/* CSS变量定义 */
:root {
    --bg-color: #F8F5F2;
    --card-bg: #FFFFFF;
    --primary-text: #3D2C1D;
    --secondary-text: #6B5B4B;
    --border-color: #DCDCDC;
    --focus-border: #A08C7D;
    --readonly-bg: #F8F5F2;
    --separator-color: #EAE5E1;
    --shadow-color: rgba(0, 0, 0, 0.08);
    --focus-shadow: rgba(160, 140, 125, 0.2);
}

/* 全局样式重置 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'PingFang SC', 'Source Han Sans CN', sans-serif;
    background: linear-gradient(135deg, #F8F5F2 0%, #E8E2DD 50%, #F0EBE6 100%);
    min-height: 100vh;
    line-height: 1.6;
    position: relative;
}

/* 背景装饰 */
body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image: 
        radial-gradient(circle at 20% 80%, rgba(160, 140, 125, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 80% 20%, rgba(61, 44, 29, 0.05) 0%, transparent 50%);
    pointer-events: none;
    z-index: -1;
}

/* 主容器 - 使用Flexbox居中 */
.container {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    padding: 10px;
}

/* 计算器卡片 */
.calculator-card {
    background: linear-gradient(145deg, #FFFFFF 0%, #FEFEFE 100%);
    padding: 25px 35px;
    border-radius: 16px;
    box-shadow: 
        0 10px 40px rgba(0, 0, 0, 0.1),
        0 2px 8px rgba(0, 0, 0, 0.05),
        inset 0 1px 0 rgba(255, 255, 255, 0.8);
    width: 100%;
    max-width: 520px;
    border: 1px solid rgba(255, 255, 255, 0.2);
    backdrop-filter: blur(10px);
}

/* 品牌标识区域 */
.brand-section {
    text-align: center;
    margin-bottom: 25px;
    padding-bottom: 20px;
    border-bottom: 2px solid var(--separator-color);
    display: flex;
    flex-direction: column;
    align-items: center;
}

/* Logo样式 */
.logo {
    width: 52px;
    height: 52px;
    object-fit: contain;
    margin-bottom: 12px;
    border-radius: 6px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    display: block;
}

/* 主标题 */
h1 {
    font-size: 22px;
    color: var(--primary-text);
    text-align: center;
    margin-bottom: 20px;
    font-weight: 600;
}

/* 输入和输出区域 */
.input-section,
.output-section {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

/* 输入组和输出组 */
.input-group,
.output-group {
    display: flex;
    align-items: center;
    gap: 15px;
}

/* 标签样式 */
label {
    font-size: 15px;
    color: var(--secondary-text);
    flex-basis: 120px;
    flex-shrink: 0;
    font-weight: 500;
}

/* 输入框和输出框基础样式 */
input {
    flex: 1;
    padding: 12px 16px;
    border: 2px solid var(--border-color);
    border-radius: 10px;
    font-size: 16px;
    color: var(--primary-text);
    font-family: inherit;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    background: linear-gradient(145deg, #FFFFFF 0%, #FAFAFA 100%);
    box-shadow: inset 0 1px 3px rgba(0, 0, 0, 0.05);
    position: relative;
    outline: none;
}

/* 输入框焦点效果 */
input[type="number"]:focus {
    border-color: var(--focus-border);
    box-shadow: 
        0 0 0 3px var(--focus-shadow),
        0 4px 12px rgba(160, 140, 125, 0.15);
    transform: translateY(-1px);
    background: linear-gradient(145deg, #FFFFFF 0%, #FFFFFF 100%);
}

/* 输入框悬停效果 */
input[type="number"]:hover:not(:focus) {
    border-color: rgba(160, 140, 125, 0.4);
    box-shadow: inset 0 1px 3px rgba(0, 0, 0, 0.08);
}

/* 只读输出框样式 */
input[readonly] {
    background: linear-gradient(145deg, #F8F5F2 0%, #F0EBE6 100%);
    font-weight: 600;
    border: 2px solid rgba(160, 140, 125, 0.2);
    cursor: default;
    color: var(--focus-border);
    box-shadow: 
        inset 0 2px 4px rgba(0, 0, 0, 0.05),
        0 1px 2px rgba(0, 0, 0, 0.1);
}

/* 结果更新动画类 */
.result-update {
    opacity: 0;
    transform: translateY(5px);
}

.result-show {
    opacity: 1;
    transform: translateY(0);
    transition: all 0.4s ease-out;
}

/* 分隔线 */
hr {
    border: none;
    height: 2px;
    background: linear-gradient(90deg, transparent 0%, var(--separator-color) 20%, var(--focus-border) 50%, var(--separator-color) 80%, transparent 100%);
    margin: 20px 0;
    border-radius: 1px;
}

/* 卡片进入动画 */
.calculator-card {
    animation: cardSlideIn 0.6s cubic-bezier(0.4, 0, 0.2, 1) forwards;
}

@keyframes cardSlideIn {
    from {
        opacity: 0;
        transform: translateY(30px) scale(0.95);
    }
    to {
        opacity: 1;
        transform: translateY(0) scale(1);
    }
}

/* 响应式设计 - 移动端适配 */
@media (max-width: 600px) {
    .container {
        padding: 8px;
        align-items: flex-start;
        padding-top: 15px;
    }
    
    .calculator-card {
        padding: 20px;
        margin: 10px;
    }
    
    .brand-section {
        margin-bottom: 20px;
        padding-bottom: 15px;
    }
    
    .logo {
        width: 42px;
        height: 42px;
        margin-bottom: 10px;
    }
    
    h1 {
        font-size: 18px;
        margin-bottom: 0;
        line-height: 1.4;
    }
    
    .input-section,
    .output-section {
        gap: 12px;
    }
    
    .input-group,
    .output-group {
        flex-direction: column;
        align-items: stretch;
        gap: 6px;
    }
    
    label {
        flex-basis: auto;
        margin-bottom: 6px;
        font-size: 14px;
    }
    
    input {
        width: 100%;
        padding: 8px 10px;
        font-size: 16px;
    }
    
    hr {
        margin: 12px 0;
    }
}

/* 输入框占位符样式 */
input::placeholder {
    color: #999;
    opacity: 0.7;
}

/* 移除数字输入框的默认箭头 (Webkit) */
input[type="number"]::-webkit-outer-spin-button,
input[type="number"]::-webkit-inner-spin-button {
    -webkit-appearance: none;
    margin: 0;
}

/* 移除数字输入框的默认箭头 (Firefox) */
input[type="number"] {
    -moz-appearance: textfield;
}

/* 确保在小屏幕上的可读性 */
@media (max-width: 480px) {
    .container {
        padding: 5px;
        padding-top: 10px;
    }
    
    .calculator-card {
        padding: 15px;
    }
    
    h1 {
        font-size: 18px;
        margin-bottom: 12px;
    }
    
    .input-section,
    .output-section {
        gap: 10px;
    }
    
    input {
        font-size: 16px; /* 防止iOS缩放 */
        padding: 8px 10px;
    }
    
    label {
        font-size: 13px;
    }
    
    hr {
        margin: 10px 0;
    }
}