*{box-sizing:border-box}body{margin:0;background:#f7f5f2}button{padding:8px 12px;border-radius:8px;border:1px solid #cfcfe0;background:#fff;cursor:pointer;font:inherit}img{max-width:100%;display:block}:root{color-scheme:light dark;font-family:DM Sans,Avenir Next,Trebuchet MS,sans-serif;--primary: #ff6b5c;--primary-light: #ff8a7d;--primary-dark: #e64d3f;--secondary: #87cbff;--secondary-light: #a8daff;--secondary-dark: #66b7ff;--gray-50: #fafafa;--gray-100: #f5f5f5;--gray-200: #e5e5e5;--gray-300: #d4d4d4;--gray-400: #a3a3a3;--gray-500: #737373;--gray-600: #525252;--gray-700: #404040;--gray-800: #262626;--gray-900: #171717;--success: #10b981;--warning: #f59e0b;--error: #ef4444;--info: #3b82f6;--ink: #111218;--ink-soft: #3e4554;--muted: #7b8190;--cream: #f7f5f2;--card: #ffffff;--accent: #ff6b5c;--accent-2: #ffc09f;--line: #e7e2da;--shadow: 0 20px 50px rgba(16, 18, 24, .12);--shadow-sm: 0 2px 8px rgba(16, 18, 24, .08);--shadow-md: 0 8px 16px rgba(16, 18, 24, .1);--shadow-lg: 0 20px 50px rgba(16, 18, 24, .12);--shadow-xl: 0 30px 60px rgba(16, 18, 24, .15);--gradient-primary: linear-gradient(135deg, #ff6b5c 0%, #ffc09f 100%);--gradient-secondary: linear-gradient(135deg, #87cbff 0%, #a8daff 100%);--gradient-bg: linear-gradient(180deg, #fdfcf9, #f7f5f2 45%, #f2efe9 100%);--gradient-hero: linear-gradient(135deg, rgba(255, 107, 92, .1) 0%, rgba(135, 203, 255, .1) 100%);--space-1: .25rem;--space-2: .5rem;--space-3: .75rem;--space-4: 1rem;--space-5: 1.25rem;--space-6: 1.5rem;--space-8: 2rem;--space-10: 2.5rem;--space-12: 3rem;--space-16: 4rem;--space-20: 5rem;--text-xs: .75rem;--text-sm: .875rem;--text-base: 1rem;--text-lg: 1.125rem;--text-xl: 1.25rem;--text-2xl: 1.5rem;--text-3xl: 1.875rem;--text-4xl: 2.25rem;--text-5xl: 3rem;--font-normal: 400;--font-medium: 500;--font-semibold: 600;--font-bold: 700;--leading-tight: 1.25;--leading-normal: 1.5;--leading-relaxed: 1.75;--radius-sm: 8px;--radius-md: 12px;--radius-lg: 16px;--radius-xl: 20px;--radius-2xl: 26px;--radius-full: 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var(--transition-base)}@media(prefers-color-scheme:dark){.nav{background:#262626e6}}.nav-brand{font-weight:var(--font-bold);letter-spacing:.02em;color:var(--ink);margin-bottom:var(--space-4);font-size:var(--text-lg)}.nav a{display:flex;align-items:center;gap:var(--space-3);text-decoration:none;color:var(--ink-soft);font-weight:var(--font-semibold);padding:var(--space-3) var(--space-3);border-radius:var(--radius-md);transition:all var(--transition-base)}.nav-icon{font-size:var(--text-xl);display:flex;align-items:center;justify-content:center}.nav-text{font-size:var(--text-base)}.nav a:hover{background:#ff6b5c14;color:var(--primary);transform:translate(4px)}.nav a.active{color:var(--primary);background:#ff6b5c1f;box-shadow:inset 0 0 0 1px #ff6b5c33}.content{padding:36px 36px 60px}.page{max-width:760px}.hero{padding:40px 36px;background:var(--card);border-radius:26px;border:1px solid var(--line);box-shadow:var(--shadow)}.hero-title{font-size:clamp(28px,5vw,44px);margin:0 0 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span{font-weight:var(--font-semibold);color:var(--ink-soft)}.difficulty-buttons{display:flex;gap:var(--space-3);margin-top:var(--space-2)}.difficulty-btn{flex:1;padding:var(--space-4) var(--space-5);border-radius:var(--radius-lg);border:2px solid var(--line);background:var(--card);color:var(--ink-soft);font-size:var(--text-base);font-weight:var(--font-semibold);cursor:pointer;transition:all var(--transition-base);display:flex;align-items:center;justify-content:center;gap:var(--space-2)}.difficulty-btn:hover{border-color:var(--primary);background:#ff6b5c0d;transform:translateY(-2px);box-shadow:var(--shadow-sm)}.difficulty-btn.active{border-color:var(--primary);background:var(--gradient-primary);color:#fff;box-shadow:var(--shadow-md)}@media(max-width:480px){.difficulty-buttons{flex-direction:column}.difficulty-btn{width:100%}}input,textarea,select{padding:12px 