:root {
    --primary: #10b981;
    /* Emerald */
    --primary-dark: #059669;
    --secondary: #06b6d4;
    /* Cyan */
    --accent: #f59e0b;
    /* Amber/Gold */
    --bg-dark: #020617;
    --card-bg: rgba(15, 23, 42, 0.7);
    --text-main: #f1f5f9;
    --text-muted: #94a3b8;
    --glass-border: rgba(255, 255, 255, 0.1);
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --crystal-shadow: 0 0 20px rgba(16, 185, 129, 0.2);
}

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

body {
    background: var(--bg-dark);
    color: var(--text-main);
    overflow-x: hidden;
    min-height: 100vh;
}

.crystal-bg {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
    background: radial-gradient(circle at 10% 20%, rgba(16, 185, 129, 0.05) 0%, transparent 40%),
        radial-gradient(circle at 90% 80%, rgba(6, 182, 212, 0.05) 0%, transparent 40%);
}

.app-container {
    display: grid;
    grid-template-columns: 280px 1fr;
    min-height: 100vh;
}

.sidebar {
    background: rgba(2, 6, 23, 0.9);
    backdrop-filter: blur(20px);
    border-right: 1px solid var(--glass-border);
    padding: 2.5rem 1.5rem;
    position: sticky;
    top: 0;
    height: 100vh;
}

.logo {
    font-size: 1.5rem;
    font-weight: 800;
    margin-bottom: 3rem;
}

.logo span {
    background: linear-gradient(to right, var(--primary), var(--secondary));
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

.nav-menu {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 0.8rem;
}

.nav-item {
    padding: 1rem;
    border-radius: 12px;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    gap: 1rem;
    color: var(--text-muted);
    font-weight: 500;
}

.nav-item:hover,
.nav-item.active {
    background: rgba(16, 185, 129, 0.1);
    color: var(--primary);
    transform: translateX(5px);
}

.nav-item.vibrant-gold {
    color: #fbbf24;
    border: 1px solid rgba(251, 191, 36, 0.4);
    font-weight: 700;
}

.nav-item.vibrant-gold:hover {
    background: rgba(251, 191, 36, 0.1);
    box-shadow: 0 0 15px rgba(251, 191, 36, 0.2);
}

.main-content {
    padding: 3rem;
    max-width: 1200px;
    margin: 0 auto;
    width: 100%;
}

.header h1 {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
}

.header p {
    color: var(--text-muted);
    margin-bottom: 3rem;
}

.content-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 2rem;
}

.info-card {
    background: var(--card-bg);
    border: 1px solid var(--glass-border);
    border-radius: 24px;
    padding: 2rem;
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.info-card:hover {
    border-color: var(--primary);
    box-shadow: var(--crystal-shadow);
    transform: translateY(-5px);
}

.card-title {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
    display: flex;
    align-items: center;
    gap: 0.75rem;
    color: var(--primary);
}

.trend-row {
    display: flex;
    justify-content: space-between;
    padding: 0.8rem 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

.trend-label {
    font-weight: 600;
    color: var(--text-main);
}

.trend-value {
    color: var(--secondary);
    font-weight: 700;
}

.color-swatch {
    width: 20px;
    height: 20px;
    border-radius: 50%;
    display: inline-block;
}

.logic-box {
    background: rgba(2, 6, 23, 0.5);
    padding: 1rem;
    border-radius: 12px;
    margin-top: 1rem;
    border-left: 3px solid var(--accent);
}

.logic-box b {
    border-bottom: 1px dashed var(--accent);
}

.formula-display {
    background: #1e293b;
    padding: 1rem;
    border-radius: 12px;
    font-family: 'Courier New', Courier, monospace;
    color: #38bdf8;
    margin: 1rem 0;
    font-size: 1.1rem;
}

.exam-tip {
    background: rgba(245, 158, 11, 0.1);
    color: var(--accent);
    padding: 1rem;
    border-radius: 12px;
    font-size: 0.9rem;
    margin-top: 1rem;
}

@media (max-width: 900px) {
    .app-container {
        grid-template-columns: 1fr;
    }

    .sidebar {
        display: none;
    }
}