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

:root {
    --bg-primary: #0a0a0f;
    --bg-secondary: #12121a;
    --bg-card: #1a1a25;
    --bg-input: #252535;
    --accent-primary: #00d4ff;
    --accent-secondary: #7b2cbf;
    --accent-glow: rgba(0, 212, 255, 0.3);
    --text-primary: #ffffff;
    --text-secondary: #a0a0b0;
    --text-muted: #606070;
    --border-color: #2a2a3a;
    --success: #00ff88;
    --error: #ff4757;
}

body {
    font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    min-height: 100vh;
    line-height: 1.6;
    background-image: 
        radial-gradient(circle at 20% 50%, rgba(0, 212, 255, 0.05) 0%, transparent 50%),
        radial-gradient(circle at 80% 80%, rgba(123, 44, 191, 0.05) 0%, transparent 50%);
}

.container {
    max-width: 800px;
    margin: 0 auto;
    padding: 2rem 1rem;
}

/* Header */
header {
    text-align: center;
    margin-bottom: 2rem;
}

.logo {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 0.5rem;
}

.binary-icon {
    font-family: 'Courier New', monospace;
    font-size: 2rem;
    font-weight: bold;
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    border: 2px solid var(--accent-primary);
    padding: 0.25rem 0.75rem;
    border-radius: 8px;
    box-shadow: 0 0 20px var(--accent-glow);
}

h1 {
    font-size: 2rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--text-primary), var(--accent-primary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

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

/* Converter Card */
.converter-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 1.5rem;
    margin-bottom: 1.5rem;
    box-shadow: 0 4px 24px rgba(0, 0, 0, 0.3);
}

label {
    display: block;
    color: var(--text-secondary);
    font-size: 0.875rem;
    font-weight: 500;
    margin-bottom: 0.5rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

input[type="text"],
input[type="number"],
select {
    width: 100%;
    padding: 0.875rem 1rem;
    background: var(--bg-input);
    border: 1px solid var(--border-color);
    border-radius: 10px;
    color: var(--text-primary);
    font-size: 1rem;
    transition: all 0.2s ease;
    margin-bottom: 1rem;
}

input[type="text"]:focus,
input[type="number"]:focus,
select:focus {
    outline: none;
    border-color: var(--accent-primary);
    box-shadow: 0 0 0 3px var(--accent-glow);
}

input[type="text"]::placeholder {
    color: var(--text-muted);
}

/* Swap Section */
.swap-section {
    display: flex;
    justify-content: center;
    margin: 0.5rem 0;
}

.swap-btn {
    background: var(--bg-input);
    border: 1px solid var(--border-color);
    border-radius: 50%;
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all 0.2s ease;
    color: var(--accent-primary);
}

.swap-btn:hover {
    background: var(--accent-primary);
    color: var(--bg-primary);
    transform: rotate(180deg);
    box-shadow: 0 0 20px var(--accent-glow);
}

.swap-btn svg {
    width: 24px;
    height: 24px;
}

/* Custom Base */
.custom-base {
    animation: slideDown 0.2s ease;
}

.custom-base.hidden {
    display: none;
}

@keyframes slideDown {
    from {
        opacity: 0;
        transform: translateY(-10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Convert Button */
.convert-btn {
    width: 100%;
    padding: 1rem;
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    border: none;
    border-radius: 10px;
    color: white;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-top: 0.5rem;
}

.convert-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 24px var(--accent-glow);
}

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

/* Results Card */
.results-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 1.5rem;
    margin-bottom: 1.5rem;
    box-shadow: 0 4px 24px rgba(0, 0, 0, 0.3);
}

.results-card h2 {
    font-size: 1.25rem;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.result-item {
    background: var(--bg-input);
    border: 1px solid var(--border-color);
    border-radius: 10px;
    padding: 1rem;
    margin-bottom: 0.75rem;
}

.result-item.primary-result {
    border-color: var(--accent-primary);
    background: linear-gradient(135deg, rgba(0, 212, 255, 0.1), rgba(123, 44, 191, 0.1));
}

.result-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 0.5rem;
}

.result-label {
    font-size: 0.75rem;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.copy-btn {
    background: transparent;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    padding: 0.25rem 0.75rem;
    color: var(--accent-primary);
    font-size: 0.75rem;
    cursor: pointer;
    transition: all 0.2s ease;
}

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

.result-value {
    font-family: 'Courier New', monospace;
    font-size: 1.125rem;
    color: var(--text-primary);
    word-break: break-all;
    min-height: 1.5rem;
}

.result-value.highlight {
    color: var(--accent-primary);
    font-weight: 600;
    font-size: 1.25rem;
}

.result-value.error {
    color: var(--error);
    font-size: 0.875rem;
}

/* Quick Conversions */
.quick-conversions {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 1.5rem;
    box-shadow: 0 4px 24px rgba(0, 0, 0, 0.3);
}

.quick-conversions h3 {
    font-size: 1rem;
    margin-bottom: 1rem;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.quick-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(80px, 1fr));
    gap: 0.5rem;
}

.quick-item {
    background: var(--bg-input);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 0.75rem 0.5rem;
    text-align: center;
    transition: all 0.2s ease;
}

.quick-item:hover {
    border-color: var(--accent-primary);
    transform: translateY(-2px);
}

.quick-num {
    display: block;
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-bottom: 0.25rem;
}

.quick-bin {
    display: block;
    font-family: 'Courier New', monospace;
    font-size: 0.75rem;
    color: var(--accent-primary);
    font-weight: 600;
}

/* Footer */
footer {
    text-align: center;
    padding: 2rem 0;
    color: var(--text-muted);
    font-size: 0.875rem;
}

/* Toast Notification */
.toast {
    position: fixed;
    bottom: 2rem;
    left: 50%;
    transform: translateX(-50%) translateY(100px);
    background: var(--success);
    color: var(--bg-primary);
    padding: 0.875rem 1.5rem;
    border-radius: 10px;
    font-weight: 600;
    opacity: 0;
    transition: all 0.3s ease;
    z-index: 1000;
}

.toast.show {
    transform: translateX(-50%) translateY(0);
    opacity: 1;
}

/* Responsive */
@media (max-width: 600px) {
    .container {
        padding: 1rem;
    }
    
    h1 {
        font-size: 1.5rem;
    }
    
    .binary-icon {
        font-size: 1.5rem;
    }
    
    .quick-grid {
        grid-template-columns: repeat(4, 1fr);
    }
}

/* Scrollbar */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: var(--bg-primary);
}

::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--text-muted);
}