/* ============================================
   munju.org - Priority-Stack Design System
   Seed: 먼저 (first, priority, precedence)
   ============================================ */

/* --- Custom Properties --- */
:root {
    --slate-dark: #1F2937;
    --slate-light: #F3F4F6;
    --silver: #E5E7EB;
    --steel: #111827;
    --stone: #6B7280;
    --crimson-priority: #E63946;
    --crimson-deep: #DC2626;
    --slate-accent: #3B82F6;
    --white: #FFFFFF;
    --offwhite: #FAFBFC;
    --hero-top: #0F172A;
    --hero-bottom: #1F2937;
    --tier3-gray: #D1D5DB;

    --font-heading: 'IBM Plex Sans', sans-serif;
    --font-body: 'Inter', sans-serif;
    --font-mono: 'IBM Plex Mono', monospace;
}

/* --- Reset & Base --- */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: var(--font-body);
    color: var(--steel);
    background-color: var(--hero-top);
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* --- Progress Line (Left Margin) --- */
.progress-line {
    position: fixed;
    left: 16px;
    top: 0;
    bottom: 0;
    width: 1px;
    background: rgba(107, 114, 128, 0.3);
    z-index: 100;
}

.progress-fill {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 0%;
    background: var(--crimson-priority);
    transition: height 0.15s ease-out;
}

.progress-marker {
    position: absolute;
    left: -10px;
    top: 0%;
    width: 21px;
    height: 21px;
    background: var(--crimson-priority);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: top 0.15s ease-out;
}

.progress-label {
    font-family: var(--font-mono);
    font-size: 0.6rem;
    font-weight: 600;
    color: var(--white);
    letter-spacing: 0;
}

/* --- Next Priority Button --- */
.next-priority-btn {
    position: fixed;
    bottom: 32px;
    left: 50%;
    transform: translateX(-50%);
    z-index: 100;
    background: var(--crimson-priority);
    color: var(--white);
    border: none;
    padding: 12px 28px;
    border-radius: 30px;
    font-family: var(--font-heading);
    font-size: 0.875rem;
    font-weight: 600;
    letter-spacing: 0.02em;
    cursor: pointer;
    transition: transform 0.15s ease, box-shadow 0.15s ease, background 0.15s ease;
    animation: pulse-shadow 2s ease-in-out infinite;
}

.next-priority-btn:hover {
    transform: translateX(-50%) translateX(4px);
    background: var(--crimson-deep);
    box-shadow: 0 4px 20px rgba(230, 57, 70, 0.4);
}

.next-priority-btn .arrow-icon {
    display: inline-block;
    margin-left: 6px;
    transition: transform 0.15s ease;
}

.next-priority-btn:hover .arrow-icon {
    transform: translateX(4px);
}

.next-priority-btn.hidden {
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.3s ease;
}

@keyframes pulse-shadow {
    0%, 100% { box-shadow: 0 2px 10px rgba(230, 57, 70, 0.25); }
    50% { box-shadow: 0 4px 25px rgba(230, 57, 70, 0.5); }
}

/* --- Tier Base --- */
.tier {
    position: relative;
    width: 100%;
}

/* --- Animate In (JS-controlled) --- */
.animate-in {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.4s ease-out, transform 0.4s ease-out;
}

.animate-in.visible {
    opacity: 1;
    transform: translateY(0);
}

.number-animate {
    opacity: 0;
    transform: scale(0.8);
    transition: opacity 0.4s ease-out, transform 0.4s ease-out;
}

.number-animate.visible {
    opacity: 1;
    transform: scale(1);
}

/* ============================================
   TIER 1: Hero Priority
   ============================================ */
.tier-1 {
    min-height: 140vh;
    background: linear-gradient(180deg, var(--hero-top) 0%, var(--hero-bottom) 100%);
    display: flex;
    align-items: flex-start;
    padding: 0;
    overflow: hidden;
}

.tier-1-bg {
    position: absolute;
    inset: 0;
    background:
        radial-gradient(ellipse 80% 60% at 20% 30%, rgba(230, 57, 70, 0.04) 0%, transparent 70%),
        radial-gradient(ellipse 60% 40% at 80% 70%, rgba(59, 130, 246, 0.03) 0%, transparent 70%);
    pointer-events: none;
}

.tier-1-content {
    position: relative;
    width: 100%;
    max-width: 1400px;
    margin: 0 auto;
    padding: 12vh 4vw 8vh 60px;
    display: grid;
    grid-template-columns: auto 1fr;
    grid-template-rows: 1fr auto;
    gap: 0;
    min-height: 100vh;
}

