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

:root {
    --primary: #0891B2;
    --primary-dark: #0E7490;
    --dark: #0F172A;
    --gray: #475569;
    --light-gray: #64748B;
    --bg: linear-gradient(180deg, #F0FDFA 0%, #E0F2FE 50%, #F1F5F9 100%);
    --white: #FFFFFF;
    --border: #E2E8F0;
}

body {
    font-family: 'Inter', -apple-system, sans-serif;
    background: var(--bg);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Header */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: 72px;
    background: var(--white);
    border-bottom: 1px solid var(--border);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 24px;
    z-index: 1000;
}

.logo img {
    height: 36px;
}

.nav {
    display: flex;
    align-items: center;
    gap: 24px;
}

.nav-link {
    color: var(--light-gray);
    text-decoration: none;
    font-size: 15px;
    font-weight: 500;
    display: flex;
    align-items: center;
    gap: 8px;
}

.nav-link:hover {
    color: var(--dark);
}

.nav-btn {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    color: var(--white);
    padding: 12px 24px;
    border-radius: 10px;
    text-decoration: none;
    font-weight: 600;
    font-size: 14px;
    display: flex;
    align-items: center;
    gap: 8px;
}

.nav-btn:hover {
    opacity: 0.9;
}

/* Main */
.main {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 100px 24px 100px;
}

.container {
    width: 100%;
    max-width: 560px;
}

.welcome-box {
    background: var(--white);
    border-radius: 20px;
    padding: 48px;
    box-shadow: 0 4px 24px rgba(0,0,0,0.06);
    text-align: center;
}

.welcome-box h1 {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--dark);
    margin-bottom: 8px;
}

.welcome-box p {
    font-size: 1.125rem;
    color: var(--light-gray);
    margin-bottom: 32px;
}

.join-form {
    margin-bottom: 32px;
}

.input-group {
    display: flex;
    gap: 12px;
}

.input-group input {
    flex: 1;
    height: 56px;
    padding: 0 20px;
    font-size: 16px;
    border: 2px solid var(--border);
    border-radius: 12px;
    outline: none;
    color: var(--dark);
}

.input-group input:focus {
    border-color: var(--primary);
}

.input-group input::placeholder {
    color: #94A3B8;
}

.btn-primary {
    height: 56px;
    padding: 0 32px;
    background: var(--dark);
    color: var(--white);
    border: none;
    border-radius: 12px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 10px;
    white-space: nowrap;
}

.btn-primary:hover {
    background: #1E293B;
}

.features {
    display: flex;
    justify-content: center;
    gap: 32px;
}

.feature {
    display: flex;
    align-items: center;
    gap: 8px;
    color: var(--light-gray);
    font-size: 14px;
}

.feature i {
    color: var(--primary);
}

/* Footer */
.footer {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    background: var(--gray);
    padding: 16px 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    z-index: 1000;
}

.footer-left img {
    height: 28px;
}

.footer-center {
    display: flex;
    gap: 20px;
}

.footer-center a {
    color: #94A3B8;
    font-size: 16px;
}

.footer-center a:hover {
    color: var(--white);
}

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

.footer-right a {
    color: #94A3B8;
    text-decoration: none;
    font-size: 13px;
}

.footer-right a:hover {
    color: var(--white);
}

.footer-right span {
    color: var(--light-gray);
    font-size: 13px;
}

/* Modal */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0,0,0,0.5);
    z-index: 2000;
    align-items: center;
    justify-content: center;
}

.modal-content {
    background: var(--white);
    border-radius: 20px;
    width: 100%;
    max-width: 480px;
    margin: 24px;
    box-shadow: 0 20px 60px rgba(0,0,0,0.2);
}

.modal-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 24px;
    border-bottom: 1px solid var(--border);
}

.modal-header h2 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--dark);
    display: flex;
    align-items: center;
    gap: 10px;
}

.modal-header h2 i {
    color: var(--primary);
}

.modal-close {
    width: 36px;
    height: 36px;
    border: none;
    background: none;
    font-size: 24px;
    color: var(--light-gray);
    cursor: pointer;
    border-radius: 8px;
}

.modal-close:hover {
    background: #F1F5F9;
    color: var(--dark);
}

.modal-body {
    padding: 24px;
}

.setting-group {
    margin-bottom: 20px;
}

.setting-group label {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 14px;
    font-weight: 500;
    color: var(--dark);
    margin-bottom: 8px;
}

.setting-group label i {
    color: var(--primary);
}

.setting-group select {
    width: 100%;
    height: 48px;
    padding: 0 16px;
    font-size: 15px;
    border: 2px solid var(--border);
    border-radius: 10px;
    outline: none;
    color: var(--dark);
    background: var(--white);
    cursor: pointer;
}

.setting-group select:focus {
    border-color: var(--primary);
}

.preview-box {
    background: #0F172A;
    border-radius: 12px;
    overflow: hidden;
    aspect-ratio: 16/9;
}

.preview-box video {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transform: scaleX(-1);
}

.modal-footer {
    padding: 20px 24px;
    border-top: 1px solid var(--border);
}

.btn-save {
    width: 100%;
    height: 48px;
    background: var(--dark);
    color: var(--white);
    border: none;
    border-radius: 10px;
    font-size: 15px;
    font-weight: 600;
    cursor: pointer;
}

.btn-save:hover {
    background: #1E293B;
}

/* Responsive */
@media (max-width: 768px) {
    .nav {
        display: none;
    }

    .input-group {
        flex-direction: column;
    }

    .btn-primary {
        width: 100%;
        justify-content: center;
    }

    .features {
        flex-direction: column;
        gap: 16px;
    }

    .footer-center {
        display: none;
    }

    .footer-right span {
        display: none;
    }

    .welcome-box {
        padding: 32px 24px;
    }

    .welcome-box h1 {
        font-size: 2rem;
    }
}