/* --- 변수 설정 (안드로이드 테마) --- */
:root {
    --android-primary: #4A90E2;   /* 부드러운 블루 */
    --android-bold: #2C3E50;      /* 다크 네이비 */
    --text-main: #1a1a1a;
    --text-sub: #70757a;
    --line-color: #e8eaed;
    --bg-white: #ffffff;
    --shadow-sm: 0 5px 15px rgba(0,0,0,0.05);
}

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

html {
    scroll-behavior: smooth; /* 클릭 시 부드러운 이동 */
}

body {
    font-family: 'Pretendard', sans-serif;
    background-color: var(--bg-white);
    color: var(--text-main);
    line-height: 1.7;
    overflow-y: scroll;
    height: 100vh;
}

/* --- 상단 네비게이션 (왼쪽 정렬) --- */
nav {
    position: fixed;
    top: 0;
    width: 100%;
    background-color: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--line-color);
    z-index: 1000;
}

.nav-container {
    max-width: 1000px;
    margin: 0 auto;
    padding: 0 20px;
    height: 70px;
    display: flex;
    align-items: center;
    justify-content: flex-start; /* 왼쪽 정렬 */
}

nav a {
    text-decoration: none;
    color: var(--text-sub);
    margin-right: 30px;
    font-size: 0.95rem;
    font-weight: 700;
    text-transform: uppercase;
    transition: 0.3s;
}

nav a:hover {
    color: var(--android-primary);
}

/* --- 메인 컨테이너 및 섹션 --- */
.container {
    max-width: 1000px;
    margin: 0 auto;
    padding: 0 20px;
}

section {
    padding: 90px 0 45px;
    border-bottom: 1px solid var(--line-color);
    scroll-margin-top: 90px;
}

#about {
    padding: 110px 0 25px;
    background: linear-gradient(180deg, #ffffff 0%, #f8f9fa 100%);
    margin: 0 -20px;
    padding-left: 20px;
    padding-right: 20px;
}

#about h2 {
    text-align: center;
    font-size: 2.8rem;
    margin-bottom: 15px;
    border: none;
    padding: 0;
    position: relative;
    display: inline-block;
    width: 100%;
}

#about h2::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 4px;
    background: var(--android-primary);
    border-radius: 2px;
}

.about-intro {
    text-align: center;
    color: var(--text-sub);
    font-size: 1.1rem;
    margin-bottom: 50px;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

#projects {
    padding-bottom: 60px;
    max-width: 1000px;
    margin: 0 auto;
}

#certificate {
    padding-bottom: 120px;
    max-width: 1000px;
    margin: 0 auto;
}

/* --- 헤더 (가운데 정렬) --- */
header {
    display: flex;
    justify-content: center;
    align-items: center;
    text-align: center;
    min-height: 100vh; /* 전체 화면 높이 차지 */
    padding: 0 20px;
    position: relative;
}

.header-content {
    max-width: 800px;
}

header h1 {
    font-size: 2.2rem;       
    color: #000000;          
    font-weight: 700;        
    margin-bottom: 30px;
}

.highlight {
    color: var(--android-primary);
    font-weight: 900;
}

/* 메인 타이틀 */
.main-title {
    font-size: 4rem;
    font-weight: 900;
    color: var(--android-bold);
    margin: 40px 0;
    letter-spacing: -2px;
    animation: fadeInUp 0.8s ease-out;
    border: none;
    border-left: none;
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.subtitle {
    font-size: 1.25rem;
    color: var(--text-sub);
    line-height: 1.8;
    margin: 30px auto 0;
    word-break: keep-all;
}

.subtitle strong {
    color: var(--android-bold);
    background: linear-gradient(to top, rgba(74, 144, 226, 0.3) 40%, transparent 40%);
    padding: 0 4px;
}

/* --- 섹션 제목 --- */
h2 {
    font-size: 2.2rem;
    margin-bottom: 25px;
    color: var(--android-bold);
    border-left: 6px solid var(--android-primary);
    padding-left: 15px;
}

/* --- About Me 섹션 (통일감 있는 디자인) --- */
.about-container {
    display: grid;
    grid-template-columns: 380px 1fr;
    gap: 0;
    margin: 20px auto 0;
    max-width: 1000px;
    background: white;
    padding: 0;
    border-radius: 20px;
    box-shadow: 0 4px 15px rgba(0,0,0,0.05);
    overflow: hidden;
    min-height: 600px;
}

