/* CSS Variables for Theming */
:root {
    --primary-color: #3498db;
    --primary-dark: #2980b9;
    --secondary-color: #2ecc71;
    --danger-color: #e74c3c;
    --dark-color: #2c3e50;
    --light-color: #ecf0f1;
    --border-color: #bdc3c7;
    --text-primary: #2c3e50;
    --text-secondary: #7f8c8d;
    --background: #ffffff;
    --shadow: rgba(0, 0, 0, 0.1);
    --transition-speed: 0.3s;
    --max-width: 1200px;
}

/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--light-color);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Container */
.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 20px;
    width: 100%;
}

/* Header and Navigation */
.header {
    background-color: var(--dark-color);
    box-shadow: 0 2px 10px var(--shadow);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.navbar {
    padding: 1rem 0;
}

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

.brand .logo {
    color: var(--light-color);
    font-size: 1.5rem;
    font-weight: bold;
    text-decoration: none;
    transition: color var(--transition-speed);
}

.brand .logo:hover {
    color: var(--primary-color);
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-link {
    color: var(--light-color);
    text-decoration: none;
    font-weight: 500;
    padding: 0.5rem 1rem;
    border-radius: 4px;
    transition: all var(--transition-speed);
}

.nav-link:hover,
.nav-link.active {
    background-color: var(--primary-color);
    color: var(--background);
}

/* Hamburger Menu (Mobile) */
.hamburger {
    display: none;
    flex-direction: column;
    cursor: pointer;
}

.hamburger .bar {
    width: 25px;
    height: 3px;
    background-color: var(--light-color);
    margin: 3px 0;
    transition: 0.3s;
}

/* Main Content */
.main {
    flex: 1;
    padding: 2rem 0;
}

.app-content {
    background-color: var(--background);
    padding: 2rem;
    border-radius: 8px;
    box-shadow: 0 4px 6px var(--shadow);
    min-height: 400px;
}

/* Page Transition Animations */
.page-enter {
    animation: fadeIn 0.4s ease-in;
}

.page-exit {
    animation: fadeOut 0.3s ease-out;
}

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

@keyframes fadeOut {
    from {
        opacity: 1;
    }
    to {
        opacity: 0;
    }
}

/* Footer */
.footer {
    background-color: var(--dark-color);
    color: var(--light-color);
    text-align: center;
    padding: 1.5rem 0;
    margin-top: auto;
}

/* Loading Overlay */
.loading-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    justify-content: center;
    align-items: center;
    z-index: 9999;
}

.loading-overlay.show {
    display: flex;
}

.spinner {
    width: 50px;
    height: 50px;
    border: 5px solid var(--light-color);
    border-top-color: var(--primary-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* Component Styles */
.card {
    background: var(--background);
    padding: 1.5rem;
    margin: 1rem 0;
    border-radius: 8px;
    box-shadow: 0 2px 4px var(--shadow);
    border-left: 4px solid var(--primary-color);
}

.btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    background-color: var(--primary-color);
    color: var(--background);
    text-decoration: none;
    border-radius: 4px;
    border: none;
    cursor: pointer;
    font-size: 1rem;
    transition: background-color var(--transition-speed);
}

.btn:hover {
    background-color: var(--primary-dark);
}

.btn-secondary {
    background-color: var(--secondary-color);
}

/* Form Styles */
.form-group {
    margin-bottom: 1.5rem;
}

.form-label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
}

.form-control {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    font-size: 1rem;
    transition: border-color var(--transition-speed);
}

.form-control:focus {
    outline: none;
    border-color: var(--primary-color);
}

/* Mobile Responsive */
@media screen and (max-width: 768px) {
    .nav-menu {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background-color: var(--dark-color);
        width: 100%;
        text-align: center;
        transition: 0.3s;
        box-shadow: 0 10px 27px var(--shadow);
        gap: 0;
    }

    .nav-menu.active {
        left: 0;
    }

    .nav-item {
        margin: 0;
    }

    .nav-link {
        display: block;
        padding: 1.5rem;
    }

    .hamburger {
        display: flex;
    }

    .hamburger.active .bar:nth-child(2) {
        opacity: 0;
    }

    .hamburger.active .bar:nth-child(1) {
        transform: translateY(9px) rotate(45deg);
    }

    .hamburger.active .bar:nth-child(3) {
        transform: translateY(-9px) rotate(-45deg);
    }

    .app-content {
        padding: 1rem;
    }
}

@media screen and (max-width: 480px) {
    .brand .logo {
        font-size: 1.2rem;
    }

    .app-content {
        padding: 0.75rem;
    }
}