/* ============================================================
   BY-HAHN PORTFOLIO SITE STYLESHEET
   ============================================================ */

@import url('../assets/fonts/fonts.css');

/* ============================================================
   [0] CSS VARIABLES - Theme System
   ============================================================ */
:root {
    /* Colors - Light Mode */
    --bg-color: #fdfdfd;
    --surface-color: #ffffff;
    --text-primary: #2d3436;
    --text-secondary: #636e72;
    --border-color: #dfe6e9;

    /* Accent Colors */
    --primary-color: #74b9ff;
    --primary-dark: #0984e3;
    --accent-color: #a29bfe;

    /* Effects */
    --shadow: 0 4px 6px rgba(0, 0, 0, 0.05);

    /* Layout */
    --container-width: 1200px;
    --header-height: 70px;
    --radius: 12px;
}

/* Dark Mode Overrides */
[data-theme="dark"] {
    --bg-color: #000000;
    --surface-color: #2d2d2d;
    --text-primary: #dfe6e9;
    --text-secondary: #b2bec3;
    --border-color: #444;
    --shadow: 0 4px 20px rgba(0, 0, 0, 0.4);
}

/* System Preference Fallback */
@media (prefers-color-scheme: dark) {
    :root:not([data-theme]) {
        --bg-color: #000000;
        --surface-color: #2d2d2d;
        --text-primary: #dfe6e9;
        --text-secondary: #b2bec3;
        --border-color: #444;
        --shadow: 0 4px 20px rgba(0, 0, 0, 0.4);
    }
}


/* ============================================================
   [1] MAIN PAGE - Main Single Page Section
   Global reset, header, navigation, buttons, utility classes
   ============================================================ */

/* 1-1. Global Reset & Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Noto Sans KR', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-primary);
    line-height: 1.6;
    transition: background-color 0.3s, color 0.3s;
}

a {
    text-decoration: none;
    color: inherit;
    transition: color 0.2s;
}

ul,
ol {
    list-style: none;
}

img {
    max-width: 100%;
    display: block;
    border-radius: var(--radius);
}

/* 1-2. Utility Classes */
.container {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 20px;
}

.hidden-visually {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    border: 0;
}

/* 1-3. Header & Navigation */
.header-fixed {
    position: sticky;
    top: 0;
    width: 100%;
    height: var(--header-height);
    background: rgba(255, 255, 255, 0.18);
    backdrop-filter: blur(16px) saturate(180%);
    -webkit-backdrop-filter: blur(16px) saturate(180%);
    z-index: 1000;
    border-bottom: 1px solid rgba(255, 255, 255, 0.25);
    border-top: 1px solid rgba(255, 255, 255, 0.08);
    box-shadow: 0 8px 32px 0 rgba(31, 38, 135, 0.10);
    display: flex;
    align-items: center;
    transition: background-color 0.3s, border-color 0.3s;
    opacity: 0.95;
}

@media (prefers-color-scheme: dark) {
    .header-fixed {
        background: rgba(34, 34, 40, 0.28);
        border-bottom: 1px solid rgba(80, 80, 100, 0.18);
        box-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.25);
    }
}

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

.logo a {
    font-family: 'Space Grotesk', sans-serif;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
    transition: color 0.2s;
}

.logo a:hover {
    color: var(--primary-dark);
}

.main-nav ul {
    display: flex;
    gap: 30px;
}

.main-nav a {
    font-weight: 500;
    color: var(--text-secondary);
}

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

.mobile-menu-btn {
    display: none;
    font-size: 1.5rem;
    cursor: pointer;
    background: none;
    border: none;
    color: var(--text-primary);
    padding: 5px;
}

.theme-toggle {
    cursor: pointer;
    background: none;
    border: 1px solid var(--border-color);
    padding: 5px 10px;
    border-radius: 20px;
    margin-left: 20px;
    color: var(--text-primary);
    font-size: 0.9rem;
    transition: border-color 0.2s;
}

.theme-toggle:hover {
    border-color: var(--primary-color);
}

/* 1-4. Hero Section */
.section-hero {
    padding: 0 !important;
    height: calc(100vh - var(--header-height));
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    position: relative;
}

