* {
    box-sizing: border-box;
}

:root {
    --bg: #f4f7fb;
    --card: rgba(255, 255, 255, 0.88);
    --card-solid: #ffffff;
    --text: #0f172a;
    --muted: #64748b;
    --line: #e2e8f0;
    --primary: #4f46e5;
    --primary-dark: #4338ca;
    --success: #22c55e;
    --danger: #ef4444;
    --shadow-lg: 0 24px 60px rgba(15, 23, 42, 0.12);
    --shadow-md: 0 14px 30px rgba(15, 23, 42, 0.08);
    --radius-xl: 30px;
    --radius-lg: 22px;
    --radius-md: 16px;
    --radius-sm: 12px;
}

html,
body {
    margin: 0;
    padding: 0;
    font-family: Inter, Arial, sans-serif;
    background:
        radial-gradient(circle at top left, #e0e7ff 0%, transparent 28%),
        radial-gradient(circle at bottom right, #dbeafe 0%, transparent 26%),
        var(--bg);
    color: var(--text);
}

body {
    min-height: 100vh;
    padding: 32px 16px;
}

.todo-section {
    width: 100%;
}

.todo-container {
    max-width: 920px;
    margin: 0 auto;
}

.todo-header {
    text-align: center;
    margin-bottom: 30px;
}

.todo-label {
    margin: 0 0 10px;
    font-size: 14px;
    font-weight: 700;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: var(--primary);
}

.todo-title {
    margin: 0;
    font-size: clamp(34px, 6vw, 58px);
    line-height: 1.02;
    font-weight: 900;
    letter-spacing: -0.04em;
}

.todo-subtitle {
    max-width: 680px;
    margin: 14px auto 0;
    font-size: 17px;
    line-height: 1.65;
    color: var(--muted);
}

.todo-app {
    background: var(--card);
    border: 1px solid rgba(255, 255, 255, 0.72);
    backdrop-filter: blur(16px);
    border-radius: var(--radius-xl);
    padding: 24px;
    box-shadow: var(--shadow-lg);
}

.todo-form {
    margin-bottom: 18px;
}

.todo-input-wrap {
    display: flex;
    gap: 14px;
    align-items: center;
}

.todo-input {
    flex: 1;
    min-width: 0;
    height: 58px;
    border: 1px solid var(--line);
    border-radius: 18px;
    padding: 0 18px;
    font-size: 16px;
    color: var(--text);
    background: #ffffff;
    outline: none;
    transition: border-color 0.22s ease, box-shadow 0.22s ease, transform 0.22s ease;
}

.todo-input:focus {
    border-color: rgba(79, 70, 229, 0.45);
    box-shadow: 0 0 0 4px rgba(79, 70, 229, 0.12);
}

.todo-add-btn {
    border: none;
    height: 58px;
    padding: 0 22px;
    border-radius: 18px;
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    color: #ffffff;
    font-size: 15px;
    font-weight: 800;
    cursor: pointer;
    box-shadow: 0 14px 24px rgba(79, 70, 229, 0.22);
    transition: transform 0.2s ease, box-shadow 0.2s ease, opacity 0.2s ease;
    white-space: nowrap;
}

.todo-add-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 18px 30px rgba(79, 70, 229, 0.28);
}

.todo-add-btn:active {
    transform: translateY(0);
}

.todo-toolbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 16px;
    margin-bottom: 18px;
    flex-wrap: wrap;
}

.todo-filters {
    display: flex;
    align-items: center;
    gap: 10px;
    flex-wrap: wrap;
}

.filter-btn,
.clear-btn {
    border: none;
    cursor: pointer;
    transition: all 0.2s ease;
}

.filter-btn {
    padding: 10px 14px;
    border-radius: 14px;
    background: #f8fafc;
    border: 1px solid var(--line);
    color: var(--muted);
    font-size: 14px;
    font-weight: 700;
}

.filter-btn:hover {
    background: #ffffff;
    color: var(--text);
}

.filter-btn.active {
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    color: #ffffff;
    border-color: transparent;
    box-shadow: 0 10px 20px rgba(79, 70, 229, 0.18);
}

