/* ============================================================
   Portfolio — 권지원 (Kwon Jiwon)
   Minimal white / clean tone
   ============================================================ */

@import url("https://cdn.jsdelivr.net/gh/orioncactus/pretendard@v1.3.9/dist/web/static/pretendard.css");
@import url("https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700;800&family=JetBrains+Mono:wght@400;500&display=swap");

:root {
    --bg: #ffffff;
    --bg-soft: #fafafa;
    --bg-card: #ffffff;
    --text: #0a0a0a;
    --text-muted: #6b7280;
    --text-subtle: #9ca3af;
    --border: #ececec;
    --border-strong: #d4d4d4;
    --accent: #111111;
    --accent-soft: #f4f4f5;
    --code-bg: #0f172a;
    --code-text: #e2e8f0;
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.04);
    --shadow-md: 0 4px 20px rgba(0, 0, 0, 0.06);

    --font-sans: "Pretendard", "Inter", -apple-system, BlinkMacSystemFont,
        "Segoe UI", Roboto, sans-serif;
    --font-mono: "JetBrains Mono", ui-monospace, "SF Mono", Menlo, monospace;

    --container: 1120px;
    --radius: 12px;
    --radius-sm: 6px;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

html {
    scroll-behavior: smooth;
    scroll-padding-top: 80px;
}

body {
    font-family: var(--font-sans);
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
    font-size: 16px;
    -webkit-text-size-adjust: 100%;
}

img {
    max-width: 100%;
    display: block;
}

a {
    color: inherit;
    text-decoration: none;
    transition: opacity 0.15s ease;
}

a:hover {
    opacity: 0.65;
}

button {
    font-family: inherit;
    cursor: pointer;
}

/* ---------- Container ---------- */
.container {
    max-width: var(--container);
    margin: 0 auto;
    padding: 0 24px;
}

/* ---------- Navigation ---------- */
.nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: 68px;
    background: rgba(255, 255, 255, 0.85);
    backdrop-filter: saturate(180%) blur(12px);
    -webkit-backdrop-filter: saturate(180%) blur(12px);
    border-bottom: 1px solid transparent;
    z-index: 50;
    transition: border-color 0.2s ease;
}

.nav.scrolled {
    border-bottom-color: var(--border);
}

.nav-inner {
    max-width: var(--container);
    margin: 0 auto;
    padding: 0 24px;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.nav-brand {
    font-weight: 700;
    font-size: 15px;
    letter-spacing: -0.01em;
}

.nav-brand .dot {
    display: inline-block;
    width: 6px;
    height: 6px;
    background: var(--accent);
    border-radius: 50%;
    margin-right: 10px;
    vertical-align: middle;
    transform: translateY(-2px);
}

.nav-menu {
    display: flex;
    gap: 32px;
    list-style: none;
}

.nav-menu a {
    font-size: 14px;
    color: var(--text-muted);
    font-weight: 500;
}

.nav-menu a:hover {
    color: var(--text);
    opacity: 1;
}

/* ---------- Section ---------- */
section {
    padding: 120px 0;
    position: relative;
}

.section-label {
    font-family: var(--font-mono);
    font-size: 12px;
    color: var(--text-muted);
    letter-spacing: 0.08em;
    text-transform: uppercase;
    margin-bottom: 20px;
    display: flex;
    align-items: center;
    gap: 12px;
}

.section-label::before {
    content: "";
    width: 24px;
    height: 1px;
    background: var(--text-muted);
    display: inline-block;
}

.section-title {
    font-size: 42px;
    font-weight: 700;
    letter-spacing: -0.03em;
    line-height: 1.15;
    margin-bottom: 20px;
}

.section-lead {
    font-size: 17px;
    color: var(--text-muted);
    max-width: 640px;
    line-height: 1.7;
    margin-bottom: 60px;
}

/* ---------- Hero ---------- */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding: 120px 0 80px;
}

.hero-inner {
    width: 100%;
}

.hero-eyebrow {
    font-family: var(--font-mono);
    font-size: 13px;
    color: var(--text-muted);
    margin-bottom: 24px;
    letter-spacing: 0.02em;
}

