:root {
    --primary-blue: #2563eb;
    --dark-slate: #1e293b;
    --light-gray: #f8fafc;
    --white: #ffffff;
    --text-secondary: #475569;
    --border-light: #e2e8f0;
    --hero-grad-start: #e0e7ff;
    --tag-blue-bg: #dbeafe;
    --tag-blue-text: #1e40af;
    --tag-yellow-bg: #fef3c7;
    --tag-yellow-text: #92400e;
    --tag-green-bg: #dcfce7;
    --tag-green-text: #166534;
}

:root.dark-mode {
    --primary-blue: #3b82f6;
    --dark-slate: #f8fafc;
    --light-gray: #0f172a;
    --white: #1e293b;
    --text-secondary: #94a3b8;
    --border-light: #334155;
    --hero-grad-start: #1e293b;
    --tag-blue-bg: rgba(37, 99, 235, 0.2);
    --tag-blue-text: #93c5fd;
    --tag-yellow-bg: rgba(217, 119, 6, 0.2);
    --tag-yellow-text: #fcd34d;
    --tag-green-bg: rgba(22, 163, 74, 0.2);
    --tag-green-text: #86efac;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

body {
    font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
    background-color: var(--light-gray);
    color: var(--dark-slate);
    line-height: 1.6;
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

/* Navigation */
nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.25rem 5%;
    background-color: var(--white);
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
    position: sticky;
    top: 0;
    z-index: 10;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-blue);
    text-decoration: none;
    letter-spacing: -0.5px;
}

.nav-controls {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.hamburger-btn {
    background: none;
    border: none;
    font-size: 1.75rem;
    color: var(--dark-slate);
    cursor: pointer;
    padding: 0.25rem 0.5rem;
    line-height: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: color 0.3s;
}

.hamburger-btn:hover {
    color: var(--primary-blue);
}

.nav-links {
    display: none;
    flex-direction: column;
    position: absolute;
    top: 100%;
    left: 0;
    width: 100%;
    background-color: var(--white);
    padding: 1.5rem 5%;
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.05);
    border-top: 1px solid var(--border-light);
    gap: 1.25rem;
}

.nav-links.show {
    display: flex;
}

.nav-links .btn-primary {
    text-align: center;
    margin-top: 0.5rem;
}

.nav-link {
    color: var(--dark-slate);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s ease;
}

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

.btn-primary {
    background-color: var(--primary-blue);
    color: var(--white);
    padding: 0.5rem 1rem;
    border-radius: 0.375rem;
    text-decoration: none;
    font-weight: 600;
    transition: background-color 0.3s;
}
.btn-primary:hover { background-color: #1d4ed8; color: var(--white); }

/* Hero Section */
.hero {
    text-align: center;
    padding: 5rem 5% 4rem;
    background: linear-gradient(180deg, var(--hero-grad-start) 0%, var(--light-gray) 100%);
}

/* Theme Toggle Button */
.theme-toggle {
    background: none;
    border: none;
    font-size: 1.25rem;
    cursor: pointer;
    padding: 0.5rem;
    border-radius: 50%;
    transition: background-color 0.3s;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--dark-slate);
}
.theme-toggle:hover {
    background-color: var(--border-light);
}

.hero h1 {
    font-size: 2.75rem;
    font-weight: 800;
    margin-bottom: 1.25rem;
    color: var(--dark-slate);
    letter-spacing: -1px;
}

.hero p {
    font-size: 1.125rem;
    color: var(--text-secondary);
    max-width: 650px;
    margin: 0 auto;
}

/* Filter Section */
.filters {
    display: flex;
    justify-content: center;
    gap: 1rem;
    padding: 2rem 5%;
    flex-wrap: wrap;
}

.filter-btn {
    background-color: var(--white);
    border: 1px solid #cbd5e1;
    padding: 0.6rem 1.5rem;
    border-radius: 9999px;
    font-size: 0.95rem;
    font-weight: 600;
    color: var(--dark-slate);
    cursor: pointer;
    transition: all 0.3s ease;
}

.filter-btn:hover {
    border-color: var(--primary-blue);
    color: var(--primary-blue);
    box-shadow: 0 4px 6px -1px rgba(37, 99, 235, 0.1);
}

.filter-btn.active {
    background-color: var(--primary-blue);
    color: var(--white);
    border-color: var(--primary-blue);
}

