* {
    font-family: 'Noto Sans KR', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
}

body {
    background: #ffffff;
    color: #37352f;
}

/* =====================
   LAYOUT
   ===================== */

.sidebar {
    position: fixed;
    left: 0;
    top: 0;
    height: 100vh;
    width: 280px;
    background: #f7f6f3;
    border-right: 1px solid #e9e7e0;
    overflow-y: auto;
    padding: 2rem 1.5rem;
}

.main-content {
    margin-left: 280px;
    padding: 3rem 4rem;
    max-width: 1200px;
}

/* =====================
   SIDEBAR COMPONENTS
   ===================== */

.profile-image {
    width: 120px;
    height: 120px;
    border-radius: 50%;
    object-fit: cover;
    margin-bottom: 1.5rem;
    border: 3px solid #ffffff;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

.nav-link {
    display: block;
    padding: 0.5rem 0;
    color: #37352f;
    text-decoration: none;
    font-size: 0.875rem;
    transition: color 0.2s;
}

.nav-link:hover {
    color: #2383e2;
}

.nav-link.active {
    color: #2383e2;
    font-weight: 500;
}

.social-link {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    color: #37352f;
    text-decoration: none;
    font-size: 0.875rem;
    margin-bottom: 0.5rem;
    transition: color 0.2s;
}

.social-link:hover {
    color: #2383e2;
}

/* =====================
   SECTION
   ===================== */

.section {
    margin-bottom: 4rem;
    scroll-margin-top: 2rem;
}

.section-title {
    font-size: 1.875rem;
    font-weight: 700;
    color: #37352f;
    margin-bottom: 1.5rem;
    border-bottom: 2px solid #e9e7e0;
    padding-bottom: 0.5rem;
}

/* =====================
   CARD
   ===================== */

.card {
    background: #ffffff;
    border: 1px solid #e9e7e0;
    border-radius: 8px;
    padding: 1.5rem;
    margin-bottom: 1.5rem;
    transition: all 0.3s;
}

.card:hover {
    box-shadow: 0 4px 12px rgba(0,0,0,0.08);
    transform: translateY(-2px);
}

/* =====================
   TAGS
   ===================== */

.tag {
    display: inline-block;
    background: #f1f0ee;
    color: #37352f;
    padding: 0.25rem 0.75rem;
    border-radius: 4px;
    font-size: 0.75rem;
    margin-right: 0.5rem;
    margin-bottom: 0.5rem;
}

.tag-blue {
    background: #e3f2fd;
    color: #1976d2;
}

/* =====================
   EXPERIENCE (TIMELINE)
   ===================== */

.timeline-item {
    position: relative;
    padding: 1.5rem 1.75rem;
    margin-bottom: 1.25rem;
    border-radius: 8px;
}

.timeline-item {
    background-color: #f7f6f3;
}

.timeline-item:last-child {
    margin-bottom: 0;
}

.experience-period {
    font-size: 0.875rem;
    color: #787774;
    margin-bottom: 0.5rem;
}

.experience-title {
    font-size: 1.25rem;
    font-weight: 600;
    color: #37352f;
    margin-bottom: 0.25rem;
}

.experience-company {
    font-size: 1rem;
    color: #787774;
    margin-bottom: 1rem;
}

.experience-desc {
    font-size: 0.975rem;
    font-weight: 500;
    color: #37352f;
    line-height: 1.7;
    margin-bottom: 1rem;
}

.experience-projects-label {
    font-size: 0.875rem;
    font-weight: 600;
    color: #37352f;
    margin-bottom: 0.4rem;
}

.experience-projects-list {
    font-size: 0.875rem;
    color: #555553;
    list-style: disc;
    padding-left: 1.25rem;
}

.experience-projects-list li {
    margin-bottom: 0.2rem;
}

/* =====================
   PROJECTS
   ===================== */

.projects-layout {
    display: flex;
    gap: 0;
    min-height: 600px;
}

.projects-list-panel {
    width: 50%;
    padding-right: 1.5rem;
    border-right: 1px solid #e9e7e0;
}

.projects-preview-panel {
    width: 50%;
    padding-left: 1.5rem;
    position: sticky;
    top: 2rem;
    align-self: flex-start;
}

.project-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 0.75rem;
}

.project-card-mini {
    background: #ffffff;
    border: 1.5px solid #e9e7e0;
    border-radius: 8px;
    padding: 1rem;
    cursor: pointer;
    transition: all 0.2s;
    position: relative;
}

.project-card-mini:hover {
    border-color: #2383e2;
    box-shadow: 0 2px 8px rgba(35,131,226,0.12);
}

.project-card-mini.active {
    border-color: #2383e2;
    background: #f0f7ff;
    box-shadow: 0 2px 12px rgba(35,131,226,0.18);
}


.project-card-mini h4 {
    font-size: 0.8rem;
    font-weight: 600;
    color: #37352f;
    margin-bottom: 0.35rem;
    line-height: 1.3;
    height: calc(0.8rem * 1.3 * 2);
    overflow: hidden;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
}

