/* ============================================================
   SULGI Portfolio · common.css
   디자인 토큰 / 공용 레이아웃 / 헤더 / 푸터
   ============================================================ */

:root {
    /* COLOR SYSTEM */
    --bg-main: #F7F8FB;
    --bg-sub: #EFF2F7;
    --bg-soft: #E4EAF2;
    --surface: #FFFFFF;

    --text-main: #1F2742;
    --text-sub: #5B688A;
    --text-light: #9AA4BD;

    --primary: #8CA3C9;
    --primary-hover: #6E89B7;
    --primary-soft: #B1C2DF;
    --primary-pale: #E6ECF7;

    --accent: #C5BFE3;
    --accent-pale: #EAE6F3;

    --border: #CFD9E8;
    --border-light: #E4EBF3;
    --border-strong: #B6C3D6;

    /* TYPOGRAPHY */
    --font-family-sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
    --font-family-serif: "Playfair Display", "Cormorant Garamond", Georgia, serif;
    --font-family-italic: "Cormorant Garamond", "Playfair Display", Georgia, serif;

    --font-size-display: clamp(56px, 10vw, 120px);
    --font-size-h1: clamp(36px, 6vw, 64px);
    --font-size-h2: clamp(28px, 4vw, 42px);
    --font-size-h3: clamp(20px, 2.5vw, 28px);
    --font-size-h4: 18px;
    --fs-body-lg: clamp(16px, 1.2vw, 18px);
    --fs-body: clamp(14px, 1vw, 15px);
    --fs-caption: 12px;

    /* SPACING */
    --space-4: 4px;
    --space-8: 8px;
    --space-12: 12px;
    --space-16: 16px;
    --space-20: 20px;
    --space-24: 24px;
    --space-32: 32px;
    --space-40: 40px;
    --space-48: 48px;
    --space-64: 64px;
    --space-80: 80px;
    --space-120: 120px;
    --space-160: clamp(100px, 15vh, 180px);

    /* EFFECTS */
    --radius-sm: 6px;
    --radius-md: 14px;
    --radius-lg: 24px;
    --radius-pill: 999px;

    --shadow-soft: 0 6px 24px rgba(28, 40, 80, 0.04);
    --shadow-hover: 0 20px 48px rgba(28, 40, 80, 0.08);

    --transition-base: 0.3s cubic-bezier(0.2, 0.8, 0.2, 1);
    --transition-slow: 0.6s cubic-bezier(0.2, 0.8, 0.2, 1);

    /* HEADER */
    --header-h: 88px;
}

/* LAYOUT STRUCTURE */
body {
    font-family: var(--font-family-sans);
    font-size: var(--fs-body);
    color: var(--text-main);
    background-color: var(--bg-main);
}

#wrap {
    width: 100%;
    position: relative;
}

.container {
    width: 100%;
    max-width: 1440px;
    margin: 0 auto;
    padding: 0 var(--space-32);
}

section {
    padding: var(--space-80) 0;
}

.content {
    display: flex;
    flex-direction: column;
    gap: var(--space-48);
}

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

.content-header .section-title {
    font-size: var(--font-size-h2);
    margin-bottom: var(--space-16);
}

.content-header .section-desc {
    font-size: var(--fs-body-lg);
    color: var(--text-sub);
}

.content-body {
    width: 100%;
}

.text-group, .hero-desc-group {
    display: flex;
    flex-direction: column;
    gap: var(--space-16);
}

.ba-group, .interview-group, .resume-group {
    width: 100%;
}

/* ANIMATIONS */
.fade-up {
    opacity: 1; /* Always visible by default */
    transform: translateY(0);
}

/* Only apply hidden state if we are sure JS will handle the reveal */
/* For now, we prioritize content visibility over animations to avoid blank screens */
.js-enabled .fade-up.init-hidden {
    opacity: 0;
    transform: translateY(20px);
}

.fade-up.is-visible {
    opacity: 1;
    transform: translateY(0);
}

/* CARDS (IMAGE + TEXT) */
.card {
    display: flex;
    flex-direction: column;
    gap: var(--space-20);
    background: var(--surface);
    border-radius: var(--radius-md);
    overflow: hidden;
    transition: transform var(--transition-base), shadow var(--transition-base);
}

.card-image {
    width: 100%;
    aspect-ratio: 16 / 10;
    overflow: hidden;
}

.card-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform var(--transition-slow);
}

.card-text {
    padding: var(--space-24);
}

/* ACCESSIBILITY */
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

.skip-link {
    position: absolute;
    left: -9999px;
    top: 0;
    padding: 10px 16px;
    background: var(--text-main);
    color: #fff;
    z-index: 3000;
}

.skip-link:focus {
    left: 0;
}

/* HEADER STYLE */
#header {
    height: var(--header-h);
    display: flex;
    align-items: center;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    background: transparent;
    transition: background var(--transition-base), border var(--transition-base);
}

#header.is-sticky {
    background: rgba(247, 248, 251, 0.8);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-light);
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo a {
    font-family: var(--font-family-serif);
    font-size: 24px;
    font-weight: 700;
    letter-spacing: 0.1em;
}

.main-nav ul {
    display: flex;
    gap: var(--space-32);
}

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

.main-nav a:hover, .main-nav a.active {
    color: var(--text-main);
}

/* MOBILE NAV */
.mobile-menu-toggle {
    display: none;
    flex-direction: column;
    gap: 6px;
    z-index: 2000;
}

.mobile-menu-toggle .bar {
    width: 24px;
    height: 2px;
    background: var(--text-main);
    transition: var(--transition-base);
}

.mobile-nav {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100vh;
    background: var(--surface);
    z-index: 1500;
    display: flex;
    align-items: center;
    justify-content: center;
    transform: translateY(-100%);
    transition: transform var(--transition-slow);
}

.mobile-nav.is-open {
    transform: translateY(0);
}

.mobile-nav ul {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--space-32);
}

.mobile-nav a {
    font-size: 24px;
    font-weight: 600;
}

/* FOOTER STYLE */
#footer {
    padding: var(--space-64) 0;
    background: var(--bg-sub);
    border-top: 1px solid var(--border);
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.footer-socials {
    display: flex;
    gap: var(--space-24);
}

.footer-copyright {
    color: var(--text-light);
    font-size: var(--fs-caption);
}