*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

:root {
    --bg: #F4F6F9;
    --surface: #FFFFFF;
    --border: #E2E8F0;
    --text-primary: #1A202C;
    --text-secondary: #718096;
    --accent: #4361EE;
    --accent-light: #EEF2FF;
    --radius: 14px;
    --shadow: 0 2px 16px rgba(0, 0, 0, 0.07);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Apple SD Gothic Neo', sans-serif;
    background: var(--bg);
    color: var(--text-primary);
    min-height: 100vh;
}

header {
    text-align: center;
    padding: 52px 24px 36px;
}

header h1 {
    font-size: 2rem;
    font-weight: 800;
    letter-spacing: -0.5px;
}

header p {
    margin-top: 8px;
    color: var(--text-secondary);
    font-size: 0.95rem;
}

main {
    max-width: 740px;
    margin: 0 auto;
    padding: 0 20px 80px;
    display: flex;
    flex-direction: column;
    gap: 20px;
}

/* Tag section */
.tag-section {
    background: var(--surface);
    border-radius: var(--radius);
    padding: 20px 24px;
    box-shadow: var(--shadow);
    display: flex;
    align-items: center;
    gap: 12px;
}

.tag-bar {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    flex: 1;
}

.tag-btn {
    padding: 8px 18px;
    border: 2px solid var(--border);
    border-radius: 20px;
    background: transparent;
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-secondary);
    cursor: pointer;
    transition: all 0.18s;
    white-space: nowrap;
}

.tag-btn:hover {
    border-color: var(--accent);
    color: var(--accent);
}

.tag-btn.active {
    background: var(--accent);
    border-color: var(--accent);
    color: #fff;
    box-shadow: 0 2px 8px rgba(67, 97, 238, 0.3);
}

/* Random button */
.random-btn {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 8px 18px;
    background: var(--text-primary);
    color: #fff;
    border: none;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.18s;
    white-space: nowrap;
    flex-shrink: 0;
}

.random-btn:hover {
    opacity: 0.8;
    transform: translateY(-1px);
}

/* PPT 슬라이드 미리보기 */
.ppt-preview {
    display: flex;
    border-radius: 10px;
    overflow: hidden;
    aspect-ratio: 16 / 9;
    margin-bottom: 24px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.12);
    background: var(--p-bg, #f5f5f5);
}

.ppt-left {
    width: 32%;
    background: var(--p-accent, #4361EE);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 12px;
    padding: 20px;
    position: relative;
    overflow: hidden;
}

.ppt-shape-circle {
    width: 52%;
    aspect-ratio: 1;
    border-radius: 50%;
    background: var(--p-shape2, rgba(255,255,255,0.3));
    opacity: 0.85;
}

.ppt-shape-rect {
    width: 68%;
    height: 16%;
    border-radius: 4px;
    background: var(--p-shape1, rgba(255,255,255,0.5));
    opacity: 0.7;
}

.ppt-shape-dot {
    width: 22%;
    aspect-ratio: 1;
    border-radius: 50%;
    background: var(--p-bg, #fff);
    opacity: 0.4;
    position: absolute;
    bottom: 12%;
    right: 12%;
}

.ppt-right {
    flex: 1;
    background: var(--p-bg, #ffffff);
    padding: 6% 7%;
    display: flex;
    flex-direction: column;
    justify-content: center;
    gap: 0;
}

.ppt-chip {
    display: inline-block;
    background: var(--p-accent, #4361EE);
    color: var(--p-bg, #fff);
    font-size: 0.55em;
    font-weight: 700;
    letter-spacing: 0.1em;
    padding: 3px 10px;
    border-radius: 20px;
    margin-bottom: 8px;
    width: fit-content;
}

.ppt-title {
    font-size: 1.15em;
    font-weight: 800;
    color: var(--p-txt, #1a1a1a);
    line-height: 1.25;
    margin-bottom: 6px;
}

.ppt-divider {
    width: 36px;
    height: 3px;
    border-radius: 2px;
    background: var(--p-shape1, #333);
    margin-bottom: 8px;
}

.ppt-sub {
    font-size: 0.65em;
    color: var(--p-txt, #333);
    opacity: 0.65;
    margin-bottom: 12px;
    line-height: 1.4;
}

.ppt-bullets {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 5px;
}

.ppt-bullets li {
    font-size: 0.6em;
    color: var(--p-txt, #333);
    opacity: 0.8;
    display: flex;
    align-items: center;
    gap: 7px;
}

.ppt-bullets li::before {
    content: '';
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background: var(--p-accent, #4361EE);
    flex-shrink: 0;
}

/* Palette result */
.palette-result {
    background: var(--surface);
    border-radius: var(--radius);
    padding: 28px;
    box-shadow: var(--shadow);
}

.result-title {
    font-size: 1rem;
    font-weight: 700;
    margin-bottom: 16px;
    display: flex;
    align-items: center;
    gap: 10px;
    flex-wrap: wrap;
}

.copy-hint {
    font-size: 0.78rem;
    font-weight: 400;
    color: var(--text-secondary);
}

.palette-swatches {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: 10px;
    margin-bottom: 16px;
}

.swatch {
    cursor: pointer;
    border-radius: 10px;
    overflow: hidden;
    border: 1px solid var(--border);
    transition: transform 0.2s, box-shadow 0.2s;
}

.swatch:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.13);
}

.swatch-color {
    height: 100px;
}

.swatch-info {
    padding: 8px 10px;
    background: var(--surface);
}

.swatch-role {
    font-size: 0.68rem;
    color: var(--text-secondary);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.03em;
    margin-bottom: 3px;
}

.swatch-hex {
    font-family: 'Courier New', monospace;
    font-size: 0.8rem;
    font-weight: 700;
    color: var(--text-primary);
}

.palette-description {
    font-size: 0.88rem;
    color: var(--text-secondary);
    line-height: 1.65;
    padding: 12px 16px;
    background: var(--bg);
    border-radius: 8px;
    border-left: 3px solid var(--accent);
}

/* Toast */
.toast {
    position: fixed;
    bottom: 32px;
    left: 50%;
    transform: translateX(-50%) translateY(12px);
    background: #1A202C;
    color: #fff;
    padding: 10px 22px;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 500;
    opacity: 0;
    transition: opacity 0.25s, transform 0.25s;
    pointer-events: none;
    white-space: nowrap;
}

.toast.show {
    opacity: 1;
    transform: translateX(-50%) translateY(0);
}

/* Responsive */
@media (max-width: 560px) {
    header h1 { font-size: 1.6rem; }

    .tag-section {
        flex-direction: column;
        align-items: flex-start;
    }

    .random-btn { align-self: flex-start; }

    .palette-swatches {
        grid-template-columns: repeat(5, minmax(56px, 1fr));
        overflow-x: auto;
    }

    .swatch-color { height: 72px; }
}