@import url('https://fonts.googleapis.com/css2?family=Noto+Sans+KR:wght@300;400;500;700;900&display=swap');

:root {
    --bg-primary: #0D1117;
    --bg-secondary: #161B27;
    --bg-card: #1E2435;
    --accent: #7B6FFF;
    --accent-light: #9B8FFF;
    --accent-glow: rgba(123, 111, 255, 0.25);
    --text-primary: #FFFFFF;
    --text-secondary: #8B8FA8;
    --btn-color: #fff;
    --btn-bg: #7B6FFF;
    --link-hover: #9B8FFF;
    --footer-link-hover: #9B8FFF;
    --input-focus-bd-color: #7B6FFF;
}

html {
    scroll-behavior: smooth;
    font-family: "Noto Sans KR", sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
}

body {
    background-color: var(--bg-primary);
}

/* ---- Header ---- */
header {
    background-color: rgba(13, 17, 23, 0.85);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid rgba(255,255,255,0.06);
}

header > .collapsible-header {
    display: flex;
    gap: 1rem;
    width: 100%;
    background-color: inherit;
    place-content: center;
    overflow: hidden;
    transition: width 0.3s ease;
}

.animated-collapse {
    transition: width 0.3s ease;
}

.header-links {
    display: flex;
    align-items: center;
    min-width: fit-content;
    border-radius: 10px;
    padding: 5px 10px;
    color: var(--text-secondary);
    transition: color 0.3s;
}

.header-links:hover {
    color: var(--accent-light);
}

/* ---- Phone frame ---- */
.phone-frame {
    width: 260px;
    height: 540px;
    border-radius: 40px;
    border: 3px solid #2A2F45;
    overflow: hidden;
    box-shadow: 0 0 0 6px #1A1F30, 0 30px 80px rgba(0,0,0,0.6), 0 0 60px var(--accent-glow);
    flex-shrink: 0;
}

.phone-frame img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    object-position: top;
    image-rendering: auto;
}

/* ---- Gradient tag ---- */
.badge-tag {
    background: linear-gradient(135deg, rgba(123,111,255,0.2), rgba(123,111,255,0.05));
    border: 1px solid rgba(123,111,255,0.4);
    color: var(--accent-light);
    border-radius: 999px;
    padding: 4px 14px;
    font-size: 0.85rem;
    font-weight: 500;
    width: fit-content;
}

/* ---- Feature cards ---- */
.feature-card {
    background: var(--bg-card);
    border: 1px solid rgba(255,255,255,0.06);
    border-radius: 20px;
    padding: 32px 28px;
    width: 300px;
    display: flex;
    flex-direction: column;
    gap: 16px;
    transition: transform 0.3s, box-shadow 0.3s;
}

.feature-card:hover {
    transform: translateY(-6px);
    box-shadow: 0 20px 60px rgba(0,0,0,0.4), 0 0 30px var(--accent-glow);
}

.feature-icon {
    width: 56px;
    height: 56px;
    border-radius: 16px;
    background: rgba(123,111,255,0.15);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 24px;
    color: var(--accent-light);
}

/* ---- CTA button ---- */
.btn-primary {
    background: var(--accent);
    color: white;
    padding: 14px 32px;
    border-radius: 999px;
    font-weight: 600;
    font-size: 1rem;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    transition: background 0.3s, transform 0.2s, box-shadow 0.3s;
    text-decoration: none;
}

.btn-primary:hover {
    background: var(--accent-light);
    transform: translateY(-2px);
    box-shadow: 0 10px 30px var(--accent-glow);
}

.btn-outline {
    border: 2px solid rgba(255,255,255,0.2);
    color: white;
    padding: 14px 32px;
    border-radius: 999px;
    font-weight: 500;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    transition: border-color 0.3s, background 0.3s;
    text-decoration: none;
}

.btn-outline:hover {
    border-color: var(--accent);
    background: rgba(123,111,255,0.1);
}

/* ---- Divider ---- */
.section-divider {
    width: 60px;
    height: 3px;
    background: var(--accent);
    border-radius: 999px;
}

/* ---- Footer ---- */
.footer-link {
    color: var(--text-secondary);
    transition: color 0.3s;
    text-decoration: none;
}

.footer-link:hover {
    color: var(--accent-light);
}

/* ---- Feature section layout ---- */
.feature-section {
    position: relative;
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 80px 8%;
    width: 100%;
    overflow: hidden;
}

