/* ====== 基础样式 ====== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Inter', 'Roboto', 'Open Sans', system-ui, sans-serif;
}

:root {
    --primary: #bf1c3f;
    --primary-hover: #a00707;
    --primary-light: rgba(191, 28, 63, 0.1);
    --secondary: #f9fafb;
    --text-primary: #1f2937;
    --text-secondary: #6b7280;
    --text-muted: #9ca3af;
    --border: #e5e7eb;
    --border-focus: #bf1c3f;
    --bg-page: linear-gradient(135deg, #f8fafc 0%, #e2e8f0 100%);
    --bg-card: #ffffff;
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 20px rgba(0, 0, 0, 0.15);
    --danger: #e53935;
    --danger-hover: #c62828;
    --success: #10b981;
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --transition: all 0.3s ease;
}
/* ====== end 基础样式 ====== */


/* ====== 页面布局 ====== */
body {
    background: var(--bg-page);
    min-height: 100vh;
    padding: 40px 20px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    color: var(--text-primary);
    line-height: 1.6;
}

.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
}

.row {
    display: flex;
    flex-wrap: wrap;
    margin: 0 -15px;
}

.justify-content-center {
    justify-content: center;
}

.col-md-6 {
    width: 100%;
    max-width: 480px;
    padding: 0 15px;
}

.mt-5 {
    margin-top: 3rem;
}

.mb-0 {
    margin-bottom: 0 !important;
}

.mb-3 {
    margin-bottom: 1rem;
}

.text-center {
    text-align: center;
}
/* ====== end 页面布局 ====== */


/* ====== 卡片样式 ====== */
.card {
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    border: none;
    overflow: hidden;
    transition: var(--transition);
    border-top: 4px solid var(--primary);
}

.card:hover {
    box-shadow: var(--shadow-lg);
}

.card-header {
    background: transparent;
    border-bottom: 1px solid var(--border);
    padding: 24px 30px 20px;
}

.card-header h3 {
    font-size: 1.75rem;
    font-weight: 600;
    color: var(--text-primary);
    text-align: center;
}

.card-body {
    padding: 30px;
}
/* ====== end 卡片样式 ====== */


/* ====== 表单样式 ====== */
form {
    width: 100%;
}

.form-label {
    display: block;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-primary);
    margin-bottom: 8px;
}

.form-label .text-danger {
    color: var(--danger);
    margin-left: 2px;
}

/* 输入框基础样式 - 覆盖 Django 默认渲染 */
input[type="text"],
input[type="email"],
input[type="password"],
input[type="number"],
input[type="tel"],
textarea,
select {
    width: 100%;
    padding: 12px 16px;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    font-size: 0.9375rem;
    color: var(--text-primary);
    background-color: #fff;
    transition: var(--transition);
    outline: none;
}

input[type="text"]:focus,
input[type="email"]:focus,
input[type="password"]:focus,
input[type="number"]:focus,
input[type="tel"]:focus,
textarea:focus,
select:focus {
    border-color: var(--border-focus);
    box-shadow: 0 0 0 3px rgba(191, 28, 63, 0.1);
}

input::placeholder {
    color: var(--text-muted);
}

/* 错误状态 */
input.is-invalid,
input:invalid:not(:placeholder-shown) {
    border-color: var(--danger);
}

.text-danger.small {
    font-size: 0.8125rem;
    color: var(--danger);
    margin-top: 6px;
    display: flex;
    align-items: center;
    gap: 4px;
}

.text-danger.small::before {
    content: "⚠";
    font-size: 0.75rem;
}

/* 帮助文本 */
.form-text {
    font-size: 0.8125rem;
    color: var(--text-secondary);
    margin-top: 6px;
    line-height: 1.5;
}
/* ====== end 表单样式 ====== */


/* ====== 按钮样式 ====== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 12px 24px;
    font-size: 1rem;
    font-weight: 500;
    line-height: 1.5;
    text-align: center;
    text-decoration: none;
    vertical-align: middle;
    cursor: pointer;
    border: none;
    border-radius: var(--radius-sm);
    transition: var(--transition);
    outline: none;
}

.btn-primary {
    background-color: var(--primary);
    color: white;
}

.btn-primary:hover {
    background-color: var(--primary-hover);
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(191, 28, 63, 0.3);
}

.btn-primary:active {
    transform: translateY(0);
}

.w-100 {
    width: 100%;
    margin-top: 10px;
}
/* ====== end 按钮样式 ====== */


/* ====== 警告提示 ====== */
.alert {
    padding: 12px 16px;
    margin-bottom: 20px;
    border: 1px solid transparent;
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
}

.alert-danger {
    background-color: rgba(229, 57, 53, 0.08);
    border-color: rgba(229, 57, 53, 0.2);
    color: var(--danger);
}

.alert-danger strong {
    font-weight: 600;
}
/* ====== end 警告提示 ====== */


/* ====== 分割线 & 链接 ====== */
hr {
    margin: 24px 0;
    border: 0;
    border-top: 1px solid var(--border);
}

.card-body > p {
    font-size: 0.9375rem;
    color: var(--text-secondary);
}

.card-body > p a {
    color: var(--primary);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
    position: relative;
}

.card-body > p a::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--primary);
    transition: width 0.3s ease;
}

.card-body > p a:hover {
    color: var(--primary-hover);
}

.card-body > p a:hover::after {
    width: 100%;
}
/* ====== end 分割线 & 链接 ====== */


/* ====== 响应式设计 ====== */
@media (max-width: 576px) {
    body {
        padding: 20px 15px;
    }
    
    .card-header {
        padding: 20px 20px 16px;
    }
    
    .card-header h3 {
        font-size: 1.5rem;
    }
    
    .card-body {
        padding: 20px;
    }
    
    .btn {
        padding: 14px 24px;
        font-size: 1rem;
    }
}

@media (max-width: 375px) {
    .card-header h3 {
        font-size: 1.25rem;
    }
}
/* ====== end 响应式设计 ====== */


/* ====== 动画效果 ====== */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.card {
    animation: fadeIn 0.5s ease-out;
}

.alert {
    animation: fadeIn 0.3s ease-out;
}
/* ====== end 动画效果 ====== */