.project-card-mini .mini-period {
    font-size: 0.65rem;
    color: #787774;
    margin-bottom: 0.2rem;
}

.project-card-mini .mini-company {
    font-size: 0.65rem;
    color: #2383e2;
    font-weight: 500;
    margin-bottom: 0.4rem;
}

.project-card-mini .mini-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.25rem;
}

.project-card-mini .mini-tag {
    font-size: 0.6rem;
    background: #f1f0ee;
    color: #37352f;
    padding: 0.1rem 0.4rem;
    border-radius: 3px;
}

.project-card-mini.active .mini-tag {
    background: #dbeafe;
    color: #1976d2;
}

/* Preview Panel */
.preview-empty {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 400px;
    color: #b5b3b0;
    text-align: center;
}

.preview-content {
    display: none;
}

.preview-content.visible {
    display: block;
}

.preview-image {
    width: 100%;
    aspect-ratio: 16/9;
    background: linear-gradient(135deg, #f1f0ee 0%, #e9e7e0 100%);
    border-radius: 10px;
    margin-bottom: 1.25rem;
    overflow: hidden;
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
    border: 1px solid #e9e7e0;
}

.preview-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    border-radius: 10px;
}

.preview-image .no-image {
    color: #b5b3b0;
    font-size: 0.875rem;
}

.preview-period {
    font-size: 0.75rem;
    color: #787774;
    margin-bottom: 0.5rem;
}

.preview-title {
    font-size: 1.5rem;
    font-weight: 700;
    color: #37352f;
    margin-bottom: 0.75rem;
}

.preview-desc {
    font-size: 0.875rem;
    line-height: 1.7;
    color: #37352f;
    margin-bottom: 1rem;
}

.preview-list {
    list-style: none;
    padding: 0;
    margin-bottom: 1rem;
}

.preview-list li {
    font-size: 0.8rem;
    color: #37352f;
    padding: 0.3rem 0;
    padding-left: 1rem;
    position: relative;
    line-height: 1.5;
}

.preview-list li::before {
    content: '→';
    position: absolute;
    left: 0;
    color: #2383e2;
    font-size: 0.75rem;
}

.preview-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.35rem;
    margin-bottom: 1.25rem;
}

.preview-links {
    display: flex;
    gap: 0.75rem;
}

.preview-link-btn {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    font-size: 0.8rem;
    padding: 0.5rem 1rem;
    border-radius: 6px;
    text-decoration: none;
    transition: all 0.2s;
}

.preview-link-btn.github {
    background: #37352f;
    color: white;
}

.preview-link-btn.github:hover {
    background: #1a1916;
}

.preview-link-btn.demo {
    background: #2383e2;
    color: white;
}

.preview-link-btn.demo:hover {
    background: #1a6bc0;
}

.preview-link-btn.disabled {
    background: #f1f0ee;
    color: #b5b3b0;
    cursor: not-allowed;
    pointer-events: none;
}

/* =====================
   CERTIFICATIONS
   ===================== */

.cert-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1rem;
}

.cert-card {
    background: #ffffff;
    border: 1px solid #e9e7e0;
    border-radius: 8px;
    padding: 1.25rem 1.5rem;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.cert-icon {
    width: 32px;
    height: 32px;
    background: #e3f2fd;
    border-radius: 6px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 0.25rem;
}

.cert-name {
    font-size: 0.875rem;
    font-weight: 600;
    color: #37352f;
    line-height: 1.4;
    min-height: 2.5em;
}

.cert-org {
    font-size: 0.75rem;
    color: #787774;
}

.cert-year {
    font-size: 0.7rem;
    background: #f1f0ee;
    color: #37352f;
    display: inline-block;
    padding: 0.15rem 0.5rem;
    border-radius: 3px;
    align-self: flex-start;
}

/* =====================
   SKILLS
   ===================== */

.skill-category {
    margin-bottom: 1.25rem;
}

.skill-category h3 {
    font-size: 1.125rem;
    font-weight: 600;
    color: #37352f;
    margin-bottom: 0.75rem;
}

.skill-list {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

/* =====================
   RESPONSIVE
   ===================== */

@media (max-width: 900px) {
    .project-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .projects-layout {
        flex-direction: column;
    }

    .projects-list-panel {
        width: 100%;
        padding-right: 0;
        border-right: none;
        border-bottom: 1px solid #e9e7e0;
        padding-bottom: 1.5rem;
        margin-bottom: 1.5rem;
    }

    .projects-preview-panel {
        width: 100%;
        padding-left: 0;
        position: relative;
        top: 0;
    }

    .project-card-mini.active::after {
        display: none;
    }
}

@media (max-width: 768px) {
    .sidebar {
        position: relative;
        width: 100%;
        height: auto;
        border-right: none;
        border-bottom: 1px solid #e9e7e0;
    }

    .main-content {
        margin-left: 0;
        padding: 2rem 1.5rem;
    }

    .cert-grid {
        grid-template-columns: repeat(1, 1fr);
    }
}