/* 全局直角，无模糊 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

/* 背景：略亮的淡黄色 */
body {
    background-color: #ffffff;  /* 淡黄油色，亮而不刺眼 */
    font-family: system-ui, 'Segoe UI', 'Roboto', sans-serif;
}

/* 加载遮罩：纯色，无模糊 */
.loading-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: #DFFF4E;
    z-index: 9999;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 1rem;
}

.loading-spinner {
    width: 48px;
    height: 48px;
    border: 5px solid #E0C260;
    border-top: 5px solid #B88A00;
    animation: spin 0.7s infinite linear;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

.loading-text {
    font-size: 1.2rem;
    font-weight: 500;
    color: #8B6B00;
    background: rgba(0,0,0,0.05);
    padding: 0.4rem 1.6rem;
}

/* 主内容初始隐藏 */
.main-content {
    display: none;
}
.main-content.visible {
    display: block;
}

/* 顶部横条：纯直角，无模糊 */
.top-bar {
    background: #FFFF00;
    border-bottom: 2px solid #E6C868;
    padding: 1rem 2rem;
    position: sticky;
    top: 0;
    width: 100%;
    z-index: 5;
}

.nav-title {
    font-size: 2rem;
    font-weight: 800;
    color: #A57C00;
    letter-spacing: -0.5px;
}

/* 主卡片：正常黄色，无模糊无圆角 */
.card {
    max-width: 860px;
    margin: 2.5rem auto;
    background: #FFFF00;   /* 正常黄色，饱和适中 */
    border: 2px solid #D4B03A;
    padding: 2rem 2rem 2.8rem;
    text-align: center;
}

.welcome-line {
    font-size: 2.2rem;
    font-weight: 700;
    color: #5C4500;
    margin-bottom: 0.5rem;
}

.sub-line {
    font-size: 1rem;
    color: #8F6F00;
    border-bottom: 1px solid #D4B03A;
    display: inline-block;
    padding-bottom: 6px;
    margin-bottom: 1.8rem;
}

/* 按钮：完全直角 */
.action-btn {
    background: #2C2400;
    border: none;
    color: #FFEFB0;
    font-size: 1.8rem;
    font-weight: 600;
    padding: 0.8rem 2rem;
    width: 80%;
    max-width: 280px;
    margin: 0.5rem auto 2rem auto;
    cursor: pointer;
    transition: 0.05s linear;
    letter-spacing: 2px;
    box-shadow: 0 5px 0 #4F3D00;
}

.action-btn:active {
    transform: translateY(2px);
    box-shadow: 0 2px 0 #4F3D00;
}

/* 图片区域：完全直角，无模糊 */
.photo-area {
    background: #FFEAA0;
    min-height: 320px;
    display: flex;
    align-items: center;
    justify-content: center;
    border: 2px solid #D4B03A;
    margin-top: 1rem;
}

.photo-placeholder {
    color: #A57C00;
    font-size: 1.1rem;
    padding: 2rem;
}

.oyster-photo {
    max-width: 100%;
    max-height: 560px;
    width: auto;
    height: auto;
    object-fit: contain;
    display: block;
}

.error-msg {
    color: #AA8200;
    padding: 1.5rem;
}

/* 移动端调整 */
@media (max-width: 680px) {
    .card {
        margin: 1rem;
        padding: 1.2rem;
    }
    .welcome-line {
        font-size: 1.6rem;
    }
    .action-btn {
        font-size: 1.4rem;
        width: 90%;
    }
    .oyster-photo {
        max-height: 380px;
    }
    .nav-title {
        font-size: 1.5rem;
    }
}