.tier-1-number {
    font-family: var(--font-heading);
    font-weight: 700;
    font-size: clamp(18rem, 60vw, 40rem);
    line-height: 0.8;
    color: var(--crimson-priority);
    text-shadow: 0 8px 40px rgba(230, 57, 70, 0.2);
    grid-row: 1;
    grid-column: 1;
    align-self: start;
    margin-top: -2vh;
    margin-left: -2vw;
    user-select: none;
    opacity: 0.95;
}

.tier-1-text {
    grid-row: 1;
    grid-column: 2;
    align-self: center;
    padding-left: 4vw;
    max-width: 600px;
}

.tier-1-headline {
    font-family: var(--font-heading);
    font-weight: 700;
    font-size: clamp(2.5rem, 6vw, 5rem);
    color: var(--offwhite);
    letter-spacing: -0.02em;
    line-height: 1.1;
    margin-bottom: 1.5rem;
}

.tier-1-body {
    font-family: var(--font-body);
    font-weight: 400;
    font-size: clamp(1rem, 1.5vw, 1.125rem);
    color: rgba(250, 251, 252, 0.8);
    line-height: 1.6;
    letter-spacing: 0.005em;
    margin-bottom: 1.25rem;
}

.tier-1-body-secondary {
    color: rgba(250, 251, 252, 0.55);
    font-size: clamp(0.9rem, 1.3vw, 1rem);
}

.korean-accent {
    font-weight: 600;
    color: var(--crimson-priority);
    letter-spacing: 0.05em;
}

.tier-1-scroll-hint {
    grid-row: 2;
    grid-column: 1 / -1;
    text-align: center;
    padding-bottom: 4vh;
}

.scroll-arrow {
    display: inline-block;
    font-size: 1.5rem;
    color: var(--slate-accent);
    animation: bounce-down 2s ease-in-out infinite;
}

@keyframes bounce-down {
    0%, 100% { transform: translateY(0); opacity: 0.6; }
    50% { transform: translateY(10px); opacity: 1; }
}

/* ============================================
   TIER 2: Secondary Priorities
   ============================================ */
.tier-2 {
    padding: 8vh 4vw 8vh 60px;
    position: relative;
}

.tier-2-inner {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    align-items: flex-start;
    gap: 3vw;
}

/* Alternating backgrounds */
.tier-2a {
    background: var(--slate-light);
    min-height: 50vh;
}

.tier-2b {
    background: var(--white);
    min-height: 25vh;
}

.tier-2c {
    background: var(--slate-light);
    min-height: 25vh;
}

.tier-2d {
    background: var(--white);
    min-height: 25vh;
}

/* Geometric separator clip-paths */
.tier-2a::before {
    content: '';
    position: absolute;
    top: -2px;
    left: 0;
    right: 0;
    height: 40px;
    background: var(--hero-bottom);
    clip-path: polygon(0 0, 100% 0, 100% 0%, 0 100%);
}

.tier-number {
    font-family: var(--font-heading);
    font-weight: 900;
    font-size: clamp(3rem, 8vw, 6rem);
    line-height: 1;
    flex-shrink: 0;
    user-select: none;
}

.tier-2-number {
    color: var(--stone);
}

.tier-content {
    flex: 1;
    padding-top: 0.5rem;
}

.tier-2-headline {
    font-family: var(--font-heading);
    font-weight: 600;
    font-size: clamp(1.5rem, 3.5vw, 2.5rem);
    color: var(--steel);
    letter-spacing: -0.02em;
    line-height: 1.15;
    margin-bottom: 1rem;
}

.tier-2-body {
    font-family: var(--font-body);
    font-weight: 400;
    font-size: clamp(1rem, 1.5vw, 1.125rem);
    color: var(--stone);
    line-height: 1.6;
    letter-spacing: 0.005em;
    max-width: 640px;
}

.tier-2-indicator {
    display: flex;
    gap: 8px;
    margin-top: 1.5rem;
}

.sequence-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--silver);
    transition: background 0.3s ease, transform 0.3s ease;
}

.sequence-dot.active {
    background: var(--slate-accent);
    transform: scale(1.3);
}

/* ============================================
   TIER 3: Tertiary Content
   ============================================ */
.tier-3 {
    background: var(--offwhite);
    padding: 8vh 4vw 8vh 60px;
}

.tier-3-grid {
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
}

.tier-3-card {
    background: var(--white);
    border: 1px solid var(--silver);
    padding: 2rem 1.5rem;
    position: relative;
    transition: transform 0.15s ease, box-shadow 0.15s ease;
}

.tier-3-card:hover {
    transform: translateX(4px);
    box-shadow: 0 4px 16px rgba(17, 24, 39, 0.08);
}

