* { margin: 0; padding: 0; box-sizing: border-box; }
body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: #0a0a0a;
    min-height: 100vh;
    display: flex;
    align-items: flex-start;
    justify-content: center;
    position: relative;
}
.bg-grid {
    position: fixed;
    top: 0; left: 0;
    width: 100%; height: 100%;
    background-image:
        linear-gradient(rgba(255,255,255,0.03) 1px, transparent 1px),
        linear-gradient(90deg, rgba(255,255,255,0.03) 1px, transparent 1px);
    background-size: 50px 50px;
    pointer-events: none;
}
.glow {
    position: fixed;
    width: 600px; height: 600px;
    border-radius: 50%;
    filter: blur(100px);
    opacity: 0.4;
    pointer-events: none;
}
.glow-1 { background: radial-gradient(circle, #00ff88 0%, transparent 70%); top: -200px; right: -200px; }
.glow-2 { background: radial-gradient(circle, #00d4ff 0%, transparent 70%); bottom: -200px; left: -200px; }
.glow-3 { background: radial-gradient(circle, #ff00ff 0%, transparent 70%); top: 50%; left: 50%; transform: translate(-50%, -50%); }

.register-wrapper {
    position: relative;
    display: flex;
    align-items: center;
    flex-direction: column;
}

.top-nav {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    min-height: 56px;
    background: linear-gradient(180deg, rgba(10,10,10,0.98) 0%, rgba(20,20,20,0.95) 100%);
    backdrop-filter: blur(20px);
    display: flex;
    align-items: center;
    padding: 0 24px;
    gap: 24px;
    z-index: 1000;
    box-sizing: border-box;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 8px;
    color: #fff;
    text-decoration: none;
    font-size: 18px;
    font-weight: 700;
    white-space: nowrap;
    margin-right: auto;
}
.nav-logo-icon {
    font-size: 22px;
}

/* 默认流水灯背景 - 流动光点 */
.top-nav::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 300%;
    height: 100%;
    background:
        radial-gradient(circle at 20% 50%, rgba(0,255,136,0.6) 0%, transparent 25%),
        radial-gradient(circle at 40% 50%, rgba(0,212,255,0.6) 0%, transparent 25%),
        radial-gradient(circle at 60% 50%, rgba(168,85,247,0.6) 0%, transparent 25%),
        radial-gradient(circle at 80% 50%, rgba(0,255,136,0.6) 0%, transparent 25%);
    animation: flowLights 4s linear infinite;
    opacity: 0.4;
    pointer-events: none;
}

@keyframes flowLights {
    0% { transform: translateX(0); }
    100% { transform: translateX(33.33%); }
}

/* 底部流动边框线 */
.top-nav::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 2px;
    background: linear-gradient(90deg,
        #00ff88, #00d4ff, #a855f7, #00d4ff, #00ff88,
        #00ff88, #00d4ff, #a855f7, #00d4ff, #00ff88);
    background-size: 200% 100%;
    animation: borderFlow 2s linear infinite;
    box-shadow: 0 0 10px rgba(0,255,136,0.8), 0 0 20px rgba(0,212,255,0.6);
}

@keyframes borderFlow {
    0% { background-position: 0% 50%; }
    100% { background-position: 200% 50%; }
}

.nav-item {
    position: relative;
    color: rgba(255,255,255,0.9);
    text-decoration: none;
    font-size: 14px;
    font-weight: 600;
    padding: 10px 24px;
    border-radius: 30px;
    transition: all 0.3s ease;
    text-transform: uppercase;
    letter-spacing: 1px;
    background: rgba(0,0,0,0.3);
    border: 1px solid rgba(255,255,255,0.15);
    white-space: nowrap;
    z-index: 1;
}

/* 默认随机颜色发光 - 始终显示霓虹效果 */
.nav-item:nth-child(1) { box-shadow: 0 0 15px rgba(0,255,136,0.4), inset 0 0 10px rgba(0,255,136,0.15); border-color: rgba(0,255,136,0.3); }
.nav-item:nth-child(2) { box-shadow: 0 0 15px rgba(0,212,255,0.4), inset 0 0 10px rgba(0,212,255,0.15); border-color: rgba(0,212,255,0.3); }
.nav-item:nth-child(3) { box-shadow: 0 0 15px rgba(168,85,247,0.4), inset 0 0 10px rgba(168,85,247,0.15); border-color: rgba(168,85,247,0.3); }

