:root {
    --bg-color: #0a0f1e;
    --card-bg: rgba(255, 255, 255, 0.05);
    --primary: #00d4ff;
    --secondary: #7c3aed;
    --accent: #ff007a;
    --text: #e2e8f0;
    --text-muted: #94a3b8;
    --glass-border: rgba(255, 255, 255, 0.1);
    --shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.8);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Inter', sans-serif;
}

body {
    background-color: var(--bg-color);
    color: var(--text);
    min-height: 100vh;
    overflow-x: hidden;
    background: radial-gradient(circle at top right, #1e1b4b, transparent),
        radial-gradient(circle at bottom left, #0f172a, transparent);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
}

header {
    text-align: center;
    margin-bottom: 3rem;
    animation: fadeInDown 1s ease-out;
}

h1 {
    font-size: 2.5rem;
    background: linear-gradient(to right, var(--primary), var(--secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 0.5rem;
}

.glass-card {
    background: var(--card-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid var(--glass-border);
    border-radius: 20px;
    padding: 2rem;
    box-shadow: var(--shadow);
    margin-bottom: 2rem;
}

.grid-input {
    display: grid;
    gap: 1rem;
    margin-bottom: 2rem;
}

.matrix-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1.5rem;
    position: relative;
    /* For scroll indicator */
}

.matrix-row {
    display: flex;
    gap: 0.5rem;
    align-items: center;
}

.matrix-input {
    width: 60px;
    height: 45px;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--glass-border);
    border-radius: 8px;
    color: var(--text);
    text-align: center;
    font-size: 1.1rem;
    transition: all 0.3s ease;
}

.matrix-input:focus {
    outline: none;
    border-color: var(--primary);
    background: rgba(0, 212, 255, 0.1);
    box-shadow: 0 0 15px rgba(0, 212, 255, 0.3);
}

.equal-sign {
    font-weight: bold;
    font-size: 1.5rem;
    margin: 0 0.5rem;
    color: var(--primary);
}

.btn {
    padding: 0.8rem 1.5rem;
    border-radius: 12px;
    border: none;
    cursor: pointer;
    font-weight: 600;
    transition: all 0.3s ease;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
}

.btn-primary {
    background: linear-gradient(45deg, var(--primary), var(--secondary));
    color: white;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(0, 212, 255, 0.4);
}

.method-selector {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
    margin-top: 2rem;
}

.method-option {
    padding: 1rem;
    border: 1px solid var(--glass-border);
    border-radius: 12px;
    cursor: pointer;
    transition: all 0.3s ease;
    text-align: center;
}

.method-option.active {
    border-color: var(--primary);
    background: rgba(0, 212, 255, 0.1);
}

.results-area {
    margin-top: 3rem;
    display: none;
}

.step-card {
    border-left: 3px solid var(--primary);
    margin-bottom: 1.5rem;
    padding: 1rem 1.5rem;
    background: rgba(255, 255, 255, 0.02);
}

@keyframes fadeInDown {
    from {
        opacity: 0;
        transform: translateY(-20px);
    }

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

/* Responsiveness */
@media (max-width: 768px) {
    .container {
        padding: 0.5rem;
    }

    h1 {
        font-size: 1.6rem;
    }

    .glass-card {
        padding: 1rem;
        border-radius: 15px;
    }

    .matrix-container {
        width: 100%;
        overflow-x: auto;
        padding-bottom: 1.5rem;
        align-items: flex-start;
        cursor: grab;
    }

    .matrix-row {
        min-width: max-content;
        padding: 0.4rem 0;
        gap: 0.3rem;
        /* Tighter gap on mobile */
    }

    .matrix-row span {
        font-size: 0.8rem;
        /* Smaller labels */
        margin-right: 2px !important;
    }

    .matrix-input {
        width: 42px;
        height: 36px;
        font-size: 0.85rem;
        border-radius: 6px;
    }

    .equal-sign {
        font-size: 1.2rem;
        margin: 0 0.2rem;
    }

    .method-selector {
        grid-template-columns: 1fr;
        gap: 0.5rem;
    }

    .method-option {
        padding: 0.8rem;
        font-size: 0.9rem;
    }

    /* Scroll indicator hint */
    .matrix-container::after {
        content: '';
        position: absolute;
        right: 0;
        top: 0;
        bottom: 0;
        width: 30px;
        background: linear-gradient(to left, var(--bg-color), transparent);
        pointer-events: none;
        opacity: 0.5;
    }
}

/* Custom Scrollbar for Matrix */
.matrix-container::-webkit-scrollbar {
    height: 6px;
}

.matrix-container::-webkit-scrollbar-track {
    background: rgba(255, 255, 255, 0.05);
    border-radius: 10px;
}

.matrix-container::-webkit-scrollbar-thumb {
    background: var(--primary);
    border-radius: 10px;
}


@media (max-width: 768px) {
    .step-card {
        padding: 0.8rem;
        font-size: 0.85rem;
    }

    .step-card table {
        font-size: 0.75rem;
    }

    footer {
        margin-top: 2rem;
        padding-bottom: 2rem;
    }
}