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

:root {
    /* Sophisticated neutral palette */
    --bg-primary: #1a1a1a;
    --bg-secondary: #252525;
    --bg-tertiary: #2f2f2f;
    --text-primary: #e8e8e8;
    --text-secondary: #a0a0a0;
    --accent-warm: #d4a574;
    --accent-red: #e63946;
    --border-subtle: #3a3a3a;
    --shadow-soft: rgba(0, 0, 0, 0.3);
    --shadow-medium: rgba(0, 0, 0, 0.5);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background: linear-gradient(135deg, #1a1a1a 0%, #2a2520 50%, #1f1f1f 100%);
    color: var(--text-primary);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
    overflow-x: hidden;
}

.container {
    width: 100%;
    max-width: 600px;
    padding: 60px 40px;
    background: var(--bg-secondary);
    border-radius: 24px;
    box-shadow: 0 20px 60px var(--shadow-medium);
    position: relative;
    opacity: 0;
    transform: translateY(20px);
    animation: fadeInUp 0.8s cubic-bezier(0.22, 1, 0.36, 1) forwards;
}

@keyframes fadeInUp {
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.header {
    text-align: center;
    margin-bottom: 60px;
}

.title {
    font-size: 32px;
    font-weight: 300;
    letter-spacing: -0.5px;
    color: var(--text-primary);
    margin-bottom: 16px;
    opacity: 0;
    transform: translateY(10px);
    animation: fadeInUp 0.6s cubic-bezier(0.22, 1, 0.36, 1) 0.2s forwards;
}

.title-underline {
    width: 80px;
    height: 2px;
    background: linear-gradient(90deg, transparent, var(--accent-warm), transparent);
    margin: 0 auto;
    opacity: 0;
    animation: fadeIn 0.8s ease-out 0.4s forwards;
}

@keyframes fadeIn {
    to {
        opacity: 1;
    }
}

.main-content {
    margin-bottom: 40px;
}

.button-container {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.btn {
    position: relative;
    display: block;
    padding: 24px 32px;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-subtle);
    border-radius: 16px;
    text-decoration: none;
    color: var(--text-primary);
    font-size: 18px;
    font-weight: 400;
    text-align: center;
    cursor: pointer;
    overflow: hidden;
    transition: transform 0.3s cubic-bezier(0.22, 1, 0.36, 1),
                box-shadow 0.3s cubic-bezier(0.22, 1, 0.36, 1),
                border-color 0.3s ease;
    opacity: 0;
    transform: translateY(20px);
}

.btn-primary {
    animation: fadeInUp 0.6s cubic-bezier(0.22, 1, 0.36, 1) 0.5s forwards;
}

.btn-secondary {
    animation: fadeInUp 0.6s cubic-bezier(0.22, 1, 0.36, 1) 0.6s forwards;
}

.btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(212, 165, 116, 0.1), transparent);
    transition: left 0.6s cubic-bezier(0.22, 1, 0.36, 1);
}

.btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 24px var(--shadow-soft);
    border-color: var(--accent-warm);
}

.btn:hover::before {
    left: 100%;
}

.btn:active {
    transform: translateY(0);
}

.btn-text {
    display: block;
    position: relative;
    z-index: 1;
    transition: opacity 0.3s ease;
}

.btn.loading .btn-text {
    opacity: 0;
}

.highlight {
    color: var(--accent-red);
    font-weight: 500;
}

.btn-loader {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.3s ease;
}

.btn.loading .btn-loader {
    opacity: 1;
}

.spinner {
    width: 24px;
    height: 24px;
    border: 3px solid var(--border-subtle);
    border-top-color: var(--accent-warm);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

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

.footer {
    text-align: center;
    padding-top: 30px;
    border-top: 1px solid var(--border-subtle);
    opacity: 0;
    animation: fadeIn 0.6s ease-out 0.8s forwards;
}

.footer-text {
    font-size: 13px;
    color: var(--text-secondary);
    letter-spacing: 0.5px;
}

/* Iframe Container */
.iframe-container {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: var(--bg-primary);
    z-index: 1000;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.4s cubic-bezier(0.22, 1, 0.36, 1);
}

.iframe-container.active {
    opacity: 1;
    pointer-events: all;
}

.content-iframe {
    width: 100%;
    height: 100%;
    border: none;
    display: block;
}

.back-btn-iframe {
    position: fixed;
    top: 20px;
    left: 20px;
    z-index: 1001;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 12px 24px;
    background: rgba(37, 37, 37, 0.95);
    backdrop-filter: blur(10px);
    border: 1px solid var(--border-subtle);
    border-radius: 12px;
    color: var(--text-primary);
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    box-shadow: 0 4px 12px var(--shadow-soft);
    transition: transform 0.2s cubic-bezier(0.22, 1, 0.36, 1),
                background-color 0.2s ease,
                border-color 0.2s ease,
                box-shadow 0.2s ease;
}

.back-btn-iframe:hover {
    transform: translateX(-4px);
    background-color: rgba(47, 47, 47, 0.95);
    border-color: var(--accent-warm);
    box-shadow: 0 6px 16px var(--shadow-medium);
}

.back-btn-iframe svg {
    transition: transform 0.2s cubic-bezier(0.22, 1, 0.36, 1);
}

.back-btn-iframe:hover svg {
    transform: translateX(-2px);
}

/* Responsive Design */
@media (max-width: 640px) {
    .container,
    .page-content {
        padding: 40px 24px;
    }

    .title {
        font-size: 24px;
    }

    .btn {
        padding: 20px 24px;
        font-size: 16px;
    }

    .page-content h2 {
        font-size: 24px;
    }
}