* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Times New Roman', serif;
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    position: relative;
    background: linear-gradient(135deg, #8b4513 0%, #a0522d 25%, #cd853f 50%, #daa520 75%, #f4a460 100%);
    color: #2f1b14;
    overflow: hidden;
}

/* 返回按钮 */
.back-button {
    position: fixed;
    top: 20px;
    left: 20px;
    z-index: 1000;
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 12px 20px;
    background: #8b4513;
    border: 2px solid #654321;
    border-radius: 25px;
    color: #f5deb3;
    text-decoration: none;
    font-size: 14px;
    font-weight: bold;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(139, 69, 19, 0.3);
    text-shadow: 1px 1px 2px rgba(0, 0, 0, 0.3);
}

.back-button:hover {
    background: #a0522d;
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(139, 69, 19, 0.4);
}

/* 复古背景 */
.vintage-background {
    position: fixed;
    width: 100vw;
    height: 100vh;
    top: 0;
    left: 0;
    pointer-events: none;
    z-index: 1;
}

.vintage-pattern {
    position: absolute;
    width: 100%;
    height: 100%;
    background-image: 
        radial-gradient(circle at 25% 25%, rgba(139, 69, 19, 0.1) 2px, transparent 2px),
        radial-gradient(circle at 75% 75%, rgba(160, 82, 45, 0.1) 2px, transparent 2px);
    background-size: 50px 50px;
    animation: patternMove 20s linear infinite;
}

.old-paper-texture {
    position: absolute;
    width: 100%;
    height: 100%;
    background: 
        radial-gradient(circle at 20% 80%, rgba(139, 69, 19, 0.1) 1px, transparent 1px),
        radial-gradient(circle at 80% 20%, rgba(160, 82, 45, 0.1) 1px, transparent 1px),
        radial-gradient(circle at 40% 40%, rgba(205, 133, 63, 0.05) 1px, transparent 1px);
    background-size: 30px 30px, 40px 40px, 20px 20px;
    opacity: 0.6;
}

.vintage-ornament {
    position: absolute;
    font-size: 30px;
    color: rgba(139, 69, 19, 0.3);
    animation: ornamentFloat 8s ease-in-out infinite;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.2);
}

.ornament-1 { top: 15%; left: 10%; animation-delay: 0s; }
.ornament-2 { top: 70%; right: 15%; animation-delay: 2s; }
.ornament-3 { bottom: 20%; left: 20%; animation-delay: 4s; }
.ornament-4 { top: 40%; right: 25%; animation-delay: 6s; }

.film-grain {
    position: absolute;
    width: 100%;
    height: 100%;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" width="100" height="100"><defs><filter id="noise"><feTurbulence baseFrequency="0.9" numOctaves="4" stitchTiles="stitch"/></filter></defs><rect width="100%" height="100%" filter="url(%23noise)" opacity="0.1"/></svg>');
    animation: grainMove 0.5s steps(8) infinite;
}

@keyframes patternMove {
    0% { transform: translateX(0) translateY(0); }
    100% { transform: translateX(50px) translateY(50px); }
}

@keyframes ornamentFloat {
    0%, 100% { transform: translateY(0px) rotate(0deg); opacity: 0.3; }
    50% { transform: translateY(-15px) rotate(5deg); opacity: 0.6; }
}

@keyframes grainMove {
    0%, 100% { transform: translate(0, 0); }
    10% { transform: translate(-5%, -5%); }
    30% { transform: translate(3%, -3%); }
    50% { transform: translate(-2%, 4%); }
    70% { transform: translate(4%, -2%); }
    90% { transform: translate(-3%, 3%); }
}

/* 表单容器 */
.form-container {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    z-index: 10;
    width: 100%;
    max-width: 420px;
    padding: 20px;
    transition: all 0.5s ease;
    opacity: 1;
    visibility: visible;
}

.form-container.hidden {
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
}

.vintage-card {
    background: #f5deb3;
    border: 3px solid #8b4513;
    border-radius: 15px;
    padding: 40px;
    box-shadow: 
        0 8px 32px rgba(139, 69, 19, 0.3),
        inset 0 1px 0 rgba(255, 255, 255, 0.3),
        inset 0 -1px 0 rgba(139, 69, 19, 0.2);
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
    background-image: 
        radial-gradient(circle at 10% 20%, rgba(139, 69, 19, 0.05) 1px, transparent 1px),
        radial-gradient(circle at 80% 80%, rgba(160, 82, 45, 0.05) 1px, transparent 1px);
    background-size: 20px 20px;
}

.vintage-card::before {
    content: '';
    position: absolute;
    top: 10px;
    left: 10px;
    right: 10px;
    bottom: 10px;
    border: 1px solid rgba(139, 69, 19, 0.2);
    border-radius: 10px;
    pointer-events: none;
}

.vintage-card:hover {
    transform: translateY(-3px);
    box-shadow: 
        0 12px 40px rgba(139, 69, 19, 0.4),
        inset 0 1px 0 rgba(255, 255, 255, 0.4);
}

.vintage-header {
    text-align: center;
    margin-bottom: 32px;
}

.vintage-card h2 {
    font-size: 28px;
    font-weight: bold;
    color: #8b4513;
    margin-bottom: 12px;
    text-shadow: 2px 2px 4px rgba(139, 69, 19, 0.2);
    letter-spacing: 1px;
}