.about-left {
    display: flex;
    flex-direction: column;
    height: 100%;
    background: linear-gradient(180deg, #2C3E50 0%, #34495e 100%);
    padding: 40px 20px;
}

.profile-card {
    background: transparent;
    padding: 0;
    border-radius: 0;
    border: none;
    text-align: center;
    transition: all 0.3s ease;
    height: 100%;
    display: flex;
    flex-direction: column;
    justify-content: flex-start;
    box-shadow: none;
}

.profile-card:hover {
    border-color: transparent;
    box-shadow: none;
}

.profile-image {
    width: 180px;
    height: 180px;
    border-radius: 50%;
    overflow: hidden;
    background: linear-gradient(135deg, #e0e0e0 0%, #f5f5f5 100%);
    margin: 0 auto 30px;
    display: flex;
    align-items: center;
    justify-content: center;
    border: 5px solid rgba(255, 255, 255, 0.2);
}

.profile-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.profile-name {
    font-size: 1.8rem;
    font-weight: 900;
    color: white;
    margin-bottom: 10px;
}

.profile-birth {
    font-size: 1rem;
    color: rgba(255, 255, 255, 0.7);
    font-weight: 500;
    margin-bottom: 25px;
    letter-spacing: 0.5px;
}

.profile-role {
    font-size: 1.3rem;
    color: #4A90E2;
    font-weight: 700;
    margin-bottom: 25px;
}

.profile-intro {
    font-size: 0.95rem;
    color: rgba(255, 255, 255, 0.85);
    line-height: 1.7;
    margin-bottom: 30px;
    padding: 0;
    word-break: keep-all;
}

.profile-tags {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
    justify-content: center;
    margin-bottom: 30px;
    max-width: 100%;
}

.profile-tags span {
    color: white;
    font-size: 0.85rem;
    font-weight: 700;
    padding: 8px 16px;
    border-radius: 20px;
    background: rgba(74, 144, 226, 0.3);
    border: 2px solid rgba(74, 144, 226, 0.5);
    flex: 0 0 calc(50% - 4px);
    text-align: center;
}

.profile-social-title {
    font-size: 0.9rem;
    color: rgba(255, 255, 255, 0.6);
    font-weight: 500;
    text-align: center;
    margin-bottom: 15px;
}

.social-links {
    display: flex;
    gap: 15px;
    justify-content: center;
    margin: 20px 0;
}

.social-icon {
    width: 50px;
    height: 50px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.1);
    border: 2px solid rgba(255, 255, 255, 0.3);
    color: white;
    transition: all 0.3s ease;
    text-decoration: none;
}

/* GitHub (1st icon) */
.social-icon:nth-child(1) {
    background: rgba(51, 51, 51, 0.2);
    border-color: rgba(51, 51, 51, 0.3);
}

.social-icon:nth-child(1):hover {
    background: #333;
    border-color: #333;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.3);
}

/* LinkedIn (2nd icon) */
.social-icon:nth-child(2) {
    background: rgba(0, 119, 181, 0.2);
    border-color: rgba(0, 119, 181, 0.3);
}

.social-icon:nth-child(2):hover {
    background: #0077b5;
    border-color: #0077b5;
    box-shadow: 0 4px 15px rgba(0, 119, 181, 0.4);
}

/* Gmail (3rd icon) */
.social-icon:nth-child(3) {
    background: rgba(234, 67, 53, 0.2);
    border-color: rgba(234, 67, 53, 0.3);
}

.social-icon:nth-child(3):hover {
    background: #ea4335;
    border-color: #ea4335;
    box-shadow: 0 4px 15px rgba(234, 67, 53, 0.4);
}

/* Tistory (4th icon) */
.social-icon:nth-child(4) {
    background: rgba(255, 85, 68, 0.2);
    border-color: rgba(255, 85, 68, 0.3);
}

.social-icon:nth-child(4):hover {
    background: #FF5544;
    border-color: #FF5544;
    box-shadow: 0 4px 15px rgba(255, 85, 68, 0.4);
}

.social-icon:hover {
    transform: translateY(-5px);
    box-shadow: 0 4px 15px rgba(74, 144, 226, 0.2);
}

.social-icon svg {
    width: 22px;
    height: 22px;
}

.profile-description {
    font-size: 0.9rem;
    color: var(--text-sub);
    line-height: 1.7;
    text-align: left;
    word-break: keep-all;
}

.about-right {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 40px 25px;
    background: #fafafa;
}

