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

:root {
    --black: #000000;
    --white: #ffffff;
    --gray-50: #fafafa;
    --gray-100: #f5f5f5;
    --gray-200: #e5e5e5;
    --gray-300: #d4d4d4;
    --gray-400: #a3a3a3;
    --gray-500: #737373;
    --gray-600: #525252;
    --gray-700: #404040;
    --gray-800: #262626;
    --gray-900: #171717;
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow: 0 1px 3px 0 rgb(0 0 0 / 0.1), 0 1px 2px -1px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: var(--gray-900);
    background-color: var(--white);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: 1.2;
    margin-bottom: 1rem;
}

h1 { font-size: 2.25rem; }
h2 { font-size: 1.875rem; }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.25rem; }

p { margin-bottom: 1rem; }

/* Navigation */
.navbar {
    background: var(--white);
    border-bottom: 1px solid var(--gray-200);
    padding: 0 1rem;
    position: sticky;
    top: 0;
    z-index: 100;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 4rem;
}

.nav-logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--black);
    text-decoration: none;
}

.nav-logo:hover {
    color: var(--gray-700);
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 2rem;
}

.nav-link {
    color: var(--gray-600);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.2s;
}

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

.nav-button {
    background: var(--black);
    color: var(--white);
    border: none;
    padding: 0.5rem 1rem;
    border-radius: 4px;
    font-weight: 500;
    cursor: pointer;
    text-decoration: none;
    display: inline-block;
    transition: background-color 0.2s;
}

.nav-button:hover {
    background: var(--gray-800);
}

/* Main Content */
.main-content {
    flex: 1;
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem 1rem;
    width: 100%;
}

/* Messages */
.messages {
    margin-bottom: 2rem;
}

.alert {
    padding: 0.75rem 1rem;
    border-radius: 4px;
    margin-bottom: 1rem;
    border-left: 4px solid;
}

.alert-success {
    background: var(--gray-50);
    border-left-color: var(--gray-400);
    color: var(--gray-800);
}

.alert-error {
    background: var(--gray-100);
    border-left-color: var(--black);
    color: var(--black);
}

/* Cards */
.card {
    background: var(--white);
    border: 1px solid var(--gray-200);
    border-radius: 8px;
    padding: 1.5rem;
    box-shadow: var(--shadow-sm);
    margin-bottom: 1.5rem;
}

.card-header {
    border-bottom: 1px solid var(--gray-200);
    padding-bottom: 1rem;
    margin-bottom: 1rem;
}

.card-title {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 0;
}

/* Forms */
.form {
    max-width: 400px;
    margin: 0 auto;
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-label {
    display: block;
    font-weight: 500;
    margin-bottom: 0.5rem;
    color: var(--gray-700);
}

.form-input {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid var(--gray-300);
    border-radius: 4px;
    font-size: 1rem;
    transition: border-color 0.2s, box-shadow 0.2s;
}

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

.form-textarea {
    resize: vertical;
    min-height: 120px;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 4px;
    font-weight: 500;
    text-align: center;
    text-decoration: none;
    cursor: pointer;
    transition: all 0.2s;
    font-size: 1rem;
}

.btn-primary {
    background: var(--black);
    color: var(--white);
}

.btn-primary:hover {
    background: var(--gray-800);
}

.btn-secondary {
    background: var(--white);
    color: var(--black);
    border: 1px solid var(--gray-300);
}

.btn-secondary:hover {
    background: var(--gray-50);
}

.btn-full {
    width: 100%;
}

/* Tables */
.table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 1rem;
}

.table th,
.table td {
    padding: 0.75rem;
    text-align: left;
    border-bottom: 1px solid var(--gray-200);
}

.table th {
    font-weight: 600;
    background: var(--gray-50);
}

/* Stats */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.stat-card {
    background: var(--white);
    border: 1px solid var(--gray-200);
    border-radius: 8px;
    padding: 1.5rem;
    text-align: center;
    box-shadow: var(--shadow-sm);
}

.stat-value {
    font-size: 2rem;
    font-weight: 700;
    color: var(--black);
    margin-bottom: 0.5rem;
}

.stat-label {
    color: var(--gray-600);
    font-size: 0.875rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

/* Loading */
.loading {
    display: inline-block;
    width: 1rem;
    height: 1rem;
    border: 2px solid var(--gray-300);
    border-top: 2px solid var(--black);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* Footer */
.footer {
    background: var(--gray-50);
    border-top: 1px solid var(--gray-200);
    padding: 2rem 1rem;
    margin-top: auto;
}

.footer-container {
    max-width: 1200px;
    margin: 0 auto;
    text-align: center;
    color: var(--gray-600);
    font-size: 0.875rem;
}

/* Hero Section */
.hero {
    text-align: center;
    padding: 4rem 0;
    background: var(--gray-50);
    margin: -2rem -1rem 2rem -1rem;
}

.hero-title {
    font-size: 3rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: var(--black);
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--gray-600);
    margin-bottom: 2rem;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

/* Responsive */
@media (max-width: 768px) {
    .nav-links {
        gap: 1rem;
    }
    
    .hero-title {
        font-size: 2rem;
    }
    
    .hero-subtitle {
        font-size: 1rem;
    }
    
    .hero-buttons {
        flex-direction: column;
        align-items: center;
    }
    
    .btn {
        min-width: 200px;
    }
    
    .stats-grid {
        grid-template-columns: 1fr;
    }
}