/* Main Grid Section */
.grid-section {
    padding: 1rem 5% 5rem;
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 2rem;
    flex-grow: 1;
}

/* Card Styles */
.card {
    background-color: var(--white);
    border-radius: 0.75rem;
    padding: 1.5rem;
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -1px rgba(0, 0, 0, 0.03);
    border: 1px solid var(--border-light);
    display: flex;
    flex-direction: column;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.card:hover {
    transform: translateY(-6px);
    box-shadow: 0 12px 20px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
}

.card-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 1rem;
}

.card-name {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--dark-slate);
}

.tag {
    font-size: 0.75rem;
    font-weight: 700;
    padding: 0.35rem 0.75rem;
    border-radius: 9999px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}
.tag.blue { background-color: var(--tag-blue-bg); color: var(--tag-blue-text); }
.tag.yellow { background-color: var(--tag-yellow-bg); color: var(--tag-yellow-text); }
.tag.green { background-color: var(--tag-green-bg); color: var(--tag-green-text); }

.card-bio {
    color: var(--text-secondary);
    font-size: 0.95rem;
    flex-grow: 1;
    margin-bottom: 1.5rem;
}

.card-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: 1rem;
    border-top: 1px solid var(--border-light);
}

.rate {
    font-size: 1.125rem;
    font-weight: 800;
    color: var(--primary-blue);
}

.action-btn {
    background-color: transparent;
    border: 2px solid var(--primary-blue);
    color: var(--primary-blue);
    padding: 0.5rem 1rem;
    border-radius: 0.5rem;
    font-weight: 600;
    font-size: 0.9rem;
    cursor: pointer;
    transition: all 0.3s ease;
}
.action-btn:hover { background-color: var(--primary-blue); color: var(--white); }

/* Footer */
footer {
    text-align: center;
    margin-top: auto;
    padding: 2rem 5%;
    background-color: var(--dark-slate);
    color: #94a3b8;
    font-size: 0.875rem;
}

/* Forms (Join Page) */
.auth-container {
    max-width: 500px;
    width: 100%;
    margin: 4rem auto;
    background: var(--white);
    padding: 2.5rem;
    border-radius: 0.75rem;
    box-shadow: 0 4px 6px -1px rgba(0,0,0,0.05);
    border: 1px solid var(--border-light);
}
.auth-container h2 { margin-bottom: 1.5rem; text-align: center; color: var(--dark-slate); }
.form-group { margin-bottom: 1.25rem; }
.form-group label { display: block; margin-bottom: 0.5rem; font-weight: 500; color: var(--dark-slate); }
.form-group input, .form-group select {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid #cbd5e1;
    border-radius: 0.375rem;
    font-size: 1rem;
    font-family: inherit;
}
.form-group input:focus, .form-group select:focus {
    outline: none;
    border-color: var(--primary-blue);
    box-shadow: 0 0 0 3px rgba(37,99,235,0.1);
}
.auth-submit {
    width: 100%;
    padding: 0.875rem;
    background-color: var(--primary-blue);
    color: var(--white);
    border: none;
    border-radius: 0.375rem;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: background-color 0.3s;
    margin-top: 1rem;
}
.auth-submit:hover { background-color: #1d4ed8; }
.auth-toggle { text-align: center; margin-top: 1.5rem; font-size: 0.95rem; }
.auth-toggle a { color: var(--primary-blue); text-decoration: none; font-weight: 600; cursor: pointer; }

/* FAQ Page */
.faq-container {
    max-width: 800px;
    margin: 3rem auto 5rem;
    padding: 0 5%;
}
details {
    background: var(--white);
    margin-bottom: 1rem;
    border-radius: 0.5rem;
    border: 1px solid var(--border-light);
    overflow: hidden;
}
summary {
    padding: 1.25rem 1.5rem;
    font-weight: 600;
    font-size: 1.1rem;
    cursor: pointer;
    list-style: none;
    display: flex;
    justify-content: space-between;
    align-items: center;
}
summary::-webkit-details-marker { display: none; }
summary::after {
    content: '+';
    color: var(--primary-blue);
    font-size: 1.5rem;
    line-height: 1;
}
details[open] summary::after { content: '−'; }
.faq-answer { padding: 0 1.5rem 1.25rem; color: var(--text-secondary); }