/* 1-5. Scroll Down Indicator */
.scroll-down {
    position: absolute;
    bottom: 38px;
    left: 50%;
    transform: translateX(-50%) translateY(0);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0px;
    cursor: pointer;
    z-index: 10;
    user-select: none;
    animation: scrollDownBounce 3s ease-in-out infinite;
}

.scroll-down span {
    display: block;
    width: 22px;
    height: 22px;
    border-right: 3px solid var(--text-secondary);
    border-bottom: 3px solid var(--text-secondary);
    transform: rotate(45deg);
    transition: border-color 0.3s ease;
}

.scroll-down span:nth-child(1) { opacity: 0.15; }
.scroll-down span:nth-child(2) { opacity: 0.55; }
.scroll-down span:nth-child(3) { opacity: 0.9; }

.scroll-down:hover span {
    border-color: var(--primary-color);
}

@keyframes scrollDownBounce {
    0%, 100% { transform: translateX(-50%) translateY(-4px); }
    50%       { transform: translateX(-50%) translateY(4px); }
}

#darkveil-container {
    position: fixed;
    top: calc(0px - var(--header-height));
    left: 0;
    width: 100%;
    z-index: 1;
}

.hero-content {
    position: relative;
    z-index: 2;
    pointer-events: auto;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    margin: auto;
    height: 100%;
}

.hero-greeting {
    font-size: 1.2rem;
    color: var(--accent-color);
    font-weight: 700;
    margin-bottom: 10px;
    text-transform: uppercase;
    letter-spacing: 2px;
}

.hero-title {
    font-size: 3.5rem;
    line-height: 1.2;
    margin-bottom: 20px;
    font-weight: 800;
}

.gradient-text {
    background: linear-gradient(120deg, var(--primary-color) 0%, var(--accent-color) 100%);
    background-clip: text;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero-subtitle {
    font-size: 1.2rem;
    color: var(--text-secondary);
    margin-bottom: 40px;
}

.hero-actions {
    display: flex;
    gap: 20px;
    justify-content: center;
    flex-wrap: wrap;
}

/* 1-5. Button Styles */
.btn {
    display: inline-block;
    padding: 12px 30px;
    border-radius: 50px;
    font-weight: 500;
    transition: all 0.3s ease;
    border: none;
    cursor: pointer;
}

.btn-cta {
    background-color: var(--primary-color);
    color: white;
    box-shadow: 0 4px 15px rgba(116, 185, 255, 0.4);
}

.btn-cta:hover {
    background-color: var(--primary-dark);
    transform: translateY(-2px);
}

.btn-resume {
    background-color: var(--primary-color);
    color: white;
    box-shadow: 0 4px 15px rgba(116, 185, 255, 0.4);
    display: flex;
    align-items: center;
    gap: 12px;
    position: relative;
}

.btn-resume::after {
    content: '';
    display: block;
    flex: 1;
    height: 2px;
    background-color: white;
    opacity: 0.6;
}

.btn-resume:hover {
    background-color: var(--primary-dark);
    transform: translateY(-2px);
}

.btn-outline {
    border: 2px solid var(--border-color);
    color: var(--text-primary);
}

.btn-outline:hover {
    border-color: var(--primary-color);
    color: var(--primary-color);
}

.btn-card {
    display: inline-block;
    margin-top: 20px;
    padding: 8px 20px;
    background-color: var(--text-primary);
    color: var(--bg-color);
    border-radius: 4px;
    font-size: 0.9rem;
}

.btn-main-resume {
    display: inline-block;
    margin-top: 20px;
    padding: 8px 20px;
    width: 230px;
    background-color: var(--text-primary);
    color: var(--bg-color);
    border-radius: 4px;
    font-size: 0.9rem;
    justify-content: center;
}

.btn-link {
    padding: 0;
    background: none;
    box-shadow: none;
    font-weight: 700;
    border-bottom: 2px solid var(--primary-color);
}


/* ============================================================
   [2] ABOUT SECTION - About Section
   HAHN acrostic, profile image, description text
   ============================================================ */

.section-about {
    padding: 130px 0 80px 0;
}

.section-title {
    font-size: 2rem;
    margin-bottom: 40px;
    text-align: center;
    position: relative;
}

