:root {
    --bg-color: #f8fafc;
    --text-color: #1e293b;
    --primary-color: #6366f1;
    --primary-hover: #4f46e5;
    --toast-bg: #1e293b;
    --toast-text: #ffffff;
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    height: 100vh;
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

.app-container {
    display: flex;
    flex-direction: column;
    height: 100%;
}

header {
    padding: 1.5rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: white;
    box-shadow: 0 1px 3px rgba(0,0,0,0.1);
    z-index: 10;
}

h1 {
    font-weight: 800;
    font-size: 1.5rem;
    letter-spacing: -0.025em;
}

h1 span {
    color: var(--primary-color);
}

.controls {
    display: flex;
    align-items: center;
    gap: 1.5rem;
}

.primary-btn {
    background-color: var(--primary-color);
    color: white;
    border: none;
    padding: 0.75rem 1.5rem;
    border-radius: 0.5rem;
    font-weight: 600;
    cursor: pointer;
    transition: background-color 0.2s, transform 0.1s;
    font-size: 1rem;
}

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

.primary-btn:active {
    transform: scale(0.98);
}

.hint {
    font-size: 0.875rem;
    color: #64748b;
}

kbd {
    background: #e2e8f0;
    border: 1px solid #cbd5e1;
    border-radius: 0.25rem;
    padding: 0.1rem 0.4rem;
    font-family: inherit;
    font-weight: 600;
    color: #475569;
}

#palette-container {
    flex: 1;
    display: flex;
    height: 100%;
    width: 100%;
}

.color-column {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    transition: flex 0.3s ease;
    position: relative;
    cursor: pointer;
    user-select: none;
}

.color-info {
    background: white;
    padding: 1rem;
    border-radius: 1rem;
    box-shadow: 0 10px 15px -3px rgba(0,0,0,0.1);
    text-align: center;
    margin-bottom: 2rem;
    transition: transform 0.2s;
}

.color-info:hover {
    transform: translateY(-5px);
}

.hex-code {
    font-family: 'JetBrains Mono', 'Courier New', Courier, monospace;
    font-weight: 600;
    font-size: 1.25rem;
    text-transform: uppercase;
    display: block;
}

.lock-btn {
    margin-top: 1rem;
    background: transparent;
    border: 1px solid #e2e8f0;
    padding: 0.5rem;
    border-radius: 0.5rem;
    cursor: pointer;
    transition: all 0.2s;
    font-size: 1.25rem;
}

.lock-btn.locked {
    background: #f1f5f9;
    border-color: var(--primary-color);
}

.toast {
    position: fixed;
    bottom: 2rem;
    left: 50%;
    transform: translateX(-50%) translateY(100px);
    background: var(--toast-bg);
    color: var(--toast-text);
    padding: 0.75rem 1.5rem;
    border-radius: 2rem;
    font-weight: 600;
    transition: transform 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    z-index: 100;
    pointer-events: none;
}

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

@media (max-width: 768px) {
    #palette-container {
        flex-direction: column;
    }
    header {
        flex-direction: column;
        gap: 1rem;
        text-align: center;
    }
    .controls {
        flex-direction: column;
        gap: 0.5rem;
    }
    .color-column {
        flex: none;
        height: 16.66%;
        width: 100%;
        justify-content: center;
    }
}