/* 移动端默认霓虹灯更强 */
@media (max-width: 768px) {
    .nav-item:nth-child(1) { box-shadow: 0 0 18px rgba(0,255,136,0.5), inset 0 0 12px rgba(0,255,136,0.2); }
    .nav-item:nth-child(2) { box-shadow: 0 0 18px rgba(0,212,255,0.5), inset 0 0 12px rgba(0,212,255,0.2); }
    .nav-item:nth-child(3) { box-shadow: 0 0 18px rgba(168,85,247,0.5), inset 0 0 12px rgba(168,85,247,0.2); }
}

/* 悬停时随机颜色变化动画 */
.nav-item:hover {
    color: #fff;
    transform: translateY(-2px) scale(1.05);
    animation: randomGlow 0.5s ease infinite alternate;
}

@keyframes randomGlow {
    0% {
        box-shadow: 0 0 20px rgba(0,255,136,0.8), 0 0 40px rgba(0,255,136,0.4), inset 0 0 15px rgba(0,255,136,0.2);
        border-color: rgba(0,255,136,0.6);
        text-shadow: 0 0 10px rgba(0,255,136,0.8);
    }
    25% {
        box-shadow: 0 0 20px rgba(0,212,255,0.8), 0 0 40px rgba(0,212,255,0.4), inset 0 0 15px rgba(0,212,255,0.2);
        border-color: rgba(0,212,255,0.6);
        text-shadow: 0 0 10px rgba(0,212,255,0.8);
    }
    50% {
        box-shadow: 0 0 20px rgba(168,85,247,0.8), 0 0 40px rgba(168,85,247,0.4), inset 0 0 15px rgba(168,85,247,0.2);
        border-color: rgba(168,85,247,0.6);
        text-shadow: 0 0 10px rgba(168,85,247,0.8);
    }
    75% {
        box-shadow: 0 0 20px rgba(255,0,136,0.8), 0 0 40px rgba(255,0,136,0.4), inset 0 0 15px rgba(255,0,136,0.2);
        border-color: rgba(255,0,136,0.6);
        text-shadow: 0 0 10px rgba(255,0,136,0.8);
    }
    100% {
        box-shadow: 0 0 20px rgba(0,200,255,0.8), 0 0 40px rgba(0,200,255,0.4), inset 0 0 15px rgba(0,200,255,0.2);
        border-color: rgba(0,200,255,0.6);
        text-shadow: 0 0 10px rgba(0,200,255,0.8);
    }
}

/* 底部下划线 */
.nav-item::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 50%;
    transform: translateX(-50%) scaleX(0);
    width: 60%;
    height: 2px;
    background: linear-gradient(90deg, transparent, #00ff88, transparent);
    transition: transform 0.3s ease;
}

.nav-item:hover::after {
    transform: translateX(-50%) scaleX(1);
    animation: lineColorChange 0.5s ease infinite alternate;
}

@keyframes lineColorChange {
    0% { background: linear-gradient(90deg, transparent, #00ff88, transparent); }
    33% { background: linear-gradient(90deg, transparent, #00d4ff, transparent); }
    66% { background: linear-gradient(90deg, transparent, #a855f7, transparent); }
    100% { background: linear-gradient(90deg, transparent, #00ffaa, transparent); }
}

/* 移动端适配 */
@media (max-width: 768px) {
    body {
        align-items: flex-start;
        padding-top: 10px;
        min-height: auto;
        height: auto;
        overflow-y: auto;
        overflow-x: hidden;
    }

    .top-nav {
        height: auto;
        min-height: 50px;
        padding: 0 12px;
        flex-wrap: nowrap;
        gap: 12px;
        width: 100%;
        box-sizing: border-box;
        position: fixed;
    }

    .nav-logo { font-size: 15px; }
    .nav-logo-icon { font-size: 18px; }

    .nav-item {
        font-size: 12px;
        padding: 8px 14px;
        letter-spacing: 0.3px;
        flex: 0 0 auto;
    }

    .register-wrapper {
        width: 100%;
        padding: 0 5px;
        box-sizing: border-box;
        align-items: flex-start;
        padding-top: 66px;
    }

    .register-container {
        width: 94%;
        max-width: none;
        padding: 2px;
        box-sizing: border-box;
        margin-top: 0;
        margin-left: auto;
        margin-right: auto;
        display: block;
    }

    .register-box {
        padding: 25px 18px;
        width: 100% !important;
        max-width: 100%;
        border-radius: 20px;
        box-sizing: border-box;
    }

