:root {
    --primary: #2CB9B3;
    --secondary: #8FD6D3;
    --accent: #FFB74D;
    --bg: #E6F7F6;
    --text: #2A5E5B;
    --error: #FF5252;
    --border: #B0D8D6;
}

/* 基础重置 */
* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

/* 布局样式 */
body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
    background: var(--bg);
    color: var(--text);
    padding: 1rem;
    min-height: 100vh;
    line-height: 1.6;
}

.container {
    max-width: 500px;
    margin: 0 auto;
    animation: fadeIn 0.6s ease;
}

/* 卡片样式 */
.card {
    background: linear-gradient(135deg, #FFFFFF 0%, #F5FDFF 100%);
    border-radius: 20px;
    padding: 2rem 1.5rem;
    box-shadow: 0 8px 32px rgba(44,185,179,0.1);
    position: relative;
    overflow: hidden;
}

.card::after {
    content: '';
    position: absolute;
    bottom: -30%;
    right: -30%;
    width: 80px;
    height: 80px;
    background: var(--primary);
    opacity: 0.1;
    border-radius: 50%;
}

/* 表单元素 */
.form-group {
    margin-bottom: 1.5rem;
    position: relative;
}

label {
    display: block;
    margin-bottom: 0.8rem;
    font-weight: 500;
    font-size: 0.95rem;
    color: var(--text);
    padding-left: 0.5rem;
}

input {
    width: 100%;
    padding: 1rem;
    border: 2px solid var(--border);
    border-radius: 12px;
    font-size: 1rem;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    background: rgba(255, 255, 255, 0.9);
    color: var(--text);
}

input::placeholder {
    color: #9CBDBB;
    opacity: 0.8;
}

input:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(44,185,179,0.15);
    transform: scale(1);
    background: rgba(255, 255, 255, 1);
}

/* 按钮样式 */
button {
    background: linear-gradient(to right, var(--primary) 0%, #3AC9C3 100%);
    color: white;
    border: none;
    padding: 1.2rem;
    border-radius: 12px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    width: 100%;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    overflow: hidden;
}

button:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(44,185,179,0.3);
}

/* 错误提示 */
#error-toast {
    position: fixed;
    bottom: -50px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--error);
    color: white;
    padding: 12px 24px;
    border-radius: 25px;
    transition: bottom 0.3s;
    white-space: nowrap;
    z-index: 1000;
    font-size: 0.9rem;
}

#error-toast.show {
    bottom: 20px;
}

/* 加载动画 */
.loader {
    width: 18px;
    height: 18px;
    border: 3px solid rgba(255,255,255,0.3);
    border-radius: 50%;
    border-top-color: #fff;
    animation: spin 1s linear infinite;
    margin: 0 auto;
}

/* 进度条 */
.progress-bar {
    height: 4px;
    background: rgba(176, 216, 214, 0.3);
    border-radius: 2px;
    margin: 1.5rem 0;
    overflow: hidden;
}

.progress {
    height: 100%;
    background: var(--primary);
    transition: width 0.4s ease;
}

/* 动画 */
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* 响应式设计 */
@media (max-width: 480px) {
    .card {
        padding: 1.5rem 1rem;
        border-radius: 16px;
    }
    
    h1 {
        font-size: 1.5rem;
    }
    
    input {
        padding: 0.9rem;
        font-size: 0.95rem;
    }
    
    button {
        padding: 1rem;
        font-size: 0.95rem;
    }
    
    #error-toast {
        font-size: 0.85rem;
        padding: 10px 20px;
    }
}

@media (max-width: 360px) {
    input {
        font-size: 0.9rem;
    }
    
    label {
        font-size: 0.9rem;
    }
}