.clear-btn {
    padding: 10px 14px;
    border-radius: 14px;
    background: #fff1f2;
    color: #be123c;
    font-size: 14px;
    font-weight: 700;
    border: 1px solid #ffe4e6;
}

.clear-btn:hover {
    background: #ffe4e6;
}

.todo-list {
    list-style: none;
    margin: 0;
    padding: 0;
    display: flex;
    flex-direction: column;
    gap: 14px;
}

.todo-item {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: 16px;
    padding: 18px;
    border-radius: 22px;
    background: var(--card-solid);
    border: 1px solid var(--line);
    box-shadow: var(--shadow-md);
    transition: transform 0.22s ease, box-shadow 0.22s ease, border-color 0.22s ease;
}

.todo-item:hover {
    transform: translateY(-2px);
    box-shadow: 0 18px 32px rgba(15, 23, 42, 0.10);
    border-color: #c7d2fe;
}

.todo-main {
    display: flex;
    align-items: flex-start;
    gap: 14px;
    flex: 1;
    min-width: 0;
}

.todo-checkbox {
    position: relative;
    width: 24px;
    height: 24px;
    margin-top: 2px;
    flex-shrink: 0;
}

.todo-checkbox input {
    position: absolute;
    inset: 0;
    opacity: 0;
    cursor: pointer;
    margin: 0;
}

.todo-checkbox-ui {
    display: block;
    width: 24px;
    height: 24px;
    border-radius: 8px;
    border: 2px solid #cbd5e1;
    background: #ffffff;
    transition: all 0.2s ease;
    position: relative;
}

.todo-checkbox input:checked + .todo-checkbox-ui {
    background: linear-gradient(135deg, var(--success), #16a34a);
    border-color: #16a34a;
    box-shadow: 0 10px 20px rgba(34, 197, 94, 0.20);
}

.todo-checkbox input:checked + .todo-checkbox-ui::after {
    content: "";
    position: absolute;
    left: 7px;
    top: 2px;
    width: 6px;
    height: 12px;
    border: solid #ffffff;
    border-width: 0 3px 3px 0;
    transform: rotate(45deg);
}

.todo-content {
    min-width: 0;
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.todo-task {
    margin: 0;
    font-size: 17px;
    font-weight: 700;
    line-height: 1.5;
    word-break: break-word;
    overflow-wrap: anywhere;
}

.todo-date {
    font-size: 13px;
    color: var(--muted);
}

.todo-item.completed .todo-task {
    color: #94a3b8;
    text-decoration: line-through;
}

.todo-item.completed {
    background: #fbfdff;
}

.todo-delete-btn {
    width: 42px;
    height: 42px;
    border: none;
    border-radius: 14px;
    background: #fff1f2;
    color: var(--danger);
    font-size: 26px;
    line-height: 1;
    cursor: pointer;
    flex-shrink: 0;
    transition: transform 0.2s ease, background 0.2s ease, box-shadow 0.2s ease;
}

.todo-delete-btn:hover {
    background: #ffe4e6;
    transform: scale(1.04);
}

.todo-footer {
    margin-top: 18px;
    padding-top: 18px;
    border-top: 1px solid var(--line);
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 12px;
    flex-wrap: wrap;
    color: var(--muted);
    font-size: 14px;
    font-weight: 600;
}

@media (max-width: 720px) {
    .todo-app {
        padding: 18px;
        border-radius: 22px;
    }

    .todo-input-wrap {
        flex-direction: row;
        align-items: center;
    }

    .todo-input {
        flex: 1;
        width: auto;
    }

    .todo-add-btn {
        width: auto;
        flex-shrink: 0;
    }

    .todo-item {
        padding: 16px;
    }
}

@media (max-width: 520px) {
    body {
        padding: 20px 12px;
    }

    .todo-toolbar,
    .todo-footer {
        flex-direction: column;
        align-items: stretch;
    }

    .todo-item {
        position: relative;
        flex-direction: row;
        align-items: flex-start;
        padding: 16px;
        padding-right: 64px;
    }

    .todo-main {
        width: 100%;
        min-width: 0;
    }

    .todo-delete-btn {
        position: absolute;
        top: 16px;
        right: 16px;
        align-self: auto;
    }
}