14px;border-radius:12px;border:1px solid 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auto}.nav{position:fixed;bottom:0;left:0;right:0;flex-direction:row;justify-content:space-around;padding:var(--space-2) var(--space-2) calc(var(--space-2) + env(safe-area-inset-bottom));border-right:none;border-top:1px solid var(--line);gap:0;z-index:100;box-shadow:0 -4px 12px #00000014}.nav-brand{display:none}.nav a{flex-direction:column;gap:var(--space-1);padding:var(--space-2) var(--space-3);flex:1;justify-content:center;align-items:center;border-radius:var(--radius-md);background:transparent;border:none;transform:none}.nav a:hover{transform:none;background:#ff6b5c14}.nav a.active{background:#ff6b5c1f}.nav-icon{font-size:var(--text-2xl)}.nav-text{font-size:var(--text-xs);font-weight:var(--font-medium)}.content{padding:var(--space-6) var(--space-5) calc(var(--space-20) + env(safe-area-inset-bottom))}}@media(max-width:768px){.hero{padding:var(--space-8) var(--space-6)}.hero-title{font-size:clamp(24px,6vw,36px)}.content{padding:var(--space-6) var(--space-4) var(--space-12)}.grid{grid-template-columns:1fr}}@media(max-width:480px){.hero{padding:var(--space-6) var(--space-5);border-radius:var(--radius-lg)}.hero-title{font-size:clamp(20px,7vw,28px)}input,textarea,select{font-size:16px;padding:var(--space-3) var(--space-4)}.primary,button{min-height:44px;width:100%}.row{flex-direction:column;align-items:stretch}}@keyframes fadeIn{0%{opacity:0;transform:translateY(20px)}to{opacity:1;transform:translateY(0)}}@keyframes float{0%,to{transform:translateY(0)}50%{transform:translateY(-20px)}}@keyframes gradient-shift{0%,to{background-position:0% 50%}50%{background-position:100% 50%}}@keyframes pulse{0%,to{opacity:1}50%{opacity:.8}}.login-container{min-height:100vh;display:flex;align-items:center;justify-content:center;padding:var(--space-6);position:relative;overflow:hidden}.login-bg-orb{position:absolute;border-radius:50%;filter:blur(80px);opacity:.6;animation:float 8s ease-in-out infinite;pointer-events:none}.login-bg-orb-1{width:400px;height:400px;background:radial-gradient(circle,rgba(255,107,92,.4),transparent);top:-100px;left:-100px;animation-delay:0s}.login-bg-orb-2{width:500px;height:500px;background:radial-gradient(circle,rgba(135,203,255,.3),transparent);bottom:-150px;right:-150px;animation-delay:2s}.login-bg-orb-3{width:300px;height:300px;background:radial-gradient(circle,rgba(255,192,159,.35),transparent);top:50%;right:10%;animation-delay:4s}.login-card{position:relative;max-width:480px;width:100%;padding:var(--space-12) var(--space-10);background:#ffffffe6;-webkit-backdrop-filter:blur(20px);backdrop-filter:blur(20px);border-radius:var(--radius-2xl);border:1px solid rgba(255,255,255,.5);box-shadow:var(--shadow-xl),0 0 0 1px #ffffff1a inset;animation:fadeIn .6s ease-out}@media(prefers-color-scheme:dark){.login-card{background:#262626e6;border:1px solid rgba(255,255,255,.1)}}.login-logo{width:80px;height:80px;margin:0 auto var(--space-6);background:var(--gradient-primary);border-radius:var(--radius-xl);display:flex;align-items:center;justify-content:center;font-size:var(--text-4xl);font-weight:var(--font-bold);color:#fff;box-shadow:var(--shadow-lg);animation:float 3s ease-in-out infinite}.login-title{font-size:var(--text-4xl);font-weight:var(--font-bold);margin:0 0 var(--space-3);text-align:center;letter-spacing:-.02em;background:var(--gradient-primary);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text}.login-subtitle{color:var(--muted);font-size:var(--text-lg);margin:0 0 