.hero-title {
    font-size: clamp(44px, 7vw, 88px);
    font-weight: 800;
    letter-spacing: -0.04em;
    line-height: 1.02;
    margin-bottom: 32px;
}

.hero-title .accent {
    display: inline-block;
    position: relative;
}

.hero-title .accent::after {
    content: "";
    position: absolute;
    left: 0;
    right: 0;
    bottom: 6px;
    height: 12px;
    background: var(--accent-soft);
    z-index: -1;
}

.hero-desc {
    font-size: 19px;
    color: var(--text-muted);
    line-height: 1.7;
    max-width: 620px;
    margin-bottom: 48px;
}

.hero-meta {
    display: flex;
    flex-wrap: wrap;
    gap: 24px;
    align-items: center;
    font-size: 14px;
    color: var(--text-muted);
}

.hero-meta a {
    color: var(--text);
    font-weight: 500;
    border-bottom: 1px solid var(--border-strong);
    padding-bottom: 2px;
}

.hero-meta .sep {
    color: var(--text-subtle);
}

/* ---------- About + Skills (좌우 2컬럼, 한 화면) ---------- */
.about-skills {
    background: var(--bg-soft);
    border-top: 1px solid var(--border);
    border-bottom: 1px solid var(--border);
    padding: 100px 0;
}

.two-col {
    display: grid;
    grid-template-columns: 1fr 1.1fr;
    gap: 80px;
    align-items: start;
}

.col-about h2 {
    font-size: 40px;
    font-weight: 700;
    letter-spacing: -0.03em;
    line-height: 1.15;
    margin-bottom: 28px;
}

.col-about p {
    font-size: 16px;
    line-height: 1.75;
    color: var(--text-muted);
    margin-bottom: 16px;
}

.col-about p:last-child {
    margin-bottom: 0;
}

.col-about strong {
    color: var(--text);
    font-weight: 600;
}

.skill-list {
    display: flex;
    flex-direction: column;
    gap: 4px;
    margin-top: 8px;
}

.skill-row {
    display: grid;
    grid-template-columns: 120px 1fr;
    gap: 20px;
    padding: 16px 0;
    border-bottom: 1px solid var(--border);
    align-items: baseline;
}

.skill-row:last-child {
    border-bottom: none;
}

.skill-row .k {
    font-family: var(--font-mono);
    font-size: 11px;
    color: var(--text-muted);
    letter-spacing: 0.08em;
    text-transform: uppercase;
}

.skill-row .v {
    font-size: 14px;
    color: var(--text);
    line-height: 1.6;
    font-weight: 500;
}

/* ---------- Timeline (수직) ---------- */
.timeline-section {
    padding: 100px 0;
}

.timeline {
    list-style: none;
    padding: 8px 0 0;
    margin: 40px 0 0;
    position: relative;
}

.timeline::before {
    content: "";
    position: absolute;
    top: 6px;
    bottom: 6px;
    left: 7px;
    width: 1px;
    background: var(--border);
}

.tl-item {
    position: relative;
    padding: 0 0 32px 40px;
}

.tl-item:last-child {
    padding-bottom: 0;
}

.tl-dot {
    position: absolute;
    top: 6px;
    left: 0;
    width: 15px;
    height: 15px;
    border-radius: 50%;
    background: var(--accent);
    box-shadow: 0 0 0 4px var(--bg);
}

.tl-item.future .tl-dot {
    background: var(--bg);
    border: 1.5px solid var(--border-strong);
}

.tl-item.highlight .tl-dot {
    background: var(--accent);
    box-shadow: 0 0 0 4px var(--bg), 0 0 0 8px var(--accent-soft);
}

.tl-date {
    font-family: var(--font-mono);
    font-size: 12px;
    color: var(--text-muted);
    letter-spacing: 0.04em;
    margin-bottom: 4px;
}

.tl-item h3 {
    font-size: 18px;
    font-weight: 700;
    letter-spacing: -0.01em;
    margin-bottom: 8px;
    line-height: 1.3;
}

