/* ========== 移动端 · 便签翻页体验 ========== */
.container {
    padding: 20px 16px;
    max-width: 100%;
}

/* 登录页特殊 */
#loginSection {
    max-width: 360px;
    margin: 30px auto;
}

/* 卡片容器 — 翻页动画关键 */
#questionsContainer {
    position: relative;
    min-height: 380px;
    margin: 20px 0 10px;
    perspective: 1200px;  /* 为3D效果准备 */
}

.question-page {
    background: rgba(253, 250, 240, 0.7);
    backdrop-filter: blur(4px);
    padding: 24px 20px;
    border-radius: 32px;
    box-shadow: var(--shadow-paper), 0 8px 20px -8px rgba(0,0,0,0.08);
    border: 1px solid rgba(230, 223, 211, 0.4);
    transition: transform 0.25s cubic-bezier(0.2, 0.9, 0.4, 1), opacity 0.2s;
    will-change: transform, opacity;
}

/* 翻页动画状态 */
.question-page.page-entering {
    animation: slideIn 0.25s ease-out;
}
.question-page.page-leaving {
    animation: slideOut 0.2s ease-in forwards;
}

@keyframes slideIn {
    0% { opacity: 0; transform: translateX(30px); }
    100% { opacity: 1; transform: translateX(0); }
}
@keyframes slideOut {
    0% { opacity: 1; transform: translateX(0); }
    100% { opacity: 0; transform: translateX(-30px); }
}

/* 如果想用3D翻页，可替换为：
@keyframes flipIn {
    0% { opacity:0; transform: rotateY(-90deg); }
    100% { opacity:1; transform: rotateY(0); }
}
@keyframes flipOut {
    0% { opacity:1; transform: rotateY(0); }
    100% { opacity:0; transform: rotateY(90deg); }
}
*/

/* 题目标题手写体 */
.question-title {
    font-family: var(--font-handwrite);
    font-size: 1.9rem;
    font-weight: 500;
    margin: 16px 0 24px;
    line-height: 1.3;
}

/* 导航按钮 */
.pagination {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin: 24px 0 16px;
}
.nav-btn, #submitBtn {
    background: transparent;
    border: 1.8px dashed var(--accent-soft);
    color: var(--ink-color);
    padding: 14px 24px;
    border-radius: 40px;
    font-weight: 500;
    font-size: 1.1rem;
    backdrop-filter: blur(4px);
    box-shadow: none;
    transition: all 0.15s;
}
.nav-btn:active, #submitBtn:active {
    background: var(--accent-soft);
    transform: translateY(2px);
    border-style: solid;
}
.nav-btn:disabled {
    opacity: 0.4;
    border-color: var(--border-light);
}
.page-info {
    font-family: var(--font-handwrite);
    font-size: 1.3rem;
}

/* 提交按钮 */
#submitBtn {
    background: var(--accent-color);
    border: none;
    color: white;
    width: 100%;
    margin-top: 10px;
}
#submitBtn:active {
    background: #b05a4e;
}

/* 进度指示器文字 */
.progress-text {
    font-size: 0.85rem;
    color: var(--ink-color);
    opacity: 0.7;
}

/* 必填/选填标记 */
.required-badge {
    background: #FCE4E0;
    color: #C46B5E;
    padding: 4px 12px;
    border-radius: 30px;
    font-size: 0.75rem;
}
.optional-badge {
    background: var(--border-light);
    color: #5E5A55;
    padding: 4px 12px;
    border-radius: 30px;
    font-size: 0.75rem;
}

/* 邀请码输入框大写 */
#inviteCode {
    text-transform: uppercase;
    font-family: monospace;
    letter-spacing: 4px;
    text-align: center;
    font-size: 1.4rem;
}