.feature-row {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 80px;
    width: 100%;
    flex-wrap: wrap;
}

.feature-row-reverse {
    flex-direction: row-reverse;
}

@media (max-width: 1024px) {
    .feature-row-reverse {
        flex-direction: column;
    }
}

.feature-text {
    display: flex;
    flex-direction: column;
    gap: 20px;
    max-width: 440px;
    flex: 1;
    min-width: 280px;
}

.feature-title {
    color: white;
    font-size: clamp(1.8rem, 3.5vw, 2.6rem);
    font-weight: 700;
    line-height: 1.25;
    margin: 0;
}

.feature-desc {
    color: var(--text-secondary);
    font-size: 1.05rem;
    line-height: 1.75;
    margin: 0;
}

.check-list {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.check-item {
    display: flex;
    align-items: center;
    gap: 10px;
    color: var(--text-secondary);
}

.check-icon {
    color: var(--accent);
    flex-shrink: 0;
}

/* ---- Feature cards grid ---- */
.cards-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
    width: 100%;
    max-width: 1000px;
}

@media (max-width: 1024px) {
    .cards-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 640px) {
    .cards-grid {
        grid-template-columns: 1fr;
    }
}

/* ---- Card content ---- */
.card-title {
    color: white;
    font-size: 1.15rem;
    font-weight: 700;
    margin: 0;
}

.card-desc {
    color: var(--text-secondary);
    font-size: 0.95rem;
    line-height: 1.65;
    margin: 0;
}

/* ---- Gallery ---- */
.gallery-scroll::-webkit-scrollbar { height: 4px; }
.gallery-scroll::-webkit-scrollbar-track { background: transparent; }
.gallery-scroll::-webkit-scrollbar-thumb { background: rgba(123,111,255,0.4); border-radius: 999px; }

.gallery-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 16px;
    flex-shrink: 0;
    scroll-snap-align: start;
}

.gallery-label {
    color: var(--text-secondary);
    font-size: 0.875rem;
    font-weight: 500;
}

.phone-frame-sm {
    width: 240px;
    height: 490px;
    border-radius: 36px;
    border: 2px solid #2A2F45;
    overflow: hidden;
    box-shadow: 0 0 0 5px #1A1F30, 0 20px 50px rgba(0,0,0,0.5);
    flex-shrink: 0;
    transition: transform 0.3s, box-shadow 0.3s;
}

.phone-frame-sm:hover {
    transform: translateY(-8px);
    box-shadow: 0 0 0 5px #1A1F30, 0 30px 70px rgba(0,0,0,0.6), 0 0 40px var(--accent-glow);
}

.phone-frame-sm img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    object-position: top;
    image-rendering: auto;
}

/* ---- Tech tags ---- */
.tech-tag {
    padding: 8px 20px;
    border-radius: 999px;
    font-size: 0.875rem;
    font-weight: 500;
    background: var(--bg-card);
    color: var(--text-secondary);
    border: 1px solid rgba(255,255,255,0.06);
}

/* ---- Misc ---- */
.opacity-0 { opacity: 0 !important; }
.opacity-100 { opacity: 1 !important; }

.material-icons.md-40 { font-size: 40px; }

/* ---- Gradient hero bg ---- */
.hero-glow {
    position: absolute;
    width: 500px;
    height: 500px;
    border-radius: 50%;
    background: radial-gradient(circle, rgba(123,111,255,0.15) 0%, transparent 70%);
    pointer-events: none;
}

/* ---- Section label ---- */
.section-label {
    color: var(--text-secondary);
    font-size: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 2px;
    font-weight: 500;
}

@media not all and (min-width: 1024px) {
    header .collapsible-header {
        position: fixed;
        right: 0px;
        flex-direction: column;
        opacity: 0;
        height: 100vh;
        min-height: 100vh;
        height: 100dvh;
        width: 0vw;
        justify-content: space-between;
        padding: 5px;
        padding-top: 5%;
        padding-bottom: 5%;
        place-items: end;
        background-color: #161B27;
        color: #fff;
        overflow-y: auto;
        box-shadow: -4px 0px 20px rgba(0,0,0,0.5);
        z-index: 100;
    }

    .phone-frame {
        width: 200px;
        height: 420px;
    }

    .feature-card {
        width: 100%;
        max-width: 400px;
    }
}