.section-title::after {
    content: '';
    display: block;
    width: 50px;
    height: 4px;
    background-color: var(--accent-color);
    margin: 10px auto 0;
    border-radius: 2px;
}

.section-subtitle {
    text-align: center;
    color: var(--text-secondary);
    margin-bottom: 30px;
}

.about-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 50px;
    align-items: center;
}

.hahn-acrostic {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.acrostic-item {
    display: flex;
    align-items: center;
    font-size: 1.5rem;
    opacity: 0;
    transform: translateX(-20px);
    transition: all 0.8s ease;
}

.acrostic-item.visible {
    opacity: 1;
    transform: translateX(0);
}

.acrostic-item .acrostic-letter {
    font-family: 'Space Grotesk', sans-serif;
    font-size: 3rem;
    font-weight: 700;
    color: var(--primary-color);
    width: 60px;
    display: inline-block;
    margin-right: 20px;
}

.about-description .profile-image {
    width: 200px;
    height: 200px;
    border-radius: 50%;
    overflow: hidden;
    margin-bottom: 20px;
    border: 4px solid var(--surface-color);
    box-shadow: var(--shadow);
}

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

.about-description {
    display: flex;
    flex-direction: column;
    justify-content: center;
}

.about-description h2 {
    font-size: 1.8rem;
    font-weight: 700;
    margin-bottom: 10px;
}

.about-description .about-role {
    font-size: 1.1rem;
    color: var(--primary-color);
    font-weight: 500;
    margin-bottom: 20px;
}

/* About Content - Right column text */
.about-content {
    display: flex;
    flex-direction: column;
    gap: 25px;
}

.about-content h3 {
    font-size: 1.3rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 10px;
}

.about-content p {
    color: var(--text-secondary);
    font-size: 1rem;
    line-height: 1.7;
}

.about-content ul {
    list-style: none;
    padding-left: 0;
}

.about-content ul li {
    position: relative;
    padding-left: 20px;
    margin-bottom: 12px;
    color: var(--text-secondary);
    line-height: 1.6;
}

.about-content ul li::before {
    content: '•';
    position: absolute;
    left: 0;
    color: var(--primary-color);
    font-weight: bold;
}

/* Full Acrostic Section */
.hahn-acrostic-full {
    margin-top: 80px;
    padding-top: 60px;
    border-top: 1px solid var(--border-color);
}

.hahn-acrostic-full .text-center {
    text-align: center;
}

.hahn-acrostic-full h3 {
    font-size: 1.8rem;
    font-weight: 700;
    margin-bottom: 50px;
    color: var(--text-primary);
}

/* Acrostic Grid Layout */
.acrostic-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 40px;
    margin-top: 40px;
}

.acrostic-item-full {
    display: flex;
    flex-direction: column;
    gap: 15px;
    padding: 30px;
    background: var(--surface-color);
    border-radius: var(--radius);
    border: 1px solid var(--border-color);
    transition: all 0.3s ease;
}

.acrostic-item-full:hover {
    transform: translateY(-5px);
    border-color: var(--primary-color);
    box-shadow: 0 12px 28px rgba(0, 0, 0, 0.12);
}

.acrostic-item-full .letter-large {
    font-family: 'Space Grotesk', sans-serif;
    font-size: 4rem;
    font-weight: 800;
    color: var(--primary-color);
    line-height: 1;
}

.acrostic-item-full h4 {
    font-size: 1.3rem;
    font-weight: 700;
    color: var(--text-primary);
    margin: 10px 0;
}

.acrostic-item-full p {
    font-size: 1rem;
    color: var(--text-secondary);
    line-height: 1.7;
    margin: 0;
}

/* Utility class for text centering */
.text-center {
    text-align: center;
}


/* ============================================================
   [3] CAREER SECTION - Career Section
   Timeline layout, career information
   ============================================================ */

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

.section-career {
    padding: 80px 0;
}

.timeline {
    position: relative;
    max-width: 860px;
    margin: 50px auto 0;
    padding: 0 20px;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 50%;
    top: 0;
    bottom: 0;
    width: 2px;
    background: linear-gradient(to bottom,
            var(--primary-color),
            var(--accent-color),
            transparent);
    transform: translateX(-50%);
}

