:root {
    --clr-bg: #0a0a0c;
    --clr-surface: #16161a;
    --clr-surface-2: #1f1f23;
    --clr-input: #23232a;
    --clr-border: #2d2d35;
    --clr-border-strong: #3d3d45;
    --clr-text: #e5e5e5;
    --clr-muted: #9ea4ad;
    --clr-accent: #ff2222;
    --clr-accent-dark: #6a0000;
    --shadow-soft: 0 10px 30px rgba(0, 0, 0, 0.5);
    --radius-md: 10px;
    --radius-lg: 16px;
    --transition-fast: 0.2s ease;
    --transition-base: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

* {box-sizing: border-box;}

body {
    background: var(--clr-bg);
    color: var(--clr-text);
    font-family: 'Segoe UI', Arial, sans-serif;
    text-align: center;
    margin: 0;
    padding: 2rem 1rem 0;
    display: flex;
    flex-direction: column;
    align-items: center;
    min-height: 100vh;
    transition: background 0.5s ease;
}

.container {
    background: var(--clr-surface);
    padding: 40px;
    width: min(380px, 92vw);
    margin: auto 0 2rem;
    border: 1px solid var(--clr-border);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-soft);
    transition: transform var(--transition-base), box-shadow var(--transition-base), border-color var(--transition-base);
}

.container:hover {
    border-color: var(--clr-border-strong);
    box-shadow: 0 14px 34px rgba(0, 0, 0, 0.6);
}

input {
    padding: 12px;
    margin: 10px 0;
    width: 100%;
    background: var(--clr-input);
    border: 1px solid var(--clr-border-strong);
    border-radius: var(--radius-md);
    color: var(--clr-text);
    outline: none;
    transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

input:focus {
    border-color: var(--clr-accent);
}

input:focus-visible {
    box-shadow: 0 0 0 3px rgba(255, 34, 34, 0.25);
}

input::placeholder {
    color: var(--clr-muted);
}

button {
    margin: 20px 0;
    padding: 12px 25px;
    background: var(--clr-accent);
    color: #fff;
    border: none;
    border-radius: var(--radius-md);
    cursor: pointer;
    font-weight: bold;
    text-transform: uppercase;
    letter-spacing: 1px;
    transition: transform var(--transition-base), box-shadow var(--transition-base), background-color var(--transition-base);
}

button:hover {
    background-color: var(--clr-accent-dark);
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(255, 34, 34, 0.28);
}

button:active {
    transform: translateY(0);
}

button:focus-visible {
    outline: 2px solid var(--clr-accent);
    outline-offset: 2px;
}

li {
    list-style: none;
    background: var(--clr-surface-2);
    margin: 8px 0;
    padding: 12px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 10px;
    border-radius: var(--radius-md);
    border-left: 4px solid var(--clr-accent);
    animation: slideIn 0.3s ease-out;
}

li button {
    margin: 0;
    padding: 8px 12px;
    border-radius: 8px;
    font-size: 0.75rem;
}

.done {
    text-decoration: line-through;
    color: var(--clr-muted);
    opacity: 0.75;
}

#todoSection {display: none;}

.fade-in {animation: fadeIn 0.6s ease-in;}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

@keyframes slideIn {
    from { opacity: 0; transform: translateX(-10px); }
    to { opacity: 1; transform: translateX(0); }
}

footer {
    background: rgba(0, 0, 0, 0.8);
    border-top: 1px solid var(--clr-border);
    margin-top: auto;
    padding: 2rem 1rem;
    text-align: center;
    width: 100%;
}

footer p {
    color: var(--clr-accent);
    font-size: 0.9rem;
    letter-spacing: 3px;
    text-transform: uppercase;
    line-height: 1.5;
    animation: pulseGlow 2.3s infinite alternate ease-in-out;
}

footer a {
    color: inherit !important;
    text-decoration: none !important;
    cursor: pointer;
}

footer a:focus-visible {
    outline: 2px solid var(--clr-accent);
    outline-offset: 2px;
}

@keyframes pulseGlow {
    from {text-shadow: 0 0 4px rgba(255, 34, 34, 0.25), 0 0 8px rgba(255, 34, 34, 0.15);}
    to {text-shadow: 0 0 8px rgba(255, 34, 34, 0.4), 0 0 16px rgba(255, 34, 34, 0.24);} }
@media (max-width: 480px) {
    body {padding: 1rem 0.75rem 0;}
    .container {padding: 24px 18px;}
    button {width: 100%;}
    footer p {letter-spacing: 2px;font-size: 0.82rem;}  }
@media (prefers-reduced-motion: reduce) {  *, *::before, *::after {animation-duration: 0.01ms !important;animation-iteration-count: 1 !important;transition-duration: 0.01ms !important;scroll-behavior: auto !important;}  }