:root {
    --bg-body: #eef1f5;
    --bg-container: #ffffff;
    --text-strong: #111827;
    --text-main: #333d4b;
    --text-muted: #6b7684;
    --border-main: #d1d8e0;
    --shadow-main: 0 4px 20px rgba(0,0,0,0.08);
    --c-indigo: #4f46e5;
    --c-purple: #9333ea;
    --c-blue: #2563eb;
}

@media (prefers-color-scheme: dark) {
    :root {
        --bg-body: #0f172a;
        --bg-container: #1e293b;
        --text-strong: #f8fafc;
        --text-main: #cbd5e1;
        --text-muted: #94a3b8;
        --border-main: #334155;
        --shadow-main: 0 8px 30px rgba(0,0,0,0.4);
        --c-indigo: #818cf8;
        --c-purple: #c084fc;
        --c-blue: #60a5fa;
    }
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }

body { background-color: var(--bg-body); padding: 20px; font-family: 'Pretendard', sans-serif; transition: background-color 0.3s, color 0.3s; color: var(--text-main); }

.container { max-width: 800px; margin: 0 auto; background: var(--bg-container); padding: 40px; border-radius: 12px; box-shadow: var(--shadow-main); transition: background 0.3s; }
@media (max-width: 600px) { .container { padding: 20px; } }

.page-header { text-align: center; margin-bottom: 50px; }
.page-header h1 { font-size: 2.2em; font-weight: 900; margin-bottom: 10px; letter-spacing: -1px; color: var(--text-strong); }
.text-gradient { background: linear-gradient(90deg, var(--c-indigo), var(--c-blue)); -webkit-background-clip: text; color: transparent; display: inline-block; }
.page-subtitle { font-size: 1.05em; color: var(--text-muted); font-weight: 600; margin-bottom: 30px; word-break: keep-all; }

.intro-desc {
    background: var(--bg-container); border: 1px solid var(--border-main);
    padding: 25px 20px; border-radius: 20px; color: var(--text-main);
    font-size: 1em; line-height: 1.6; text-align: center;
    box-shadow: 0 5px 20px rgba(0,0,0,0.02); position: relative; overflow: hidden; font-weight: 500; word-break: keep-all;
}
.intro-desc::before { content: ''; position: absolute; top: 0; left: 0; right: 0; height: 4px; background: linear-gradient(90deg, var(--c-indigo), var(--c-purple)); }
.intro-desc strong { color: var(--text-strong); font-weight: 900; box-shadow: inset 0 -10px 0 rgba(79, 70, 229, 0.15); padding: 0 2px; }

.all-types-grid { display: grid; grid-template-columns: 1fr; gap: 20px; }
@media (min-width: 600px) { .all-types-grid { grid-template-columns: repeat(auto-fill, minmax(320px, 1fr)); } }

.thumb-ui-card {
    border-radius: 20px; padding: 40px 20px; position: relative; overflow: hidden;
    display: flex; flex-direction: column; align-items: center; text-align: center;
    box-shadow: 0 10px 30px rgba(0,0,0,0.1); transition: transform 0.3s;
}
.thumb-ui-card:hover { transform: translateY(-5px); box-shadow: 0 15px 40px rgba(0,0,0,0.2); }
.thumb-ui-card::before, .thumb-ui-card::after { content: ''; position: absolute; border-radius: 50%; z-index: 0; pointer-events: none; }
.thumb-ui-card::before { width: 300px; height: 300px; top: -100px; left: -100px; }
.thumb-ui-card::after { width: 250px; height: 250px; bottom: -80px; right: -80px; opacity: 0.8; }

.ui-card-content { position: relative; z-index: 10; display: flex; flex-direction: column; align-items: center; width: 100%; }
.ui-badge {
    display: inline-block; background: rgba(255, 255, 255, 0.1); border: 1px solid rgba(255, 255, 255, 0.25);
    backdrop-filter: blur(10px); -webkit-backdrop-filter: blur(10px);
    padding: 6px 20px; border-radius: 30px; color: rgba(255, 255, 255, 0.95);
    font-size: 1.1em; font-weight: 800; letter-spacing: 3px; margin-bottom: 15px;
}
.ui-title { font-size: 1.6em; font-weight: 900; color: #ffffff; text-shadow: 0 4px 10px rgba(0,0,0,0.5); word-break: keep-all; line-height: 1.3; margin: 0 0 25px 0; }

.btn-download {
    background: rgba(255,255,255,0.9); color: #111; border: none;
    padding: 12px 24px; font-size: 0.95em; font-weight: 900; border-radius: 25px;
    cursor: pointer; transition: all 0.2s ease; box-shadow: 0 4px 15px rgba(0,0,0,0.2);
    width: 100%; max-width: 250px;
}
.btn-download:hover { background: #ffffff; transform: translateY(-2px); box-shadow: 0 6px 20px rgba(255,255,255,0.3); }
.btn-download:active { transform: translateY(0); }
.btn-download:disabled { opacity: 0.7; cursor: not-allowed; }

