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

body {
    font-family: 'Inter', sans-serif;
    line-height: 1.6;
    color: #333;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

.header {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.logo-icon {
    font-size: 1.5rem;
}

.logo-text {
    font-size: 1.25rem;
    font-weight: 700;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.nav {
    display: flex;
    gap: 0.5rem;
}

.nav-link {
    padding: 0.5rem 1rem;
    border-radius: 20px;
    text-decoration: none;
    color: #666;
    font-weight: 500;
    transition: all 0.3s;
}

.nav-link:hover {
    color: #667eea;
}

.nav-link.active {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
}

.section {
    display: none;
    padding: 3rem 0;
    min-height: calc(100vh - 80px);
}

.section.active {
    display: block;
}

.hero-content {
    text-align: center;
    color: white;
    padding: 3rem 0;
}

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

.hero-content p {
    font-size: 1.1rem;
    margin-bottom: 2rem;
    opacity: 0.9;
}

.step-indicator {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 1rem;
    margin: 3rem 0;
}

.step-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
}

.step-num {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.3);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 1.2rem;
}

.step-item.completed .step-num {
    background: white;
    color: #667eea;
}

.step-name {
    font-size: 0.9rem;
    font-weight: 500;
}

.step-line {
    width: 80px;
    height: 2px;
    background: rgba(255, 255, 255, 0.3);
}

.btn-primary {
    background: white;
    color: #667eea;
    border: none;
    padding: 0.8rem 2rem;
    border-radius: 25px;
    font-weight: 600;
    font-size: 1rem;
    cursor: pointer;
    transition: all 0.3s;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.2);
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.2);
    color: white;
    border: 2px solid white;
    padding: 0.6rem 1.5rem;
    border-radius: 20px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s;
}

.btn-secondary:hover {
    background: white;
    color: #667eea;
}

.section-header {
    text-align: center;
    margin-bottom: 3rem;
    color: white;
}

.section-header h2 {
    font-size: 2rem;
    margin-bottom: 0.5rem;
}

.section-header p {
    opacity: 0.9;
}

.topic-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.topic-card {
    background: white;
    border-radius: 20px;
    padding: 2rem;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
}

.topic-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.2);
}

.topic-card.selected {
    border: 3px solid #667eea;
}

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

.topic-card h3 {
    margin-bottom: 0.5rem;
    color: #333;
}

.topic-card p {
    color: #666;
    font-size: 0.9rem;
}

.custom-topic {
    display: flex;
    justify-content: center;
    gap: 1rem;
    background: white;
    padding: 1.5rem;
    border-radius: 15px;
    max-width: 600px;
    margin: 0 auto;
}

.custom-topic input {
    flex: 1;
    padding: 0.8rem 1rem;
    border: 2px solid #e0e0e0;
    border-radius: 10px;
    font-size: 1rem;
}

.custom-topic input:focus {
    outline: none;
    border-color: #667eea;
}

.plan-container {
    background: white;
    border-radius: 20px;
    padding: 2rem;
    max-width: 800px;
    margin: 0 auto;
}

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

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
    color: #333;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 0.8rem 1rem;
    border: 2px solid #e0e0e0;
    border-radius: 10px;
    font-size: 1rem;
    font-family: inherit;
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: #667eea;
}

.device-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-bottom: 0.5rem;
}

.tag {
    background: #f0f0f0;
    padding: 0.4rem 1rem;
    border-radius: 15px;
    font-size: 0.9rem;
    cursor: pointer;
    transition: all 0.3s;
}

.tag:hover {
    background: #667eea;
    color: white;
}

.tag.selected {
    background: #667eea;
    color: white;
}

.architecture-diagram {
    display: flex;
    flex-direction: column;
    gap: 1rem;
    align-items: center;
}

.arch-box {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 1rem 3rem;
    border-radius: 10px;
    font-weight: 600;
    position: relative;
}

.arch-box::after {
    content: '';
    position: absolute;
    bottom: -20px;
    left: 50%;
    transform: translateX(-50%);
    border-left: 10px solid transparent;
    border-right: 10px solid transparent;
    border-top: 15px solid #764ba2;
}

.arch-layer:last-child .arch-box::after {
    display: none;
}

.next-btn,
.complete-btn {
    width: 100%;
    margin-top: 1rem;
}

.implement-container {
    background: white;
    border-radius: 20px;
    padding: 2rem;
    max-width: 900px;
    margin: 0 auto;
}

.implement-tabs {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 2rem;
    border-bottom: 2px solid #e0e0e0;
}

.tab-btn {
    padding: 0.8rem 1.5rem;
    border: none;
    background: none;
    font-weight: 500;
    cursor: pointer;
    color: #666;
    position: relative;
    transition: all 0.3s;
}

.tab-btn:hover {
    color: #667eea;
}

.tab-btn.active {
    color: #667eea;
}

.tab-btn.active::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    right: 0;
    height: 2px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
}

.tab-content {
    display: none;
}

.tab-content.active {
    display: block;
}

.language-select,
.comm-options {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
}

.language-option,
.comm-option {
    padding: 0.8rem 1.5rem;
    background: #f0f0f0;
    border-radius: 10px;
    cursor: pointer;
    transition: all 0.3s;
}

.language-option:hover,
.comm-option:hover {
    background: #667eea;
    color: white;
}

.language-option.selected,
.comm-option.selected {
    background: #667eea;
    color: white;
}

.canvas-placeholder {
    background: #f9f9f9;
    border: 2px dashed #e0e0e0;
    border-radius: 10px;
    padding: 3rem;
    text-align: center;
    color: #999;
}

.canvas-placeholder span {
    font-size: 3rem;
    display: block;
    margin-bottom: 0.5rem;
}

.test-list {
    display: flex;
    flex-direction: column;
    gap: 0.8rem;
}

.test-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.test-item input[type="checkbox"] {
    width: 20px;
    height: 20px;
    cursor: pointer;
}

.test-item label {
    cursor: pointer;
}

.smart-tip-bar {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.98);
    backdrop-filter: blur(10px);
    box-shadow: 0 -5px 20px rgba(0, 0, 0, 0.1);
    z-index: 1000;
    padding: 1rem 0;
}

.smart-tip-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    align-items: center;
    gap: 1rem;
}

.tip-icon {
    font-size: 1.8rem;
    flex-shrink: 0;
}

.tip-content {
    flex: 1;
    min-height: 2rem;
    display: flex;
    align-items: center;
}

.tip-content p {
    margin: 0;
    color: #333;
    line-height: 1.5;
}

.tip-loading {
    display: flex;
    gap: 0.3rem;
    align-items: center;
}

.tip-loading span {
    width: 8px;
    height: 8px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border-radius: 50%;
    animation: bounce 1.4s infinite ease-in-out both;
}

.tip-loading span:nth-child(1) { animation-delay: -0.32s; }
.tip-loading span:nth-child(2) { animation-delay: -0.16s; }
.tip-loading span:nth-child(3) { animation-delay: 0s; }

@keyframes bounce {
    0%, 80%, 100% { transform: scale(0); }
    40% { transform: scale(1); }
}

.section {
    padding-bottom: 100px;
}

@media (max-width: 768px) {
    .nav {
        display: none;
    }

    .hero-content h1 {
        font-size: 1.8rem;
    }

    .step-indicator {
        flex-wrap: wrap;
    }

    .step-line {
        width: 40px;
    }

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

    .smart-tip-container {
        flex-direction: column;
        text-align: center;
    }
}