/* css/style.css - V2601R2 Visual Upgrade */

/* --- 1. 全局设置 --- */
body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background-color: #F1F5F9; /* 浅灰底色 */
    color: #1E293B;
    -webkit-tap-highlight-color: transparent;
    overflow: hidden; /* 防止背景滚动 */
    /* 确保 PC 端居中 */
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    min-height: 100dvh;
    margin: 0;
}

/* --- 2. 呼吸光晕背景 (Mesh Gradient) --- */
body::before {
    content: '';
    position: fixed;
    top: -20%;
    left: -20%;
    width: 140%;
    height: 140%;
    /* 蓝色和橙色的弥散光斑 */
    background: 
        radial-gradient(circle at 20% 30%, rgba(37, 99, 235, 0.15) 0%, transparent 50%),
        radial-gradient(circle at 80% 80%, rgba(249, 115, 22, 0.1) 0%, transparent 50%);
    z-index: -1;
    animation: breathe 8s ease-in-out infinite alternate;
    pointer-events: none;
}

@keyframes breathe {
    0% { transform: scale(1); opacity: 0.8; }
    100% { transform: scale(1.05); opacity: 1; }
}

/* --- 3. App Shell (手机容器) --- */
#app-root {
    width: 100%;
    max-width: 28rem; /* 448px (PC端限制宽度) */
    height: 100vh;
    height: 100dvh;
    background-color: rgba(248, 250, 252, 0.8); /* 半透明背景 */
    position: relative;
    overflow: hidden;
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.25); /* PC端深投影 */
    display: flex;
    flex-direction: column;
}

/* --- 4. 高级卡片样式 (Glassmorphism) --- */
.card-glass {
    background: rgba(255, 255, 255, 0.85);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid rgba(255, 255, 255, 0.5); /* 极细白边 */
    box-shadow: 
        0 4px 6px -1px rgba(0, 0, 0, 0.05), 
        0 2px 4px -1px rgba(0, 0, 0, 0.03);
    transition: transform 0.1s ease, box-shadow 0.1s ease;
}

.card-glass:active {
    transform: scale(0.98);
}

/* --- 5. 矢量背景类 (用于头图) --- */
/* 蓝色主题 (EPA/Home) */
.bg-vector-blue {
    background: linear-gradient(135deg, #2563EB 0%, #1E40AF 100%);
    position: relative;
    overflow: hidden;
}
.bg-vector-blue::after {
    content: '';
    position: absolute;
    top: -50px; right: -50px;
    width: 200px; height: 200px;
    background: rgba(255,255,255,0.1);
    border-radius: 50%;
    filter: blur(40px);
}

/* 深色主题 (Exams) */
.bg-vector-dark {
    background: linear-gradient(135deg, #0F172A 0%, #1E293B 100%);
    position: relative;
    overflow: hidden;
}
.bg-vector-dark::before {
    content: '';
    position: absolute;
    bottom: -20px; left: -20px;
    width: 150px; height: 150px;
    background: rgba(249, 115, 22, 0.15); /* 橙色光 */
    border-radius: 50%;
    filter: blur(30px);
}

/* --- 6. 通用工具 --- */
.no-scrollbar::-webkit-scrollbar { display: none; }
.no-scrollbar { -ms-overflow-style: none; scrollbar-width: none; }

.safe-pb {
    padding-bottom: 20px;
    padding-bottom: env(safe-area-inset-bottom);
}
.fixed-bottom-safe {
    padding-bottom: env(safe-area-inset-bottom);
    bottom: 0;
}

.page-hidden { display: none; }
.page-visible { 
    display: flex; flex-direction: column; height: 100%; 
    animation: fadeUp 0.3s cubic-bezier(0.16, 1, 0.3, 1); 
    overflow-y: auto; 
}
@keyframes fadeUp {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

.nav-active { color: #2563EB; font-weight: 600; }
.nav-active i { transform: translateY(-3px); filter: drop-shadow(0 4px 6px rgba(37, 99, 235, 0.2)); }