.tl-item .tl-note {
    font-size: 13px;
    color: var(--text-muted);
    font-weight: 500;
    margin-left: 8px;
    font-family: var(--font-mono);
}

.tl-desc {
    font-size: 14px;
    color: var(--text-muted);
    line-height: 1.6;
    margin-bottom: 12px;
}

.tl-sublist {
    list-style: none;
    padding: 0;
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    margin-top: 4px;
}

.tl-sublist li {
    font-size: 12px;
    font-family: var(--font-mono);
    color: var(--text);
    padding: 4px 12px;
    background: var(--bg-soft);
    border: 1px solid var(--border);
    border-radius: 999px;
}

.tl-item.future h3,
.tl-item.future .tl-date {
    color: var(--text-subtle);
}

/* ---------- Projects ---------- */
.projects-list {
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.project-card {
    display: block;
    padding: 40px 40px 36px;
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    transition: border-color 0.2s ease, transform 0.2s ease,
        box-shadow 0.2s ease;
    color: inherit;
    text-decoration: none;
    position: relative;
}

.project-card:hover {
    border-color: var(--border-strong);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
    opacity: 1;
}

.project-idx {
    font-family: var(--font-mono);
    font-size: 12px;
    color: var(--text-muted);
    letter-spacing: 0.08em;
    margin-bottom: 12px;
    display: block;
}

.project-card h3 {
    font-size: 42px;
    font-weight: 800;
    letter-spacing: -0.03em;
    line-height: 1.1;
    margin-bottom: 12px;
}

.project-card .sub {
    font-size: 17px;
    color: var(--text-muted);
    margin-bottom: 20px;
    line-height: 1.55;
    max-width: 720px;
}

.project-card .meta {
    font-family: var(--font-mono);
    font-size: 12px;
    color: var(--text-subtle);
    margin-bottom: 22px;
    letter-spacing: 0.02em;
}

.project-card .meta .dot {
    margin: 0 8px;
    color: var(--border-strong);
}

.tag-list {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.tag {
    font-size: 12px;
    font-family: var(--font-mono);
    color: var(--text-muted);
    padding: 4px 10px;
    background: var(--bg-soft);
    border: 1px solid var(--border);
    border-radius: 999px;
    letter-spacing: 0.02em;
}

.project-arrow {
    position: absolute;
    top: 40px;
    right: 40px;
    font-size: 22px;
    color: var(--text-subtle);
    transition: transform 0.2s ease, color 0.2s ease;
}

.project-card:hover .project-arrow {
    color: var(--text);
    transform: translateX(4px);
}

/* ---------- Contact ---------- */
.contact {
    background: var(--bg-soft);
    border-top: 1px solid var(--border);
    text-align: center;
    padding: 140px 0;
}

.contact h2 {
    font-size: clamp(36px, 5vw, 56px);
    font-weight: 700;
    letter-spacing: -0.03em;
    margin-bottom: 24px;
    line-height: 1.15;
}

.contact p {
    font-size: 17px;
    color: var(--text-muted);
    margin-bottom: 40px;
}

.contact-links {
    display: flex;
    justify-content: center;
    gap: 16px;
    flex-wrap: wrap;
}

.contact-link {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    padding: 14px 24px;
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: 999px;
    font-size: 14px;
    font-weight: 500;
    color: var(--text);
    transition: border-color 0.2s ease, transform 0.2s ease;
}

.contact-link:hover {
    border-color: var(--accent);
    transform: translateY(-1px);
    opacity: 1;
}

.contact-link.primary {
    background: var(--accent);
    color: #fff;
    border-color: var(--accent);
}

/* ---------- Footer ---------- */
.footer {
    padding: 40px 0;
    border-top: 1px solid var(--border);
    text-align: center;
    font-size: 13px;
    color: var(--text-subtle);
    font-family: var(--font-mono);
}

/* ============================================================
   Project Detail Page  ( PPT-slide style )
   ============================================================ */