.timeline-item {
    position: relative;
    margin-bottom: 60px;
    width: 100%;
    animation: fadeInUp 0.5s ease both;
}

.timeline-item:nth-child(1) { animation-delay: 0.05s; }
.timeline-item:nth-child(2) { animation-delay: 0.15s; }
.timeline-item:nth-child(3) { animation-delay: 0.25s; }
.timeline-item:nth-child(4) { animation-delay: 0.35s; }
.timeline-item:nth-child(5) { animation-delay: 0.45s; }
.timeline-item:nth-child(6) { animation-delay: 0.55s; }

.timeline-item:nth-child(odd) .timeline-content {
    margin-left: auto;
    margin-right: calc(50% + 36px);
    text-align: right;
}

.timeline-item:nth-child(even) .timeline-content {
    margin-left: calc(50% + 36px);
    margin-right: auto;
    text-align: left;
}

.timeline-dot {
    position: absolute;
    left: 50%;
    top: 8px;
    width: 18px;
    height: 18px;
    background: var(--primary-color);
    border: 3px solid var(--bg-color);
    border-radius: 50%;
    transform: translateX(-50%);
    z-index: 2;
    box-shadow: 0 0 0 6px rgba(116, 185, 255, 0.15);
    transition: all 0.3s ease;
}

.timeline-item:hover .timeline-dot {
    transform: translateX(-50%) scale(1.25);
}

.timeline-item[data-category="military"]:hover .timeline-dot {
    background: #74b9ff;
    box-shadow: 0 0 0 10px rgba(116, 185, 255, 0.25);
}

.timeline-item[data-category="club"]:hover .timeline-dot {
    background: #a29bfe;
    box-shadow: 0 0 0 10px rgba(162, 155, 254, 0.25);
}

.timeline-item[data-category="research"]:hover .timeline-dot {
    background: #55efc4;
    box-shadow: 0 0 0 10px rgba(85, 239, 196, 0.25);
}

.timeline-item[data-category="education"]:hover .timeline-dot {
    background: #fdcb6e;
    box-shadow: 0 0 0 10px rgba(253, 203, 110, 0.25);
}

/* Category badge */
.timeline-category {
    display: inline-block;
    font-size: 0.68rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 1.5px;
    padding: 3px 10px;
    border-radius: 20px;
    margin-bottom: 10px;
}

.timeline-category.military  { background: rgba(116, 185, 255, 0.15); color: #74b9ff; }
.timeline-category.club      { background: rgba(162, 155, 254, 0.15); color: #a29bfe; }
.timeline-category.research  { background: rgba(85, 239, 196, 0.15);  color: #55efc4; }
.timeline-category.education { background: rgba(253, 203, 110, 0.15); color: #fdcb6e; }

.timeline-content {
    background: var(--surface-color);
    padding: 26px 30px;
    border-radius: 14px;
    box-shadow: var(--shadow);
    transition: all 0.3s ease;
    border: 1px solid var(--border-color);
    border-top: 3px solid var(--border-color);
}

/* Top accent colour by category */
.timeline-item[data-category="military"]  .timeline-content { border-top-color: #74b9ff; }
.timeline-item[data-category="club"]      .timeline-content { border-top-color: #a29bfe; }
.timeline-item[data-category="research"]  .timeline-content { border-top-color: #55efc4; }
.timeline-item[data-category="education"] .timeline-content { border-top-color: #fdcb6e; }

.timeline-content:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 28px rgba(0, 0, 0, 0.12);
    border-color: var(--primary-color);
}

.timeline-date {
    font-size: 0.8rem;
    color: var(--primary-color);
    font-weight: 700;
    margin-bottom: 10px;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.timeline-content h3 {
    font-size: 1.2rem;
    color: var(--text-primary);
    font-weight: 700;
    margin-bottom: 4px;
    line-height: 1.4;
}

.timeline-content h4 {
    font-size: 0.92rem;
    color: var(--text-secondary);
    font-weight: 500;
    margin-bottom: 14px;
}

.timeline-content p,
.timeline-content ul {
    font-size: 0.92rem;
    color: var(--text-secondary);
    line-height: 1.7;
}

