:root {
    /* Color Palette */
    --primary: #6366f1; /* Indigo */
    --primary-hover: #4f46e5;
    --background: #0f172a; /* Slate 900 */
    --surface: #1e293b; /* Slate 800 */
    --surface-hover: #334155; /* Slate 700 */
    --text-main: #f8fafc; /* Slate 50 */
    --text-muted: #94a3b8; /* Slate 400 */
    --danger: #ef4444;
    --success: #22c55e;
    
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    font-family: 'Inter', system-ui, -apple-system, sans-serif;
    background-color: var(--background);
    color: var(--text-main);
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
}

a {
    color: var(--primary);
    text-decoration: none;
    transition: color 0.2s;
}

a:hover {
    color: var(--primary-hover);
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 1rem;
}

h1 { font-size: 2.5rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.25rem; }
p { margin-bottom: 1rem; color: var(--text-muted); }

/* Layout */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
}

/* Forms */
.form-group {
    margin-bottom: 1.25rem;
}

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

input[type="text"],
input[type="email"],
input[type="password"] {
    width: 100%;
    padding: 0.75rem 1rem;
    border-radius: var(--radius-md);
    border: 1px solid var(--surface-hover);
    background-color: var(--surface);
    color: var(--text-main);
    font-size: 1rem;
    transition: border-color 0.2s;
}

input:focus {
    outline: none;
    border-color: var(--primary);
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.75rem 1.5rem;
    border-radius: var(--radius-md);
    font-weight: 600;
    font-size: 1rem;
    cursor: pointer;
    transition: all 0.2s;
    border: none;
}

.btn-primary {
    background-color: var(--primary);
    color: #fff;
}

.btn-primary:hover {
    background-color: var(--primary-hover);
    transform: translateY(-1px);
}

/* Cards */
.card {
    background-color: var(--surface);
    border-radius: var(--radius-lg);
    padding: 1.5rem;
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
}

/* Nav */
.navbar {
    background-color: var(--surface);
    padding: 1rem 0;
    border-bottom: 1px solid var(--surface-hover);
}
.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}
.navbar-brand {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-main);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}
.nav-links {
    display: flex;
    gap: 1.5rem;
}

/* Alerts */
.alert {
    padding: 1rem;
    border-radius: var(--radius-md);
    margin-bottom: 1rem;
}
.alert-error {
    background-color: rgba(239, 68, 68, 0.1);
    border: 1px solid var(--danger);
    color: #fca5a5;
}
.alert-success {
    background-color: rgba(34, 197, 94, 0.1);
    border: 1px solid var(--success);
    color: #86efac;
}

/* Auth Pages */
.auth-container {
    max-width: 400px;
    margin: 4rem auto;
}