/* --- Modern Variables & Root Settings --- */
:root {
    --primary-color: #4a90e2;
    --primary-hover: #357abd;
    --secondary-color: #1a1a2e; /* Deep Navy for Header */
    --accent-color: #f1c40f;    /* Gold for Admin/Highlight */
    --danger-color: #dc3545;
    --success-color: #28a745;
    --text-main: #333333;
    --text-muted: #6c757d;
    --bg-body: #f4f7f6;
    --white: #ffffff;
    --shadow: 0 4px 15px rgba(0, 0, 0, 0.08);
    --radius: 10px;
    --transition: all 0.3s ease;
}

/* --- Base Reset --- */
* {
    box-sizing: border-box;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Arial, sans-serif;
    background-color: var(--bg-body);
    color: var(--text-main);
    margin: 0;
    padding: 0;
    line-height: 1.6;
}

.container {
    width: 90%;
    max-width: 1200px;
    margin: auto;
}

/* --- Professional Header (Replaced Old Styles) --- */
.main-header {
    background: var(--secondary-color);
    color: var(--white);
    padding: 12px 0;
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: 0 4px 20px rgba(0,0,0,0.2);
}

.header-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 1.6rem;
    font-weight: 800;
    color: var(--white);
    text-decoration: none;
}

.logo i {
    color: var(--primary-color);
    font-size: 1.8rem;
}

/* Navigation Menu */
.nav-menu ul {
    display: flex;
    align-items: center;
    list-style: none;
    margin: 0;
    padding: 0;
    gap: 8px;
}

.nav-menu li a {
    color: #cbd5e0;
    text-decoration: none;
    padding: 10px 16px;
    font-size: 0.95rem;
    font-weight: 500;
    border-radius: var(--radius);
    transition: var(--transition);
    display: flex;
    align-items: center;
    gap: 8px;
}

.nav-menu li a:hover {
    color: var(--white);
    background: rgba(255, 255, 255, 0.1);
}

/* Special Menu Classes */
.btn-register {
    background: var(--primary-color);
    color: var(--white) !important;
}

.btn-register:hover {
    background: var(--primary-hover) !important;
}

.btn-logout {
    color: #ff7675 !important;
}

.admin-link {
    color: var(--accent-color) !important;
}

/* --- Content Wrapper & Cards --- */
.main-content, .content-wrapper {
    padding: 30px;
    background: var(--white);
    margin-top: 30px;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    min-height: 60vh;
}

/* --- Forms & UI Elements --- */
.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    color: var(--text-main);
}

.form-group input, .form-group select {
    width: 100%;
    padding: 12px 15px;
    border: 1px solid #e0e0e0;
    border-radius: 8px;
    font-size: 1rem;
    transition: var(--transition);
}

.form-group input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(74, 144, 226, 0.1);
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 12px 24px;
    font-size: 1rem;
    font-weight: 600;
    color: var(--white);
    background-color: var(--primary-color);
    border: none;
    border-radius: 8px;
    cursor: pointer;
    text-decoration: none;
    transition: var(--transition);
}

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

.btn-danger { background-color: var(--danger-color); }
.btn-danger:hover { background-color: #c82333; }
.btn-secondary { background-color: #6c757d; }

/* --- Subscription Cards --- */
.subscription-card {
    display: flex;
    align-items: center;
    padding: 25px;
    border-radius: var(--radius);
    margin-bottom: 25px;
    color: white;
    transition: transform 0.3s ease;
}

.subscription-card:hover { transform: scale(1.01); }
.subscription-card.active { background: linear-gradient(135deg, #28a745, #1e7e34); }
.subscription-card.expired { background: linear-gradient(135deg, #dc3545, #bd2130); }

.subscription-card .icon { font-size: 3rem; margin-right: 25px; opacity: 0.9; }
.subscription-card .content h3 { margin: 0; font-size: 1.6rem; }

/* --- Tables & Data --- */
.payment-details-table {
    margin: 25px 0;
    border: 1px solid #eee;
    border-radius: 8px;
    overflow: hidden;
}

.payment-details-table table {
    width: 100%;
    border-collapse: collapse;
}

.payment-details-table th, .payment-details-table td {
    padding: 15px;
    text-align: left;
    border-bottom: 1px solid #eee;
}

.payment-details-table th {
    background-color: #f9fafb;
    color: var(--text-muted);
    font-size: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.payment-details-table td {
    font-family: 'Courier New', monospace;
    font-weight: 600;
}

/* --- Mobile Responsiveness --- */
.nav-toggle { display: none; }

@media (max-width: 992px) {
    .nav-toggle-label {
        display: block;
        cursor: pointer;
        padding: 10px;
    }

    .nav-toggle-label span, .nav-toggle-label span::before, .nav-toggle-label span::after {
        display: block;
        background: white;
        height: 2px;
        width: 25px;
        position: relative;
        transition: 0.3s;
    }
    .nav-toggle-label span::before { content: ""; position: absolute; top: -8px; width: 100%; background: white; height: 2px; }
    .nav-toggle-label span::after { content: ""; position: absolute; bottom: -8px; width: 100%; background: white; height: 2px; }

    .nav-menu {
        position: absolute;
        top: 100%;
        left: 0;
        width: 100%;
        background: var(--secondary-color);
        max-height: 0;
        overflow: hidden;
        transition: max-height 0.4s ease;
    }

    .nav-menu ul {
        flex-direction: column;
        padding: 20px;
        gap: 5px;
    }

    .nav-toggle:checked ~ .nav-menu { max-height: 100vh; }
}

/* --- Footer --- */
footer {
    background: var(--secondary-color);
    color: rgba(255,255,255,0.6);
    text-align: center;
    padding: 40px 20px;
    margin-top: 50px;
    font-size: 0.9rem;
}
```