:root{--bg-color: #f8f9fa;--text-color: #212529;--card-bg: #ffffff;--primary-color: #2563eb;--secondary-color: #6c757d;--border-color: #dee2e6;--input-bg: #f1f3f5;--success-color: #198754;--error-color: #dc3545;--font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol"}@media(prefers-color-scheme:dark){:root{--bg-color: #121212;--text-color: #e0e0e0;--card-bg: #1e1e1e;--primary-color: #4dabf7;--secondary-color: #adb5bd;--border-color: #343a40;--input-bg: #2c2c2c}}*{box-sizing:border-box;margin:0;padding:0}body{background-color:var(--bg-color);color:var(--text-color);font-family:var(--font-family);line-height:1.6;font-size:16px;-webkit-font-smoothing:antialiased}#root{display:flex;justify-content:center;min-height:100vh;padding:1rem}.app-container{width:100%;max-width:600px;background-color:var(--card-bg);border-radius:12px;box-shadow:0 4px 12px #0000000d;padding:1.5rem;display:flex;flex-direction:column}header{margin-bottom:2rem;text-align:center}h1{font-size:1.5rem;font-weight:700;color:var(--primary-color);margin-bottom:.5rem;letter-spacing:-.5px}.date-display{font-size:.9rem;color:var(--secondary-color);font-weight:500}form{display:flex;flex-direction:column;gap:1.5rem}.form-group{display:flex;flex-direction:column;gap:.5rem;animation:fadeIn .5s ease-out}label{font-size:.95rem;font-weight:600;color:var(--text-color)}input,textarea{width:100%;padding:1rem;border-radius:8px;border:1px solid var(--border-color);background-color:var(--input-bg);color:var(--text-color);font-family:inherit;font-size:1rem;transition:border-color .2s,box-shadow .2s;resize:vertical}input:focus,textarea:focus{outline:none;border-color:var(--primary-color);box-shadow:0 0 0 3px #2563eb1a}textarea{min-height:100px}.short-input{min-height:50px}.add-heading-btn{background:none;border:2px dashed var(--border-color);color:var(--secondary-color);padding:.75rem;border-radius:8px;cursor:pointer;font-weight:600;transition:all .2s;text-align:center}.add-heading-btn:hover{border-color:var(--primary-color);color:var(--primary-color)}.submit-btn{background-color:var(--primary-color);color:#fff;border:none;padding:1rem;font-size:1.1rem;font-weight:700;border-radius:8px;cursor:pointer;margin-top:1rem;transition:transform .1s,opacity .2s;position:sticky;bottom:1rem;box-shadow:0 4px 6px #0000001a;z-index:10}.submit-btn:active{transform:scale(.98)}.submit-btn:disabled{opacity:.7;cursor:not-allowed}.message{padding:1rem;border-radius:8px;text-align:center;margin-bottom:1rem;font-weight:500}.message.success{background-color:d1e7dd;color:var(--success-color);background-color:#1987541a}.message.error{color:var(--error-color);background-color:#dc35451a}@keyframes fadeIn{0%{opacity:0;transform:translateY(10px)}to{opacity:1;transform:translateY(0)}}.hidden{display:none}.modal-overlay{position:fixed;inset:0;background-color:#00000080;display:flex;align-items:center;justify-content:center;z-index:1000;-webkit-backdrop-filter:blur(2px);backdrop-filter:blur(2px);animation:fadeIn .2s ease-out}.modal-content{background-color:var(--card-bg);padding:1.5rem;border-radius:12px;width:90%;max-width:400px;box-shadow:0 10px 25px #0000001a;animation:slideUp .3s cubic-bezier(.16,1,.3,1)}.modal-title{font-size:1.1rem;font-weight:700;margin-bottom:1rem;color:var(--text-color)}.modal-actions{display:flex;gap:1rem;margin-top:1.5rem;justify-content:flex-end}.btn-secondary{background-color:transparent;border:1px solid var(--border-color);color:var(--text-color);padding:.5rem 1rem;border-radius:6px;cursor:pointer;font-weight:500}.btn-primary{background-color:var(--primary-color);color:#fff;border:none;padding:.5rem 1rem;border-radius:6px;cursor:pointer;font-weight:500}@keyframes slideUp{0%{opacity:0;transform:translateY(20px) scale(.96)}to{opacity:1;transform:translateY(0) scale(1)}}