:root {
    --bg-primary: #000000;
    --bg-secondary: #0c0c0c;
    --bg-tertiary: #1a1a1a;
    --text-primary: #ffffff;
    --text-secondary: rgba(255, 255, 255, 0.7);
    --text-tertiary: rgba(255, 255, 255, 0.5);
    --accent-primary: #0071e3;
    --accent-secondary: #38b7ff;
    --border-color: rgba(255, 255, 255, 0.1);
    --shadow-color: rgba(0, 0, 0, 0.5);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: -apple-system, BlinkMacSystemFont, 'SF Pro Text', 'Helvetica Neue', sans-serif;
}

body {
    background: var(--bg-primary);
    color: var(--text-primary);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    position: relative;
    overflow-x: hidden;
}

.particles-container {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 0;
}

.container {
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    min-height: 90vh;
    padding: 2rem;
    position: relative;
    z-index: 1;
}

.content {
    max-width: 500px;
    width: 100%;
    text-align: center;
    background-color: rgba(12, 12, 12, 0.8);
    padding: 3rem 2rem;
    border-radius: 20px;
    box-shadow: 0 20px 50px rgba(0, 0, 0, 0.3);
    backdrop-filter: blur(30px);
    -webkit-backdrop-filter: blur(30px);
    border: 1px solid var(--border-color);
    animation: fadeUp 0.8s ease-out;
    position: relative;
    overflow: hidden;
}

.content::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(0, 113, 227, 0.05) 0%, transparent 60%);
    z-index: -1;
}

@keyframes fadeUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.logo-container {
    position: relative;
    width: 100px;
    height: 100px;
    margin: 0 auto 2rem;
}

.logo-pulse {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    margin: auto;
    width: 100px;
    height: 100px;
    border-radius: 20px;
    background: radial-gradient(circle, rgba(0, 113, 227, 0.3) 0%, transparent 70%);
    opacity: 0.8;
    animation: pulse 3s infinite ease-in-out;
}

@keyframes pulse {
    0% {
        transform: scale(0.8);
        opacity: 0.5;
    }
    50% {
        transform: scale(1.2);
        opacity: 0.2;
    }
    100% {
        transform: scale(0.8);
        opacity: 0.5;
    }
}

.logo {
    width: 80px;
    height: 80px;
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    border-radius: 18px;
    display: flex;
    justify-content: center;
    align-items: center;
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    box-shadow: 0 8px 20px rgba(0, 113, 227, 0.4);
}

.logo i {
    font-size: 36px;
    color: white;
}

h1 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    letter-spacing: -0.5px;
    background: linear-gradient(to right, var(--text-primary), var(--text-secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    font-family: 'SF Pro Display', -apple-system, BlinkMacSystemFont, sans-serif;
}

.accent {
    color: var(--accent-primary);
    -webkit-text-fill-color: var(--accent-primary);
}

h2 {
    font-size: 1.2rem;
    font-weight: 500;
    margin-bottom: 1.5rem;
    color: var(--text-secondary);
    letter-spacing: 0.5px;
}

.content > p {
    font-size: 1rem;
    color: var(--text-secondary);
    margin-bottom: 3rem;
    line-height: 1.6;
}

.features {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 0.8rem;
    margin-bottom: 2.5rem;
}

.feature {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    background-color: rgba(26, 26, 26, 0.7);
    padding: 0.7rem 1rem;
    border-radius: 30px;
    font-size: 0.85rem;
    color: var(--text-secondary);
    transition: all 0.3s ease;
    border: 1px solid rgba(255, 255, 255, 0.03);
}

.feature:hover {
    transform: translateY(-3px) scale(1.05);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
    background-color: rgba(0, 113, 227, 0.15);
    border-color: rgba(0, 113, 227, 0.2);
}

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

.signin-container {
    background-color: rgba(26, 26, 26, 0.7);
    padding: 2rem;
    border-radius: 15px;
    border: 1px solid var(--border-color);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
    width: 100%;
    max-width: 360px;
    margin: 0 auto;
}

.signin-text {
    font-size: 1rem;
    margin-bottom: 1.5rem;
    color: var(--text-secondary);
}

.g_id_signin {
    display: flex !important;
    justify-content: center !important;
    margin-bottom: 1.5rem;
}

.terms {
    font-size: 0.75rem;
    color: var(--text-tertiary);
    margin-top: 1.5rem;
    line-height: 1.5;
}

.terms a {
    color: var(--accent-primary);
    text-decoration: none;
    position: relative;
    transition: all 0.2s ease;
}