.section-subtitle {
    font-size: 2rem;
    font-weight: 900;
    color: var(--android-bold);
    margin-bottom: 40px;
    padding-bottom: 0;
    border-bottom: none;
    width: 100%;
    text-align: left;
    position: relative;
}

.section-subtitle::before {
    content: '💬';
    margin-right: 12px;
    font-size: 1.8rem;
}

.interview-list {
    display: flex;
    flex-direction: column;
    gap: 30px;
    max-width: 100%;
    width: 100%;
}

.interview-item {
    background: white;
    padding: 25px;
    border-radius: 15px;
    border: 2px solid #e8eaed;
    transition: all 0.3s ease;
    text-align: left;
    box-shadow: 0 2px 6px rgba(0,0,0,0.02);
}

.interview-item:hover {
    border-color: var(--android-primary);
    transform: translateY(-3px);
    box-shadow: 0 4px 15px rgba(0,0,0,0.05);
}

.question {
    font-size: 1.15rem;
    font-weight: 800;
    color: var(--android-bold);
    margin-bottom: 15px;
    line-height: 1.6;
}

.answer {
    font-size: 1rem;
    color: var(--text-main);
    line-height: 1.9;
    word-break: keep-all;
    text-align: left;
}

.answer strong {
    color: var(--android-bold);
    background: linear-gradient(to top, rgba(74, 144, 226, 0.2) 40%, transparent 40%);
    padding: 0 3px;
    font-weight: 700;
}

/* --- Career 섹션 (타임라인) --- */
.career-filter {
    display: flex;
    justify-content: flex-start;
    margin-bottom: 30px;
    margin-top: 20px;
    gap: 15px;
}

.filter-btn {
    background: linear-gradient(135deg, var(--android-primary) 0%, #667eea 100%);
    color: white;
    border: none;
    padding: 12px 28px;
    border-radius: 25px;
    font-size: 0.95rem;
    font-weight: 700;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 3px 12px rgba(74, 144, 226, 0.25);
    position: relative;
    overflow: hidden;
}

.filter-btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, rgba(255,255,255,0.2) 0%, rgba(255,255,255,0) 100%);
    transition: left 0.5s ease;
}

.filter-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 18px rgba(74, 144, 226, 0.35);
}

.filter-btn:hover::before {
    left: 100%;
}

.filter-btn:active {
    transform: translateY(0);
}

.filter-btn:not(.active) {
    background: linear-gradient(135deg, #95a5a6 0%, #7f8c8d 100%);
    box-shadow: 0 3px 12px rgba(127, 140, 141, 0.25);
}

.filter-btn:not(.active):hover {
    box-shadow: 0 5px 18px rgba(127, 140, 141, 0.35);
}

.filter-btn.active {
    background: linear-gradient(135deg, var(--android-primary) 0%, #667eea 100%);
    box-shadow: 0 3px 12px rgba(74, 144, 226, 0.25);
}

.filter-btn.active:hover {
    box-shadow: 0 5px 18px rgba(74, 144, 226, 0.35);
}

.filter-count {
    font-size: 0.85rem;
    font-weight: 600;
    opacity: 0.85;
    margin-left: 5px;
}

.timeline {
    position: relative;
    max-width: 900px;
    margin: 0 auto;
    padding: 20px 0;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 220px;
    top: 0;
    bottom: 0;
    width: 2px;
    background: var(--line-color);
}

.timeline-item {
    display: flex;
    margin-bottom: 40px;
    position: relative;
    transition: opacity 0.3s ease, transform 0.3s ease;
}

.timeline-item::before {
    content: '';
    position: absolute;
    left: 214px;
    top: 8px;
    width: 14px;
    height: 14px;
    border-radius: 50%;
    background: var(--android-primary);
    border: 3px solid white;
    box-shadow: 0 0 0 2px var(--android-primary);
    z-index: 1;
}

.timeline-date {
    width: 200px;
    padding-right: 20px;
    text-align: right;
    font-weight: 700;
    color: var(--android-primary);
    font-size: 0.9rem;
    flex-shrink: 0;
    line-height: 1.4;
}

.timeline-content {
    flex: 1;
    background: #fcfcfc;
    padding: 22px 25px;
    border-radius: 12px;
    border: 1px solid var(--line-color);
    margin-left: 30px;
    transition: all 0.3s ease;
    box-shadow: 0 2px 6px rgba(0,0,0,0.02);
}

.timeline-content:hover {
    border-color: var(--android-primary);
    box-shadow: 0 3px 10px rgba(0,0,0,0.05);
    transform: translateX(5px);
}