.timeline-content ul {
    padding: 0;
    list-style: none;
}

.timeline-content ul li {
    position: relative;
    padding-left: 16px;
}

.timeline-content ul li::before {
    content: '–';
    position: absolute;
    left: 0;
    color: var(--primary-color);
}

/* Right-aligned (odd) items: flip bullet to right */
.timeline-item:nth-child(odd) .timeline-content ul li {
    padding-left: 0;
    padding-right: 16px;
    text-align: right;
}

.timeline-item:nth-child(odd) .timeline-content ul li::before {
    display: none;
}

.timeline-item:nth-child(odd) .timeline-content ul li::after {
    content: '–';
    position: absolute;
    right: 0;
    color: var(--primary-color);
}

.timeline-note {
    font-size: 0.78rem !important;
    opacity: 0.65;
    margin-top: 8px;
    font-style: italic;
}


/* ============================================================
   [4] SKILLS SECTION - Skills Section
   Tech stack, badge styles, interactive tooltips
   ============================================================ */

.section-skills {
    padding: 80px 0;
}

.skill-category {
    margin-bottom: 40px;
}

.skill-category h3 {
    font-size: 1.2rem;
    margin-bottom: 15px;
    color: var(--text-secondary);
}

.skill-list {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
}

.skill-badge {
    position: relative;
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 8px 16px;
    background-color: var(--surface-color);
    border: 1px solid var(--border-color);
    border-radius: 20px;
    font-size: 0.9rem;
    font-weight: 500;
    transition: all 0.2s;
}

.skill-badge.interactive {
    cursor: pointer;
    user-select: none;
}

.skill-badge.interactive:hover,
.skill-badge.interactive:focus-visible {
    transform: scale(1.05);
    border-color: var(--primary-color);
    color: var(--primary-color);
    box-shadow: 0 2px 12px rgba(116, 185, 255, 0.2);
}

.skill-badge.interactive:active {
    transform: scale(0.98);
}

/* Project count badge */
.skill-count {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 20px;
    height: 20px;
    padding: 0 6px;
    background: var(--primary-color);
    color: #fff;
    font-size: 0.7rem;
    font-weight: 700;
    border-radius: 10px;
    line-height: 1;
}

/* Hover tooltip */
.skill-tooltip {
    position: absolute;
    bottom: calc(100% + 10px);
    left: 50%;
    transform: translateX(-50%);
    min-width: 200px;
    max-width: 280px;
    padding: 12px 16px;
    background: var(--surface-color);
    border: 1px solid var(--border-color);
    border-radius: 10px;
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.15);
    font-size: 0.85rem;
    text-align: left;
    z-index: 100;
    pointer-events: none;

    opacity: 0;
    visibility: hidden;
    transition: opacity 0.2s, visibility 0.2s, transform 0.2s;
    transform: translateX(-50%) translateY(4px);
}

.skill-tooltip.visible {
    opacity: 1;
    visibility: visible;
    transform: translateX(-50%) translateY(0);
}

/* Tooltip arrow */
.skill-tooltip::after {
    content: '';
    position: absolute;
    top: 100%;
    left: 50%;
    transform: translateX(-50%);
    border: 6px solid transparent;
    border-top-color: var(--border-color);
}

.skill-tooltip::before {
    content: '';
    position: absolute;
    top: 100%;
    left: 50%;
    transform: translateX(-50%);
    border: 5px solid transparent;
    border-top-color: var(--surface-color);
    z-index: 1;
}

.skill-tooltip strong {
    display: block;
    margin-bottom: 6px;
    color: var(--primary-color);
    font-size: 0.8rem;
}

.tooltip-project-list {
    margin: 0;
    padding: 0;
    list-style: none;
}

.tooltip-project-list li {
    padding: 3px 0;
    color: var(--text-primary);
    font-size: 0.8rem;
    border-bottom: 1px solid var(--border-color);
}

.tooltip-project-list li:last-child {
    border-bottom: none;
}

.tooltip-hint {
    display: block;
    margin-top: 8px;
    font-size: 0.7rem;
    color: var(--text-secondary);
    text-align: center;
    font-style: italic;
}

.tooltip-empty {
    color: var(--text-secondary);
    font-style: italic;
    font-size: 0.8rem;
}


