:root {
    /* Light Mode Variables (Default) */
    --bg-color: #f8fafc;
    --card-bg: #ffffff;
    --text-main: #1e293b;
    --text-muted: #64748b;
    --primary-color: #3b82f6;
    --border-color: #e2e8f0;
    --danger-color: #e11d48;
    --danger-bg: #fff1f2;
    --code-bg: #f1f5f9;
    --code-text: #0f172a;
    --radius: 12px;
    --shadow-sm: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -1px rgba(0, 0, 0, 0.03);
    --shadow-hover: 0 10px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.1);
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

[data-theme="dark"] {
    /* Dark Mode Variables */
    --bg-color: #0f172a;
    --card-bg: #1e293b;
    --text-main: #f8fafc;
    --text-muted: #94a3b8;
    --primary-color: #60a5fa;
    --border-color: #334155;
    --danger-color: #fb7185;
    --danger-bg: rgba(225, 29, 72, 0.15); /* Translucent red */
    --code-bg: #0b1120;
    --code-text: #e2e8f0;
    --shadow-sm: 0 4px 6px -1px rgba(0, 0, 0, 0.3), 0 2px 4px -1px rgba(0, 0, 0, 0.2);
    --shadow-hover: 0 10px 25px -5px rgba(0, 0, 0, 0.4), 0 8px 10px -6px rgba(0, 0, 0, 0.3);
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-main);
    line-height: 1.6;
    padding: 2rem;
    margin: 0;
    transition: background-color 0.3s ease, color 0.3s ease;
}

.guide-section {
    max-width: 900px;
    margin: 0 auto;
}

/* Top Controls (Theme + Lang) */
.top-controls {
    display: flex;
    justify-content: flex-end;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.theme-btn {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    padding: 0.4rem 0.6rem;
    border-radius: 6px;
    font-size: 1.1rem;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
}

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

.lang-bar {
    display: flex;
    gap: 0.5rem;
}

.lang-btn {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    padding: 0.4rem 0.8rem;
    border-radius: 6px;
    font-size: 0.85rem;
    font-weight: 600;
    cursor: pointer;
    color: var(--text-muted);
    transition: var(--transition);
}

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

.lang-btn.active {
    background: var(--primary-color);
    color: #ffffff;
    border-color: var(--primary-color);
}

/* Section Header */
.section-header {
    text-align: center;
    margin-bottom: 3rem;
}

.section-header h2 {
    font-size: 2.25rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    letter-spacing: -0.02em;
    color: var(--text-main);
}

.section-header p {
    color: var(--text-muted);
    font-size: 1.1rem;
}

/* Cards */
.step-card {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    padding: 2rem;
    margin-bottom: 1.5rem;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}

.step-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-hover);
}

.step-card h3 {
    margin-top: 0;
    color: var(--primary-color);
    font-size: 1.25rem;
}

.step-card p {
    color: var(--text-muted);
    margin-bottom: 1.25rem;
}

/* Lists */
.guide-list {
    list-style: none;
    padding: 0;
    margin: 0;
}

.guide-list li {
    position: relative;
    padding-left: 1.5rem;
    margin-bottom: 0.75rem;
    color: var(--text-main);
}

.guide-list li::before {
    content: "→";
    position: absolute;
    left: 0;
    color: var(--primary-color);
    font-weight: bold;
}

code {
    background-color: var(--code-bg);
    padding: 0.2rem 0.4rem;
    border-radius: 4px;
    font-family: monospace;
    font-size: 0.9em;
    color: var(--code-text);
}

/* Options Grid */
.installation-options {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
    margin-top: 1.5rem;
}

.option-box {
    background: var(--bg-color);
    border: 1px solid var(--border-color);
    padding: 1.5rem;
    border-radius: 8px;
    transition: var(--transition);
}

.option-box h4 {
    margin-top: 0;
    font-size: 1.1rem;
    color: var(--text-main);
}

.option-box .benefit {
    display: inline-block;
    margin-top: 1rem;
    font-size: 0.85rem;
    font-style: italic;
    color: var(--text-muted);
}

/* Troubleshooting Section */
.troubleshoot-container {
    margin-top: 3.5rem;
    padding-top: 2rem;
    border-top: 2px dashed var(--border-color);
}

.troubleshoot-header {
    margin-bottom: 2rem;
}

.troubleshoot-header h2 {
    color: var(--text-main);
}

.mini-label {
    display: inline-block;
    background-color: var(--danger-bg);
    color: var(--danger-color);
    padding: 0.25rem 0.75rem;
    border-radius: 999px;
    font-size: 0.85rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 0.5rem;
}

.setup-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
}

.troubleshoot-card {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-left: 4px solid var(--danger-color);
    border-radius: var(--radius);
    padding: 1.5rem;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}

.troubleshoot-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-hover);
}

.troubleshoot-card h4 {
    margin-top: 0;
    margin-bottom: 1rem;
    font-size: 1.1rem;
    color: var(--text-main);
}

.troubleshoot-card .guide-list li::before {
    content: "•";
    color: var(--danger-color);
}

/* =========================================
   Mobile Responsiveness (Media Queries)
   ========================================= */
@media (max-width: 768px) {
    body {
        padding: 1rem; /* Reduce outer spacing */
    }

    .top-controls {
        justify-content: space-between; /* Spread theme and lang buttons */
        margin-bottom: 2rem;
    }

    .lang-btn {
        padding: 0.4rem 0.6rem;
        font-size: 0.8rem; /* Slightly smaller text for narrow screens */
    }

    .section-header h2 {
        font-size: 1.75rem; /* Scale down main heading */
    }

    .section-header p {
        font-size: 1rem;
    }

    .step-card {
        padding: 1.25rem; /* Reduce card inner spacing */
    }

    .step-card h3 {
        font-size: 1.15rem;
    }

    .installation-options {
        /* Force single column on mobile */
        grid-template-columns: 1fr; 
        gap: 1rem;
    }

    .option-box {
        padding: 1.25rem;
    }

    .troubleshoot-container {
        margin-top: 2.5rem;
        padding-top: 1.5rem;
    }

    .setup-grid {
        /* Force single column on mobile */
        grid-template-columns: 1fr; 
        gap: 1rem;
    }

    .troubleshoot-card {
        padding: 1.25rem;
    }
}

/* Optional: Target very small screens (like older iPhones) */
@media (max-width: 375px) {
    .top-controls {
        flex-direction: column-reverse; /* Stack controls vertically */
        align-items: stretch;
        gap: 1rem;
    }
    
    .lang-bar {
        justify-content: stretch;
    }

    .lang-btn {
        flex: 1; /* Make lang buttons take equal width */
        text-align: center;
    }
}