.project-detail {
    padding-top: 68px;
}

/* Cover slide */
.slide {
    padding: 100px 0;
    border-bottom: 1px solid var(--border);
}

.slide:last-child {
    border-bottom: none;
}

.slide-inner {
    max-width: var(--container);
    margin: 0 auto;
    padding: 0 24px;
}

.slide-num {
    font-family: var(--font-mono);
    font-size: 12px;
    color: var(--text-muted);
    letter-spacing: 0.1em;
    margin-bottom: 24px;
    display: inline-block;
    padding: 4px 10px;
    background: var(--accent-soft);
    border-radius: 4px;
}

.slide-title {
    font-size: 34px;
    font-weight: 700;
    letter-spacing: -0.02em;
    margin-bottom: 40px;
    line-height: 1.2;
}

.slide-title.large {
    font-size: 56px;
    margin-bottom: 32px;
}

.cover {
    padding: 80px 0 100px;
    border-bottom: 1px solid var(--border);
}

.cover-eyebrow {
    font-family: var(--font-mono);
    font-size: 13px;
    color: var(--text-muted);
    letter-spacing: 0.1em;
    text-transform: uppercase;
    margin-bottom: 20px;
}

.cover-title {
    font-size: clamp(48px, 7vw, 88px);
    font-weight: 800;
    letter-spacing: -0.04em;
    line-height: 1;
    margin-bottom: 20px;
}

.cover-sub {
    font-size: 18px;
    color: var(--text-muted);
    margin-bottom: 40px;
    max-width: 720px;
    line-height: 1.6;
}

/* Info table */
.info-table {
    width: 100%;
    border-collapse: collapse;
    max-width: 860px;
}

.info-table tr {
    border-bottom: 1px solid var(--border);
}

.info-table th {
    text-align: left;
    padding: 18px 0;
    font-size: 13px;
    font-weight: 600;
    color: var(--text-muted);
    width: 180px;
    vertical-align: top;
    font-family: var(--font-mono);
    letter-spacing: 0.02em;
}

.info-table td {
    padding: 18px 0;
    font-size: 15px;
    color: var(--text);
    line-height: 1.65;
}

.info-table td ul {
    list-style: none;
    padding: 0;
}

.info-table td ul li {
    padding-left: 14px;
    position: relative;
    margin-bottom: 4px;
}

.info-table td ul li::before {
    content: "·";
    position: absolute;
    left: 4px;
    color: var(--text-muted);
}

/* Stack grid */
.stack-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 16px;
    max-width: 860px;
}

.stack-item {
    display: flex;
    align-items: baseline;
    gap: 16px;
    padding: 16px 20px;
    background: var(--bg-soft);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
}

.stack-item .k {
    font-family: var(--font-mono);
    font-size: 11px;
    color: var(--text-muted);
    letter-spacing: 0.08em;
    text-transform: uppercase;
    flex-shrink: 0;
    min-width: 80px;
}

.stack-item .v {
    font-size: 14px;
    color: var(--text);
    font-weight: 500;
}

/* Feature list */
.feature-list {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 20px;
}

.feature-item {
    padding: 28px 24px;
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: var(--radius);
}

.feature-item h4 {
    font-size: 15px;
    font-weight: 700;
    margin-bottom: 10px;
    color: var(--text);
}

.feature-item p {
    font-size: 14px;
    color: var(--text-muted);
    line-height: 1.6;
}

/* Problem-solve block */
.pns {
    margin-top: 32px;
    display: grid;
    gap: 24px;
}

.pns-block {
    padding: 32px;
    background: var(--bg-soft);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    border-left: 3px solid var(--accent);
}

.pns-block h4 {
    font-size: 20px;
    font-weight: 700;
    margin-bottom: 24px;
    letter-spacing: -0.01em;
}

.pns-row {
    display: grid;
    grid-template-columns: 90px 1fr;
    gap: 20px;
    padding: 14px 0;
    border-top: 1px solid var(--border);
}

