/* ==========================================
   ✨ 刷题系统 2.0 · 高定现代极简主义皮肤
   ========================================== */

/* 全局基底：柔和高雅的中性色底色 */
body {
    font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", "Helvetica Neue", Arial, sans-serif;
    background: radial-gradient(circle at top center, #fdfbf7 0%, #f4f5f7 100%) !important;
    color: #1d1d1f !important; /* 苹果官网同款标志深灰，比死黑更高级 */
    margin: 0;
    padding: 40px 20px;
    display: flex;
    justify-content: center;
    align-items: flex-start;
    min-height: 100vh;
    box-sizing: border-box;
    letter-spacing: -0.01em !important;
    overflow-auto: auto !important;
}

/* 呼吸感悬浮容器 */
#home, #app {
    background: rgba(255, 255, 255, 0.85) !important;
    backdrop-filter: blur(20px); /* 朦胧的毛玻璃质感 */
    -webkit-backdrop-filter: blur(20px);
    width: 100%;
    max-width: 580px;
    padding: 40px;
    border-radius: 20px; /* 更圆润优雅的弧度 */
    border: 1px solid rgba(255, 255, 255, 0.6);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.04), 
                0 1px 8px rgba(0, 0, 0, 0.02) !important;
    box-sizing: border-box;
    transition: all 0.3s cubic-bezier(0.25, 1, 0.5, 1);
}

/* 艺术感大标题 */
h1 {
    text-align: center;
    color: #1d1d1f !important;
    font-size: 26px;
    font-weight: 700;
    letter-spacing: -0.02em;
    margin-bottom: 40px;
    background: linear-gradient(135deg, #1d1d1f 0%, #434343 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

h2 {
    font-size: 20px;
    font-weight: 600;
    color: #2c3e50 !important;
    line-height: 1.6;
    margin-bottom: 28px;
}

/* 极简高级感按钮 */
button {
    display: block;
    width: 100%;
    padding: 16px;
    margin: 18px 0;
    background: #1d1d1f !important; /* 哑光黑，沉稳且极其现代 */
    color: #ffffff !important;
    border: none !important;
    border-radius: 10px;
    font-size: 16px;
    font-weight: 500;
    cursor: pointer;
    box-shadow: 0 4px 12px rgba(0,0,0,0.05);
    transition: all 0.25s ease;
}

button:hover {
    background: #333336 !important;
    transform: translateY(-1px);
    box-shadow: 0 6px 20px rgba(0,0,0,0.1);
}

/* 莫兰迪色系随机按钮 */
#home button:nth-of-type(2) {
    background: #e2e8f0 !important; /* 灰蓝色调，沉静不突兀 */
    color: #334155 !important;
}
#home button:nth-of-type(2):hover {
    background: #cbd5e1 !important;
}

/* 顶部轻量化信息栏 */
#top {
    font-size: 13px;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: #86868b !important; /* 优雅的辅助灰 */
    padding-bottom: 16px;
    border-bottom: 1px solid #e5e5e7;
    margin-bottom: 28px;
}

/* 奢华感交互选项卡片 */
.opt {
    background-color: #ffffff !important;
    color: #1d1d1f !important;
    border: 1px solid #e5e5e7 !important; 
    border-radius: 12px;
    padding: 18px 20px;
    margin: 14px 0;
    font-size: 16px;
    font-weight: 400;
    line-height: 1.4;
    cursor: pointer;
    transition: all 0.2s cubic-bezier(0.2, 0.8, 0.2, 1);
}

/* 悬浮微动效：轻微上浮 + 柔和外阴影 */
.opt:hover {
    border-color: #1d1d1f !important;
    transform: translateY(-2px);
    box-shadow: 0 6px 16px rgba(0, 0, 0, 0.04);
}

/* 优雅克制的正确反馈：温润的低饱和度绿 */
.opt.correct {
    background: #f0fdf4 !important;
    border-color: #4ade80 !important;
    color: #166534 !important;
    font-weight: 500;
    box-shadow: 0 4px 12px rgba(74, 222, 128, 0.15) !important;
}

/* 优雅克制的错误反馈：高级低饱和粉红 */
.opt.wrong {
    background: #fef2f2 !important;
    border-color: #f87171 !important;
    color: #991b1b !important;
    font-weight: 500;
    box-shadow: 0 4px 12px rgba(248, 113, 113, 0.15) !important;
}

/* 底部轻量题号卡网格 */
#grid {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-top: 40px;
    padding-top: 24px;
    border-top: 1px solid #e5e5e7;
}

/* 几何极简题号按钮 */
.qbtn {
    width: 34px;
    height: 34px;
    background-color: transparent !important;
    color: #86868b !important;
    border: 1px solid #e5e5e7 !important;
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 13px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
}
.qbtn:hover {
    border-color: #1d1d1f !important;
    color: #1d1d1f !important;
}

/* 题号状态：莫兰迪纯色填充 */
.qbtn[style*="background: rgb(76, 175, 80)"], 
.qbtn[style*="background: #4caf50"] {
    background: #4ade80 !important;
    color: white !important;
    border-color: transparent !important;
}
.qbtn[style*="background: rgb(244, 67, 54)"], 
.qbtn[style*="background: #f44336"] {
    background: #f87171 !important;
    color: white !important;
    border-color: transparent !important;
}