/* ============================================================
   [5] PROJECTS SECTION - Projects Section
   Project cards, grid layout
   ============================================================ */

.section-projects,
.section-blog {
    padding: 100px 0 80px 0;
}

.project-grid,
.blog-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 30px;
    margin-bottom: 40px;
}

.project-card,
.blog-card {
    background-color: var(--surface-color);
    border-radius: var(--radius);
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: all 0.3s ease;
    border: 1px solid transparent;
}

.project-card:hover,
.blog-card:hover {
    transform: translateY(-5px);
    border-color: var(--primary-color);
}

.card-image img {
    width: 100%;
    height: 200px;
    object-fit: cover;
}

.card-content {
    padding: 20px;
}

.project-name {
    font-size: 1.2rem;
    margin-bottom: 10px;
    font-weight: 600;
}

.project-tags {
    margin-bottom: 15px;
}

.project-tags span {
    display: inline-block;
    font-size: 0.8rem;
    color: var(--accent-color);
    background: rgba(162, 155, 254, 0.1);
    padding: 2px 8px;
    border-radius: 4px;
    margin-right: 5px;
    margin-bottom: 5px;
}

.project-desc {
    color: var(--text-secondary);
    margin-bottom: 15px;
}

.card-links {
    display: flex;
    gap: 15px;
    align-items: center;
}

.card-links a {
    font-weight: 700;
    font-size: 0.9rem;
    color: var(--text-primary);
    border-bottom: 2px solid var(--accent-color);
    transition: color 0.2s;
}

.card-links a:hover {
    color: var(--primary-color);
}

.view-more-wrapper {
    text-align: center;
}


/* ============================================================
   [6] CONTACT SECTION - Contact Section
   Contact info, profile card, social links
   ============================================================ */

.section-contact {
    padding: 130px 0 80px 0;
}

.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: start;
}

.contact-info-section h2 {
    font-size: 2rem;
    margin-bottom: 2rem;
    color: var(--text-primary);
    padding: 15px 0 0 0;
}

.contact-method {
    margin-bottom: 2.5rem;
}

.contact-method h3 {
    font-size: 1.3rem;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.contact-method p {
    margin-bottom: 0.3rem;
}

.contact-method a {
    color: var(--primary-color);
    font-weight: 500;
    transition: color 0.2s;
}

.contact-method a:hover {
    color: var(--primary-dark);
}

.contact-desc {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.contact-card-section {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 600px;
}

#profile-card-container {
    width: 100%;
    max-width: 400px;
}

/* Footer */
.main-footer {
    padding: 80px 0;
    background-color: var(--surface-color);
    text-align: center;
    border-top: 1px solid var(--border-color);
}

.footer-title {
    font-size: 1.5rem;
    margin-bottom: 20px;
}

.contact-info {
    margin-bottom: 20px;
}

.contact-info p {
    color: var(--text-secondary);
}

.social-links {
    margin: 20px 0;
}

.social-links a {
    margin: 0 10px;
    color: var(--text-secondary);
    font-weight: 500;
    transition: color 0.2s;
}

.social-links a:hover {
    color: var(--primary-color);
}

.copyright {
    color: var(--text-secondary);
    font-size: 0.8rem;
    margin-top: 20px;
}


/* ============================================================
   [7] UTILITY & ADDITIONAL STYLES
   Fonts, mobile responsive design
   ============================================================ */

.caveat-font {
    font-family: 'Caveat', cursive;
    font-weight: 400;
}


/* ============================================================
   [8] MOBILE RESPONSIVE - Mobile Responsive Design
   ============================================================ */

@media (max-width: 1024px) {
    .contact-grid {
        grid-template-columns: 1fr;
        gap: 40px;
    }

    .contact-card-section {
        min-height: auto;
    }

    #profile-card-container {
        max-width: 350px;
        margin: 0 auto;
    }
}

@media (max-width: 768px) {

    /* Header adjustments */
    .header-fixed .container {
        gap: 10px;
    }

    .theme-toggle {
        margin-left: 10px;
    }

    /* Mobile Menu */
    .mobile-menu-btn {
        display: block;
    }

    .main-nav {
        position: absolute;
        top: var(--header-height);
        left: 0;
        right: 0;
        width: 100%;
        background-color: var(--surface-color);
        border-bottom: 1px solid var(--border-color);
        padding: 20px;
        display: none;
        flex-direction: column;
    }