.pns-row:first-of-type {
    border-top: none;
    padding-top: 0;
}

.pns-row .label {
    font-family: var(--font-mono);
    font-size: 11px;
    color: var(--text-muted);
    letter-spacing: 0.1em;
    text-transform: uppercase;
    padding-top: 3px;
}

.pns-row .content {
    font-size: 15px;
    color: var(--text);
    line-height: 1.7;
}

.pns-row .content ol,
.pns-row .content ul {
    padding-left: 20px;
}

.pns-row .content li {
    margin-bottom: 6px;
}

.pns-row .content .result {
    padding: 12px 16px;
    background: var(--bg);
    border-radius: var(--radius-sm);
    border: 1px solid var(--border);
    font-weight: 500;
}

/* Metric */
.metric-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 20px;
    margin-top: 32px;
}

.metric {
    padding: 28px 24px;
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    text-align: left;
}

.metric .k {
    font-size: 12px;
    color: var(--text-muted);
    font-family: var(--font-mono);
    letter-spacing: 0.05em;
    margin-bottom: 12px;
}

.metric .v {
    font-size: 28px;
    font-weight: 700;
    letter-spacing: -0.02em;
    color: var(--text);
    margin-bottom: 4px;
}

.metric .delta {
    font-size: 13px;
    color: var(--text-muted);
    font-family: var(--font-mono);
}

.metric .delta.pos {
    color: #059669;
}

.metric .delta.neg {
    color: #dc2626;
}

/* Detail nav */
.detail-back {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    font-size: 14px;
    color: var(--text-muted);
    margin-bottom: 24px;
    font-family: var(--font-mono);
}

.detail-back:hover {
    color: var(--text);
    opacity: 1;
}

.slide-nav {
    padding: 60px 0;
    display: flex;
    justify-content: space-between;
    gap: 24px;
    border-top: 1px solid var(--border);
}

.slide-nav a {
    flex: 1;
    padding: 24px;
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    transition: border-color 0.2s ease, transform 0.2s ease;
    max-width: 320px;
}

.slide-nav a:hover {
    border-color: var(--border-strong);
    transform: translateY(-2px);
    opacity: 1;
}

.slide-nav .dir {
    font-family: var(--font-mono);
    font-size: 11px;
    color: var(--text-muted);
    letter-spacing: 0.1em;
    text-transform: uppercase;
    margin-bottom: 6px;
}

.slide-nav .name {
    font-size: 16px;
    font-weight: 600;
    color: var(--text);
}

.slide-nav .next {
    text-align: right;
    margin-left: auto;
}

/* Placeholder (콘텐츠 미확정) */
.placeholder {
    display: inline-block;
    padding: 2px 8px;
    background: #fef3c7;
    color: #92400e;
    border-radius: 4px;
    font-size: 13px;
    font-family: var(--font-mono);
}

/* ============================================================
   Scroll reveal
   ============================================================ */
.reveal {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.7s ease, transform 0.7s ease;
    will-change: opacity, transform;
}

.reveal.in {
    opacity: 1;
    transform: none;
}

/* ============================================================
   Responsive
   ============================================================ */
@media (max-width: 900px) {
    section {
        padding: 80px 0;
    }
    .about-skills {
        padding: 80px 0;
    }
    .two-col {
        grid-template-columns: 1fr;
        gap: 48px;
    }
    .project-card {
        padding: 28px 24px;
    }
    .project-card h3 {
        font-size: 32px;
    }
    .project-arrow {
        display: none;
    }
    .slide {
        padding: 60px 0;
    }
    .slide-title {
        font-size: 26px;
    }
    .slide-title.large {
        font-size: 36px;
    }
    .info-table th {
        width: 120px;
        font-size: 12px;
    }
    .pns-row {
        grid-template-columns: 1fr;
        gap: 8px;
    }
    .slide-nav {
        flex-direction: column;
    }
    .slide-nav .next {
        text-align: left;
        margin-left: 0;
    }
}

@media (max-width: 640px) {
    .nav-menu {
        display: none;
    }
    .section-title {
        font-size: 32px;
    }
    .hero-meta {
        gap: 12px;
    }
    .hero-meta .sep {
        display: none;
    }
}