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

:root {
    --primary-color: #2563eb;
    --primary-dark: #1d4ed8;
    --secondary-color: #64748b;
    --background: #0f172a;
    --surface: #1e293b;
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --accent: #3b82f6;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
    background: var(--background);
    color: var(--text-primary);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
    position: relative;
}

.container {
    text-align: center;
    padding: 2rem;
    max-width: 600px;
    width: 100%;
    z-index: 10;
    position: relative;
}

.content {
    background: var(--surface);
    border-radius: 24px;
    padding: 3rem 2rem;
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.5);
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.logo {
    margin-bottom: 1.5rem;
}

.logo img {
    max-width: 180px;
    height: auto;
}

.logo-text {
    font-size: 2rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary-color), var(--accent));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.icon {
    width: 80px;
    height: 80px;
    margin: 0 auto 1.5rem;
    background: linear-gradient(135deg, var(--primary-color), var(--accent));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    animation: pulse 2s ease-in-out infinite;
}

.icon svg {
    width: 40px;
    height: 40px;
    color: white;
}

@keyframes pulse {
    0%, 100% {
        transform: scale(1);
        box-shadow: 0 0 0 0 rgba(59, 130, 246, 0.4);
    }
    50% {
        transform: scale(1.05);
        box-shadow: 0 0 0 20px rgba(59, 130, 246, 0);
    }
}

h1 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 0.75rem;
    background: linear-gradient(135deg, #fff, #94a3b8);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.subtitle {
    color: var(--text-secondary);
    font-size: 1.1rem;
    line-height: 1.6;
    margin-bottom: 2rem;
}

.progress-container {
    margin: 2rem 0;
}

.progress-bar {
    background: rgba(255, 255, 255, 0.1);
    border-radius: 100px;
    height: 8px;
    overflow: hidden;
    margin-bottom: 0.75rem;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--primary-color), var(--accent));
    border-radius: 100px;
    width: 0%;
    transition: width 1.5s ease-out;
    position: relative;
}

.progress-fill::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.3), transparent);
    animation: shimmer 2s infinite;
}

@keyframes shimmer {
    0% { transform: translateX(-100%); }
    100% { transform: translateX(100%); }
}

.progress-text {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.contact {
    margin-top: 2rem;
    padding-top: 2rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.contact p {
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
    font-size: 0.95rem;
}

.contact a {
    color: var(--accent);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s ease;
}

.contact a:hover {
    color: var(--primary-color);
}

.social {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-top: 1.5rem;
}

.social a {
    width: 44px;
    height: 44px;
    background: rgba(255, 255, 255, 0.05);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-secondary);
    transition: all 0.3s ease;
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.social a:hover {
    background: var(--primary-color);
    color: white;
    transform: translateY(-3px);
}

.social svg {
    width: 20px;
    height: 20px;
}

footer {
    margin-top: 2rem;
    color: var(--text-secondary);
    font-size: 0.85rem;
}

/* Background Shapes */
.background-shapes {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    overflow: hidden;
    z-index: 1;
    pointer-events: none;
}

.shape {
    position: absolute;
    border-radius: 50%;
    filter: blur(80px);
    opacity: 0.3;
}

.shape-1 {
    width: 400px;
    height: 400px;
    background: var(--primary-color);
    top: -100px;
    right: -100px;
    animation: float 8s ease-in-out infinite;
}

.shape-2 {
    width: 300px;
    height: 300px;
    background: #8b5cf6;
    bottom: -50px;
    left: -50px;
    animation: float 10s ease-in-out infinite reverse;
}

.shape-3 {
    width: 200px;
    height: 200px;
    background: var(--accent);
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    animation: float 6s ease-in-out infinite;
}

@keyframes float {
    0%, 100% {
        transform: translate(0, 0);
    }
    50% {
        transform: translate(30px, 30px);
    }
}

/* Responsive */
@media (max-width: 640px) {
    .content {
        padding: 2rem 1.5rem;
    }

    h1 {
        font-size: 1.75rem;
    }

    .subtitle {
        font-size: 1rem;
    }

    .icon {
        width: 60px;
        height: 60px;
    }

    .icon svg {
        width: 30px;
        height: 30px;
    }
}

/* Light Theme Support */
body.light-theme {
    --background: #f8fafc;
    --surface: #ffffff;
    --text-primary: #0f172a;
    --text-secondary: #64748b;
}

body.light-theme .content {
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.15);
}

body.light-theme h1 {
    background: linear-gradient(135deg, #0f172a, #475569);
    -webkit-background-clip: text;
    background-clip: text;
}

/* Language Switcher */
.language-switcher {
    position: fixed;
    top: 1.5rem;
    right: 1.5rem;
    display: none;
    gap: 0.5rem;
    z-index: 100;
}

.lang-btn {
    padding: 0.5rem 1rem;
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: 8px;
    color: var(--text-secondary);
    font-size: 0.85rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
}

.lang-btn:hover {
    background: rgba(255, 255, 255, 0.15);
    color: var(--text-primary);
}

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

/* Signup Form */
.signup-section {
    margin-top: 2rem;
    padding: 1.5rem;
    background: rgba(255, 255, 255, 0.05);
    border-radius: 16px;
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.signup-title {
    color: var(--text-primary);
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 1rem;
}

.signup-form {
    display: flex;
    gap: 0.75rem;
    flex-wrap: wrap;
    justify-content: center;
}

.signup-form input[type="email"] {
    flex: 1;
    min-width: 200px;
    padding: 0.875rem 1.25rem;
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: 12px;
    color: var(--text-primary);
    font-size: 1rem;
    outline: none;
    transition: all 0.3s ease;
}

.signup-form input[type="email"]::placeholder {
    color: var(--text-secondary);
}

.signup-form input[type="email"]:focus {
    border-color: var(--accent);
    background: rgba(255, 255, 255, 0.15);
}

.signup-form button {
    padding: 0.875rem 2rem;
    background: linear-gradient(135deg, var(--primary-color), var(--accent));
    border: none;
    border-radius: 12px;
    color: white;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
}

.signup-form button:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.3);
}

.signup-form button:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none;
}

.signup-message {
    margin-top: 1rem;
    font-size: 0.9rem;
    min-height: 1.5rem;
}

.signup-message.success {
    color: #22c55e;
}

.signup-message.error {
    color: #ef4444;
}

/* Chinese Font Support */
html[lang="zh-CN"] h1,
html[lang="zh-CN"] .subtitle,
html[lang="zh-CN"] .signup-title {
    font-family: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", sans-serif;
}

/* Responsive adjustments */
@media (max-width: 640px) {
    .language-switcher {
        top: 1rem;
        right: 1rem;
    }

    .lang-btn {
        padding: 0.4rem 0.75rem;
        font-size: 0.8rem;
    }

    .signup-form {
        flex-direction: column;
    }

    .signup-form input[type="email"],
    .signup-form button {
        width: 100%;
    }
}