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

:root {
    --bg: #000000;
    --border: #1a1a1a;
    --text-primary: #ffffff;
    --text-secondary: #888888;
    --text-muted: #555555;
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
}

/* Accessibility: visually hidden but accessible to screen readers */
.visually-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

html,
body {
    height: 100%;
}

body {
    font-family: var(--font-family);
    background: var(--bg);
    color: var(--text-primary);
    min-height: 100vh;
    line-height: 1.6;
    display: flex;
    align-items: center;
    justify-content: center;
}

.container {
    max-width: 600px;
    padding: 2rem;
    text-align: center;
}

.header {
    margin-bottom: 2rem;
}

.header h1 {
    font-size: 2rem;
    font-weight: 600;
    letter-spacing: -0.02em;
    margin-bottom: 0.5rem;
}

.tagline {
    color: var(--text-secondary);
    font-size: 0.95rem;
    font-weight: 300;
}

.bookmarklet-section {
    padding: 2rem;
    border: 1px solid var(--border);
}

.instruction {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-bottom: 1rem;
}

.bookmarklet-btn {
    display: inline-block;
    position: relative;
    padding: 1rem 2.5rem;
    font-size: 1rem;
    font-weight: 500;
    font-family: inherit;
    color: #ffffff;
    background: #0a0a0a;
    border: none;
    border-radius: 50px;
    text-decoration: none;
    cursor: grab;
    overflow: hidden;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.bookmarklet-btn::before {
    content: '';
    position: absolute;
    inset: 0;
    border-radius: 50px;
    padding: 2px;
    background: linear-gradient(135deg,
            #1a237e,
            #4a148c,
            #b71c1c,
            #ff6f00,
            #ffc107,
            #1a237e);
    background-size: 300% 300%;
    animation: gradient-wave 4s ease infinite;
    -webkit-mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
    -webkit-mask-composite: xor;
    mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
    mask-composite: exclude;
}

.bookmarklet-btn::after {
    content: '';
    position: absolute;
    inset: 2px;
    border-radius: 48px;
    background: #0a0a0a;
    z-index: -1;
}

@keyframes gradient-wave {
    0% {
        background-position: 0% 50%;
    }

    50% {
        background-position: 100% 50%;
    }

    100% {
        background-position: 0% 50%;
    }
}

.bookmarklet-btn:hover {
    transform: scale(1.02);
    box-shadow: 0 0 30px rgba(255, 193, 7, 0.15), 0 0 60px rgba(26, 35, 126, 0.1);
}

.bookmarklet-btn:active {
    cursor: grabbing;
    transform: scale(0.98);
}

.note {
    color: var(--text-muted);
    font-size: 0.8rem;
    margin-top: 1rem;
}

.usage {
    margin-top: 2rem;
    padding-top: 2rem;
    border-top: 1px solid var(--border);
    text-align: left;
}

.usage-title {
    color: var(--text-secondary);
    font-size: 0.85rem;
    margin-bottom: 0.75rem;
    margin-top: 1.5rem;
}

.usage-title:first-child {
    margin-top: 0;
}

.usage ol {
    color: var(--text-muted);
    font-size: 0.8rem;
    padding-left: 1.25rem;
}

.usage ol li {
    margin-bottom: 0.35rem;
}

@media (max-width: 480px) {
    .container {
        padding: 1rem;
    }

    .header h1 {
        font-size: 1.5rem;
    }

    .bookmarklet-section {
        padding: 1.5rem;
    }
}