.timeline-title {
    font-size: 1.3rem;
    font-weight: 700;
    color: var(--android-bold);
    margin-bottom: 12px;
}

.timeline-description {
    font-size: 1rem;
    color: var(--text-main);
    line-height: 1.7;
    margin-bottom: 15px;
}

.timeline-divider {
    height: 1px;
    background: var(--line-color);
    margin: 20px 0 15px;
}

.timeline-subtitle {
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--android-bold);
    margin-bottom: 12px;
}

.timeline-tags {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
}

.timeline-tags span {
    color: var(--android-primary);
    font-size: 0.8rem;
    font-weight: 700;
    padding: 5px 12px;
    border-radius: 12px;
    background: rgba(74, 144, 226, 0.1);
    border: 1px solid rgba(74, 144, 226, 0.3);
}

/* --- 프로젝트 카드 --- */
.project-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 25px;
}

.card {
    background: #fcfcfc;
    padding: 25px;
    border-radius: 15px;
    border: 1px solid var(--line-color);
    transition: all 0.3s ease;
    box-shadow: 0 2px 6px rgba(0,0,0,0.02);
}

.card:hover {
    border-color: var(--android-primary);
    transform: translateY(-10px);
    box-shadow: 0 8px 20px rgba(0,0,0,0.05);
}

.card h3 {
    font-size: 1.5rem;
    margin-bottom: 12px;
    color: var(--android-bold);
}

.card p {
    line-height: 1.8;
}

.card p strong {
    font-weight: 700;
    color: var(--android-bold);
}

.project-detail {
    color: var(--text-sub);
    font-size: 0.95rem;
}

.tags {
    font-weight: 700;
    color: var(--android-primary);
    font-size: 0.85rem;
    margin-bottom: 12px;
}

.more-link {
    display: inline-block;
    margin-top: 18px;
    color: var(--android-primary);
    font-weight: 700;
    text-decoration: none;
}

/* --- 프로젝트 모달 --- */
.modal {
    display: none;
    position: fixed;
    z-index: 2000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    overflow: auto;
    background-color: rgba(0, 0, 0, 0.6);
    animation: fadeIn 0.3s;
}

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

.modal-content {
    background-color: #ffffff;
    margin: 5% auto;
    padding: 35px;
    border-radius: 15px;
    max-width: 800px;
    width: 90%;
    box-shadow: 0 10px 40px rgba(0,0,0,0.2);
    max-height: 90vh;
    overflow-y: auto;
    position: relative;
}

@keyframes slideIn {
    from {
        transform: translateY(-50px);
        opacity: 0;
    }
    to {
        transform: translateY(0);
        opacity: 1;
    }
}

.close {
    color: #aaa;
    position: absolute;
    top: 20px;
    right: 30px;
    font-size: 35px;
    font-weight: bold;
    cursor: pointer;
    transition: 0.3s;
}

.close:hover {
    color: #000;
}

.modal-title {
    font-size: 2rem;
    font-weight: 800;
    color: var(--android-bold);
    margin-bottom: 20px;
}

.modal-tags {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
    margin-bottom: 25px;
}

.modal-tag {
    background: rgba(74, 144, 226, 0.1);
    color: var(--android-primary);
    padding: 6px 14px;
    border-radius: 15px;
    font-size: 0.85rem;
    font-weight: 600;
    border: 1px solid rgba(74, 144, 226, 0.3);
}

.modal-images {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 15px;
    margin-bottom: 30px;
}

.project-image {
    width: 100%;
    height: auto;
    border-radius: 10px;
    object-fit: cover;
    border: 1px solid var(--line-color);
    transition: transform 0.3s ease;
    cursor: pointer;
}

.project-image:hover {
    transform: scale(1.05);
    box-shadow: 0 4px 12px rgba(0,0,0,0.15);
}

.modal-info {
    background: linear-gradient(135deg, rgba(102, 126, 234, 0.08) 0%, rgba(118, 75, 162, 0.08) 100%);
    padding: 0;
    border-radius: 15px;
    margin-bottom: 35px;
    border-left: 4px solid var(--android-primary);
    box-shadow: 0 2px 8px rgba(0,0,0,0.03);
    overflow: hidden;
}

.modal-info p {
    margin: 0;
    padding: 18px 25px;
    font-size: 1.05rem;
    line-height: 1.8;
    border-bottom: 1px solid rgba(0,0,0,0.05);
    display: flex;
    align-items: center;
    gap: 12px;
    transition: all 0.3s ease;
}