var(--space-8);text-align:center;line-height:var(--leading-relaxed)}.login-button{width:100%;padding:var(--space-4) var(--space-6);font-size:var(--text-lg);font-weight:var(--font-semibold);background:var(--gradient-primary);background-size:200% 200%;color:#fff;border:none;border-radius:var(--radius-lg);cursor:pointer;box-shadow:var(--shadow-lg);transition:transform var(--transition-base),box-shadow var(--transition-base);animation:gradient-shift 3s ease infinite}.login-button:hover{transform:translateY(-2px);box-shadow:var(--shadow-xl)}.login-button:active{transform:translateY(0)}.login-info{margin-top:var(--space-6);padding:var(--space-4);background:var(--gradient-hero);border-radius:var(--radius-md);border:1px dashed var(--line);text-align:center;color:var(--muted);font-size:var(--text-sm)}.primary{display:inline-flex;align-items:center;justify-content:center;padding:var(--space-3) var(--space-5);border-radius:var(--radius-lg);background:var(--ink);color:#fff;border:none;cursor:pointer;font-weight:var(--font-semibold);text-decoration:none;box-shadow:var(--shadow-md);transition:transform var(--transition-base),box-shadow var(--transition-base),background var(--transition-base)}.primary:hover{transform:translateY(-2px);box-shadow:var(--shadow-lg);background:var(--gray-700)}.primary:active{transform:translateY(0);box-shadow:var(--shadow-sm)}.ghost{display:inline-flex;align-items:center;gap:var(--space-2);padding:var(--space-2) var(--space-4);border-radius:var(--radius-md);background:var(--card);border:1px solid var(--line);text-decoration:none;color:var(--ink-soft);font-weight:var(--font-semibold);transition:all var(--transition-base)}.ghost:hover{border-color:var(--ink-soft);background:var(--gray-50);transform:translateY(-1px)}input,textarea,select{padding:var(--space-3) var(--space-4);border-radius:var(--radius-md);border:1px solid var(--line);font:inherit;background:var(--card);color:var(--ink);transition:border-color var(--transition-base),box-shadow var(--transition-base),background var(--transition-base)}input:focus,textarea:focus,select:focus{outline:none;border-color:var(--primary);box-shadow:0 0 0 3px #ff6b5c1a}.hero{padding:var(--space-10) var(--space-10);background:var(--card);border-radius:var(--radius-2xl);border:1px solid var(--line);box-shadow:var(--shadow-lg);transition:all var(--transition-base)}.tile{padding:var(--space-5);background:var(--card);border-radius:var(--radius-lg);border:1px solid var(--line);text-decoration:none;font-weight:var(--font-semibold);color:var(--ink);text-align:left;box-shadow:var(--shadow-md);transition:all var(--transition-base);cursor:pointer}.tile:hover{transform:translateY(-4px);box-shadow:var(--shadow-lg);border-color:var(--primary-light)}.page{animation:fadeIn .4s ease-out}.spinner{display:inline-flex;align-items:center;justify-content:center}.spinner-circle{border-radius:50%;border:3px solid rgba(0,0,0,.1);border-top-color:var(--primary);animation:spin .8s linear infinite}.spinner-sm .spinner-circle{width:16px;height:16px;border-width:2px}.spinner-md .spinner-circle{width:24px;height:24px;border-width:3px}.spinner-lg .spinner-circle{width:40px;height:40px;border-width:4px}.spinner-primary .spinner-circle{border-color:#ff6b5c33;border-top-color:var(--primary)}.spinner-white .spinner-circle{border-color:#ffffff4d;border-top-color:#fff}.spinner-muted .spinner-circle{border-color:#0000001a;border-top-color:var(--muted)}@media(prefers-color-scheme:dark){.spinner-circle{border-color:#ffffff1a}.spinner-muted .spinner-circle{border-color:#ffffff1a;border-top-color:var(--muted)}}.loading{display:inline-block;width:20px;height:20px;border:3px solid rgba(255,255,255,.3);border-radius:50%;border-top-color:#fff;animation:spin .8s linear infinite}@keyframes spin{to{transform:rotate(360deg)}}