    .main-nav.active {
        display: flex;
    }

    .main-nav ul {
        flex-direction: column;
        gap: 15px;
        align-items: flex-start;
    }

    /* Hero Section */
    .hero-title {
        font-size: 2.5rem;
    }

    .hero-subtitle {
        font-size: 1rem;
    }

    .hero-actions {
        flex-direction: column;
        align-items: center;
    }

    .btn-cta {
        justify-content: center;
        margin: 0 auto;
    }

    .btn-resume {
        justify-content: center;
        width: 260px;
        margin: 0 auto;
    }

    .btn-resume::after {
        display: none;
    }

    .btn-main-resume {
        margin: 0 auto;
    }


    /* About Section */
    .about-grid {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .hahn-acrostic {
        align-items: center;
    }

    .acrostic-item .acrostic-letter {
        margin-right: 10px;
        font-size: 2.5rem;
    }

    .about-description .profile-image {
        margin: 0 auto 20px;
    }

    .about-content {
        text-align: center;
    }

    .about-content ul li {
        padding-left: 20px;
    }

    /* Full Acrostic Grid - Mobile */
    .acrostic-grid {
        grid-template-columns: 1fr;
        gap: 30px;
    }

    .acrostic-item-full {
        padding: 25px;
    }

    .acrostic-item-full .letter-large {
        font-size: 3.5rem;
    }

    .acrostic-item-full h4 {
        font-size: 1.1rem;
    }

    /* Skills */
    .skill-list {
        justify-content: center;
    }

    /* Cards */
    .project-grid,
    .blog-grid {
        grid-template-columns: 1fr;
    }

    /* Timeline */
    .timeline::before {
        left: 20px;
    }

    .timeline-item:nth-child(odd) .timeline-content,
    .timeline-item:nth-child(even) .timeline-content {
        margin-left: 50px;
        margin-right: 0;
        text-align: left;
    }

    .timeline-dot {
        left: 20px;
    }

    .timeline-content {
        padding: 18px 20px;
    }

    .timeline-content h3 {
        font-size: 1.1rem;
    }

    .timeline-content h4 {
        font-size: 0.88rem;
    }

    /* On mobile, all bullets are left-aligned */
    .timeline-item:nth-child(odd) .timeline-content ul li {
        padding-left: 16px;
        padding-right: 0;
        text-align: left;
    }

    .timeline-item:nth-child(odd) .timeline-content ul li::before {
        display: block;
    }

    .timeline-item:nth-child(odd) .timeline-content ul li::after {
        display: none;
    }

    /* Footer */
    .main-footer {
        padding: 40px 0;
    }

    section:not(.pc-card) {
        padding: 60px 0;
    }

    .section-title {
        font-size: 1.5rem;
    }

    .contact-info-section h2 {
        font-size: 1.5rem;
    }

    .contact-method h3 {
        font-size: 1.1rem;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 2rem;
    }

    .hero-greeting {
        font-size: 1rem;
    }

    .btn {
        padding: 10px 20px;
        font-size: 0.9rem;
    }
    
    .btn-main-resume {
        margin: 0 auto;
    }

    .section-title {
        font-size: 1.3rem;
    }

    .acrostic-item .acrostic-letter {
        font-size: 2rem;
        width: 50px;
    }

    .acrostic-item-full {
        padding: 20px;
    }

    .acrostic-item-full .letter-large {
        font-size: 2.5rem;
    }

    .acrostic-item-full h4 {
        font-size: 1rem;
    }

    .timeline {
        padding: 0 10px;
    }

    .timeline::before {
        left: 10px;
    }

    .timeline-dot {
        left: 10px;
        width: 12px;
        height: 12px;
        border-width: 3px;
    }

    .timeline-item:nth-child(odd) .timeline-content,
    .timeline-item:nth-child(even) .timeline-content {
        margin-left: 35px;
    }

    .timeline-content {
        padding: 15px;
    }

    .timeline-content h3 {
        font-size: 1.1rem;
    }

    .timeline-date {
        font-size: 0.8rem;
    }
}