:root{--color-primary: #667eea;--color-primary-light: #8795f0;--color-primary-dark: #4a5ecc;--color-secondary: #764ba2;--color-secondary-light: #9567b8;--color-secondary-dark: #5a3580;--color-accent: #ff7675;--color-accent-light: #ff9897;--color-accent-dark: #e35554;--color-success: #00b894;--color-success-light: #55efc4;--color-warning: #fdcb6e;--color-warning-dark: #f39c12;--color-error: #e74c3c;--color-error-light: #ff6b6b;--color-text: #2d3436;--color-text-secondary: #636e72;--color-text-light: #b2bec3;--color-bg: #f5f7fa;--color-bg-alt: #dfe6e9;--color-card: #ffffff;--color-border: #e0e0e0;--color-category-bg: #e3f2fd;--color-category-text: #1565c0;--color-category-ta-bg: #ffebee;--color-category-ta-text: #c62828;--color-difficulty-bg: #fff3e0;--color-difficulty-text: #ef6c00;--color-sno-bg: #eeeeee;--color-sno-text: #616161;--font-main: "Outfit", "Segoe UI", system-ui, sans-serif;--font-tamil: "Noto Sans Tamil", "Latha", "Vijaya", sans-serif;--font-mono: "Fira Code", "Consolas", monospace;--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;--space-0: 0;--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;--radius-sm: 4px;--radius-md: 8px;--radius-lg: 12px;--radius-xl: 20px;--radius-full: 9999px;--border-thin: 1px;--border-medium: 2px;--border-thick: 3px;--shadow-sm: 0 2px 4px rgba(0, 0, 0, .05);--shadow-md: 0 4px 15px rgba(0, 0, 0, .1);--shadow-lg: 0 10px 30px rgba(0, 0, 0, .1);--shadow-xl: 0 20px 40px rgba(0, 0, 0, .15);--shadow-inset: inset 0 0 20px rgba(0, 0, 0, .05);--transition-fast: all .15s ease;--transition-base: all .3s cubic-bezier(.4, 0, .2, 1);--transition-slow: all .5s ease;--z-base: 1;--z-dropdown: 100;--z-sticky: 500;--z-modal: 1000;--z-tooltip: 1100;--z-overlay: 1200;--slide-width: 800px;--slide-height: 600px;--control-panel-height: auto;--nav-button-size: 44px;--gradient-primary: linear-gradient(135deg, var(--color-primary) 0%, var(--color-secondary) 100%);--gradient-bg: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);--gradient-success: linear-gradient(135deg, var(--color-success) 0%, var(--color-success-light) 100%);--gradient-error: linear-gradient(135deg, var(--color-error) 0%, var(--color-error-light) 100%)}:root{--primary: var(--color-primary);--secondary: var(--color-secondary);--accent: var(--color-accent);--bg: var(--color-bg);--card-bg: var(--color-card);--text: var(--color-text);--shadow: var(--shadow-lg);--transition: var(--transition-base);--font-main: var(--font-main)}:root{--primary: #667eea;--secondary: #764ba2;--accent: #ff7675;--bg: #f5f7fa;--card-bg: #ffffff;--text: #2d3436;--glass-bg: rgba(255, 255, 255, .7);--glass-border: rgba(255, 255, 255, .4);--shadow: 0 10px 40px rgba(0, 0, 0, .08);--shadow-inner: inset 0 2px 4px rgba(0, 0, 0, .05);--transition: all .3s cubic-bezier(.4, 0, .2, 1);--font-main: "Outfit", "Segoe UI", sans-serif}body{font-family:var(--font-main);margin:0;padding-top:60px;background:linear-gradient(135deg,#f5f7fa,#c3cfe2);display:flex;flex-direction:column;justify-content:center;align-items:center;height:100vh;box-sizing:border-box;overflow:hidden;color:var(--text)}.app-header{position:fixed;top:0;left:0;right:0;height:60px;background:linear-gradient(135deg,var(--primary) 0%,var(--secondary) 100%);color:#fff;z-index:1200;display:flex;justify-content:space-between;align-items:center;padding:0 20px;box-shadow:0 2px 10px #0000001a}.header-left{display:flex;align-items:center}.home-btn{background:#fff3;border:none;color:#fff;width:40px;height:40px;border-radius:50%;display:flex;align-items:center;justify-content:center;font-size:1.2rem;cursor:pointer;transition:var(--transition);text-decoration:none}.home-btn:hover{background:#fff;color:var(--primary);transform:scale(1.1)}.header-title{font-size:1.1rem;font-weight:600;margin:0;position:absolute;left:50%;transform:translate(-50%);white-space:nowrap}.header-right{display:flex;align-items:center}.settings-toggle{background:transparent;border:none;color:#fff;font-size:1.5rem;cursor:pointer;padding:8px;border-radius:50%;transition:var(--transition);display:flex;align-items:center;justify-content:center}.settings-toggle:hover{background:#ffffff1a;transform:rotate(30deg)}.control-panel{position:fixed;top:60px;left:0;right:0;background:#fff;background:linear-gradient(135deg,#667eeaf2,#764ba2f2);-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px);color:#fff;z-index:1100;box-shadow:0 10px 30px #0003;transition:transform .3s cubic-bezier(.4,0,.2,1),opacity .3s ease;transform:translateY(-120%);opacity:0;max-height:80vh;overflow-y:auto;border-bottom-left-radius:16px;border-bottom-right-radius:16px}.control-panel.open{transform:translateY(0);opacity:1}.control-content{padding:20px;display:flex;flex-direction:column;gap:15px}.control-row{display:flex;align-items:center;gap:15px;flex-wrap:wrap}.control-label{font-weight:600;min-width:90px;font-size:.9rem}.pill-group{display:flex;gap:10px}.pill-button{background:#fff3;border:2px solid rgba(255,255,255,.3);color:#fff;padding:8px 20px;border-radius:20px;cursor:pointer;transition:var(--transition);font-size:.9em;font-weight:600}.pill-button:hover{background:#ffffff4d;transform:translateY(-2px)}.pill-button:active{transform:translateY(1px) scale(.95)}.pill-button.active{background:#fff;color:var(--primary);border-color:#fff}.action-button{background:#ffffff26;border:1px solid rgba(255,255,255,.3);color:#fff;padding:6px 15px;border-radius:20px;cursor:pointer;transition:var(--transition);font-size:.85rem;font-weight:600;display:flex;align-items:center;gap:6px}.action-button:hover{background:#ffffff40;transform:translateY(-2px)}.action-button.active{background:#fff;color:var(--primary);border-color:#fff;box-shadow:0 2px 10px #0000001a}.category-dropdown{position:relative;min-width:250px}.dropdown-button{background:#fff3;border:2px solid rgba(255,255,255,.3);color:#fff;padding:8px 15px;border-radius:8px;cursor:pointer;width:100%;text-align:left;display:flex;justify-content:space-between;align-items:center;font-size:.9em;box-sizing:border-box}.dropdown-menu{position:absolute;top:100%;left:0;right:0;background:#fff;color:#333;border-radius:8px;margin-top:5px;box-shadow:0 10px 25px #0003;max-height:300px;overflow-y:auto;display:none;z-index:1100}.dropdown-menu.show{display:block}.dropdown-item{padding:10px 15px;display:flex;align-items:center;gap:10px;cursor:pointer;transition:background .2s;border-bottom:1px solid #f0f0f0}.dropdown-item:hover{background:#f9f9f9}.navigation{position:absolute;bottom:30px;width:auto;max-width:90%;left:50%;transform:translate(-50%);display:flex;justify-content:center;align-items:center;gap:16px;z-index:20;padding:10px;background:transparent;backdrop-filter:none;-webkit-backdrop-filter:none;border:none;box-shadow:none}.nav-btn,button.nav-btn{background:#fff;color:var(--text);border:2px solid