.thumb-box {
    width: 1280px; height: 720px; position: relative; overflow: hidden;
    display: flex; flex-direction: column; justify-content: center; align-items: center; background-color: #111;
}
.thumb-box::before, .thumb-box::after { content: ''; position: absolute; border-radius: 50%; z-index: 0; pointer-events: none; }
.thumb-box::before { width: 1200px; height: 1200px; top: -300px; left: -300px; }
.thumb-box::after { width: 1000px; height: 1000px; bottom: -300px; right: -300px; opacity: 0.8; }
.watermark { position: absolute; top: 50%; left: 50%; transform: translate(-50%, -50%); font-size: 450px; font-weight: 900; color: #ffffff; opacity: 0.04; z-index: 1; white-space: nowrap; letter-spacing: -10px; pointer-events: none; user-select: none; }
.content { position: relative; z-index: 10; text-align: center; display: flex; flex-direction: column; align-items: center; }
.code-badge { display: inline-block; background: rgba(255, 255, 255, 0.1); border: 2px solid rgba(255, 255, 255, 0.25); backdrop-filter: blur(15px); -webkit-backdrop-filter: blur(15px); padding: 12px 35px; border-radius: 50px; color: rgba(255, 255, 255, 0.95); font-size: 34px; font-weight: 800; letter-spacing: 8px; margin-bottom: 30px; box-shadow: 0 10px 30px rgba(0,0,0,0.15); }
.title { font-size: 85px; font-weight: 900; color: #ffffff; text-shadow: 0 15px 40px rgba(0,0,0,0.5), 0 2px 10px rgba(0,0,0,0.4); word-break: keep-all; line-height: 1.3; margin: 0; }
.divider { width: 80px; height: 6px; background: rgba(255, 255, 255, 0.8); border-radius: 3px; margin: 45px auto; box-shadow: 0 4px 15px rgba(0,0,0,0.3); }
.subtitle { font-size: 24px; font-weight: 700; color: rgba(255, 255, 255, 0.6); letter-spacing: 5px; }

.theme-dcsv { background-color: #1a0505; } .theme-dcsv::before { background: radial-gradient(circle, #991b1b 0%, transparent 70%); } .theme-dcsv::after { background: radial-gradient(circle, #dc2626 0%, transparent 70%); }
.theme-dcsf { background-color: #022c22; } .theme-dcsf::before { background: radial-gradient(circle, #065f46 0%, transparent 70%); } .theme-dcsf::after { background: radial-gradient(circle, #10b981 0%, transparent 70%); }
.theme-dcev { background-color: #2e0219; } .theme-dcev::before { background: radial-gradient(circle, #9d174d 0%, transparent 70%); } .theme-dcev::after { background: radial-gradient(circle, #e11d48 0%, transparent 70%); }
.theme-dcef { background-color: #082f49; } .theme-dcef::before { background: radial-gradient(circle, #0e7490 0%, transparent 70%); } .theme-dcef::after { background: radial-gradient(circle, #06b6d4 0%, transparent 70%); }
.theme-dmsv { background-color: #170b3b; } .theme-dmsv::before { background: radial-gradient(circle, #4c1d95 0%, transparent 70%); } .theme-dmsv::after { background: radial-gradient(circle, #7c3aed 0%, transparent 70%); }
.theme-dmsf { background-color: #0f172a; } .theme-dmsf::before { background: radial-gradient(circle, #0369a1 0%, transparent 70%); } .theme-dmsf::after { background: radial-gradient(circle, #38bdf8 0%, transparent 70%); }
.theme-dmev { background-color: #2e023b; } .theme-dmev::before { background: radial-gradient(circle, #86198f 0%, transparent 70%); } .theme-dmev::after { background: radial-gradient(circle, #d946ef 0%, transparent 70%); }
.theme-dmef { background-color: #064e3b; } .theme-dmef::before { background: radial-gradient(circle, #15803d 0%, transparent 70%); } .theme-dmef::after { background: radial-gradient(circle, #22c55e 0%, transparent 70%); }
.theme-ucsv { background-color: #111827; } .theme-ucsv::before { background: radial-gradient(circle, #1e3a8a 0%, transparent 70%); } .theme-ucsv::after { background: radial-gradient(circle, #3b82f6 0%, transparent 70%); }
.theme-ucsf { background-color: #422006; } .theme-ucsf::before { background: radial-gradient(circle, #b45309 0%, transparent 70%); } .theme-ucsf::after { background: radial-gradient(circle, #fbbf24 0%, transparent 70%); }
.theme-ucev { background-color: #1e1b4b; } .theme-ucev::before { background: radial-gradient(circle, #3730a3 0%, transparent 70%); } .theme-ucev::after { background: radial-gradient(circle, #6366f1 0%, transparent 70%); }
.theme-ucef { background-color: #431407; } .theme-ucef::before { background: radial-gradient(circle, #c2410c 0%, transparent 70%); } .theme-ucef::after { background: radial-gradient(circle, #f97316 0%, transparent 70%); }
.theme-umsv { background-color: #2e1065; } .theme-umsv::before { background: radial-gradient(circle, #6b21a8 0%, transparent 70%); } .theme-umsv::after { background: radial-gradient(circle, #a855f7 0%, transparent 70%); }
.theme-umsf { background-color: #451a03; } .theme-umsf::before { background: radial-gradient(circle, #b45309 0%, transparent 70%); } .theme-umsf::after { background: radial-gradient(circle, #f59e0b 0%, transparent 70%); }
.theme-umev { background-color: #083344; } .theme-umev::before { background: radial-gradient(circle, #0e7490 0%, transparent 70%); } .theme-umev::after { background: radial-gradient(circle, #06b6d4 0%, transparent 70%); }
.theme-umef { background-color: #4c0519; } .theme-umef::before { background: radial-gradient(circle, #be123c 0%, transparent 70%); } .theme-umef::after { background: radial-gradient(circle, #fb7185 0%, transparent 70%); }

@keyframes fadeIn { from { opacity: 0; transform: translateY(20px); } to { opacity: 1; transform: translateY(0); } }
.footer-copyright { text-align: center; margin-top: 40px; padding-bottom: 30px; font-size: 0.9em; }
.footer-copyright a { color: var(--text-muted); text-decoration: none; font-weight: 500; transition: color 0.3s; }
.footer-copyright a:hover { color: var(--text-main); text-decoration: underline; }