.modal-info p:last-child {
    border-bottom: none;
}

.modal-info p:hover {
    background: rgba(74, 144, 226, 0.05);
    transform: translateX(5px);
}

.modal-info strong {
    min-width: 100px;
    font-weight: 700;
    color: var(--android-primary);
    display: inline-flex;
    align-items: center;
    gap: 8px;
}

.modal-section {
    margin-bottom: 40px;
    padding: 28px;
    background: white;
    border-radius: 18px;
    box-shadow: 0 3px 12px rgba(0,0,0,0.04);
    transition: all 0.3s ease;
    border: 2px solid transparent;
}

.modal-section:hover {
    box-shadow: 0 4px 12px rgba(0,0,0,0.05);
    transform: translateY(-3px);
    border-color: rgba(74, 144, 226, 0.1);
}

.modal-section h3 {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--android-bold);
    margin-bottom: 25px;
    position: relative;
    padding-left: 20px;
    display: flex;
    align-items: center;
    gap: 12px;
}

.modal-section h3::before {
    content: '';
    position: absolute;
    left: 0;
    top: 50%;
    transform: translateY(-50%);
    width: 6px;
    height: 75%;
    background: var(--gradient-android);
    border-radius: 3px;
}

.modal-section p {
    margin: 15px 0;
    line-height: 1.9;
    color: var(--text-main);
}

.modal-section p strong {
    color: var(--android-primary);
    font-weight: 700;
    margin-right: 8px;
    display: inline-block;
}

.modal-section > p:first-of-type {
    padding: 15px;
    background: linear-gradient(135deg, rgba(74, 144, 226, 0.05) 0%, rgba(118, 75, 162, 0.05) 100%);
    border-radius: 10px;
    border-left: 3px solid var(--android-primary);
}

.modal-section code {
    background: linear-gradient(135deg, rgba(74, 144, 226, 0.12) 0%, rgba(118, 75, 162, 0.12) 100%);
    padding: 6px 14px;
    border-radius: 8px;
    font-family: 'Courier New', monospace;
    font-size: 0.95rem;
    color: var(--android-primary);
    border: 2px solid rgba(74, 144, 226, 0.25);
    display: inline-block;
    margin: 5px 0;
    font-weight: 600;
    box-shadow: 0 2px 4px rgba(74, 144, 226, 0.08);
    transition: all 0.3s ease;
}

.modal-section code:hover {
    transform: translateY(-2px);
    box-shadow: 0 3px 8px rgba(74, 144, 226, 0.15);
    background: linear-gradient(135deg, rgba(74, 144, 226, 0.18) 0%, rgba(118, 75, 162, 0.18) 100%);
}

.tech-stack {
    display: flex;
    gap: 14px;
    flex-wrap: wrap;
}

.tech-badge {
    background: var(--android-primary);
    color: white;
    padding: 12px 22px;
    border-radius: 25px;
    font-size: 0.95rem;
    font-weight: 600;
    box-shadow: 0 3px 10px rgba(74, 144, 226, 0.1);
    transition: all 0.3s ease;
    border: 2px solid transparent;
}

.tech-badge:hover {
    transform: translateY(-4px) scale(1.08);
    box-shadow: 0 6px 20px rgba(74, 144, 226, 0.2);
    border-color: rgba(255,255,255,0.3);
}

.feature-list {
    list-style: none;
    padding: 0;
    display: grid;
    gap: 15px;
}

.feature-list li {
    padding: 18px 18px 18px 48px;
    position: relative;
    line-height: 1.9;
    border-bottom: none;
    background: linear-gradient(135deg, rgba(74, 144, 226, 0.03) 0%, transparent 100%);
    border-radius: 12px;
    border-left: 3px solid transparent;
    transition: all 0.3s ease;
    box-shadow: 0 2px 8px rgba(0,0,0,0.02);
}

.feature-list li:hover {
    background: linear-gradient(135deg, rgba(74, 144, 226, 0.08) 0%, rgba(118, 75, 162, 0.05) 100%);
    border-left-color: var(--android-primary);
    transform: translateX(5px);
    box-shadow: 0 5px 15px rgba(0,0,0,0.04);
}

.feature-list li::before {
    content: "✓";
    position: absolute;
    left: 15px;
    top: 20px;
    color: white;
    font-weight: bold;
    font-size: 1.1rem;
    width: 28px;
    height: 28px;
    background: var(--gradient-android);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 2px 8px rgba(74, 144, 226, 0.1);
}