.vintage-line {
    width: 80px;
    height: 2px;
    background: linear-gradient(90deg, transparent, #8b4513, transparent);
    margin: 0 auto 12px auto;
    position: relative;
}

.vintage-line::before,
.vintage-line::after {
    content: '❦';
    position: absolute;
    top: -8px;
    font-size: 16px;
    color: #8b4513;
}

.vintage-line::before { left: -20px; }
.vintage-line::after { right: -20px; }

.subtitle {
    color: #a0522d;
    font-size: 14px;
    font-weight: 500;
    font-style: italic;
}

/* 表单样式 */
.form-group {
    position: relative;
    margin-bottom: 24px;
}

.form-group input {
    width: 100%;
    padding: 16px 12px 8px 12px;
    border: none;
    background: rgba(255, 255, 255, 0.8);
    font-size: 16px;
    color: #2f1b14;
    outline: none;
    border-radius: 8px;
    transition: all 0.3s ease;
    font-family: 'Times New Roman', serif;
    border: 2px solid rgba(139, 69, 19, 0.2);
}

.form-group input:focus {
    background: rgba(255, 255, 255, 0.95);
    border-color: #8b4513;
    box-shadow: 0 0 15px rgba(139, 69, 19, 0.2);
}

.form-group label {
    position: absolute;
    top: 16px;
    left: 12px;
    color: #8b4513;
    font-size: 16px;
    pointer-events: none;
    transition: all 0.3s ease;
    font-family: 'Times New Roman', serif;
    font-weight: 500;
}

.form-group input:focus + label,
.form-group input:valid + label {
    top: 4px;
    font-size: 12px;
    color: #654321;
    font-weight: bold;
}

.vintage-underline {
    position: absolute;
    bottom: 0;
    left: 12px;
    right: 12px;
    height: 2px;
    background: linear-gradient(90deg, #8b4513, #a0522d, #8b4513);
    transform: scaleX(0);
    transition: all 0.3s ease;
    border-radius: 1px;
}

.form-group input:focus ~ .vintage-underline {
    transform: scaleX(1);
}

/* 验证码组 */
.verification-group {
    display: flex;
    align-items: flex-end;
    gap: 12px;
}

.verification-group input {
    flex: 1;
}

.verify-btn {
    padding: 10px 20px;
    background: linear-gradient(145deg, #cd853f, #b8860b);
    border: 2px solid #8b4513;
    border-radius: 8px;
    color: #2f1b14;
    font-size: 14px;
    cursor: pointer;
    transition: all 0.3s ease;
    white-space: nowrap;
    font-family: 'Times New Roman', serif;
    font-weight: bold;
    text-shadow: 1px 1px 2px rgba(255, 255, 255, 0.3);
}

.verify-btn:hover {
    background: linear-gradient(145deg, #daa520, #cd853f);
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(139, 69, 19, 0.3);
}

/* 复古按钮 */
.vintage-btn {
    width: 100%;
    padding: 16px;
    margin: 32px 0 24px 0;
    background: linear-gradient(145deg, #8b4513, #654321);
    color: #f5deb3;
    border: 2px solid #654321;
    border-radius: 10px;
    font-size: 16px;
    font-weight: bold;
    cursor: pointer;
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
    font-family: 'Times New Roman', serif;
    text-transform: uppercase;
    letter-spacing: 1px;
    text-shadow: 1px 1px 2px rgba(0, 0, 0, 0.3);
}

.vintage-btn:hover {
    background: linear-gradient(145deg, #a0522d, #8b4513);
    transform: translateY(-3px);
    box-shadow: 0 8px 25px rgba(139, 69, 19, 0.4);
}

.vintage-shadow {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, transparent, rgba(0, 0, 0, 0.2), transparent);
    transition: all 0.3s ease;
}

.vintage-btn:hover .vintage-shadow {
    height: 8px;
    background: linear-gradient(90deg, transparent, rgba(0, 0, 0, 0.3), transparent);
}

/* 附加链接 */
.additional-links {
    text-align: center;
    font-size: 14px;
}

.additional-links a {
    color: #8b4513;
    text-decoration: none;
    transition: all 0.3s ease;
    font-weight: 500;
    position: relative;
}

.additional-links a::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    width: 0;
    height: 1px;
    background: #8b4513;
    transition: all 0.3s ease;
}

.additional-links a:hover::after {
    width: 100%;
}

.additional-links a:hover {
    color: #654321;
}

.divider {
    margin: 0 12px;
    color: #a0522d;
    font-weight: bold;
}

/* 响应式设计 */
@media (max-width: 480px) {
    .form-container {
        padding: 16px;
    }
    
    .vintage-card {
        padding: 24px;
    }
    
    .vintage-card h2 {
        font-size: 24px;
    }
    
    .back-button {
        top: 16px;
        left: 16px;
        padding: 10px 16px;
        font-size: 13px;
    }
    
    .vintage-ornament {
        display: none;
    }
}

/* 加载动画 */
@keyframes vintageFadeIn {
    from {
        opacity: 0;
        transform: translateY(30px) scale(0.9);
        filter: sepia(100%);
    }
    to {
        opacity: 1;
        transform: translateY(0) scale(1);
        filter: sepia(20%);
    }
}

.vintage-card {
    animation: vintageFadeIn 1s ease-out;
    filter: sepia(20%);
}