rgba(0,0,0,.1);padding:0;width:48px;height:48px;border-radius:20px;cursor:pointer;font-size:1.2rem;transition:var(--transition);display:flex;align-items:center;justify-content:center;box-shadow:0 4px 10px #00000014}.nav-btn:hover:not(:disabled){background:#fff;transform:translateY(-3px);box-shadow:0 8px 18px #0000001f;color:var(--primary);border-color:var(--primary)}.nav-btn:active:not(:disabled){transform:translateY(1px) scale(.9)}.nav-btn:disabled{opacity:.15;cursor:not-allowed;background:#f0f0f0;border-color:#e0e0e0;box-shadow:none;color:#999}.nav-btn.reveal-mode{background:linear-gradient(135deg,var(--primary) 0%,var(--secondary) 100%);color:#fff;border:none;box-shadow:0 4px 12px #667eea4d}.nav-btn.reveal-mode:hover:not(:disabled){box-shadow:0 6px 15px #667eea66;transform:translateY(-2px)}.nav-btn svg{width:20px;height:20px;stroke-width:2.5}.progress-bar-container{height:6px;background:#f0f0f0;border-radius:3px;overflow:hidden}.progress-bar{height:100%;background:linear-gradient(90deg,var(--primary),var(--secondary));width:0%;transition:width .3s ease}.slide-counter{font-weight:600;font-size:1rem;color:#757575;min-width:80px;text-align:center;align-self:center;display:flex;align-items:center;justify-content:center;height:45px}.speaker-button{background:none;border:none;cursor:pointer;color:#6c757d;padding:5px;display:flex;align-items:center;justify-content:center;transition:all .2s ease}.speaker-button:hover{color:#4c6ef5;transform:scale(1.1)}.speaker-button svg{width:22px;height:22px;stroke-width:2.5}.speaker-button-overlay{position:absolute;bottom:10px;right:10px;background:#fffc;-webkit-backdrop-filter:blur(4px);backdrop-filter:blur(4px);border:none;border-radius:50%;width:36px;height:36px;display:flex;align-items:center;justify-content:center;cursor:pointer;color:var(--primary);box-shadow:0 4px 10px #0000001a;transition:all .3s ease;z-index:10}.speaker-button-overlay:hover{transform:scale(1.1);background:#fff;color:var(--secondary)}.speaker-button-overlay svg{width:18px;height:18px;stroke-width:2.5}.slide-container{width:900px;max-width:95vw;height:80vh;min-height:550px;max-height:800px;background:var(--card-bg);border-radius:20px;box-shadow:0 10px 40px #00000014;position:relative;margin:20px 0;box-sizing:border-box;overflow:hidden;display:flex;flex-direction:column;padding-bottom:120px}.category-badge,.category-badge-ta,.sno-badge,.difficulty-badge{position:absolute;padding:6px 16px;border-radius:20px;font-weight:600;z-index:5;font-size:.85em;letter-spacing:.02em;border:1px solid transparent}.category-badge{top:25px;left:40px;background:linear-gradient(135deg,#e3f2fd,#bbdefb);color:#1565c0;border-color:#1565c01a}.category-badge-ta{top:65px;left:40px;background:linear-gradient(135deg,#ffebee,#ffcdd2);color:#c62828;border-color:#c628281a}.sno-badge{top:25px;right:40px;background:#fff;color:#757575;border-radius:50%;width:32px;height:32px;display:flex;justify-content:center;align-items:center;box-shadow:0 2px 8px #0000000d;border:1px solid rgba(0,0,0,.05)}.difficulty-badge{top:65px;right:40px;background:linear-gradient(135deg,#fff3e0,#ffe0b2);color:#ef6c00;border-color:#ef6c001a}.circular-timer{position:fixed;left:calc(50% + 480px);top:50%;transform:translateY(-50%);width:250px;height:250px;display:flex;align-items:center;justify-content:center;z-index:100}.timer-visual{position:absolute;top:0;left:0;width:100%;height:100%;border-radius:50%;background:conic-gradient(var(--primary) 