:root { --navy: #1a365d; --blue: #2b6cb0; --green: #38a169; --gray: #f7fafc; }
body { font-family: 'Segoe UI', sans-serif; background: var(--gray); margin: 0; }
.nav { background: var(--navy); color: white; padding: 1rem 2rem; display: flex; justify-content: space-between; }
.container { max-width: 1000px; margin: 2rem auto; padding: 0 1rem; }
.card { background: white; padding: 2rem; border-radius: 12px; box-shadow: 0 4px 6px rgba(0,0,0,0.1); margin-bottom: 2rem; }
.drop-zone { border: 2px dashed #cbd5e0; padding: 3rem; text-align: center; border-radius: 8px; cursor: pointer; transition: 0.3s; }
.drop-zone:hover { border-color: var(--blue); background: #ebf8ff; }
table { width: 100%; border-collapse: collapse; margin-top: 1rem; }
th { background: var(--navy); color: white; padding: 12px; text-align: left; }
td { padding: 12px; border-bottom: 1px solid #e2e8f0; }
.btn { padding: 10px 20px; border: none; border-radius: 6px; cursor: pointer; font-weight: bold; }
.btn-primary { background: var(--blue); color: white; }
.status-balanced { color: var(--green); font-weight: bold; }

/* Base Colors & Variables */
:root {
    --navy: #1a365d;
    --blue: #2b6cb0;
    --green: #38a169;
    --gray-bg: #f7fafc;
    --border: #e2e8f0;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background: var(--gray-bg);
    color: #2d3748;
    margin: 0;
    line-height: 1.5;
}

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

/* Nav & Hero */
.nav {
    background: var(--navy);
    color: white;
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-links a {
    color: white;
    text-decoration: none;
    margin-left: 20px;
    font-size: 0.9rem;
}

.hero {
    background: linear-gradient(135deg, var(--navy) 0%, var(--blue) 100%);
    color: white;
    padding: 4rem 0;
    text-align: center;
    margin-bottom: -4rem; /* Overlap effect */
}

.hero h1 { font-size: 2.5rem; margin-bottom: 1rem; }
.hero p { font-size: 1.2rem; opacity: 0.9; }

/* Auth Card */
.auth-wrapper {
    max-width: 400px;
    margin: 0 auto;
    position: relative;
    z-index: 10;
}

.auth-tabs {
    display: flex;
    margin-bottom: 2rem;
    border-bottom: 1px solid var(--border);
}

.auth-tabs button {
    flex: 1;
    background: none;
    border: none;
    padding: 1rem;
    cursor: pointer;
    font-weight: 600;
    color: #718096;
}

.auth-tabs button.active {
    color: var(--blue);
    border-bottom: 2px solid var(--blue);
}

/* Forms */
.form-group { margin-bottom: 1.5rem; }
.form-group label { display: block; font-size: 0.85rem; font-weight: 600; margin-bottom: 0.5rem; }
.form-group input {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid var(--border);
    border-radius: 6px;
    box-sizing: border-box;
}

.btn-full { width: 100%; margin-top: 1rem; }

/* Features */
.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-top: 4rem;
    text-align: center;
}

.feature-item h3 { color: var(--navy); }

/* Footer */
.footer {
    margin-top: 5rem;
    padding: 2rem 0;
    background: white;
    border-top: 1px solid var(--border);
    text-align: center;
    font-size: 0.85rem;
}

.card {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
}