:root {
    --primary-color: #F38020;
    --primary-dark: #d16f1a;
    --primary-light: #ffa154;
    --text-primary: #111827;
    --text-secondary: #6b7280;
    --border-color: #e5e7eb;
    --bg-primary: #ffffff;
    --bg-secondary: #f9fafb;
    --bg-hover: #f3f4f6;
    --success-color: #10b981;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background: var(--bg-secondary);
    color: var(--text-primary);
    line-height: 1.6;
}

.app-container {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Header */
.app-header {
    background: var(--bg-primary);
    border-bottom: 1px solid var(--border-color);
    padding: 1rem 2rem;
    box-shadow: var(--shadow-sm);
    position: sticky;
    top: 0;
    z-index: 100;
}

.header-content {
    max-width: 1400px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

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

.logo h1 {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
}

.header-actions {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.user-info {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.5rem 1rem;
    background: var(--bg-secondary);
    border-radius: 8px;
}

.user-email {
    font-size: 0.875rem;
    color: var(--text-primary);
    font-weight: 500;
}

.btn-link {
    background: none;
    border: none;
    color: var(--primary-color);
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    padding: 0;
    text-decoration: underline;
    font-family: inherit;
}

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

.btn-secondary {
    padding: 0.5rem 1rem;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    color: var(--text-primary);
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
    font-family: inherit;
}

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

/* Login Modal */
.login-modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(4px);
    z-index: 10000;
    justify-content: center;
    align-items: center;
    animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

.login-modal-content {
    background: var(--bg-primary);
    border-radius: 16px;
    box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
    max-width: 480px;
    width: 90%;
    padding: 3rem;
    animation: slideUp 0.4s ease;
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.login-header {
    text-align: center;
    margin-bottom: 2rem;
}

.login-header svg {
    margin: 0 auto 1rem;
}

.login-header h2 {
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.login-header p {
    color: var(--text-secondary);
    font-size: 0.9375rem;
}

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

.form-group label {
    display: block;
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.form-group input[type="email"] {
    width: 100%;
    padding: 0.75rem 1rem;
    font-size: 1rem;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    background: var(--bg-primary);
    color: var(--text-primary);
    transition: all 0.2s;
    font-family: inherit;
}

.form-group input[type="email"]:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(243, 128, 32, 0.1);
}

.btn-primary {
    width: 100%;
    padding: 0.875rem 1.5rem;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    font-family: inherit;
}

.btn-primary:hover {
    transform: translateY(-1px);
    box-shadow: 0 10px 15px -3px rgba(243, 128, 32, 0.3);
}

.login-footer {
    margin-top: 2rem;
    text-align: center;
}

.login-footer p {
    font-size: 0.8125rem;
    color: var(--text-secondary);
}

/* Main Views */
.main-view {
    display: none;
}

.main-view.active {
    display: block;
}

/* Home View */
.hero-section {
    max-width: 1400px;
    margin: 3rem auto 2rem;
    padding: 0 2rem;
    text-align: center;
}

.hero-section h2 {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 1rem;
}

.hero-section p {
    font-size: 1.125rem;
    color: var(--text-secondary);
}

.modules-grid {
    max-width: 1400px;
    margin: 0 auto 4rem;
    padding: 0 2rem;
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 2rem;
}

.module-card {
    background: var(--bg-primary);
    border-radius: 12px;
    padding: 2rem;
    box-shadow: var(--shadow-md);
    border: 2px solid transparent;
    transition: all 0.2s;
}

.module-card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-light);
}

.module-card.coming-soon {
    opacity: 0.6;
}

.module-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.module-card h3 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.module-card p {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    line-height: 1.6;
}

.btn-module {
    width: 100%;
    padding: 0.75rem 1.5rem;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 0.9375rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
    font-family: inherit;
}

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

.coming-soon-badge {
    display: inline-block;
    padding: 0.5rem 1rem;
    background: var(--bg-secondary);
    color: var(--text-secondary);
    border-radius: 6px;
    font-size: 0.875rem;
    font-weight: 500;
}

/* Module View */
.module-header {
    max-width: 1400px;
    margin: 2rem auto;
    padding: 0 2rem;
}

.btn-back {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    color: var(--text-primary);
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
    margin-bottom: 1.5rem;
    font-family: inherit;
}

.btn-back:hover {
    background: var(--bg-hover);
}

.module-header h2 {
    font-size: 2rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.module-header p {
    font-size: 1.125rem;
    color: var(--text-secondary);
}

.module-content {
    max-width: 1400px;
    margin: 0 auto 4rem;
    padding: 0 2rem;
    display: grid;
    grid-template-columns: 280px 1fr;
    gap: 2rem;
}

/* Module Sidebar */
.module-sidebar {
    position: sticky;
    top: 100px;
    height: fit-content;
}

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

.nav-item {
    padding: 0.75rem 1rem;
    background: var(--bg-primary);
    border: 2px solid var(--border-color);
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.2s;
    text-align: left;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-primary);
    font-family: inherit;
}

.nav-item:hover {
    border-color: var(--primary-light);
    background: var(--bg-hover);
}

.nav-item.active {
    border-color: var(--primary-color);
    background: linear-gradient(135deg, #fff 0%, #fff9f5 100%);
    color: var(--primary-color);
}

/* Content Area */
.content-area {
    background: var(--bg-primary);
    border-radius: 12px;
    padding: 2rem;
    box-shadow: var(--shadow-md);
}

.section {
    display: none;
}

.section.active {
    display: block;
    animation: fadeIn 0.3s ease;
}

.section h3 {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 1.5rem;
    padding-bottom: 0.75rem;
    border-bottom: 2px solid var(--border-color);
}

.content-item {
    margin-bottom: 1.5rem;
    padding: 1rem;
    background: var(--bg-secondary);
    border-radius: 8px;
}

.content-item.list {
    display: flex;
    gap: 0.75rem;
    align-items: flex-start;
}

.content-item .bullet {
    color: var(--primary-color);
    font-weight: 700;
    font-size: 1.25rem;
    line-height: 1.6;
}

.content-item p {
    margin: 0;
    color: var(--text-primary);
    line-height: 1.8;
}

/* Responsive */
@media (max-width: 1024px) {
    .module-content {
        grid-template-columns: 1fr;
    }

    .module-sidebar {
        position: relative;
        top: 0;
    }

    .sections-nav {
        flex-direction: row;
        overflow-x: auto;
        padding-bottom: 0.5rem;
    }

    .nav-item {
        white-space: nowrap;
    }
}

@media (max-width: 768px) {
    .hero-section h2 {
        font-size: 2rem;
    }

    .modules-grid {
        grid-template-columns: 1fr;
    }

    .module-header h2 {
        font-size: 1.5rem;
    }

    .user-info {
        flex-direction: column;
        gap: 0.25rem;
        padding: 0.5rem;
    }
}

@media (max-width: 640px) {
    .app-header {
        padding: 1rem;
    }

    .header-content {
        flex-wrap: wrap;
    }

    .login-modal-content {
        padding: 2rem;
    }

    .content-area {
        padding: 1.5rem;
    }
}