffffff;
    width: 100%;
    max-width: 680px;
    max-height: 88vh;
    border-radius: 18px;
    box-shadow: 0 16px 48px rgba(0, 0, 0, 0.25);
    display: flex;
    flex-direction: column;
    overflow: hidden;
    animation: modalPopIn 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

.modal-card.math-proof-modal {
    max-width: 780px;
}

@keyframes modalPopIn {
    0% { transform: scale(0.92); opacity: 0; }
    100% { transform: scale(1); opacity: 1; }
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 16px 22px;
    background: #fbf9f6;
    border-bottom: 1px solid #e8e0d8;
}

.modal-header h2 {
    font-size: 1.25rem;
    color: #4e342e;
    font-weight: 800;
}

.modal-close {
    background: transparent;
    border: none;
    font-size: 1.6rem;
    color: #8d6e63;
    cursor: pointer;
    line-height: 1;
    padding: 0 4px;
    transition: color 0.15s ease;
}

.modal-close:hover {
    color: #d81b60;
}

.modal-body {
    padding: 20px 24px;
    overflow-y: auto;
    font-size: 0.95rem;
    line-height: 1.65;
    color: #3e2723;
}

/* 原题图解展示 */
.rule-img-box {
    text-align: center;
    margin-bottom: 16px;
    background: #f5efe8;
    border-radius: 12px;
    padding: 12px;
}

.rule-orig-img {
    max-width: 100%;
    max-height: 280px;
    border-radius: 8px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.12);
}

.rule-text-content h3 {
    font-size: 1.05rem;
    color: #5d4037;
    margin: 12px 0 6px;
}

.rule-text-content p {
    margin-bottom: 8px;
}

.highlight-question {
    background: #fff3e0;
    border-left: 4px solid #ff9800;
    padding: 10px 14px;
    border-radius: 4px;
    margin: 12px 0;
}

/* 奥数证明弹窗样式 */
.proof-quiz-section {
    background: #fce4ec;
    border: 1.5px solid #f8bbd0;
    border-radius: 12px;
    padding: 14px 18px;
    margin-bottom: 20px;
}

.proof-quiz-section h3 {
    color: #ad1457;
    margin-bottom: 10px;
    font-size: 1rem;
}

.quiz-row {
    display: flex;
    align-items: center;
    gap: 8px;
    flex-wrap: wrap;
}

.quiz-row input {
    width: 90px;
    padding: 6px 10px;
    border: 1px solid #c2185b;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 700;
    text-align: center;
}

.quiz-feedback {
    margin-top: 10px;
    font-size: 0.92rem;
    line-height: 1.5;
    padding: 8px 12px;
    border-radius: 8px;
    display: none;
}

.quiz-feedback.success {
    display: block;
    background: #e8f5e9;
    color: #1b5e20;
    border: 1px solid #81c784;
}

.quiz-feedback.error {
    display: block;
    background: #ffebee;
    color: #c62828;
    border: 1px solid #ef9a9a;
}

.proof-lead {
    font-size: 1.05rem;
    background: #fdfaf6;
    padding: 12px;
    border-radius: 8px;
    border: 1px solid #ebdcd0;
    margin-bottom: 16px;
}

.proof-step-card {
    background: #faf8f5;
    border: 1px solid #e0d7ce;
    border-radius: 10px;
    padding: 14px 16px;
    margin-bottom: 14px;
}

.proof-step-card h4 {
    color: #4a148c;
    margin-bottom: 8px;
    font-size: 0.98rem;
}

.math-formula-box {
    text-align: center;
    margin: 12px 0;
}

.math-formula {
    display: inline-block;
    text-align: center;
    font-family: "Cambria Math", "Latin Modern Math", "STIX Two Math", "Georgia", "Times New Roman", serif;
    font-size: 1.4rem;
    color: #b71c1c;
    font-weight: 700;
    padding: 10px 24px;
    background: #fff8e1;
    border: 1.5px solid #ffe082;
    border-radius: 10px;
    box-shadow: 0 3px 8px rgba(0, 0, 0, 0.05);
    letter-spacing: 0.5px;
}

.math-formula em {
    font-style: italic;
    font-family: "Cambria Math", "Latin Modern Math", "Times New Roman", serif;
}

.math-formula sub {
    font-size: 0.75em;
    font-style: normal;
    vertical-align: sub;
}

.math-func {
    font-style: normal;
    font-family: inherit;
    font-weight: 800;
    color: #4a148c;
}

.proof-table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 8px;
    text-align: center;
}

.proof-table th, .proof-table td {
    border: 1px solid #d7ccc8;
    padding: 8px;
}

.proof-table th {
    background: #efebe9;
    color: #4e342e;
}

/* 皮肤选择网格 */
.skin-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 14px;
    padding: 16px 20px;
}

.skin-card {
    background: #fcfbf9;
    border: 2px solid #e0d7ce;
    border-radius: 12px;
    padding: 14px;
    cursor: pointer;
    transition: all 0.2s ease;
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.skin-card:hover {
    border-color: #8d6e63;
    transform: translateY(-2px);
}

.skin-card.active {
    border-color: #d81b60;
    background: #fff5f8;
    box-shadow: 0 4px 12px rgba(216, 27, 96, 0.2);
}

.skin-preview-row {
    display: flex;
    gap: 8px;
    margin-top: 6px;
}

/* 胜利弹窗 */
.win-content {
    padding: 30px 24px;
}

.win-trophy {
    font-size: 4rem;
    animation: bounce 1.2s infinite;
}

.win-stars {
    font-size: 1.6rem;
    margin: 8px 0;
    color: #ffb300;
}

.win-badge {
    font-size: 1.4rem;
    font-weight: 800;
    color: #1b5e20;
    margin-bottom: 12px;
}

.win-desc {
    color: #4e342e;
    font-size: 1.05rem;
    line-height: 1.6;
}

@keyframes bounce {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-12px); }
}