.challenge-list {
    list-style: none;
    padding: 0;
    display: grid;
    gap: 25px;
}

.challenge-list li {
    padding: 25px;
    margin-bottom: 0;
    background: linear-gradient(135deg, rgba(74, 144, 226, 0.04) 0%, rgba(118, 75, 162, 0.04) 100%);
    border-radius: 15px;
    border-left: 5px solid var(--android-primary);
    line-height: 1.9;
    box-shadow: 0 3px 10px rgba(0,0,0,0.02);
    transition: all 0.4s ease;
    position: relative;
    overflow: hidden;
}

.challenge-list li::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 5px;
    height: 100%;
    background: var(--gradient-android);
}

.challenge-list li:hover {
    transform: translateX(8px);
    box-shadow: 0 5px 15px rgba(0,0,0,0.04);
    background: linear-gradient(135deg, rgba(74, 144, 226, 0.08) 0%, rgba(118, 75, 162, 0.06) 100%);
}

.challenge-list li strong {
    display: inline-block;
    margin-bottom: 12px;
    font-weight: 700;
    font-size: 1.05rem;
    padding: 8px 14px;
    border-radius: 8px;
    background: white;
    box-shadow: 0 2px 6px rgba(0,0,0,0.02);
}

.challenge-list li strong:first-child {
    color: #e74c3c;
}

.challenge-list li strong:nth-child(3) {
    color: #27ae60;
}

.challenge-list li strong:nth-child(5) {
    color: var(--android-primary);
}

.achievement-list {
    list-style: none;
    padding: 0;
    display: grid;
    gap: 18px;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
}

.achievement-list li {
    padding: 18px 18px 18px 50px;
    position: relative;
    line-height: 1.9;
    font-size: 1.05rem;
    background: linear-gradient(135deg, rgba(74, 144, 226, 0.06) 0%, transparent 100%);
    border-radius: 12px;
    transition: all 0.3s ease;
    border: 2px solid transparent;
}

.achievement-list li:hover {
    background: linear-gradient(135deg, rgba(74, 144, 226, 0.12) 0%, rgba(118, 75, 162, 0.08) 100%);
    transform: translateY(-3px) scale(1.02);
    border-color: rgba(74, 144, 226, 0.3);
    box-shadow: 0 3px 10px rgba(0,0,0,0.04);
}

.achievement-list li::before {
    content: "✅";
    position: absolute;
    left: 18px;
    top: 20px;
    font-size: 1.5rem;
    filter: drop-shadow(0 2px 4px rgba(0,0,0,0.1));
}

.future-plans-list {
    list-style: none;
    padding: 0;
    display: grid;
    gap: 18px;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
}

.future-plans-list li {
    padding: 18px;
    position: relative;
    line-height: 1.9;
    font-size: 1.05rem;
    background: linear-gradient(135deg, rgba(255, 152, 0, 0.06) 0%, transparent 100%);
    border-radius: 12px;
    transition: all 0.3s ease;
    border: 2px solid transparent;
}

.future-plans-list li:hover {
    background: linear-gradient(135deg, rgba(255, 152, 0, 0.12) 0%, rgba(255, 87, 34, 0.08) 100%);
    transform: translateY(-3px) scale(1.02);
    border-color: rgba(255, 152, 0, 0.3);
    box-shadow: 0 3px 10px rgba(255, 152, 0, 0.15);
}

.future-plans-list li::before {
    content: '';
    position: absolute;
    left: 18px;
    top: 20px;
}

/* --- 공통 박스 및 링크 --- */
.content-box {
    background: #f9f9f9;
    padding: 25px;
    border-radius: 12px;
}

a {
    color: var(--android-primary);
    transition: 0.3s;
}

.career-section-title {
    font-size: 2.2rem;
    margin-bottom: 25px;
    color: var(--android-bold);
    border-left: 6px solid var(--android-primary);
    padding-left: 15px;
    margin-top: 60px;
    text-align: left;
}

.project-section-title {
    font-size: 1.6rem;
    margin-top: 60px;
    margin-bottom: 30px;
    color: var(--android-bold);
    font-weight: 700;
    text-align: left;
    padding-left: 10px;
    border-left: 4px solid var(--android-primary);
}

#career {
    max-width: 1000px;
    margin: 0 auto;
}

.certificate-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 25px;
    max-width: 900px;
    margin: 0 auto;
    padding-bottom: 20px;
}

