:root {
    /* Light Mode Variables */
    --bg-color: #f8f9fa;
    --card-bg: #ffffff;
    --text-color: #2c3e50;
    --text-muted: #6c757d;
    --accent-color: #007bff;
    --accent-hover: #0056b3;
    --border-color: #e9ecef;
    --shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
    --font-main: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

[data-theme="dark"] {
    /* Dark Mode Variables */
    --bg-color: #121212;
    --card-bg: #1e1e1e;
    --text-color: #e0e0e0;
    --text-muted: #a0a0a0;
    --accent-color: #3f90f3;
    --accent-hover: #72aee6;
    --border-color: #333333;
    --shadow: 0 4px 6px rgba(0, 0, 0, 0.3);
}

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

body {
    background-color: var(--bg-color);
    color: var(--text-color);
    font-family: var(--font-main);
    line-height: 1.6;
    transition: background-color 0.3s ease, color 0.3s ease;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Header */
header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 2rem;
    background-color: var(--card-bg);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 100;
    transition: background-color 0.3s ease, border-color 0.3s ease;
}

.brand {
    font-size: 1.25rem;
    font-weight: 700;
    letter-spacing: -0.5px;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.brand i {
    color: var(--accent-color);
}

.actions {
    display: flex;
    gap: 1rem;
    align-items: center;
}

button.icon-btn {
    background: none;
    border: none;
    color: var(--text-color);
    font-size: 1.2rem;
    cursor: pointer;
    padding: 0.5rem;
    border-radius: 50%;
    transition: background-color 0.2s, color 0.2s;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
}

button.icon-btn:hover {
    background-color: var(--border-color);
    color: var(--accent-color);
}

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

.hero {
    text-align: center;
    padding: 4rem 1rem;
}

.hero h1 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    font-weight: 800;
}

.hero p {
    font-size: 1.1rem;
    color: var(--text-muted);
    max-width: 600px;
    margin: 0 auto 2rem;
}

.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.card {
    background-color: var(--card-bg);
    border-radius: 12px;
    padding: 2rem;
    box-shadow: var(--shadow);
    transition: transform 0.2s, box-shadow 0.2s, background-color 0.3s ease;
    border: 1px solid var(--border-color);
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 15px rgba(0,0,0,0.1);
    border-color: var(--accent-color);
}

.card-icon {
    font-size: 2rem;
    color: var(--accent-color);
    margin-bottom: 1.5rem;
}

.card h3 {
    margin-bottom: 0.5rem;
    font-weight: 600;
}

.card p {
    color: var(--text-muted);
    font-size: 0.95rem;
}

/* Footer */
footer {
    text-align: center;
    padding: 2rem;
    color: var(--text-muted);
    font-size: 0.875rem;
    border-top: 1px solid var(--border-color);
    margin-top: auto;
}

/* Utility */
.hidden {
    display: none !important;
}