@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700;800&display=swap');

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    outline: none;
    -webkit-tap-highlight-color: transparent;
}

body, html {
    min-height: 100%;
    font-family: 'Inter', sans-serif;
    background: #0f172a;
    background: linear-gradient(135deg, #0f172a 0%, #1e1b4b 50%, #0f172a 100%);
    color: #e2e8f0;
    overflow-x: hidden;
}

body {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 20px;
}

.container {
    background: linear-gradient(135deg, rgba(30, 41, 59, 0.9) 0%, rgba(15, 23, 42, 0.95) 100%);
    border-radius: 24px;
    padding: 50px 40px;
    text-align: center;
    max-width: 480px;
    width: 100%;
    box-shadow: 
        0 25px 80px rgba(0, 0, 0, 0.6),
        0 0 0 1px rgba(99, 102, 241, 0.2),
        inset 0 1px 0 rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(99, 102, 241, 0.25);
    position: relative;
    overflow: hidden;
}

.container::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(99, 102, 241, 0.08) 0%, transparent 70%);
    pointer-events: none;
}

.logo {
    width: 80px;
    height: 80px;
    margin: 0 auto 25px;
    position: relative;
    z-index: 1;
}

.logo svg {
    width: 100%;
    height: 100%;
    filter: drop-shadow(0 4px 15px rgba(99, 102, 241, 0.4));
}

h1 {
    font-size: 2.4em;
    margin-bottom: 20px;
    color: #f8fafc;
    font-weight: 800;
    position: relative;
    z-index: 1;
    letter-spacing: -0.02em;
    line-height: 1.2;
}

.instruction {
    font-size: 1.05em;
    color: #94a3b8;
    margin: 25px 0;
    line-height: 1.7;
    background: rgba(30, 41, 59, 0.5);
    padding: 20px;
    border-radius: 12px;
    border-left: 4px solid #6366f1;
    position: relative;
    z-index: 1;
}

.key-button {
    display: block;
    background: linear-gradient(135deg, #6366f1 0%, #4f46e5 100%);
    color: white;
    padding: 18px 36px;
    text-decoration: none;
    border-radius: 16px;
    font-weight: 700;
    margin: 16px auto;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    border: none;
    cursor: pointer;
    font-size: 16px;
    font-family: 'Inter', sans-serif;
    box-shadow: 
        0 8px 30px rgba(99, 102, 241, 0.35),
        0 2px 4px rgba(0, 0, 0, 0.2);
    width: 100%;
    max-width: 320px;
    position: relative;
    z-index: 1;
    overflow: hidden;
}

.key-button::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
    transition: left 0.5s;
}

.key-button:hover {
    transform: translateY(-3px);
    box-shadow: 
        0 12px 40px rgba(99, 102, 241, 0.45),
        0 4px 8px rgba(0, 0, 0, 0.25);
}

.key-button:hover::before {
    left: 100%;
}

.secondary-button {
    background: transparent !important;
    border: 2px solid rgba(99, 102, 241, 0.5) !important;
    box-shadow: none !important;
    color: #c7d2fe !important;
}

.secondary-button:hover {
    background: rgba(99, 102, 241, 0.15) !important;
    border-color: rgba(99, 102, 241, 0.8) !important;
    box-shadow: 0 8px 30px rgba(99, 102, 241, 0.2) !important;
}

.processing {
    background: linear-gradient(135deg, #10b981 0%, #059669 100%) !important;
    pointer-events: none;
}

.spinner {
    display: inline-block;
    width: 14px;
    height: 14px;
    border: 2px solid rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    border-top-color: white;
    animation: spin 0.8s linear infinite;
    margin-right: 10px;
    vertical-align: middle;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

.features {
    display: flex;
    justify-content: center;
    gap: 20px;
    margin-top: 35px;
    flex-wrap: wrap;
    position: relative;
    z-index: 1;
}

.feature-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    padding: 15px;
    background: rgba(30, 41, 59, 0.4);
    border-radius: 12px;
    border: 1px solid rgba(99, 102, 241, 0.15);
    min-width: 90px;
    transition: all 0.3s ease;
}

.feature-item:hover {
    background: rgba(99, 102, 241, 0.1);
    border-color: rgba(99, 102, 241, 0.3);
    transform: translateY(-2px);
}

.feature-icon {
    font-size: 1.8em;
}

.feature-text {
    font-size: 0.8em;
    color: #94a3b8;
    font-weight: 500;
}

.footer {
    margin-top: 40px;
    text-align: center;
    color: #64748b;
    font-size: 0.9em;
    position: relative;
    z-index: 1;
}

/* Responsive */
@media (max-width: 480px) {
    .container {
        padding: 35px 25px;
        border-radius: 20px;
    }
    
    h1 {
        font-size: 1.9em;
    }
    
    .instruction {
        font-size: 0.95em;
        padding: 16px;
    }
    
    .key-button {
        padding: 16px 28px;
        font-size: 15px;
    }
    
    .features {
        gap: 12px;
    }
    
    .feature-item {
        min-width: 80px;
        padding: 12px;
    }
    
    .feature-icon {
        font-size: 1.5em;
    }
    
    .feature-text {
        font-size: 0.75em;
    }
}

/* Smooth scroll */
html {
    scroll-behavior: smooth;
}

/* Selection color */
::selection {
    background: rgba(99, 102, 241, 0.3);
    color: #f8fafc;
}