:root {
    --bg-color: #ffffff;
    --text-color: #111111;
    --text-secondary: #666666;
    --border-color: #e0e0e0;
    --sidebar-bg: #ffffff;
    --accent-color: #2563eb; /* Default blue, can be overridden */
    --accent-hover: #1d4ed8;
    --danger-color: #ef4444;
    --font-main: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --radius-md: 8px;
    --radius-lg: 12px;
}

* { 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: 1.5;
    -webkit-font-smoothing: antialiased;
    display: flex;
    height: 100vh;
    overflow: hidden;
}

/* Layout */
#app {
    display: flex;
    width: 100%;
    height: 100%;
}

/* Sidebar */
.sidebar {
    width: 250px;
    background: var(--sidebar-bg);
    border-right: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    padding: 1.5rem;
    flex-shrink: 0;
    transition: transform 0.3s ease;
}

.logo-area {
    font-weight: 700;
    font-size: 1.25rem;
    margin-bottom: 2rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.logo-icon {
    width: 24px;
    height: 24px;
    background: var(--text-color);
    border-radius: 4px;
}

.nav-links {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    flex: 1;
}

.nav-item {
    text-decoration: none;
    color: var(--text-secondary);
    padding: 0.75rem 1rem;
    border-radius: var(--radius-md);
    transition: all 0.2s;
    font-weight: 500;
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.nav-item:hover, .nav-item.active {
    background-color: #f3f4f6;
    color: var(--text-color);
}

.user-section {
    border-top: 1px solid var(--border-color);
    padding-top: 1rem;
    margin-top: auto;
}

.user-profile {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    cursor: pointer;
}

.avatar {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    background: #e5e7eb;
}

/* Main Content */
#main-content {
    flex: 1;
    overflow-y: auto;
    padding: 2rem;
    position: relative;
    background: #ffffff;
}

.top-bar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
    padding-bottom: 1rem;
    border-bottom: 1px solid transparent; 
}

.search-bar {
    background: #f3f4f6;
    padding: 0.5rem 1rem;
    border-radius: 20px;
    width: 300px;
    display: flex;
    align-items: center;
    color: var(--text-secondary);
}

/* Homepage Grid */
.hero-section {
    text-align: center;
    margin-bottom: 3rem;
    padding: 2rem 0;
}
.hero-title { font-size: 2.5rem; font-weight: 800; letter-spacing: -0.05em; margin-bottom: 1rem; }
.hero-subtitle { font-size: 1.25rem; color: var(--text-secondary); max-width: 600px; margin: 0 auto 2rem; }
.btn-cta {
    background: var(--text-color);
    color: white;
    padding: 0.75rem 1.5rem;
    border-radius: 30px;
    font-weight: 600;
    text-decoration: none;
    display: inline-block;
}

.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 2rem;
}

.card {
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    overflow: hidden;
    transition: transform 0.2s, box-shadow 0.2s;
    background: white;
    cursor: pointer;
}

.card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}

.card-thumb {
    height: 160px;
    width: 100%;
    background: linear-gradient(135deg, #f3f4f6 0%, #e5e7eb 100%);
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 3rem;
    color: inherit;
}

.card-content { padding: 1rem; }
.card-title { font-weight: 700; margin-bottom: 0.25rem; font-size: 1.1rem; }
.card-desc { font-size: 0.9rem; color: var(--text-secondary); margin-bottom: 1rem; line-height: 1.4; }
.card-footer { display: flex; justify-content: space-between; align-items: center; font-size: 0.8rem; color: var(--text-secondary); }
.badge { background: #f3f4f6; padding: 2px 8px; border-radius: 4px; font-weight: 500; }

/* How It Works */
.steps-section {
    margin-top: 5rem;
    padding: 3rem 0;
    border-top: 1px solid var(--border-color);
}
.steps-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}
.step-item {
    padding: 1.5rem;
    background: #fafafa;
    border-radius: var(--radius-lg);
    border: none;
}
.step-num {
    font-size: 2rem;
    font-weight: 800;
    opacity: 0.2;
    margin-bottom: 0.5rem;
}

/* Mobile */
.mobile-toggle { display: none; background: none; border: none; font-size: 1.5rem; cursor: pointer; }
@media (max-width: 768px) {
    .sidebar { position: fixed; height: 100%; z-index: 50; transform: translateX(-100%); border-right: 1px solid #333; }
    .sidebar.open { transform: translateX(0); }
    .mobile-toggle { display: block; margin-right: 1rem; }
    #main-content { padding: 1rem; }
}