:root {
    --bg-color: #0b0f19; /* Deep dark blue */
    --surface-color: rgba(255, 255, 255, 0.03);
    --surface-border: rgba(255, 255, 255, 0.08);
    --primary-color: #3b82f6;
    --primary-glow: rgba(59, 130, 246, 0.5);
    --accent-color: #8b5cf6;
    --text-main: #f8fafc;
    --text-muted: #94a3b8;
    --font-family: 'Outfit', sans-serif;
}

body {
    background-color: var(--bg-color);
    color: var(--text-main);
    font-family: var(--font-family);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    overflow-x: hidden;
}

/* Background Gradients for Premium Look */
body::before {
    content: '';
    position: fixed;
    top: -20%;
    left: -10%;
    width: 60%;
    height: 60%;
    background: radial-gradient(circle, var(--primary-glow) 0%, rgba(11, 15, 25, 0) 60%);
    z-index: -1;
    filter: blur(100px);
}
body::after {
    content: '';
    position: fixed;
    bottom: -20%;
    right: -10%;
    width: 60%;
    height: 60%;
    background: radial-gradient(circle, rgba(139, 92, 246, 0.3) 0%, rgba(11, 15, 25, 0) 60%);
    z-index: -1;
    filter: blur(100px);
}

/* Glassmorphism Cards */
.glass-nav {
    background: rgba(11, 15, 25, 0.4);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--surface-border);
}

.glass-card {
    background: var(--surface-color);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--surface-border);
    border-radius: 1.5rem;
    padding: 2rem;
    box-shadow: 0 4px 30px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.glass-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.2);
    border-color: rgba(255, 255, 255, 0.12);
}

.glass-footer {
    background: rgba(11, 15, 25, 0.8);
    backdrop-filter: blur(20px);
    border-top: 1px solid var(--surface-border);
}

/* Typography elements */
h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
}

.text-gradient {
    background: linear-gradient(135deg, #60a5fa, #c084fc);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

/* Forms */
.form-select, .form-control {
    background-color: rgba(0,0,0,0.3) !important;
    border: 1px solid var(--surface-border) !important;
    color: var(--text-main) !important;
    border-radius: 0.75rem;
    padding: 0.75rem 1rem;
    transition: all 0.2s ease;
}

.form-select:focus, .form-control:focus {
    box-shadow: 0 0 0 0.25rem var(--primary-glow) !important;
    border-color: var(--primary-color) !important;
}

.form-select option {
    background-color: var(--bg-color);
    color: var(--text-main);
}

/* Custom Buttons */
.btn-primary-custom {
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    border: none;
    color: white;
    font-weight: 600;
    border-radius: 0.75rem;
    padding: 0.75rem 1.5rem;
    transition: all 0.3s ease;
}

.btn-primary-custom:hover {
    box-shadow: 0 0 20px rgba(96, 165, 250, 0.5);
    transform: scale(1.02);
    color: white;
}

.btn-secondary-custom {
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--surface-border);
    color: var(--text-main);
    font-weight: 600;
    border-radius: 0.75rem;
    padding: 0.75rem 1.5rem;
    transition: all 0.3s ease;
}

.btn-secondary-custom:hover {
    background: rgba(255, 255, 255, 0.1);
    color: white;
}

/* Nav Links */
.nav-link-custom {
    color: var(--text-muted);
    text-decoration: none;
    font-size: 0.95rem;
    transition: color 0.2s ease;
}

.nav-link-custom:hover {
    color: var(--primary-color);
}

/* Result Grids */
.metric-box {
    background: rgba(0,0,0,0.2);
    border: 1px solid rgba(255,255,255,0.05);
    border-radius: 1rem;
    padding: 1.5rem;
    text-align: center;
    transition: all 0.3s ease;
    height: 100%;
    display: flex;
    flex-direction: column;
    justify-content: center;
}
.metric-box:hover {
    background: rgba(0,0,0,0.3);
    border-color: var(--primary-color);
}
.metric-value {
    font-size: 1.7rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    background: linear-gradient(to right, #ffffff, #94a3b8);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}
.metric-label {
    color: var(--text-muted);
    font-size: 0.85rem;
    text-transform: uppercase;
    letter-spacing: 1px;
    font-weight: 500;
}

/* Main Result Boxes */
.main-result-box {
    text-align: center;
    padding: 2rem;
    border-radius: 1rem;
    background: linear-gradient(135deg, rgba(59, 130, 246, 0.1), rgba(139, 92, 246, 0.1));
    border: 1px solid rgba(59, 130, 246, 0.2);
    height: 100%;
    display: flex;
    flex-direction: column;
    justify-content: center;
}
.main-result-value {
    font-size: 3.5rem;
    font-weight: 800;
    line-height: 1;
    margin-bottom: 0.5rem;
    background: linear-gradient(135deg, #60a5fa, #c084fc);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

/* Calendar Styles */
.calendar-container {
    background: rgba(0,0,0,0.2);
    border-radius: 1rem;
    padding: 1.5rem;
}
.calendar-header {
    text-align: center;
    font-weight: bold;
    margin-bottom: 1rem;
    font-size: 1.2rem;
}
.calendar-grid {
    display: grid;
    grid-template-columns: repeat(7, 1fr);
    gap: 0.25rem;
    text-align: center;
}
.calendar-day-header {
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--text-muted);
    padding-bottom: 0.5rem;
}
.calendar-day {
    padding: 0.5rem 0;
    border-radius: 0.5rem;
    background: rgba(255,255,255,0.02);
    font-size: 0.9rem;
    display: flex;
    align-items: center;
    justify-content: center;
}
.calendar-day.highlight-birth {
    background: var(--primary-color);
    color: white;
    font-weight: bold;
    box-shadow: 0 0 15px var(--primary-glow);
}
.calendar-day.highlight-next {
    background: var(--accent-color);
    color: white;
    font-weight: bold;
    box-shadow: 0 0 15px rgba(139, 92, 246, 0.5);
}
.calendar-day.empty {
    background: transparent;
}

#result-section {
    display: none;
    animation: fadeIn 0.5s ease;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

.copy-feedback {
    display: none;
    font-size: 0.85rem;
    color: #4ade80;
    margin-top: 0.5rem;
}