    .mascot-cat {
        display: none;
    }

    .glow {
        width: 150px;
        height: 150px;
        filter: blur(30px);
        opacity: 0.15;
    }

    .btn-register {
        padding: 14px;
        font-size: 15px;
    }

    .form-group {
        margin-bottom: 14px;
    }

    .form-group input, .form-group select {
        padding: 12px 14px;
        font-size: 14px;
    }

    .logo {
        margin-bottom: 25px;
    }

    .logo-icon {
        width: 60px;
        height: 60px;
        font-size: 28px;
    }
}

@media (max-width: 480px) {
    .top-nav {
        padding: 8px 6px;
        gap: 10px;
        min-height: 50px;
    }

    .nav-item {
        font-size: 11px;
        padding: 8px 12px;
        letter-spacing: 0.2px;
    }

    .register-wrapper {
        padding-top: 56px;
    }

    .register-container {
        width: 96%;
        padding: 2px;
    }

    .register-box {
        padding: 20px 15px;
    }

    .logo h1 {
        font-size: 20px;
    }

    .logo p {
        font-size: 12px;
    }

    .btn-register {
        padding: 12px;
        font-size: 14px;
    }

    .divider {
        margin: 12px 0;
    }

    .links a {
        font-size: 12px;
    }

    .links {
        margin-top: 15px;
    }

    .two-col {
        gap: 10px;
    }
}

@media (max-width: 360px) {
    .register-container {
        width: 98%;
        padding: 2px;
    }

    .register-box {
        padding: 18px 12px;
    }

    .nav-item {
        padding: 6px 10px;
        font-size: 10px;
    }

    .two-col {
        grid-template-columns: 1fr;
        gap: 8px;
    }
}

.register-container {
    position: relative;
    padding: 3px;
    border-radius: 24px;
    background: conic-gradient(from 0deg at 50% 50%, #00ff88 0deg, #00d4ff 90deg, #a855f7 180deg, #00d4ff 270deg, #00ff88 360deg);
    animation: borderRotate 4s linear infinite;
    box-shadow: 0 0 60px rgba(0,212,255,0.3);
    margin-top: 80px;
    box-sizing: border-box;
}
@keyframes borderRotate { 0% { filter: hue-rotate(0deg); } 100% { filter: hue-rotate(360deg); } }

.register-box {
    background: rgba(20,20,20,0.98);
    backdrop-filter: blur(20px);
    border-radius: 22px;
    padding: 40px 35px;
    width: 450px;
    position: relative;
    z-index: 1;
    box-sizing: border-box;
}
.register-box::before {
    content: '';
    position: absolute;
    top: 0; left: 0; right: 0;
    height: 1px;
    background: linear-gradient(90deg, transparent, rgba(0,212,255,0.3), transparent);
}
.logo { text-align: center; margin-bottom: 18px; }
.logo-icon {
    width: 70px; height: 70px;
    background: linear-gradient(135deg, #00ff88 0%, #00d4ff 100%);
    border-radius: 18px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 15px;
    font-size: 32px;
    box-shadow: 0 10px 40px rgba(0,255,136,0.3);
}
.logo h1 { color: #fff; font-size: 26px; font-weight: 700; }
.logo p { color: rgba(255,255,255,0.5); font-size: 13px; margin-top: 6px; }

