:root {
    --bg-color: #0f172a;
    --card-bg: rgba(30, 41, 59, 0.7);
    --text-color: #e2e8f0;
    --accent-color: #38bdf8;
    --accent-hover: #0ea5e9;
    --border-color: rgba(148, 163, 184, 0.1);
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background-color: var(--bg-color);
    background-image: 
        radial-gradient(at 0% 0%, hsla(253,16%,7%,1) 0, transparent 50%), 
        radial-gradient(at 50% 0%, hsla(225,39%,30%,1) 0, transparent 50%), 
        radial-gradient(at 100% 0%, hsla(339,49%,30%,1) 0, transparent 50%);
    color: var(--text-color);
    margin: 0;
    min-height: 100vh;
    display: flex;
}

/* Sidebar */
.sidebar {
    width: 250px;
    background: rgba(15, 23, 42, 0.95);
    backdrop-filter: blur(10px);
    border-right: 1px solid var(--border-color);
    padding: 2rem 1rem;
    display: flex;
    flex-direction: column;
    position: fixed;
    height: 100vh;
    top: 0;
    left: 0;
    z-index: 100;
}

.brand {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--accent-color);
    margin-bottom: 2rem;
    text-align: center;
    letter-spacing: -0.025em;
    text-transform: uppercase;
}

.nav-links {
    list-style: none;
    padding: 0;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.nav-link {
    display: block;
    padding: 0.75rem 1rem;
    color: var(--text-color);
    text-decoration: none;
    border-radius: 0.5rem;
    transition: all 0.2s ease;
    font-weight: 500;
}

.nav-link:hover, .nav-link.active {
    background: rgba(56, 189, 248, 0.1);
    color: var(--accent-color);
}

/* Main Content */
.main-content {
    margin-left: 250px;
    padding: 2rem;
    width: 100%;
    box-sizing: border-box;
}

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

h1, h2, h3 {
    margin-top: 0;
    font-weight: 700;
}

h1 {
    font-size: 2.25rem;
    margin-bottom: 1.5rem;
    background: linear-gradient(to right, #38bdf8, #818cf8);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

/* Cards */
.card {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 1rem;
    padding: 1.5rem;
    margin-bottom: 2rem;
    backdrop-filter: blur(12px);
    box-shadow: var(--shadow);
}

.grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.5rem;
}

/* Forms */
.form-group {
    margin-bottom: 1rem;
}

label {
    display: block;
    margin-bottom: 0.5rem;
    font-size: 0.875rem;
    font-weight: 500;
    color: #94a3b8;
}

input[type="text"], 
input[type="number"], 
select, 
textarea {
    width: 100%;
    padding: 0.75rem;
    border-radius: 0.5rem;
    border: 1px solid var(--border-color);
    background: rgba(15, 23, 42, 0.6);
    color: var(--text-color);
    font-family: monospace;
    transition: border-color 0.2s;
    box-sizing: border-box;
}

input:focus, 
select:focus, 
textarea:focus {
    outline: none;
    border-color: var(--accent-color);
    box-shadow: 0 0 0 2px rgba(56, 189, 248, 0.2);
}

button.btn-primary {
    background: linear-gradient(135deg, var(--accent-color), var(--accent-hover));
    color: #0f172a;
    border: none;
    padding: 0.75rem 1.5rem;
    border-radius: 0.5rem;
    font-weight: 600;
    cursor: pointer;
    transition: transform 0.1s;
    width: 100%;
    margin-top: 1rem;
}

button.btn-primary:hover {
    opacity: 0.9;
    transform: translateY(-1px);
}

button.btn-primary:active {
    transform: translateY(0);
}

/* Plots & Logs */
.plot-container img {
    max-width: 100%;
    border-radius: 0.5rem;
    border: 1px solid var(--border-color);
}

pre {
    background: rgba(0,0,0,0.3);
    padding: 1rem;
    border-radius: 0.5rem;
    overflow-x: auto;
    font-size: 0.875rem;
    color: #a5b4fc;
}

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

.fade-in {
    animation: fadeIn 0.5s ease-out forwards;
}