.cert-card {
    background: #fcfcfc;
    padding: 25px;
    border-radius: 12px;
    border: 1px solid var(--line-color);
    text-align: center;
    transition: all 0.3s ease;
    box-shadow: 0 2px 6px rgba(0,0,0,0.02);
}

.cert-card:hover {
    border-color: var(--android-primary);
    transform: translateY(-5px);
    box-shadow: 0 6px 15px rgba(0,0,0,0.05);
}

.cert-icon {
    font-size: 3rem;
    margin-bottom: 15px;
}

.cert-card h4 {
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--android-bold);
    margin-bottom: 10px;
    line-height: 1.4;
}

.cert-card .cert-date {
    color: var(--android-primary);
    font-size: 0.95rem;
    font-weight: 600;
}

.cert-org {
    color: var(--text-sub);
    font-size: 0.85rem;
    margin-top: 8px;
    font-weight: 500;
}

.cert-number {
    color: var(--text-sub);
    font-size: 0.8rem;
    margin-top: 5px;
    font-family: 'Courier New', monospace;
}

/* --- 푸터 --- */
footer {
    text-align: center;
    padding: 40px 0;
    color: var(--text-sub);
    font-size: 0.9rem;
}

/* 모바일 대응 */
@media (max-width: 768px) {
    header {
        padding: 80px 0 45px;
    }
    section {
        padding: 30px 0;
    }
    
    #about {
        padding: 70px 0 25px;
        margin: 0;
        padding-left: 20px;
        padding-right: 20px;
    }
    
    #about h2 {
        font-size: 2.2rem;
    }
    
    .about-intro {
        font-size: 1rem;
        margin-bottom: 30px;
    }
    
    .about-container {
        grid-template-columns: 1fr;
        gap: 0;
        padding: 0;
    }

    .about-left {
        padding: 35px 20px;
    }

    .about-right {
        padding: 35px 20px;
    }

    .profile-image {
        width: 150px;
        height: 150px;
    }

    .profile-name {
        font-size: 1.6rem;
    }

    .profile-birth {
        font-size: 0.9rem;
    }
    
    .profile-social-title {
        font-size: 0.8rem;
    }

    .profile-role {
        font-size: 1.1rem;
    }

    .section-subtitle {
        font-size: 1.6rem;
    }
    
    .interview-item {
        padding: 20px;
    }
    
    .question {
        font-size: 1.05rem;
    }
    
    .answer {
        font-size: 0.95rem;
    }
    
    .main-title {
        font-size: 3rem;
    }

    .timeline::before {
        left: 20px;
    }

    .timeline-item {
        flex-direction: column;
        padding-left: 50px;
    }

    .timeline-item::before {
        left: 14px;
    }

    .timeline-item[data-type="education"] {
        display: flex;
    }
    
    .timeline-item[data-type="education"][style*="display: none"] {
        display: none !important;
    }

    .timeline-date {
        width: 100%;
        text-align: left;
        padding-right: 0;
        margin-bottom: 10px;
    }

    .timeline-content {
        margin-left: 0;
    }
    
    .modal-app-header {
        flex-direction: column;
        align-items: center;
        text-align: center;
        gap: 20px;
    }
    
    .modal-app-icon {
        width: 100px;
        height: 100px;
    }
    
    .modal-title-section {
        align-items: center;
    }
}

/* --- 스크롤 다운 버튼 --- */
.scroll-down {
    position: absolute;
    bottom: 40px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 10px;
    color: var(--android-primary);
    font-size: 0.9rem;
    font-weight: 600;
    text-decoration: none;
    transition: all 0.3s ease;
    cursor: pointer;
}

.scroll-down:hover {
    color: var(--android-bold);
    transform: translateX(-50%) translateY(-5px);
}

.scroll-down svg {
    animation: bounce 2s ease-in-out infinite;
}

@keyframes bounce {
    0%, 100% {
        transform: translateY(0);
    }
    50% {
        transform: translateY(10px);
    }
}

.pattern-box {
    margin-bottom: 30px;
    padding: 22px;
    background: linear-gradient(135deg, rgba(74, 144, 226, 0.03) 0%, rgba(118, 75, 162, 0.03) 100%);
    border: 2px solid rgba(74, 144, 226, 0.2);
    border-radius: 15px;
    box-shadow: 0 2px 8px rgba(74, 144, 226, 0.05);
    transition: all 0.3s ease;
}

.pattern-box:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(74, 144, 226, 0.1);
    border-color: var(--android-primary);
    background: linear-gradient(135deg, rgba(74, 144, 226, 0.06) 0%, rgba(118, 75, 162, 0.06) 100%);
}