.terms a:hover {
    color: var(--accent-secondary);
}

.terms a::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    width: 100%;
    height: 1px;
    background-color: var(--accent-primary);
    transform: scaleX(0);
    transform-origin: left;
    transition: transform 0.3s ease;
}

.terms a:hover::after {
    transform: scaleX(1);
}

/* Username input form styling */
#username-container {
    width: 100%;
}

.input-group {
    margin-bottom: 1.5rem;
}

.username-field-container {
    position: relative;
    width: 100%;
}

.at-symbol {
    position: absolute;
    left: 15px;
    top: 50%;
    transform: translateY(-50%);
    color: var(--accent-primary);
    font-weight: bold;
    font-size: 1rem;
    z-index: 5;
}

#username-input {
    width: 100%;
    padding: 12px 15px 12px 30px;
    background-color: rgba(30, 30, 30, 0.7);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    color: var(--text-primary);
    font-size: 1rem;
    transition: all 0.3s ease;
    margin-bottom: 5px;
}

.username-preview {
    margin: 5px 0;
    font-size: 0.9rem;
    color: var(--accent-primary);
    font-weight: 500;
    animation: fadeIn 0.3s ease-in-out;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(-5px); }
    to { opacity: 1; transform: translateY(0); }
}

#username-input:focus {
    outline: none;
    border-color: var(--accent-primary);
    box-shadow: 0 0 0 2px rgba(0, 113, 227, 0.2);
}

.validation-message {
    font-size: 0.85rem;
    margin: 5px 0;
    min-height: 1.2em;
    padding-left: 2px;
}

.validation-message.valid {
    color: #4cd964;
}

.validation-message.invalid {
    color: #ff3b30;
}

.input-help {
    font-size: 0.8rem;
    color: var(--text-tertiary);
    text-align: left;
    margin-left: 2px;
}

.username-submit {
    width: 100%;
    padding: 12px;
    background: var(--accent-primary);
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
    margin-bottom: 0.5rem;
}

.username-submit:hover {
    background: var(--accent-secondary);
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
}

.username-submit:active {
    transform: translateY(0);
}

footer {
    text-align: center;
    padding: 1.5rem;
    color: var(--text-tertiary);
    font-size: 0.8rem;
    background-color: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    position: relative;
    z-index: 1;
}

/* Responsive design */
@media (max-width: 600px) {
    .content {
        padding: 2.5rem 1.5rem;
    }
    
    h1 {
        font-size: 2.2rem;
    }
    
    h2 {
        font-size: 1rem;
    }
    
    .content > p {
        font-size: 0.9rem;
    }
    
    .features {
        gap: 0.7rem;
    }
    
    .feature {
        padding: 0.6rem 0.9rem;
        font-size: 0.8rem;
    }
    
    .logo-container {
        width: 90px;
        height: 90px;
    }
    
    .logo {
        width: 70px;
        height: 70px;
    }
    
    .logo i {
        font-size: 32px;
    }
    
    #username-input {
        padding: 10px 12px;
        font-size: 0.9rem;
    }
    
    .username-submit {
        padding: 10px;
        font-size: 0.9rem;
    }
}

/* Loading indicator for Google Sign-In */
.signin-loading {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    margin-bottom: 1.5rem;
    padding: 1rem;
}

.signin-spinner {
    width: 32px;
    height: 32px;
    margin-bottom: 10px;
    border: 3px solid rgba(0, 113, 227, 0.2);
    border-top: 3px solid var(--accent-primary);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

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

/* Manual sign-in fallback */
#manual-signin {
    width: 100%;
    margin-bottom: 1.5rem;
}

#manual-signin p {
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin-bottom: 1rem;
}

#manual-signin-form {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

#manual-name {
    padding: 10px 15px;
    border: 1px solid var(--border-color);
    background-color: rgba(26, 26, 26, 0.7);
    border-radius: 6px;
    font-size: 0.95rem;
    color: var(--text-primary);
    transition: all 0.3s ease;
}

#manual-name:focus {
    outline: none;
    border-color: var(--accent-primary);
    box-shadow: 0 0 0 2px rgba(0, 113, 227, 0.2);
}

.manual-signin-button {
    padding: 10px 15px;
    background: var(--accent-primary);
    color: white;
    border: none;
    border-radius: 6px;
    font-size: 0.95rem;
    cursor: pointer;
    transition: all 0.3s ease;
    margin-top: 5px;
}

.manual-signin-button:hover {
    background: var(--accent-secondary);
}