:root {
    --bg: #f7f8fa;
    --card: #ffffff;
    --text: #1f2937;
    --muted: #6b7280;
    --border: #e5e7eb;
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --secondary: #64748b;
    --success: #10b981;
    --error: #ef4444;
}

* { box-sizing: border-box; }

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
    margin: 0;
    padding: 0;
}

.container {
    max-width: 720px;
    margin: 0 auto;
    padding: 24px;
}

.app-header {
    background: linear-gradient(135deg, #1e3a8a 0%, #2563eb 100%);
    color: #fff;
    padding: 20px 0;
    box-shadow: 0 4px 12px rgba(37, 99, 235, 0.15);
}

.app-header h1 {
    margin: 0;
    font-size: 22px;
}

.app-header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 12px;
}

.app-header .header-right {
    display: flex;
    align-items: center;
    gap: 16px;
}

.app-header nav a {
    color: rgba(255,255,255,0.9);
    text-decoration: none;
    margin-left: 20px;
    font-size: 14px;
}

.app-header nav a:hover {
    color: #fff;
    text-decoration: underline;
}

.lang-selector {
    width: auto;
    padding: 6px 10px;
    font-size: 14px;
    border: 1px solid rgba(255,255,255,0.5);
    background: rgba(255,255,255,0.15);
    color: #fff;
    border-radius: 8px;
    cursor: pointer;
}

.lang-selector option {
    color: #1f2937;
}

.card {
    background: var(--card);
    border-radius: 12px;
    padding: 28px;
    margin-top: 24px;
    box-shadow: 0 1px 3px rgba(0,0,0,0.06);
    border: 1px solid var(--border);
}

.form-card {
    max-width: 480px;
    margin-left: auto;
    margin-right: auto;
}

h2 {
    margin: 0 0 20px;
    font-size: 20px;
}

label {
    display: block;
    margin: 16px 0 6px;
    font-size: 14px;
    color: var(--text);
}

input, select {
    width: 100%;
    padding: 10px 12px;
    border: 1px solid var(--border);
    border-radius: 8px;
    font-size: 15px;
    background: #fff;
}

input:disabled {
    background: #f3f4f6;
    color: var(--muted);
}

input:focus, select:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.btn {
    display: inline-block;
    padding: 10px 20px;
    border: none;
    border-radius: 8px;
    font-size: 15px;
    cursor: pointer;
    text-decoration: none;
    margin-top: 20px;
    margin-right: 10px;
}

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

.btn-primary:hover {
    background: var(--primary-dark);
}

.btn-secondary {
    background: var(--secondary);
    color: #fff;
}

.btn-secondary:hover {
    background: #475569;
}

.actions {
    margin-top: 24px;
}

.message {
    margin-top: 16px;
    padding: 12px;
    border-radius: 8px;
    font-size: 14px;
    display: none;
}

.message.success {
    display: block;
    background: #d1fae5;
    color: #065f46;
    border: 1px solid #a7f3d0;
}

.message.error {
    display: block;
    background: #fee2e2;
    color: #991b1b;
    border: 1px solid #fecaca;
}

.muted {
    color: var(--muted);
    font-size: 14px;
    margin-top: 16px;
}

.muted a {
    color: var(--primary);
    text-decoration: none;
}

hr {
    border: none;
    border-top: 1px solid var(--border);
    margin: 24px 0;
}