/* 프로젝트 UI 스크린샷 */
.modal-ui-screenshots {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 30px;
    margin-top: 40px;
    padding: 30px;
    background: linear-gradient(135deg, rgba(74, 144, 226, 0.03) 0%, rgba(118, 75, 162, 0.03) 100%);
    border-radius: 15px;
    border: 2px solid rgba(74, 144, 226, 0.1);
}

.screenshot-box {
    background: white;
    border-radius: 12px;
    padding: 20px;
    box-shadow: 0 3px 10px rgba(0,0,0,0.05);
    transition: all 0.3s ease;
    border: 1px solid #e8eaed;
    text-align: center;
}

.screenshot-box:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 20px rgba(0,0,0,0.1);
    border-color: var(--android-primary);
}

.screenshot-title {
    font-size: 1.1rem;
    font-weight: 800;
    color: var(--android-bold);
    margin-bottom: 8px;
    text-align: center;
}

.screenshot-description {
    font-size: 0.9rem;
    color: var(--text-sub);
    margin-bottom: 15px;
    line-height: 1.6;
    text-align: center;
}

.screenshot-image {
    width: 100%;
    height: auto;
    border-radius: 8px;
    border: 2px solid #e8eaed;
    transition: all 0.3s ease;
}

.screenshot-image:hover {
    transform: scale(1.02);
    border-color: var(--android-primary);
    box-shadow: 0 5px 15px rgba(74, 144, 226, 0.2);
}

@media (max-width: 768px) {
    .modal-ui-screenshots {
        grid-template-columns: 1fr;
        gap: 20px;
        padding: 20px;
    }
}

.pattern-box:last-child {
    margin-bottom: 0;
}

.pattern-box p {
    margin: 12px 0;
}

.pattern-box p:first-child {
    margin-top: 0;
}

.pattern-box p:last-child {
    margin-bottom: 0;
}

.modal-app-header {
    display: flex;
    align-items: center;
    gap: 25px;
    margin-bottom: 30px;
    padding-bottom: 25px;
    border-bottom: 2px solid #e8eaed;
}

.modal-app-icon {
    width: 120px;
    height: 120px;
    border-radius: 24px;
    object-fit: cover;
    box-shadow: 0 5px 20px rgba(0,0,0,0.15);
    border: 3px solid #e8eaed;
    transition: all 0.3s ease;
}

.modal-app-icon:hover {
    transform: scale(1.05);
    box-shadow: 0 8px 30px rgba(74, 144, 226, 0.3);
    border-color: var(--android-primary);
}

.modal-title-section {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.modal-title-section .modal-title {
    margin-bottom: 0;
}

.modal-title-section .modal-tags {
    margin-bottom: 0;
}

/* 모달 버튼 스타일 */
.modal-buttons {
    display: flex;
    gap: 15px;
    flex-wrap: wrap;
    margin-top: 30px;
}

.btn-github {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    padding: 12px 24px;
    background: linear-gradient(135deg, #24292e 0%, #1a1e22 100%);
    color: white;
    text-decoration: none;
    border-radius: 8px;
    font-weight: 600;
    transition: all 0.3s ease;
    border: 2px solid transparent;
}

.btn-github:hover {
    background: linear-gradient(135deg, #2d333b 0%, #24292e 100%);
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(36, 41, 46, 0.4);
    border-color: #58a6ff;
}

.btn-playstore {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    padding: 12px 24px;
    background: linear-gradient(135deg, #01875f 0%, #019267 100%);
    color: white;
    text-decoration: none;
    border-radius: 8px;
    font-weight: 600;
    transition: all 0.3s ease;
    border: 2px solid transparent;
}

.btn-playstore:hover {
    background: linear-gradient(135deg, #019267 0%, #01a572 100%);
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(1, 135, 95, 0.4);
    border-color: #00c896;
}

.toggle-icon {
    font-size: 0.85rem;
    color: var(--android-primary);
    transition: all 0.3s ease;
    user-select: none;
    padding: 4px 12px;
    background: rgba(74, 144, 226, 0.1);
    border-radius: 15px;
    font-weight: 600;
}

.toggle-icon:hover {
    background: rgba(74, 144, 226, 0.2);
    transform: scale(1.05);
}

.modal-section.ui-collapsed {
    padding-bottom: 15px;
    margin-bottom: 20px;
}

.modal-section.ui-collapsed h3 {
    margin-bottom: 0;
}