:root {
    /* Color Palette - Modern, Trustworthy, Global */
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --primary-light: #eff6ff;
    --accent: #f59e0b;
    --success: #10b981;
    --error: #ef4444;
    
    /* Neutral Colors */
    --bg-main: #f8fafc;
    --bg-card: #ffffff;
    --text-main: #0f172a;
    --text-muted: #64748b;
    --border: #e2e8f0;
    
    /* Layout Constants */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 24px;
    --shadow: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px 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);
    
    /* Transitions */
    --transition: all 0.2s ease;
}

* {
    box-sizing: border-box;
    -webkit-font-smoothing: antialiased;
}

body {
    margin: 0;
    padding: 0;
    font-family: 'Plus Jakarta Sans', system-ui, -apple-system, sans-serif;
    background-color: var(--bg-main);
    color: var(--text-main);
    line-height: 1.5;
    overflow-x: hidden;
}

/* Layout Components */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

/* Navbar */
.nav {
    height: 72px;
    background: var(--bg-card);
    border-bottom: 1px solid var(--border);
    display: flex;
    align-items: center;
    position: sticky;
    top: 0;
    z-index: 100;
}

.nav-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    width: 100%;
}

.logo {
    font-size: 24px;
    font-weight: 800;
    color: var(--primary);
    text-decoration: none;
    display: flex;
    align-items: center;
    gap: 8px;
}

.nav-links {
    display: flex;
    gap: 32px;
    align-items: center;
}

.nav-link {
    text-decoration: none;
    color: var(--text-muted);
    font-weight: 500;
    transition: var(--transition);
}

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

/* Buttons */
.btn {
    padding: 12px 24px;
    border-radius: var(--radius-sm);
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    border: none;
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    font-size: 14px;
}

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

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-1px);
}

.btn-outline {
    background: transparent;
    border: 1px solid var(--border);
    color: var(--text-main);
}

.btn-outline:hover {
    background: var(--bg-main);
    border-color: var(--text-muted);
}

/* Hero Section */
.hero {
    padding: 80px 0;
    display: grid;
    grid-template-columns: 1.2fr 1fr;
    gap: 60px;
    align-items: center;
}

.hero-content h1 {
    font-size: 56px;
    line-height: 1.1;
    margin-bottom: 24px;
    font-weight: 800;
    letter-spacing: -0.02em;
}

.hero-content p {
    font-size: 18px;
    color: var(--text-muted);
    margin-bottom: 40px;
    max-width: 500px;
}

/* Calculator Card */
.calc-card {
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    padding: 32px;
    box-shadow: var(--shadow-lg);
    border: 1px solid var(--border);
}

.calc-title {
    font-size: 20px;
    font-weight: 700;
    margin-bottom: 24px;
    display: flex;
    align-items: center;
    gap: 12px;
}

.calc-field {
    margin-bottom: 20px;
}

.calc-label {
    display: block;
    font-size: 14px;
    font-weight: 600;
    margin-bottom: 8px;
    color: var(--text-muted);
}

.calc-input-group {
    display: flex;
    background: var(--bg-main);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    overflow: hidden;
}

.calc-input {
    flex: 1;
    padding: 14px 16px;
    border: none;
    background: transparent;
    font-size: 18px;
    font-weight: 600;
    width: 100%;
}

.calc-input:focus {
    outline: none;
}

.calc-select {
    padding: 0 16px;
    border: none;
    background: var(--border);
    font-weight: 600;
    cursor: pointer;
}

/* Flow Line */
.flow-container {
    position: relative;
    padding: 10px 0;
}

.flow-step {
    display: flex;
    align-items: center;
    gap: 16px;
    padding: 8px 0;
    position: relative;
}

.flow-line {
    position: absolute;
    left: 11px;
    top: 24px;
    bottom: -16px;
    width: 2px;
    background: var(--border);
    z-index: 1;
}

.flow-dot {
    width: 24px;
    height: 24px;
    border-radius: 50%;
    background: var(--primary-light);
    border: 2px solid var(--primary);
    z-index: 2;
    display: flex;
    align-items: center;
    justify-content: center;
}

.flow-dot-inner {
    width: 8px;
    height: 8px;
    background: var(--primary);
    border-radius: 50%;
}