.tier-3-number {
    font-family: var(--font-mono);
    font-weight: 600;
    font-size: 1.5rem;
    color: var(--tier3-gray);
    letter-spacing: 0.1em;
    display: block;
    margin-bottom: 0.75rem;
}

.tier-3-headline {
    font-family: var(--font-heading);
    font-weight: 600;
    font-size: 1.125rem;
    color: var(--steel);
    letter-spacing: -0.01em;
    line-height: 1.2;
    margin-bottom: 0.5rem;
}

.tier-3-body {
    font-family: var(--font-body);
    font-weight: 400;
    font-size: 0.875rem;
    color: var(--stone);
    line-height: 1.5;
}

/* ============================================
   CODA: Final Section
   ============================================ */
.coda {
    background: var(--slate-dark);
    min-height: 50vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: left;
    padding: 8vh 4vw 8vh 60px;
}

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

.coda-text {
    font-family: var(--font-heading);
    font-weight: 700;
    font-size: clamp(1.5rem, 3vw, 2.5rem);
    color: var(--white);
    letter-spacing: -0.02em;
    line-height: 1.2;
    margin-bottom: 1rem;
}

.coda-korean {
    font-family: var(--font-heading);
    font-weight: 700;
    font-size: clamp(3rem, 8vw, 6rem);
    color: var(--crimson-priority);
    letter-spacing: 0.05em;
    margin-bottom: 2rem;
    opacity: 0.9;
}

.return-btn {
    background: transparent;
    border: 2px solid var(--crimson-priority);
    color: var(--crimson-priority);
    padding: 12px 28px;
    border-radius: 30px;
    font-family: var(--font-heading);
    font-size: 0.875rem;
    font-weight: 600;
    letter-spacing: 0.02em;
    cursor: pointer;
    transition: background 0.15s ease, color 0.15s ease, transform 0.15s ease;
}

.return-btn:hover {
    background: var(--crimson-priority);
    color: var(--white);
    transform: translateX(4px);
}

.return-btn .arrow-icon {
    display: inline-block;
    margin-left: 6px;
}

/* ============================================
   Interactive Elements
   ============================================ */
a {
    color: var(--slate-accent);
    text-decoration: none;
    transition: color 0.15s ease, transform 0.15s ease;
}

a:hover {
    color: var(--crimson-priority);
    transform: translateX(4px);
}

/* ============================================
   Mobile Responsive (480px)
   ============================================ */
@media (max-width: 768px) {
    .progress-line {
        left: 8px;
    }

    .progress-marker {
        width: 16px;
        height: 16px;
        left: -7px;
    }

    .progress-label {
        font-size: 0.5rem;
    }

    .tier-1-content {
        grid-template-columns: 1fr;
        padding: 8vh 4vw 6vh 40px;
    }

    .tier-1-number {
        font-size: clamp(8rem, 50vw, 16rem);
        grid-column: 1;
        margin-left: -1vw;
    }

    .tier-1-text {
        grid-column: 1;
        padding-left: 0;
        margin-top: -4rem;
    }

    .tier-1-headline {
        font-size: clamp(2rem, 8vw, 3.5rem);
    }

    .tier-2 {
        padding: 5vh 4vw 5vh 40px;
    }

    .tier-2-inner {
        flex-direction: column;
        gap: 1rem;
    }

    .tier-number {
        font-size: clamp(1.5rem, 5vw, 2.5rem);
    }

    .tier-2a {
        min-height: auto;
    }

    .tier-2b, .tier-2c, .tier-2d {
        min-height: auto;
    }

    .tier-3 {
        padding: 5vh 4vw 5vh 40px;
    }

    .tier-3-grid {
        grid-template-columns: 1fr;
        gap: 1rem;
    }

    .tier-3-card {
        padding: 1.5rem 1rem;
    }

    .tier-3-number {
        font-size: clamp(1rem, 3vw, 1.25rem);
    }

    .coda {
        padding: 6vh 4vw 6vh 40px;
    }

    .next-priority-btn {
        bottom: 20px;
        right: 20px;
        left: auto;
        transform: none;
        padding: 10px 20px;
        font-size: 0.8rem;
        border-radius: 50%;
        width: 56px;
        height: 56px;
        display: flex;
        align-items: center;
        justify-content: center;
    }

    .next-priority-btn span:not(.arrow-icon) {
        display: none;
    }

    .next-priority-btn:hover {
        transform: translateX(0);
    }
}

@media (max-width: 480px) {
    .tier-1-number {
        font-size: clamp(6rem, 40vw, 10rem);
    }

    .tier-1-headline {
        font-size: clamp(1.75rem, 7vw, 2.5rem);
    }

    .tier-2-headline {
        font-size: clamp(1.25rem, 5vw, 1.75rem);
    }
}