/* CSS Variables */
:root {
    /* Brand teal family */
    --brand-primary: #1D9E75;
    --brand-dark: #0F6E56;
    --brand-light: #E1F5EE;
    --brand-cream: #FAF5EA;
    --brand-border: rgba(29, 158, 117, 0.28);
    --brand-muted: rgba(15, 110, 86, 0.65);

    /* Legacy aliases */
    --primary-color: var(--brand-primary);
    --primary-hover: var(--brand-dark);
    --primary-light: var(--brand-light);
    --secondary-color: #212529;
    --background-color: #f8f9fa;
    --text-color: #212529;
    --border-color: var(--brand-border);
    --text-muted: #6c757d;
    --white: #fff;

    /* Bootstrap overrides */
    --bs-primary: #1D9E75;
    --bs-primary-rgb: 29, 158, 117;
    --bs-info: #E1F5EE;
    --bs-info-rgb: 225, 245, 238;
    --bs-link-color: #1D9E75;
    --bs-link-hover-color: #0F6E56;

    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;

    /* Shadows */
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 2px 4px rgba(0, 0, 0, 0.1);

    /* Z-index */
    --z-navbar: 1030;

    /* Transitions */
    --transition-base: all 0.2s ease-in-out;
}

/* Base Styles */
html {
    font-size: 16px;
}

body {
    background-color: var(--background-color);
    padding-top: 56px;
    color: var(--text-color);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Layout */
.navbar {
    box-shadow: var(--shadow-md);
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: var(--z-navbar);
    transition: var(--transition-base);
}

/* Components */
.card {
    box-shadow: var(--shadow-sm);
    border: none;
    transition: var(--transition-base);
}

.card-header {
    background-color: var(--white);
    border-bottom: 1px solid var(--border-color);
}

.card-featured {
    border-top: 3px solid var(--brand-primary);
    overflow: hidden;
}

/* Buttons */
.btn {
    transition: var(--transition-base);
}

.btn-primary {
    background-color: var(--brand-primary);
    border-color: var(--brand-primary);
}

.btn-primary:hover,
.btn-primary:focus,
.btn-primary:active {
    background-color: var(--brand-dark);
    border-color: var(--brand-dark);
}

.btn-outline-primary {
    color: var(--brand-primary);
    border-color: var(--brand-primary);
}

.btn-outline-primary:hover,
.btn-outline-primary:focus,
.btn-outline-primary.active,
.btn-outline-primary:active {
    background-color: var(--brand-primary);
    border-color: var(--brand-primary);
    color: #fff;
}

.btn-outline-dark {
    color: var(--secondary-color);
    border-color: var(--secondary-color);
}

.btn-outline-dark:hover {
    background-color: var(--secondary-color);
    border-color: var(--secondary-color);
    color: var(--white);
}

/* Tags & badges */
.badge.bg-info,
.bg-info {
    background-color: var(--brand-light) !important;
    color: var(--brand-dark) !important;
}

.badge-post,
.badge-comment {
    background-color: var(--brand-primary) !important;
    color: #fff !important;
}

/* Likes */
.like-btn.btn-primary,
.like-btn.active,
.like-btn:hover {
    background-color: var(--brand-primary);
    border-color: var(--brand-primary);
    color: #fff;
}

/* Form focus */
.form-control:focus,
.form-select:focus {
    border-color: var(--brand-primary);
    box-shadow: 0 0 0 0.2rem rgba(29, 158, 117, 0.2);
}

/* Topic thumbnail placeholders */
.topic-thumbnail-placeholder {
    background: linear-gradient(145deg, var(--brand-light) 0%, rgba(29, 158, 117, 0.18) 100%);
}

.topic-thumbnail-placeholder i {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    font-size: 2rem;
    color: var(--brand-primary);
    opacity: 0.85;
}

/* Avatar placeholders */
.profile-picture-placeholder {
    background: linear-gradient(145deg, var(--brand-light) 0%, rgba(29, 158, 117, 0.2) 100%) !important;
    color: var(--brand-primary) !important;
}

/* Social Login */
.socialaccount_provider.google {
    color: #DB4437;
    transition: var(--transition-base);
}

.socialaccount_provider.google:hover {
    color: var(--white);
}

/* Utilities */
.login-or {
    position: relative;
    text-align: center;
    margin: var(--spacing-md) 0;
}

.login-or::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 0;
    right: 0;
    height: 1px;
    background: var(--border-color);
}

.span-or {
    position: relative;
    background: var(--white);
    padding: 0 var(--spacing-md);
    color: var(--text-muted);
}

.text-primary {
    color: var(--brand-primary) !important;
}

/* Main Content */
main {
    flex: 1 0 auto;
}

/* Footer */
.footer {
    flex-shrink: 0;
}

/* Responsive Design */
@media (max-width: 768px) {
    :root {
        --spacing-md: 0.75rem;
        --spacing-lg: 1rem;
    }

    .navbar {
        padding: var(--spacing-sm);
    }

    html {
        font-size: 14px;
    }
}