.form-group { margin-bottom: 18px; position: relative; }
.form-group label {
    display: block;
    color: rgba(255,255,255,0.7);
    font-size: 12px;
    margin-bottom: 8px;
    text-transform: uppercase;
    letter-spacing: 1px;
}
.form-group label span { color: #00d4ff; }
.input-wrap { position: relative; }
.form-group input, .form-group select {
    width: 100%;
    padding: 14px 16px;
    background: rgba(0,0,0,0.3);
    border: 1px solid rgba(255,255,255,0.1);
    border-radius: 10px;
    color: #fff;
    font-size: 14px;
    transition: all 0.3s;
}
.form-group input:focus, .form-group select:focus {
    outline: none;
    border-color: #00d4ff;
    background: rgba(0,0,0,0.5);
    box-shadow: 0 0 15px rgba(0,212,255,0.2);
}
.form-group input::placeholder { color: rgba(255,255,255,0.3); }
.btn-register {
    width: 100%;
    padding: 16px;
    background: linear-gradient(135deg, #00ff88 0%, #00d4ff 100%);
    border: none;
    border-radius: 10px;
    color: #000;
    font-size: 16px;
    font-weight: 700;
    cursor: pointer;
    transition: all 0.3s;
    margin-top: 8px;
    text-transform: uppercase;
    letter-spacing: 2px;
}
.btn-register:hover { transform: translateY(-2px); box-shadow: 0 10px 30px rgba(0,212,255,0.4); }
.alert { padding: 12px; border-radius: 8px; margin-bottom: 15px; font-size: 13px; text-align: center; }
.alert-success { background: rgba(0,255,136,0.1); border: 1px solid rgba(0,255,136,0.3); color: #00ff88; }
.alert-error { background: rgba(255,0,100,0.1); border: 1px solid rgba(255,0,100,0.3); color: #ff5090; }
.links { text-align: center; margin-top: 20px; }
.links a { color: rgba(255,255,255,0.5); text-decoration: none; font-size: 13px; transition: color 0.3s; }
.links a:hover { color: #00d4ff; }
.divider { display: flex; align-items: center; margin: 20px 0; color: rgba(255,255,255,0.3); font-size: 12px; }
.divider::before, .divider::after { content: ''; flex: 1; height: 1px; background: rgba(255,255,255,0.1); }
.divider span { padding: 0 15px; }
.captcha-wrap { display: flex; gap: 10px; align-items: center; }
.captcha-img {
    display: flex;
    align-items: center;
    gap: 8px;
    cursor: pointer;
    user-select: none;
    background: rgba(0,0,0,0.3);
    border-radius: 10px;
    padding: 5px 10px;
    border: 1px solid rgba(255,255,255,0.1);
}
.captcha-img canvas { border-radius: 6px; }
.captcha-img span { font-size: 11px; color: #00d4ff; }
.btn-code {
    padding: 12px 14px;
    background: linear-gradient(135deg, #00d4ff 0%, #a855f7 100%);
    color: #fff;
    border: none;
    border-radius: 8px;
    font-size: 12px;
    cursor: pointer;
    white-space: nowrap;
    font-weight: 600;
}
.btn-code:hover { opacity: 0.9; }
.btn-code:disabled { background: #333; cursor: not-allowed; opacity: 0.6; }
.code-error { color: #ff5090; font-size: 11px; margin-top: 5px; }
.two-col { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }

/* ===== CSS绘制的小猫 - 趴在霓虹框上 ===== */
.mascot-cat {
    position: absolute;
    right: -230px;
    top: 50%;
    transform: translateY(-50%) scale(4);
    transform-origin: top center;
    width: 80px;
    height: 100px;
    z-index: 10;
    cursor: pointer;
    filter: drop-shadow(3px 3px 8px rgba(0,0,0,0.5));
    transition: transform 0.3s ease;
}
.mascot-cat:hover {
    transform: translateY(-50%) scale(4.1);
}

/* 猫身体 - 部分隐藏在框后 */
.cat-body {
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 50px;
    height: 60px;
    background: linear-gradient(135deg, #4ade80 0%, #22c55e 100%);
    border-radius: 25px 25px 20px 20px;
    z-index: 1;
}

/* 猫头 */
.cat-head {
    position: absolute;
    top: 10px;
    left: 50%;
    transform: translateX(-50%);
    width: 55px;
    height: 50px;
    background: linear-gradient(135deg, #4ade80 0%, #22c55e 100%);
    border-radius: 50%;
    z-index: 2;
    box-shadow: 0 2px 10px rgba(0,0,0,0.2);
}

/* 耳朵 */
.cat-ear {
    position: absolute;
    width: 0;
    height: 0;
    border-left: 10px solid transparent;
    border-right: 10px solid transparent;
    border-bottom: 18px solid #22c55e;
    top: -8px;
    z-index: 1;
}
.cat-ear.left { left: 5px; transform: rotate(-20deg); }
.cat-ear.right { right: 5px; transform: rotate(20deg); }
.cat-ear::after {
    content: '';
    position: absolute;
    top: 8px;
    left: -5px;
    width: 0;
    height: 0;
    border-left: 5px solid transparent;
    border-right: 5px solid transparent;
    border-bottom: 8px solid #86efac;
}

/* 眼睛容器 */
.cat-eyes {
    position: absolute;
    top: 18px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    gap: 12px;
    z-index: 3;
}

/* 眼球 */
.cat-eye {
    width: 14px;
    height: 14px;
    background: #fff;
    border-radius: 50%;
    position: relative;
    overflow: hidden;
    box-shadow: inset 0 1px 3px rgba(0,0,0,0.2);
}

