:root {
    --bg-color: #f8fafc;
    --card-bg: #ffffff;
    --primary: #3b82f6;
    --primary-hover: #2563eb;
    --secondary: #10b981;
    --secondary-hover: #059669;
    --text-main: #1e293b;
    --text-muted: #64748b;
    --border-color: #e2e8f0;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -1px rgba(0, 0, 0, 0.03);
    --shadow-hover: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

body {
    background-color: var(--bg-color);
    color: var(--text-main);
    line-height: 1.5;
}

/* Navigation */
nav {
    background-color: var(--card-bg);
    border-bottom: 1px solid var(--border-color);
    padding: 1rem 2rem;
    display: flex;
    justify-content: center;
    gap: 1rem;
    position: sticky;
    top: 0;
    z-index: 100;
}

.nav-btn {
    background: none;
    border: none;
    font-size: 0.95rem;
    font-weight: 600;
    color: var(--text-muted);
    cursor: pointer;
    padding: 0.5rem 1rem;
    border-radius: 8px;
    transition: var(--transition);
}

.nav-btn:hover, .nav-btn.active {
    color: var(--primary);
    background-color: #eff6ff;
}

/* Layout */
.container {
    max-width: 1000px;
    margin: 2rem auto;
    padding: 0 1.5rem;
}

.page {
    display: none;
    animation: fadeIn 0.4s ease-in-out;
}

.page.active {
    display: block;
}

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

/* Typography */
h1 { margin-bottom: 0.5rem; color: var(--text-main); }
h2 { margin-bottom: 1rem; color: var(--text-main); font-size: 1.25rem; }
p.subtitle { color: var(--text-muted); margin-bottom: 2rem; }

/* Cards & Grid */
.grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.card {
    background-color: var(--card-bg);
    border-radius: 12px;
    padding: 1.5rem;
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow);
    transition: var(--transition);
    margin-bottom: 1.5rem;
}

.card:hover {
    box-shadow: var(--shadow-hover);
    transform: translateY(-2px);
}

/* Progress Bars */
.progress-wrapper { margin-bottom: 1rem; }
.progress-header { display: flex; justify-content: space-between; font-size: 0.875rem; font-weight: 600; margin-bottom: 0.5rem; }
.progress-bar { height: 8px; background-color: var(--border-color); border-radius: 4px; overflow: hidden; }
.progress-fill { height: 100%; background-color: var(--primary); border-radius: 4px; transition: width 1s ease-in-out; }

/* Info Section */
.info-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; font-size: 0.875rem; }
.info-item { background: #f1f5f9; padding: 0.75rem; border-radius: 8px; text-align: center; }
.info-item span { display: block; font-weight: bold; font-size: 1.125rem; color: var(--primary); }

/* Forms, Inputs & Buttons */
textarea, select, input[type="text"] {
    width: 100%;
    padding: 0.75rem 1rem;
    border-radius: 8px;
    border: 1px solid var(--border-color);
    font-size: 0.9rem;
    margin-bottom: 1rem;
    background-color: #f8fafc;
    transition: var(--transition);
}

textarea#jsonInput { height: 300px; font-family: monospace; resize: vertical; }
textarea:focus, select:focus, input[type="text"]:focus { outline: none; border-color: var(--primary); box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1); }

.btn-group { display: flex; gap: 1rem; flex-wrap: wrap; }
.btn { padding: 0.75rem 1.5rem; border-radius: 8px; border: none; font-weight: 600; cursor: pointer; transition: var(--transition); display: inline-flex; align-items: center; justify-content: center; }
.btn-primary { background-color: var(--primary); color: white; }
.btn-primary:hover { background-color: var(--primary-hover); }
.btn-success { background-color: var(--secondary); color: white; width: 100%; }
.btn-success:hover { background-color: var(--secondary-hover); }
.btn-secondary { background-color: white; color: var(--text-main); border: 1px solid var(--border-color); }
.btn-secondary:hover { background-color: #f1f5f9; }

/* Timeline UI */
.timeline {
    position: relative;
    padding-left: 2rem;
    margin-top: 1.5rem;
}
.timeline::before {
    content: '';
    position: absolute;
    left: 0.5rem;
    top: 0;
    bottom: 0;
    width: 2px;
    background-color: var(--border-color);
}
.timeline-item {
    position: relative;
    margin-bottom: 1.5rem;
}
.timeline-dot {
    position: absolute;
    left: -2.35rem;
    top: 0.25rem;
    width: 1rem;
    height: 1rem;
    border-radius: 50%;
    background-color: var(--primary);
    border: 3px solid white;
    box-shadow: 0 0 0 2px var(--primary);
}
.timeline-content {
    background: #f8fafc;
    padding: 1rem;
    border-radius: 8px;
    border: 1px solid var(--border-color);
}
.timeline-header {
    display: flex;
    justify-content: space-between;
    margin-bottom: 0.5rem;
    font-size: 0.875rem;
}
.timeline-name { font-weight: 700; color: var(--text-main); }
.timeline-date { color: var(--text-muted); font-size: 0.75rem; }
.timeline-text { color: var(--text-main); font-size: 0.95rem; }

/* Links */
.link-card { display: block; text-decoration: none; color: inherit; text-align: center; }
.link-icon { font-size: 2.5rem; margin-bottom: 1rem; }

/* Toast */
.toast {
    position: fixed; bottom: 20px; right: 20px; background: var(--secondary); color: white; padding: 1rem 2rem;
    border-radius: 8px; font-weight: 600; opacity: 0; transform: translateY(20px); transition: var(--transition); z-index: 1000;
}
.toast.show { opacity: 1; transform: translateY(0); }

/* Two Column Layout */
.split-layout { display: grid; grid-template-columns: 1fr 2fr; gap: 1.5rem; }
@media (max-width: 768px) { .split-layout { grid-template-columns: 1fr; } }

/* ==========================================================================
   MEDIA QUERY: Optimasi Otomatis untuk Layar HP (Maksimal 600px)
   ========================================================================== */
@media (max-width: 600px) {
    nav {
        padding: 0.75rem;
        gap: 0.5rem;
        flex-wrap: wrap;
    }

    .nav-btn {
        font-size: 0.85rem;
        padding: 0.4rem 0.6rem;
        flex: 1 1 40%;
        text-align: center;
    }

    .container {
        margin: 1rem auto;
        padding: 0 0.75rem;
    }

    .card {
        padding: 1rem;
        margin-bottom: 1rem;
    }

    h1 { font-size: 1.5rem; }
    h2 { font-size: 1.1rem; }
    p.subtitle { margin-bottom: 1.25rem; font-size: 0.9rem; }

    #dashboard .grid {
        grid-template-columns: 1fr !important;
        gap: 1rem;
    }

    .card div[style*="grid-template-columns"] {
        gap: 0.25rem !important;
    }
    
    .card span[style*="font-size: 1.125rem"] {
        font-size: 1rem !important;
    }
    
    .card small {
        font-size: 0.65rem !important;
    }
}

/* Scrollbar Minimalis Khusus untuk Timeline Window */
#timelineContainer::-webkit-scrollbar {
    width: 6px;
}
#timelineContainer::-webkit-scrollbar-track {
    background: transparent;
}
#timelineContainer::-webkit-scrollbar-thumb {
    background: #cbd5e1;
    border-radius: 10px;
}
#timelineContainer::-webkit-scrollbar-thumb:hover {
    background: #94a3b8;
}