360deg,#f0f0f0 0);transition:background .3s ease;box-shadow:inset 0 0 20px #0000000d,0 8px 30px #00000026}.timer-content{position:relative;z-index:2;display:flex;flex-direction:column;align-items:center;justify-content:center;background:#fffffff2;width:190px;height:190px;border-radius:50%;box-shadow:0 4px 15px #0000001a}.timer-display{font-family:var(--font-main);font-weight:700;font-size:3rem;color:var(--secondary);line-height:1}.timer-btn{background:none;border:none;color:var(--primary);cursor:pointer;font-size:2.5rem;padding:0;margin-top:8px;display:flex;align-items:center;justify-content:center;transition:var(--transition)}.timer-btn:hover{color:var(--secondary);transform:scale(1.2)}.circular-timer.alarm .timer-visual{background:conic-gradient(var(--accent) 360deg,#fff5f5 0)!important;animation:pulse-fill .5s infinite alternate}@keyframes pulse-fill{0%{transform:scale(1)}to{transform:scale(1.1);box-shadow:0 0 15px #ff767566}}@media(max-width:1400px){.circular-timer{right:20px;left:auto;width:180px;height:180px}.circular-timer .timer-content{width:140px;height:140px}.circular-timer .timer-display{font-size:2rem}.circular-timer .timer-btn{font-size:2rem;margin-top:6px}}@media(max-width:1000px){.circular-timer{width:120px;height:120px;right:10px}.circular-timer .timer-content{width:90px;height:90px}.circular-timer .timer-display{font-size:1.3rem}.circular-timer .timer-btn{font-size:1.5rem;margin-top:4px}}@media(max-width:768px){.circular-timer{position:fixed;inset:auto auto 20px 50%;transform:translate(-50%);width:70px;height:70px}.circular-timer .timer-content{width:55px;height:55px}.circular-timer .timer-display{font-size:.9rem}.circular-timer .timer-btn{font-size:1rem;margin-top:0}.header-title{font-size:1rem}}.pwa-update-banner{position:fixed;bottom:20px;left:50%;transform:translate(-50%) translateY(100px);background:linear-gradient(135deg,var(--primary) 0%,var(--secondary) 100%);color:#fff;padding:12px 20px;border-radius:12px;box-shadow:0 8px 30px #667eea66;display:flex;align-items:center;gap:12px;z-index:10000;font-family:var(--font-main);opacity:0;transition:transform .4s cubic-bezier(.4,0,.2,1),opacity .3s ease}.pwa-update-banner.show{transform:translate(-50%) translateY(0);opacity:1}.pwa-update-icon{font-size:1.3rem;animation:spin 2s linear infinite}@keyframes spin{0%{transform:rotate(0)}to{transform:rotate(360deg)}}.pwa-update-text{font-weight:500;font-size:.95rem}.pwa-update-btn{background:#fff;color:var(--primary);border:none;padding:8px 16px;border-radius:20px;cursor:pointer;font-weight:600;font-size:.85rem;transition:var(--transition)}.pwa-update-btn:hover{background:#f0f0f0;transform:scale(1.05)}.pwa-update-close{background:transparent;border:none;color:#ffffffb3;font-size:1.4rem;cursor:pointer;padding:0 4px;line-height:1;transition:color .2s}.pwa-update-close:hover{color:#fff}@media(max-width:480px){.pwa-update-banner{left:10px;right:10px;transform:translate(0) translateY(100px);bottom:10px}.pwa-update-banner.show{transform:translate(0) translateY(0)}.header-title{font-size:.9rem}}:focus-visible{outline:3px solid var(--accent);outline-offset:2px}.progress-bar-container{position:fixed;top:0;left:0;width:100%;height:4px;background:#ffffff1a;z-index:2000}.progress-bar{height:100%;background:var(--accent);transition:width .3s cubic-bezier(.4,0,.2,1);box-shadow:0 0 10px #ff767580}