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

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

:root {
    --bg-color: #0f172a;      /* Slate 900 */
    --surface-color: #1e293b; /* Slate 800 */
    --primary-color: #38bdf8; /* Sky 400 */
    --on-primary: #0f172a;    /* Darkest slate for text on primary */
    --text-primary: #f1f5f9;  /* Slate 100 */
    --text-secondary: #94a3b8;/* Slate 400 */
    --border-color: #334155;  /* Slate 700 */
    --error-color: #ef4444;   /* Red 500 */
    --success-bg: rgba(16, 185, 129, 0.1);
    --success-text: #34d399;
    --radius: 12px;
    --transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
}

body {
    font-family: 'Inter', system-ui, -apple-system, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-primary);
    line-height: 1.6;
    padding: 2rem;
    min-height: 100vh;
    display: flex;
    justify-content: center;
}

.container {
    width: 100%;
    max-width: 900px;
}

header {
    margin-bottom: 3rem;
    text-align: center;
}

.back-link {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.9rem;
    font-weight: 500;
    transition: var(--transition);
    margin-bottom: 1rem;
    width: fit-content;
}

.back-link:hover {
    color: var(--primary-color);
    transform: translateX(-4px);
}

h1 {
    font-family: 'Outfit', sans-serif;
    font-size: 2.5rem;
    font-weight: 800;
    margin-bottom: 0.5rem;
    background: linear-gradient(to right, #7dd3fc, #38bdf8);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    letter-spacing: -0.025em;
}

.subtitle {
    color: var(--text-secondary);
    font-size: 1.1rem;
    font-weight: 400;
}

.input-section {
    background-color: var(--surface-color);
    border-radius: var(--radius);
    padding: 2rem;
    margin-bottom: 2rem;
    border: 1px solid var(--border-color);
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
}

label {
    display: block;
    font-size: 0.8125rem;
    font-weight: 600;
    margin-bottom: 0.75rem;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

input {
    width: 100%;
    padding: 0.75rem 1rem;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    font-size: 1rem;
    background-color: var(--bg-color);
    color: var(--text-primary);
    font-family: 'JetBrains Mono', monospace;
    transition: var(--transition);
}

input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(56, 189, 248, 0.15);
}

.quick-buttons {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
    margin-top: 1.25rem;
}

.quick-btn {
    padding: 0.3rem 0.6rem;
    background-color: rgba(56, 189, 248, 0.1);
    color: var(--primary-color);
    border: 1px solid rgba(56, 189, 248, 0.2);
    border-radius: 6px;
    font-size: 0.75rem;
    font-weight: 700;
    cursor: pointer;
    transition: var(--transition);
    font-family: 'JetBrains Mono', monospace;
}

.quick-btn:hover {
    background-color: var(--primary-color);
    color: var(--bg-color);
    border-color: var(--primary-color);
}

.quick-btn:active {
    transform: translateY(1px);
}

.examples {
    font-size: 0.8125rem;
    color: var(--text-secondary);
    margin-top: 1.5rem;
    padding-top: 1.5rem;
    border-top: 1px solid var(--border-color);
}

.results-section {
    display: none;
    background-color: var(--surface-color);
    border-radius: var(--radius);
    padding: 2rem;
    border: 1px solid var(--border-color);
    margin-top: 2rem;
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
}

.results-section.active {
    display: block;
}

h2 {
    font-family: 'Outfit', sans-serif;
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
    color: var(--text-primary);
    display: flex;
    align-items: center;
    gap: 1rem;
}

.address-type-badge {
    padding: 0.25rem 0.75rem;
    border-radius: 9999px;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.025em;
}

.address-type-badge.private {
    background-color: rgba(56, 189, 248, 0.1);
    color: var(--primary-color);
}

.address-type-badge.public {
    background-color: var(--success-bg);
    color: var(--success-text);
}

.address-type-badge.special {
    background-color: rgba(245, 158, 11, 0.1);
    color: #fbbf24;
}

.results-table {
    width: 100%;
    border-collapse: collapse;
}

.results-table td {
    padding: 0.75rem 0;
    border-bottom: 1px solid var(--border-color);
}

.results-table tr:last-child td {
    border-bottom: none;
}

.result-label {
    width: 30%;
    font-size: 0.8125rem;
    color: var(--text-secondary);
    font-weight: 500;
    vertical-align: middle;
}

.result-value {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.9375rem;
    color: var(--text-primary);
    /* Flex alignment for Left Value / Right Button */
    display: flex;
    justify-content: space-between;
    align-items: center;
    text-align: left;
    word-break: break-all; /* Ensure long IPv6 doesn't overflow */
}

.copy-btn {
    background: transparent;
    border: none;
    cursor: pointer;
    padding: 0.25rem;
    color: var(--text-secondary); /* Default state */
    transition: var(--transition);
    border-radius: 4px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    margin-left: 1rem; /* Space between value and button */
    flex-shrink: 0; /* Don't shrink button */
}

.copy-btn:hover {
    color: var(--primary-color);
    background-color: rgba(56, 189, 248, 0.1);
}

.copy-btn.copied {
    color: var(--success-text);
    background-color: var(--success-bg);
}

.error-message {
    color: var(--error-color);
    background-color: rgba(239, 68, 68, 0.1);
    border: 1px solid rgba(239, 68, 68, 0.2);
    border-radius: 8px;
    padding: 1rem;
    margin-top: 1rem;
    display: none;
    font-size: 0.875rem;
    font-weight: 500;
}

.error-message.active {
    display: block;
}

@media (max-width: 640px) {
    body {
        padding: 1rem;
    }
    .input-section, .results-section {
        padding: 1.5rem;
    }
    h1 {
        font-size: 2rem;
    }
}