/* 瞳孔 - 会跟随鼠标 */
.cat-pupil {
    position: absolute;
    width: 7px;
    height: 7px;
    background: #1a1a1a;
    border-radius: 50%;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    transition: transform 0.1s ease-out;
}
.cat-pupil::after {
    content: '';
    position: absolute;
    width: 3px;
    height: 3px;
    background: #fff;
    border-radius: 50%;
    top: 1px;
    right: 1px;
}

/* 眨眼动画 */
@keyframes blink {
    0%, 90%, 100% { transform: scaleY(1); }
    95% { transform: scaleY(0.1); }
}
.cat-eye.blinking {
    animation: blink 3s infinite;
}

/* 鼻子 */
.cat-nose {
    position: absolute;
    top: 32px;
    left: 50%;
    transform: translateX(-50%);
    width: 6px;
    height: 4px;
    background: #86efac;
    border-radius: 50%;
    z-index: 3;
}

/* 嘴巴 */
.cat-mouth {
    position: absolute;
    top: 38px;
    left: 50%;
    transform: translateX(-50%);
    width: 16px;
    height: 8px;
    z-index: 3;
}
.cat-mouth::before,
.cat-mouth::after {
    content: '';
    position: absolute;
    width: 8px;
    height: 8px;
    border-bottom: 2px solid #333;
    border-radius: 0 0 8px 8px;
    top: -4px;
}
.cat-mouth::before { left: 0; transform: rotate(20deg); }
.cat-mouth::after { right: 0; transform: rotate(-20deg); }

/* 胡须 */
.cat-whiskers {
    position: absolute;
    top: 28px;
    left: 50%;
    transform: translateX(-50%);
    width: 70px;
    height: 20px;
    z-index: 3;
}
.whisker {
    position: absolute;
    width: 15px;
    height: 1px;
    background: rgba(0,0,0,0.3);
    top: 5px;
}
.whisker.left { left: 0; transform: rotate(10deg); }
.whisker.left:nth-child(2) { top: 10px; transform: rotate(0deg); }
.whisker.right { right: 0; transform: rotate(-10deg); }
.whisker.right:nth-child(4) { top: 10px; transform: rotate(0deg); }

/* 爪子 - 趴在边框上 */
.cat-paws {
    position: absolute;
    top: 45px;
    left: -5px;
    width: 30px;
    height: 20px;
    z-index: 4;
}
.paw {
    position: absolute;
    width: 12px;
    height: 15px;
    background: linear-gradient(135deg, #86efac 0%, #4ade80 100%);
    border-radius: 50% 50% 40% 40%;
    box-shadow: 0 2px 5px rgba(0,0,0,0.2);
}
.paw:nth-child(1) { left: 0; top: 0; }
.paw:nth-child(2) { left: 14px; top: 2px; }

/* 尾巴 */
.cat-tail {
    position: absolute;
    bottom: 5px;
    right: 5px;
    width: 30px;
    height: 60px;
    background: linear-gradient(135deg, #22c55e 0%, #4ade80 100%);
    border-radius: 15px;
    z-index: 0;
    transform-origin: bottom center;
    animation: tailWag 2s ease-in-out infinite;
}
@keyframes tailWag {
    0%, 100% { transform: rotate(-5deg); }
    50% { transform: rotate(5deg); }
}

/* 点击时的互动动画 */
.mascot-cat.interacting .cat-head {
    animation: headTilt 0.5s ease;
}
@keyframes headTilt {
    0%, 100% { transform: translateX(-50%) rotate(0); }
    25% { transform: translateX(-50%) rotate(-10deg); }
    75% { transform: translateX(-50%) rotate(10deg); }
}

.mascot-cat.interacting .cat-tail {
    animation: tailHappy 0.5s ease;
}
@keyframes tailHappy {
    0%, 100% { transform: rotate(0deg); }
    50% { transform: rotate(20deg); }
}

/* 输入时的反应 */
.mascot-cat.typing .cat-pupil {
    transform: translate(-50%, -50%) scale(0.8);
}
.mascot-cat.typing .cat-eye {
    animation: focusEyes 1s ease infinite;
}
@keyframes focusEyes {
    0%, 100% { transform: scaleY(1); }
    50% { transform: scaleY(1.1); }
}

/* 呼吸动画 */
.cat-body {
    animation: breathe 3s ease-in-out infinite;
}
@keyframes breathe {
    0%, 100% { transform: translateX(-50%) scale(1); }
    50% { transform: translateX(-50%) scale(1.02); }
}