.flow-info {
    flex: 1;
}

.flow-label {
    font-size: 13px;
    color: var(--text-muted);
}

.flow-value {
    font-weight: 700;
    font-size: 15px;
}

/* Registration & Login Pages */
.auth-page {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 40px 24px;
    background: var(--bg-main);
}

.auth-card {
    background: var(--bg-card);
    width: 100%;
    max-width: 480px;
    padding: 48px;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    border: 1px solid var(--border);
}

.auth-header {
    text-align: center;
    margin-bottom: 32px;
}

.auth-header h1 {
    font-size: 28px;
    margin-bottom: 8px;
    font-weight: 800;
}

.auth-header p {
    color: var(--text-muted);
}

.form-group {
    margin-bottom: 24px;
}

.form-label {
    display: block;
    font-weight: 600;
    font-size: 14px;
    margin-bottom: 8px;
    color: var(--text-main);
}

.form-input {
    width: 100%;
    padding: 12px 16px;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    font-size: 16px;
    background: var(--bg-main);
    transition: var(--transition);
}

.form-input:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px var(--primary-light);
}

.auth-footer {
    text-align: center;
    margin-top: 32px;
    color: var(--text-muted);
    font-size: 14px;
}

.auth-footer a {
    color: var(--primary);
    text-decoration: none;
    font-weight: 600;
}

/* Dashboard & Interaction Components */
.dashboard-layout {
    display: grid;
    grid-template-columns: 280px 1fr;
    min-height: 100vh;
}

.sidebar {
    background: var(--bg-card);
    border-right: 1px solid var(--border);
    padding: 32px 24px;
    display: flex;
    flex-direction: column;
}

.sidebar-nav {
    margin-top: 40px;
    display: flex;
    flex-direction: column;
    gap: 8px;
    flex: 1;
}

.sidebar-link {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 16px;
    text-decoration: none;
    color: var(--text-muted);
    font-weight: 600;
    border-radius: var(--radius-sm);
    transition: var(--transition);
}

.sidebar-link:hover, .sidebar-link.active {
    background: var(--primary-light);
    color: var(--primary);
}

.main-content {
    padding: 40px;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
    margin-bottom: 40px;
}

.stat-card {
    background: var(--bg-card);
    padding: 24px;
    border-radius: var(--radius-md);
    border: 1px solid var(--border);
}

.stat-label {
    font-size: 14px;
    color: var(--text-muted);
    font-weight: 600;
    margin-bottom: 8px;
}

.stat-value {
    font-size: 24px;
    font-weight: 800;
}

.table-container {
    background: var(--bg-card);
    border-radius: var(--radius-md);
    border: 1px solid var(--border);
    overflow: hidden;
}

.table {
    width: 100%;
    border-collapse: collapse;
}

.table th {
    text-align: left;
    padding: 16px 24px;
    background: var(--bg-main);
    border-bottom: 1px solid var(--border);
    font-size: 13px;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-muted);
}

.table td {
    padding: 16px 24px;
    border-bottom: 1px solid var(--border);
}

.status-badge {
    padding: 4px 10px;
    border-radius: 12px;
    font-size: 12px;
    font-weight: 700;
}

.status-completed { background: #d1fae5; color: #065f46; }
.status-pending { background: #fef3c7; color: #92400e; }

/* Features */
.features {
    padding: 100px 0;
    background: white;
}

.section-header {
    text-align: center;
    max-width: 600px;
    margin: 0 auto 60px;
}

.section-header h2 {
    font-size: 36px;
    font-weight: 800;
    margin-bottom: 16px;
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 32px;
}

.feature-card {
    padding: 40px;
    border-radius: var(--radius-md);
    background: var(--bg-main);
    transition: var(--transition);
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow);
}

.feature-icon {
    width: 48px;
    height: 48px;
    background: var(--primary-light);
    color: var(--primary);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 24px;
}

/* Utils */
.text-primary { color: var(--primary); }
.badge {
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 12px;
    font-weight: 700;
    background: var(--primary-light);
    color: var(--primary);
    display: inline-block;
}

.placeholder-icon {
    display: inline-block;
    width: 24px;
    height: 24px;
    background: currentColor;
    opacity: 0.2;
    border-radius: 4px;
}

/* Responsive */
@media (max-width: 992px) {
    .hero {
        grid-template-columns: 1fr;
        text-align: center;
    }
    .hero-content p {
        margin: 0 auto 40px;
    }
    .feature-grid {
        grid-template-columns: 1fr;
    }
}